Spartina alterniflora was introduced into coastal areas in China, the carbon storage of the original ecosystem was changed after years of growth and succession in the intertidal zone, but the influence mechanism remains to be further studied. In order to further explore the evolution characteristics of organic carbon storage in tidal flat due to S. alterniflora invasion, we took S. alterniflora wetland in Guangxi Beibu Gulf for about six years as the research object, and analyzed the organic carbon and related physical and chemical indexes of samples collected in August, November 2018 and January, March 2019. The results were as follows:(1)the average annual aboveground carbon storage of S. alterniflora was 9.68 t·hm^-2, which was higher than that of underground roots(5.56 t·hm^-2).(2)The soil carbon storage of S. alterniflora invasion was significantly higher than that of S. alterniflora plant itself, and the soil carbon storage in spring was significantly higher than that in other seasons.(3)The C/N ratio of soil ranged from 3.53 to 9.67, indicating that the organic carbon of S. alterniflora invasion community was greatly affected by tidal input of sea source.(4)The total carbon storage of S. alterniflora ecosystem was significantly positively correlated with soil carbon storage, and the seasonal variation was consistent.(5)With the extension of invasion time, the organic carbon storage in S. alterniflora ecosystem showed a gradually increasing trend, indicating that the invasion of S. alterniflora increased the organic carbon storage and improved the carbon sequestration capacity in bare flat. This study provides reference for the scientific evaluation of the impact of S. alterniflora invasion on carbon storage in bare flat.]]> 2021/7/5 15:46:28 1, LIANG Shaoxin², TAO Yuhua^1*, WANG Xueping¹, DUAN Yitao¹]]> HUANG Xing¹, LIANG Shaoxin², TAO Yuhua^1*, WANG Xueping¹, DUAN Yitao¹ 40true Heritiera littoralis seedlings, we used 2-year-old H. littoralis seedlings as plant material, and a pot experiment was set up with fertilization treatment of 6 levels, i.e., CK(0 g per plant), N1(10 g per plant), N2(15 g per plant), N3(20 g per plant), N4(25 g per plant)and N5(30 g per plant). This experiment lasted for 140 d, and the differences in growth, biomass, leaf chlorophyll content, photosynthetic parameters and chlorophyll fluorescence parameters were compared across different fertilization levels. The results were as follows:(1)The growth(seedling height and ground diameter), biomass(leaf, stem and root), leaf chlorophyll content [Chl a, Chl b and Chl(a+b)], leaf net photosynthetic rate(P_n), transpiration rate(T_r), stomatal conductance(G_s), water use efficiency(WUE), maximum photochemical efficiency(F_v/F_m), actual photosynthetic efficiency(ΦPS Ⅱ), apparent photosynthetic quantum transfer efficiency(ETR)and photochemical quenching coefficient(q_P)all displayed a hump-shaped trend with increasing fertilization, while intercellular CO₂ concentration(C_i)and non-photochemical quenching coefficient(NPQ)displayed a decreasing trend.(2)The growth, biomass, gas exchange parameters and chlorophyll fluorescence parameters of H. littoralis seedlings had different responses to fertilization. Specifically, seedling chlorophyll content, root mass and total biomass maximized at the fertilization level of 10 g per plant, seedling growth(height and ground diameter), leaf and stem mass maximized at 20 g per plant, and gas exchange parameters(P_n, T_r and G_s), chlorophyll fluorescence parameters(F_v/F_m, ΦPS Ⅱ, ETR and q_P)maximized at 30 g per plant. In conclusion, our results suggested that an appropriate amount of fertilization can significantly enhance the leaf chlorophyll content, stomatal conductance, photochemical efficiency and electron transfer rate in H. littoralis seedlings, resulting in lower heat dissipation and thus higher photosynthetic capacity, while over-fertilization can induce photoinhibition in H. littoralis seedlings, which decreases photochemical efficiency and suppresses seedling growth.]]> 2021/7/5 15:46:28 *, GAN Xianhua, LI Yifan, TANG Chengbo, QIU Pengji]]> ZHANG Weiqiang, HUANG Fangfang^*, GAN Xianhua, LI Yifan, TANG Chengbo, QIU Pengji 39true Barringtonia racemosa is a typical semi-mangrove plant with important medicinal and ornamental values, but it has been listed as an endangered plant and needs urgent protection. In order to explore the effects of different flooding levels, flooding durations, and water salinity on the growth of B. racemosa, the best environmental combination suitable for the survival of B. racemosa was screened out. In this study, two-year-old B. racemosa seedlings were used as experimental materials to simulate all-day tides. The L₉(3⁴)orthogonal test design was used to analyze its growth and physiological indicators. The results were as follows:(1)The first group(the flooded water level was ground height, the flooded time was 4 h, and the water salinity was 4‰), the fourth group(the flooded water level was height under branch, the flooded time was 4 h, the water salinity was 8‰), and the sixth group(the flooded water level was height under branch, the flooded time was 12 h, and the water salinity was 4‰)were most suitable for the growth of B. racemosa.(2)The MDA content in the leaves of plants in the fifth group(the flooded water level was height under branch, the flooded time was 8 h, and the water salinity was 12‰)was the highest, while the POD, CAT activities and soluble sugar content also reached the highest, indicating that it could effectively resist adversity by activating the protective enzyme system and regulating osmotic substances.(3)The 7th-9th groups(the flooded water level was plant height)all showed dead plants, and the mortality rate was 33.33%, 8.33% and 25% respectively. Among them, the 9th group increased in plant height, ground diameter and number of leaves both were the least. All the above results indicate that B. racemosa exhibits better morphological adaptation and stronger resistance in environmental combinations where the flooded water level was less than height under branch, the flooded time was less than 12 h, and the water salinity was less than 12‰. It grows under tidal water flooded environment with salinity, while the flooded water level and water salinity have a significant effect on the growth of B. racemosa, and the flooded time has no significant effect on the overall plant.]]> 2021/7/5 15:46:28 1, TAN Xiaohui^2*, DENG Xu¹, WU Yushuang¹, WU Min¹, YANG Xiangchun¹, LI Jinling¹]]> LIANG Fang¹, TAN Xiaohui^2*, DENG Xu¹, WU Yushuang¹, WU Min¹, YANG Xiangchun¹, LI Jinling¹ 38true Salicornia europaea is a kind of salt tolerant plant with important edible and medicinal value. Because this coastal plant grow in extreme salt tolerant environment, the diversity of its endophytic fungi and their active secondary metabolites may be distinctive from other plants. In our study, the endophytic fungi were isolated and purified, and the diversity of endophytic fungi was analyzed by RAPD, then the endophytic fungi were identified by ITS gene analysis. Finally, their activity inhibiting several aquatic spoilage bacteria was screened. The results were as follows:(1)A total of 14 endophytic fungi with different morphological characteristics were isolated from Salicornia europaea in Beibu Gulf. According to the RAPD analysis, these endophytic fungi had six different genetic types. The sequence analysis of ITS gene showed that these fungi had high sequence similarity with Curvularia lunata, Aspergillus candidus, Guarantaria mangiferae and Neocamarosporium chichastianum, and three of which showed relatively lower similarity with Neocamarosporium chichastianum IBRC-M:30126, which indicated 94%-95%. From the phylogenetic tree and colony morphology, three endophytic fungi, named YJCY2, YJCY3 and YJCG2, may be a new species closely related to Neocamarosporium salicornicola.(2)The antibacterial experiment showed that the extract content of strain YJCJ3 was a strong antibacterial activity to Vibrio parahaemolyticus, and the methanol, petroleum ether and ethyl acetate solution of the mycelium extract had a strong inhibiting activity against Vibrio parahaemolyticus. YJCJ5 showed a broad spectrum to inhibit several aquatic spoilage bacteria Buttiauxella noackiae, Aeromonas dhakensis and Buttiauxella gaviniae, in which the petroleum ether and ethyl acetate solution of mycelium inhibited the growth of Buttiauxella noackiae and Aeromonas dhakensis, while the extract content of methanol and petroleum ether solution inhibited the activities ofButtiauxella gaviniae. Our result is significant, for that the diversity of endophytic fungi in Salicornia europaea was extremely abundant, and that new endophytic fungi could be isolated and identified from this plant, a variety of whose active extracts can be screened and used to inhibit the growth of spoilage bacteria in aquatic products showing good potential for their utilization in this area.]]> 2021/7/5 15:46:28 2,3, FANG Huaiyi³, CAO Hongming¹, GONG Bin^1,2*, DENG Zongjian², CHEN Meihua⁴, SONG Jingjing³, ZHANG Hong²]]> ZHANG Yanqiu^2,3, FANG Huaiyi³, CAO Hongming¹, GONG Bin^1,2*, DENG Zongjian², CHEN Meihua⁴, SONG Jingjing³, ZHANG Hong² 37true Pisonia grandis is a dominant and tool species in the South China coral islands and an important role in windbreak and sand fixation and vegetation restoration. Here the stems of P. grandis were used as explants, the effects of different basal media, plant growth regulators(PGRs)and activated charcoal(AC)on axillary shoot proliferation, rooting and transplanting were studied. A rapid shoot proliferation and plant regeneration system was established. The results were as follows:(1)MS medium was suitable for the shoot proliferation and subculture period was 60 d, and the optimal shoot proliferation medium was MS medium that supplemented with 2.0 mg 瘙 簚 L^-1 6-BA + 0.1 mg 瘙 簚 L^-1 NAA and the shoot proliferation coefficient was 5.52;(2)The rooting percentage was 96.0% on the MS medium supplemented with 1.0 mg·L^-1 IBA, however, the rooting percentage decreased to 42.4% as the medium was supplemented with 1.6 g·L^-1 AC;(3)The plantlets that was cultured on the MS medium supplemented with AC, the transplanting survival percentage was 93.9%, while the transplanting survival percentage was 78.3% on the medium supplemented without AC. This study provides technological basis for large-scale proliferation and regeneration of P. grandis.]]> 2021/7/5 15:46:28 1,2, LIANG Hanzhi², CHEN Shuangyan^1,2, XIONG Yuping², WU Kunlin², ZHENG Feng², JIAN Shuguang², REN Hai², ZENG Songjun², MA Guohua^2*]]> YU Xincheng^1,2, LIANG Hanzhi², CHEN Shuangyan^1,2, XIONG Yuping², WU Kunlin², ZHENG Feng², JIAN Shuguang², REN Hai², ZENG Songjun², MA Guohua^2* 36true Hernandia nymphaeifolia to the tropical coral islands with harsh conditions of seasonal drought, strong light, and saline-alkali soil, we investigated the morphological and anatomical structures, antioxidant capacity, content of osmotic adjustments, and photosynthetic pigments in leaves of H. nymphaeifolia individuals that grown on the experimental nursery in Wenchang City, and that transplanted to the tropical coral islands, Hainan Province. The results were as follows:(1)Compared to H. nymphaeifolia plants grown in the experimental nursery, those plants transplanted to the tropical islands had lower specific leaf area(by 33%)and stomatal density(by 15%), thicker leaf(by 36%), more developed spongy tissue and more closely arranged palisade tissue(by 24% and 80%, respectively), which enable it to make more efficient use of light and water resources, to improve photosynthesis and to reduce transpiration, in the coral island environment.(2)After transplanted to the coral islands, the chlorophyll content of H. nymphaeifolia significantly decreased(by 86%), while proline content, superoxide dismutase, catalase, and peroxidase activity significantly increased(by 130%, 615%, 209% and 369%, respectively), which can protect its photosynthetic system and avoid the damage of plant cell membrane permeability caused by the adverse environment of coral islands. Our results indicated that H. nymphaeifolia had good ecophysiological adaptability to the environment of drought, strong light and saline-alkali soil in tropical coral islands. Therefore, H. nymphaeifolia can be used as a tool species for vegetation restoration on tropical coral islands and coastal areas.]]> 2021/7/5 15:46:28 1,2, LIU Nan^2,3, CAI Hongyue², WANG Jun², CHEN Ping¹, JIAN Shuguang^2*]]> ZHOU Wanmin^1,2, LIU Nan^2,3, CAI Hongyue², WANG Jun², CHEN Ping¹, JIAN Shuguang^2* 35true Chromolaena odorata occurred in some native plant communities on the Paracel Islands, which may cause serious harm to its fragile forest ecosystem. In order to understand the ecophysiological adaptabilities of C. odorata to the tropical coral islands, we investigated the morphological and anatomical structures, physiological characteristics and the nutrient contents in the leaves of C. odorata growing in the suburbs of Wenchang City and forest gaps on the Paracel Islands. The results showed that the plants of C. odorata growing in the Paracel Islands had thicker leaves, lower stomatal density, lower chlorophylla and malondialdehyde(MDA)contents, higher level of superoxide dismutase(SOD)and catalase(CAT)activities than that growing in Wenchang City, which are beneficial to acclimate to the adverse environments of strong light and seasonal drought, and may cause greater invasiveness of the plants. Therefore, it is necessary to strengthen the monitoring and control of C. odorata during the process of protection and restoration on the vegetation of the tropical coral islands.]]> 2021/7/5 15:46:28 1,2, LIU Nan¹, JIAN Shuguang^1* LIAO Mengcheng^1,2, LIU Nan¹, JIAN Shuguang^1* 34true Guettarda speciosa is a typical tropical coastal plant, which plays an important role in windproof and sand-fixing in island and coastal zones and vegetation ecological restoration. We studied the morphological and anatomical characteristics, antioxidant capacity, stress resistant material contents and nutritional element contents of paulodendrum under the natural environment Yongxing Island of Paracel Islands. The results were as follows:(1)The ratio of palisade tissue to sponge tissue, leaf thickness and other structures increased with the increase of drought degree, which could effectively reduce the water loss in plants and save water;(2)The activities of superoxide dismutase and catalase in the body increased rapidly, and the contents of proline also increased continuously, which proved that G. speciosa has a strong ability to resist drought;(3)The contents of nutrients in the root were low, but the contents of nutrients in the leaves were high, and the rates of total chlorophyll contents decreasing were slow, indicating that G. speciosa can use nutrients efficiently and suffer little damage from drought stress. It can be concluded that G. speciosa has strong drought resistance ability and can grow normally in the environment with poor soil moisture, which can be introduced to Spratly Islands.]]> 2021/7/5 15:46:28 1,2, LIU Dongming^2*, JIAN Shuguang², WANG Faguo², ZHAO Wenzhong³]]> LI Xiaoying^1,2, LIU Dongming^2*, JIAN Shuguang², WANG Faguo², ZHAO Wenzhong³ 33true 2022/9/3 13:46:31 *]]> GAO Chenghai, XIA Jialang, LIANG Kaoyun, LIU Yonghong, YI Xiangxi^* 32true 2022/9/3 13:46:31 1, ZHU Xiaotong¹, WANG Wansheng², DU Yuncai², WANG Yanying², LIANG Qiming¹, ZHENG Liting¹, YAN Enrong^1*]]> XU Mingshan¹, ZHU Xiaotong¹, WANG Wansheng², DU Yuncai², WANG Yanying², LIANG Qiming¹, ZHENG Liting¹, YAN Enrong^1* 31true Ipomoea pes-caprae is an important sand-fixing plant widely distributed in southern coastal sandy land. In order to explore the adaptation mechanism of I. pes-caprae to environmental changes in different seasons, the seasonal changes of its leaf physiological traits were studied. In this paper, I. pes-caprae grown up naturally in coastal sand of Guangxi was taken as experimental material, and the physiological indexes such as the contents of chlorophyll, the contents of osmotic substance, antioxidant enzyme activities and chlorophyll fluorescence parameters of the I. pes-caprae leaves in different seasons were measured, and the correlation analysis and principal component analysis were also carried out. The results were as follows:(1)Chlorophyll contents had the same trend with season changes, which was significantly higher in spring than those in other three seasons, but chlorophyll a/b had no significant change among seasons.(2)F_v/F_m and F_v/F_o of chlorophyll fluorescence parameters also had the same change trends, which were significantly higher in summer and winter than those in spring and autumn.(3)Proline content increased gradually with seasons, and reached the highest level in winter. Soluble sugar content in winter was significantly higher than those in other three seasons. There was no significant differences in malondialdehyde(MDA)contents among seasons.(4)The activities of superoxide dismutase(SOD)and catalase(CAT)in spring were significantly higher than those in other seasons, but there was no significant differences among summer, autumn and winter. There was no significant differences in peroxidase(POD)activities among seasons.(5)There was a certain correlation between physiological indexes and climate factors by correlation analysis and principal component analysis. Temperature and sunshine duration significantly affected the contents of soluble sugar. Chlorophyll contents and antioxidant enzyme activities could better reflect the response of I. pes-caprae leaves to seasonal climate change. To sum up, the chlorophyll a/b can be kept stable by adjusting the contents of chlorophyll a and chlorophyll b, and meanwhile, the contents of osmotic adjustment substances and the activities of antioxidant enzymes can improve it to adapt to seasonal changes, among which photosynthesis and antioxidant enzymes system are the key factors affecting its seasonal adaptability.]]> 2022/9/3 13:46:31 *, HUA Bin, QUAN Jiahui, LIU Jinchi]]> JIN Yun, ZHU Liqiong, ZHAO Lijun^*, HUA Bin, QUAN Jiahui, LIU Jinchi 30true Kandelia candel, Bruguiera gymnorrhiza, Rhizophora stylosa, and their habitats, in Guangxi coastal area. Then 22 samples were divided according to different parts such as roots, stems, leaves, flowers, fruits and soils. Eight different culture media were used to isolate culturable bacteria, and 16S rRNA gene sequences were used to identify bacteria and analyze diversity. For cultured bacteria, the antibacterial and enzyme activities of fermented crude extracts were screened with Kirby-Bauer method and spot planting method, respectively. The results were as follows:(1)Based on sequencing results of 16S rRNA gene, a total of 35 strains of culturable bacteria were isolated, belonging to 28 genera and 23 families. Bacillus accounted for 14.3% of the total bacteria, which was the dominant bacteria. Meanwhile, 11 potential new bacterial species were found.(2)Four strains of bacteria showed antibacterial activities, 16 strains had enzyme activities, and Bacillus was the dominant strain in enzyme activities. The above results show that Guangxi true mangrove plants are rich in bacterial diversity, and some bacteria show antibacterial activities and enzyme activities. The new bacterial species and active strains had certain development potential in the new antibiotics and enzymes application.]]> 2022/9/3 13:46:31 *]]> LI Fangting, LI Mi, XU Shufen, WANG Huimin, LIU Yonghong, GAO Chenghai^* 29true Casuarina equisetifolia coastal protection forest(CCPF)in Hainan Island has been seriously affected as C. equisetifolia itself can not regenerate naturally. In this paper, Haikou CCPF was taken as the test area of the natural habitat, and a total of 36 treatment combinations were designed by using 5-factor 2-level factor test method to explore the impact factors and barrier factors of C. equisetifolia seed germination and seedling survival. The results were as follows:(1)The treatment combination with the highest seed germination rate of C. equisetifolia was canopy gap-not watering-sandy soil-water retention-covering soil(GJ0SBM), with 37.33% of the germination rate, which was significantly higher than those of other treatment combinations(P<0.05). The treatment combination with the highest average plant height was canopy gap-watering-red soil-no water retention-not covering soil(GJRB0M0), with the plant height of 6.43 cm in 53 d, which was significantly higher than those of other treatment combinations(P<0.05). The treatment combination with the highest survival rate was canopy gap-watering-sandy soil-water retention-covering soil(GJSBM), with 79.00% of the survival rate for 73 d, which was significantly higher than those of other treatment combinations(P<0.05).(2)Stand light conditions and covering soil patterns were the impact factors for seed germination rate and germination potential of C. equisetifolia, while water retention patterns had significant effects on seed germination speed.(3)Stand light conditions were the impact factors for C. equisetifolia seedling plant height.(4)Watering treatment was the main factor affecting the survival rate of C. equisetifolia seedlings. In summary, the barrier mechanism of C. equisetifolia natural regeneration unable to survive in Hainan dry season is not for the seed germination, but for the lack of necessary water, resulting in the failure of C. equisetifolia itself natural regeneration.]]> 2022/9/3 13:46:31 *]]> WANG Yu, HAO Qingyu^* 28true Casuarina equisetifolia plantations, three forest plantations were selected, i.e. pure plantation of Casuarina equisetifolia, mixed plantation with Casuarina equisetifolia and Calophyllum inophyllum, mixed plantation with Casuarina equisetifolia and Acacia auriculiformis in coastal sandy land at Northern Hainan Island. By collecting soil profile samples from different plantations, the distribution characteristics of soil physico-chemical properties and their differences among plantations were discussed. The results were as follows:(1)Compared with the pure plantation of Casuarina equisetifolia, the mixed plantation with Casuarina equisetifolia and Calophyllum inophyllum significantly increased pH by 6.11% and 5.97% at the humus horizon and 20-40 cm soil depth, respectively.(2)Compared with the pure plantation of Casuarina equisetifolia, the contents of soil organic carbon(SOC)was increased by 69.8%-358.3% and 90.2%-908.3%, and the contents of soil total nitrogen(TN)was increased by 44.1%-160.7% and 31.4%-210.7% in different soil depths of two mixed plantations, respectively; The contents of soil total phosphorus(TP)increased by 20.8%-39.6% in different soil depths from 0-100 cm in mixed plantation with Casuarina equisetifolia and Calophyllum inophyllum, and increased by 25.0%-39.6% of 20-100 cm soil depth of mixed plantation with Casuarina equisetifolia and Acacia auriculiformis; The mixed plantation with Casuarina equisetifolia and Acacia auriculiformis showed the better improving effect on available nutrients in humus horizon than the other plantations, while both mixed plantations could significantly increase the available potassium contents in different soil depths.(3)Variance analysis showed that plantation type and soil depth had significantly interactive effects on the contents of SOC, TN, TP, available phosphorus(AP), nitrate nitrogen(NO₃^--N)and ammonium nitrogen(NH₄⁺-N). In conclusion, the mixed Casuarina equisetifolia plantations can significantly improve the soil fertility. Hence, in order to ensure the sustainable production, more attention should be paid to the mixed plantation structures, especially with Acacia auriculiformis, to get better fertility.]]> 2022/9/3 13:46:31 1, XUE Yang¹, SU Shaofeng¹, LIN Zhipan¹, LEI Xiangling², WANG Yaoshan^2*]]> WANG Xiaoyan¹, XUE Yang¹, SU Shaofeng¹, LIN Zhipan¹, LEI Xiangling², WANG Yaoshan^2* 27true Casuarina equisetifolia and Acacia confusa, we respectively watered the seeds and seedlings of the two kinds of plants with the solutions of NaCl(salt)and KH₂PO₄(phosphorus)in different concentrations, and then determined their growth indicators, respectively. The results were as follows:(1)High salt concentration solutions significantly inhibited seed germination and had a certain effect on the growth of seedlings, however, the effects of salt stress on seed gemination and growth were different. The salt tolerance of Acacia confusa seed germination was higher than that of Casuarina equisetifolia. The biggest relative salt damage rate of Acacia confusa was 23.03% and that of Casuarina equisetifolia was 89.15%. As the concentration of NaCl increased, the germination rate, germination potential, germination index and vitality index of Casuarina equisetifolia and Acacia confusa seeds decreased. And the maximums of the four germination indexes of Casuarina equisetifolia seed were 38.70%, 34.67%, 18.70 and 0.055, and of Acacia confusa seeds were 76.67%, 62.22%, 48.46 and 6.11, respectively.(2)The height and root length of the plants decreased with the increase of salt concentration. The plant heights of Casuarina equisetifolia and Acacia confusa were 12.29 to 6.01 mm and 48.27 to 17.33 mm, and the root lengths were 8.57 to 1.45 mm and 33.41 to 5.88 mm, respectively. The biomass of root, stem and leaf as well as root shoot ratio of Acacia confusa gradually decreased with the increase of salt concentration, but the differences between the treatments of Casuarina equisetifolia were not obvious. 0.6% and 0.4% salt stress were the thresholds for seed germination and seedling growth of the two plants, respectively.(3)The seed and seedling of Acacia confusa were more tolerant to low-phosphorus environment than Casuarina equisetifolia, and there was a difference in the optimum phosphorus concentration between the two. When the phosphorus concentration was 0.1 mmol·L^-1, the seed germination rate(49.33%), germination index(23.12%)and vitality index(0.093)of Casuarina equisetifolia, as well as the biomass of root, stem and leaf, all reached the maximum. In the 5 mmol·L^-1 treatment, the maximums of germination rate(81.11%), germination potential(62.22%), gemination index(38.23), vitality index(5.07), plant height(54.48 mm)and root length(37.16 mm)of Acacia confusa seeds all appeared, while their germination was inhibited in the treatment of 10 mmol·L^-1. Therefore, when sowing the seed of coastal defense forest or planting its seedling, the sowing or planting mode must be selected according to the soil salt and phosphorus contents.]]> 2023/5/12 15:53:21 1,2, LUO Qian^1,2, XIA Xinhui^1,2, PAN Guoying^1,2, LI Maojin³, JIANG Chuanyang⁴, SU Qingui³,CHEN Can^1,2*]]> YUAN Feng^1,2, LUO Qian^1,2, XIA Xinhui^1,2, PAN Guoying^1,2, LI Maojin³, JIANG Chuanyang⁴, SU Qingui³,CHEN Can^1,2* 26true Acacia confusa is an important species in coastal shelter forests. In order to explore the effects of salt and phosphorus fertilization on leaf photosynthesis and nutrient characteristics of the seedlings. NaCl solutions were configured in the concentrations of 0%(B₀), 0.2%(B₁), 0.4%(B₂), 0.6%(B₃)and 0.8%(B₄), and superphosphate solutions in the concentrations of 0 g·kg^-1(P₀), 0.5 g·kg^-1(P₁), and 1.5 g·kg^-1(P₂). The photosynthesis and nutrient characteristics of the seedlings were determined after being watered by the 6 combined solutions of salt-phosphorus coupling fertilization. The results were as follows:(1)Salt stress significantly inhibited the growth and development of the seedlings, and the higher the salt content, the greater the effect. Phosphorus application under low-salt stress was unfavorable to the growth of the seedlings, while phosphorus application under medium-high one significantly slowed down the inhibition of the seedling growth.(2)The greater the salt stress, the higher the effects on the photosynthesis of the seedlings. The stomatal closure degree of phosphorus application increased under low and medium salt stress, which aggravated the effect of salt stress on photosynthesis of the seedlings. Appropriate phosphorus application under high-salt stress could significantly improve the photosynthetic capacity of the seedlings.(3)Salt stress significantly reduced chlorophyll content and caused harm to photosystem II. Phosphorus fertilization on the seedlings under low-salt stress had adverse effects on chlorophyll synthesis. Appropriate fertilization of phosphorus in high-salt stress could increase chlorophyll synthesis, stabilize cell membrane structure, and improve the potential photosynthetic capacity of leaves.(4)Salt stress had strong interference on the contents of Fe, Mn, Na, Cu and other metal elements in leaves. Phosphorus application under salt stress could effectively promote the absorption of some elements by seedlings. In conclusion, phosphorus application after salt stress can improve the photosynthesis and nutrient absorption ability of A. confusa seedlings on the whole. The results provides a theoretical and practical basis for improving the salt tolerance and phosphorus utilization rate of A. confusa, and have guiding significance for the sustainable management of coastal shelter forests.]]> 2023/5/12 15:53:21 1,2, CHEN Can^1,2*, YUAN Feng^1,2, JIANG Chuanyang³, JIN Xuewei^1,2, CHEN Zichuan^1,2, LIN Han^1,2, WU Chengzhen^2,4]]> CHEN Zengyan^1,2, CHEN Can^1,2*, YUAN Feng^1,2, JIANG Chuanyang³, JIN Xuewei^1,2, CHEN Zichuan^1,2, LIN Han^1,2, WU Chengzhen^2,4 25true Sonneratia apetala, Kandelia obovata, Bruguiera gymnorhiza, Aegiceras corniculatum, Acanthus ilicifolius, Acrostichum aureum, Heritiera littoralis and Hibiscus tiliaceus)under different light intensity treatments(100%, 45%, 30%, and 10% of natural light intensity)were studied using shading control experiment. The results were as follows:(1)Low light intensities had little effect on the leaf soluble protein contents of Bruguiera gymnorhiza, Acanthus ilicifolius and Acrostichum aureum, whereas the other five species showed a decreasing trend of leaf soluble protein contents with the decline in light intensity.(2)The activities of superoxide dismutase(SOD)and ascorbate peroxidase(APX)in the leaves of Bruguiera gymnorhiza, Acanthus ilicifolius and Acrostichum aureum under 10% of natural light intensity treatment had no significant differences compared with the control, while the other five mangrove species showed a decreasing trend of all the five antioxidant enzyme activities. In conclusion, the results indicate that Bruguiera gymnorhiza, Acanthus ilicifolius and Acrostichum aureum are suitable to be planted under the forest with high canopy density, while Sonneratia apetala, Kandelia obovata, Aegiceras corniculatum, Heritiera littoralis, Hibiscus tiliaceus are suitable to be planted under the forest with lower canopy density or planted as middle and upper layer tree species in mangrove. The results of this study provide theoretical guidance for the optimal allocation of artificial mangrove communities.]]> 2023/5/12 15:53:21 1, 3, LI Ting^{1, 3}, JING Yuhang^1,3, CAO Honglin^1,2,3, YE Wanhui^1,2,3, SHEN Hao^1,2,3*]]> ZHU Yimin^{1, 3}, LI Ting^{1, 3}, JING Yuhang^1,3, CAO Honglin^1,2,3, YE Wanhui^1,2,3, SHEN Hao^1,2,3* 24true Bruguiera gymnorhiza and the biological activity of bacterial metabolites, and looked for anti-HBV drug source strains. Pure culture technique and 16S rRNA molecular biology technique were employed to determine the species of bacteria and analyze the species diversity. Using HepG2.2.15 cell line as a model, the anti-HBV activity of bacterial metabolites was tested by MTT and PCR techniques. The secondary metabolites of active bacteria were preliminary analyzed by LC-HRMS technique. The results were as follows:(1)A total of 59 species of bacteria were obtained, belonging to 4 phyla, 5 classes, 14 orders, 23 families, and 36 genera, among which Bacillus was the dominant genus. Strains GXIMD07402, GXIMD07665 and GXIMD07384 were potential new species of Pseudooceanicola, Thioclava and Aestuariibaculum, respectively.(2)The results of anti-HBV activity showed that GXIMD07366, GXIMD07616, GXIMD07384, GXIMD07550 and GXIMD07445X could significantly reduce the level of HBV DNA in the supernatant of HepG2.2.15 cells(P<0.05), and the inhibition rates were 51%, 47%, 63%, 52% and 47%.(3)Four main secondary metabolites of the highly active strain GXIMD07384 were preliminarily identified as Adenosine, Cyclo(L-Pro-L-OMet), Acremine G and 7,8-dimethylbenzo[g]pteridine -2,4(1H,3H)-dione. The results of the study confirm that the species diversity of culturable bacteria in the habitat of Bruguiera gymnorhiza is rich, and it contains strains that can produce anti-HBV active compounds, which provide a basis for the subsequent application of marine microbial resources.]]> 2023/5/12 15:53:21 *]]> HOU Shishi, LIANG Kaoyun, GAO Chenghai, JIANG Cuiping, TANG Qianqian, LIU Yonghong, YI Xiangxi^* 23true Suriana maritima is a coastal ornamental plant species distributing only on the South China Sea Islands in China, at present. In order to understand the ecological and biological characteristics of S. maritima, we investigated the morphological and anatomical structure of stem and leaf, the antioxidant enzyme activity and osmotic adjustments contents in leaf of S. maritima, and nutrient element contents in leaf and soil of S. maritima growing on the Paracel Islands, by field investigation and sampling for analysis. The results were as follows:(1)S. maritima had small and thick leaf, well-developed palisade tissue, and low stomatal density(8.64 n·mm^-2), which make it easy to maintain water in the body and suitable for drought and high saline-alkali environments. The chlorophyll content(0.76 mg·g^-1)of the leaf was low, the total antioxidant capacity(589.50 U·g^-1)and proline content(1 123.64 μg·g^-1)were high, indicating that S. maritima had high photosynthetic utilization efficiency and strong antioxidant capacity.(2)Though the nutrient in natural growing soil was poor, the contents of organic carbon, nitrogen and phosphorus in leaf of S. maritima were relatively high(490.27, 18.10, and 3.81 g·kg^-1, respectively), indicating a high nutrient utilization efficiency and good adaptability of S. maritima to poor soil. In conclusion, S. maritima has a good adaptability to the environment of strong radiation, drought, high saline-alkali and poor soil on tropical coral islands, and can be used as a tool species for revegetation and landscaping on tropical coral islands. The results provide a theoretical basis for its protection, development and utilization.]]> 2023/5/12 15:53:21 1,2, LIN Ruoyi^1,3, LIU Nan¹, REN Hai¹, XU Beibei^1,2, JIAN Shuguang^1*]]> ZHOU Wanmin^1,2, LIN Ruoyi^1,3, LIU Nan¹, REN Hai¹, XU Beibei^1,2, JIAN Shuguang^1* 22true Acanthus ebracteatus is a special kind of rare mangrove plant, possessing great medicinal value. In this paper, in order to study the diversity of endophytic and rhizosphere culturable bacteria in the A. ebracteatus, we explored new potential bacterial species and strains with special biological activities. The culturable bacteria were isolated from A. ebracteatus by dilution separation method. The bacterial diversity was investigated based on the 16S rRNA gene sequence analysis. In addition, the confrontation experiment and lawn predation assay were utilized to screen bacteria with anti-microorganism activities. The results were as follows:(1)A total of 144 culturable bacteria were isolated from A. ebracteatus root, stems, leaves, flowers and rhizosphere soil. These bacteria were affiliated into 66 species based on the analysis of the 16S rRNA gene sequence. The bacterial genera Bacillus and Streptomyces were dominant in plant tissue and rhizosphere soil with that of the value 15.1% and 13.6%, respectively.(2)The bioactivity assays revealed that there were 29 strains with anti-fungal activity and 10 strain possessing a broad spectrum of anti-fungal activity. Among them, the Streptomyces strains had the strongest antagonistic effect, and the active strain Y129 was a potential new species.(3)A total of five strains showed predation activity on Staphylococcus aureus, multi-drug resistance Staphylococcus aureus and Escherichia coli. Pseudomonas had the strongest predatory activity, and the active strain Y90 was a potential new species. In conclusion, A. ebracteatus and their rhizosphere soil contain rich bacterial germplasm resources and have a variety of functional strains, which can be used as one of the sources of biocontrol bacteria and medicinal bacteria. This study provides the theoretical reference for improving the efficacy and cultivation of A. ebracteatus.]]> 2023/5/12 15:53:21 1, HUANG Yuanlin ¹, ZHU Junhua², HU Wenjin³, WANG Qiaozhen¹, HUANG Shushi¹, PAN Xinli^1*]]> LI Zhe¹, HUANG Yuanlin ¹, ZHU Junhua², HU Wenjin³, WANG Qiaozhen¹, HUANG Shushi¹, PAN Xinli^1* 21true Kandelia obovata and Bruguiera sexangular in Dongzhaigang National Nature Reserve. The effects of major ecological factors on net photosynthetic rate were analyzed by using path analysis. The results were as follows:(1)The daily average net photosynthetic rate of Kandelia obovata in the dry season(8.43 μmol^-2·s^-1)was slightly lower than that in the rainy season(8.67 μmol^-2·s^-1), and the difference was not significant. In contrast, the rate of Bruguiera sexangular in the dry season(7.03 μmol^-2·s^-1)was significantly lower than that in the rainy season(9.41 μmol^-2·s^-1). The rate of Kandelia obovata was significantly higher than that of Bruguiera sexangular in dry season, while the rate of Kandelia obovata was significantly lower than that of Bruguiera sexangular in rainy season.(2)The daily average variations of transpiration rate, stomatal conductance and intercellular CO₂ concentration of Kandelia obovata were smaller than those of Bruguiera sexangular and the water use efficiency was also lower than that of B. sexangular in dry and rainy seasons.(3)There was a phenomenon of “midday depression of photosynthesis” in both dry and rainy seasons of Kandelia obovata and Bruguiera sexangular. In dry season, the main reason for the phenomenon of Kandelia obovata might be due to non-stomatal limitation, while Bruguiera sexangular due to stomatal limitation. In rainy season, the phenomena of two mangrove plants were both mainly caused by stomatal limitation.(4)In the dry season, the main decision factor affecting the net photosynthetic rate of Kandelia obovata was photosynthetically active radiation, and the main limiting factor was relative humidity, while ecological factors played a limiting role on the net photosynthetic rate of Bruguiera sexangular of which saturated water vapor pressure difference was the main limiting factor. In the rainy season, the main decision factor was photosynthetically active radiation, and the main limiting factor was saturated water vapor pressure difference for both Kandelia obovata and Bruguiera sexangular. In summary, Kandelia obovata is more adaptable to habitat changes, and Bruguiera sexangular not only has better drought tolerance performance, but also more suitable for hot and rainy habitats, which will be the scientific reference for the selection of plant for restoration and reconstruction of degraded mangroves.]]> 2023/5/12 15:53:21 *, MEI Minhua]]> ZHENG Xiong, YE Wenwei, ZHAO Congju^*, MEI Minhua 20true Thalassia hemprichii as the research object, a simulation experiment was carried out in a solar greenhouse with high temperature(41.0-44.5 ℃)and strong light(633-1 682 μmol·m^-2·s^-1)environmental conditions. The effects of different desiccation time(0, 10, 20, 40, 60, 90 min·d^-1, continuous for 7 d)on the growth rate, photosynthetic pigment content and photosynthetic fluorescence parameters of the leaves, as well as on the activities of antioxidant enzymes and the contents of nonstructural carbohydrates and secondary metabolites of leaves and roots were studied. The results were as follows:(1)The diurnal periodic photothermal desiccation of ≤10 min·d^-1 had no significant effect on the growth rate and physiological characteristics of T. hemprichii(P>0.05).(2)Under the photothermal desiccation conditions, the damage of T. hemprichii leaves increased, the color of leaves changed from green to brown, and the growth rate of leaves decreased with the extension of desiccation time. Meanwhile, the photosynthetic pigment content, chlorophyll a/chlorophyll b and the chlorophyll fluorescence parameters of leaves showed a downward trend; the contents of MDA and soluble sugar and the activities of POD, SOD and CAT of leaves and roots showed an upward trend; whereas the contents of starch, total phenol and total flavonoids in leaves increased first and then decreased.(3)The diurnal periodic photothermal desiccation of 90 min·d^-1 was the upper limit of incomplete inactivation for T. hemprichii chloroplast PS Ⅱ photosynthetic reaction center. In summary, a long term photothermal desiccation stress during tidal cycle has negative impacts on the growth and physiological characteristics for T. hemprichii. The results provide the reference for understanding the distribution of tropical seagrasses in the intertidal zone and the location selection of seagrass meadows for ecological restoration.]]> 2023/12/2 12:35:43 1,3, SHI Yunfeng^2*, CAI Jiali^1,3, ZHAO Muqiu², SHI Zhiqiang¹, LUO Huijue³, HAN Qiuying¹]]> LI Zhaoyang^1,3, SHI Yunfeng^2*, CAI Jiali^1,3, ZHAO Muqiu², SHI Zhiqiang¹, LUO Huijue³, HAN Qiuying¹ 19true 2023/12/2 12:35:43 *]]> ZHOU Youxiu, YANG Guimei, QIN Zibo, YANG Yuhua, JIANG Yandong, HUANG Liujing^* 18true Zizania latifolia, an emergent plant in the lakeside zone of the Napahai Wetland in the northwest of Yunnan Province, were studied by using an open-top chamber. The results were as follows:(1)In the temperature-increasing range of 4 ℃, the aboveground stem of Z. latifolia responded to warming mainly by increasing the thickness of the epidermal structure to increase the epidermal water loss. The response strategy of the underground stem was the same as that of the aboveground stem when the temperature was increased by 2 ℃, while the response to the temperature increase was mainly through reducing the sizes of the vascular structure to reduce the risk of cavitation when the temperature were increased by 4 ℃.(2)Annual maximum temperature(MAX)and nighttime accumulated temperature(NAT)were the key factors affecting the stem anatomical structure of Z. latifolia, but both of which only have significant effects on the sieve tube size of the underground stem(R²=0.838, P<0.01).(3)The thickness of inner epidermal cells was the main traits of the aboveground stem in response to the warming, and was significantly and positively correlated with temperature factors. The size of the vessel and sieve tube was the main trait of the underground stem response to the warming, and they were negatively correlated with temperature factors. The results indicate that there are differences in response strategies of the aboveground stem and underground stem of Z. latifolia to the temperature increase, which provides a scientific basis for revealing the response laws of plateau wetland plants to climate warming and ecological adaptation strategies. Based on the current climate warming context, we need to further investigate and supplement the ecological response processes and laws of more plateau wetland plants with more scientific experimental methods in the future.]]> 2023/12/2 12:35:43 1,2, SUN Mei^1,2*, LIU Zhenya^1,2, BAN Qitang³, WEI Jiagong³, LU Hanyun³, YANG Hangmei^1,2]]> CHEN Hongyi^1,2, SUN Mei^1,2*, LIU Zhenya^1,2, BAN Qitang³, WEI Jiagong³, LU Hanyun³, YANG Hangmei^1,2 17true Rhizophora stylosa, Talipariti tiliaceum, Sonneratia apetala, Aegiceras corniculatum, and Pluchea indica)was cultured by enrichment media and then isolated the culturable bacteria. The culturable bacteria were purified by six different isolation media. The diversity of culturable bacteria was analyzed by the 16S rRNA gene sequence information. Antimicrobial activities(Staphylococcus epidermidis, methicillin-resistant S. aureus, and Pseudomonas aeruginosa)of the culturable bacteria were analyzed by disk diffusion method. The results were as follows:(1)A total of 120 strains were isolated from seven rhizosphere soil samples of mangrove plants which could be classified into 35 families and 47 genera, among which five potential new species were obtained. The dominant genus was Streptomyces sp.(14.2%).(2)It was found that the crude extracts of nine strains had antibacterial activity against at least one pathogen. The results indicate that there are abundant culturable bacteria and potential new antibiotics resources in the mangrove rhizosphere soils from the Maowei Sea.]]> 2023/12/2 12:35:43 1,2, LI Mi^1,2, XU Shufen^1,2, LI Fangting^1,2, YI Xiangxi^1,2, LIU Yonghong^1,2, GAO Chenghai^1,2*]]> LI Wangjing^1,2, LI Mi^1,2, XU Shufen^1,2, LI Fangting^1,2, YI Xiangxi^1,2, LIU Yonghong^1,2, GAO Chenghai^1,2* 16true Aucuba and to reveal their interspecies relationship, the chloroplast genomes of six Aucuba species including A. chinensis and A. japonica var. variegata as well as Garrya buxifolia were sequenced using next-generation sequencing technology. The chloroplast genomes were assembled and annotated using bioinformatics software. The genome characteristics, sequence comparison and phylogeny were analyzed based on the chloroplast genomes. The results were as follows:(1)Six Aucuba species chloroplast genomes exhibited typical quadripartite circular structure(i.e., LSC, SSC, IRB and IRA)and were between 157 891-158 325 bp in length. A total of 114 genes were annotated(except the duplicate genes on IRs), including 80 protein-coding genes(CDS), 30 tRNA genes and 4 rRNA genes.(2)A total of 29 high-frequency codons prefer ending in A/U, and a total of 100 optimal codons of these six sequences were filtered out, including 12 were shared by six Aucuba species.(3)A total of 270 interspersed repeats, 133 tandem repeats and 412 SSR loci were detected in the six Aucuba chloroplast genomes.(4)Comparative analysis result of six Aucuba species revealed a highly conserved chloroplast genome sequence.(5)Ten highly divergent regions were identified based on nucleotide diversity analysis.(6)The phylogenetic trees were constructed using maximum likelihood(ML)and Bayesian(BI)showing a similar topology. The results supported that genus Aucuba was monophyletic with high support rate, as a sister to genus Garrya. The complete chloroplast genomes of these five Aucuba species and one Garrya species is firstly sequenced in the study. The results reveal the interspecies relationships and the taxonomic status of genus Aucuba, and provide references for the classification, identification and phylogeny of the genus Aucuba.]]> 2023/12/2 12:35:43 *]]> LI Juan, TONG Jiayun, FAN Zhichao, TONG Yi ^* 15true Bruguiera gymnorhiza hypocotyl is a common marine herbal medicine of the Jing people used in the treatment of hepatitis B. Firstly, MTT and real-time fluorescence quantitative PCR methods were used to determine the anti-HBV activity of different extracted parts of B. gymnorhiza hypocotyl, the chemical constituents of the active extraction parts were isolated and identified using modern chromatographic techniques and spectroscopic methods, an in vitro screening model was employed to test the anti-HBV activity of obtained compounds. The results were as follows:(1)The n-butanol phase of the hypocotyl exhibited anti-HBV activity;(2)A total of 11 compounds were isolated and structurally identified, namely uridine(1), thymidine(2), adenosine(3), oryzalactam(4), n-butyl-O-D-fructopyranoside(5), nortetillapyrone(6),(4R,6S)-4-methoxyl-2,3-dihydroaquilegiolide(7),(4R,6S)-2-dihydromenisdaurilide(8), gallcatechin(9), 1-(4-hydroxy-3-methoxy)-phenyl-2-[4-(1,2,3-trihydroxypropyl)-2-methoxy]-phenoxy-1,3-propandiol(10), and(-)-lyoniresinol-9-O-β-D-xylopyrano-side(11), among them, compounds 4, 5, 7 and 8 were firstly obtained from B. gymnorhiza, and Compound 4 showed anti-HBV activity with an inhibition rate of 23.59%. The study clarify the chemical composition of the anti-HBV of B. gymnorhiza hypocotyl.]]> 2023/12/2 12:35:43 *]]> LIANG Kaoyun, HOU Shishi, GAO Chenghai, LIU Yonghong, YI Xiangxi^* 14true Aegiceras corniculatum, antibacterial activity of ferment extract of endophytic fungi was used as evaluation index to screen active strains, the chemical constituents were separated on the basis of bioactivity-guiding method combined with various chromatographic techniques and identified by spectral technique together with comparison with literature data, and the antibacterial activity of pure compounds was determined by microplate method. The results were as follows:(1)Sixteen taxa of endophytic fungi isolated from A. corniculatum were distributed in 2 classes, 7 orders, 10 families and 10 genera. Fusarium was dominant genus. The ferment extract of endophytic fungi GXIMD02029 and GXIMD02039 displayed different levels of inhibitory effects on Bacillus subtilis, Staphylococcus epidermidis, methicillin-resistant S. aureus, Micrococcus luteus, Actinomyces viscosity, and Staphylococcus aureus when that of GXIMD02038 against methicillin-resistant S. aureus, Micrococcus luteus, and Staphylococcus aureus.(2)Seven pure compounds were isolated from endophytic fungi Phomopsis sp. GXIMD02029 and identified as(15R)-acetoxydothiorelone A(1), cytosporone B(2), pestalotiopsone H(3), pestalotiopsone B(4), 4-Hydroxybenzaldehyde(5), p-Hydroxybenzoic acid(6), N-(2-phenylethyl)acetamide(7).(3)Compounds 1 and 2 showed different levels of antibacterial effects. Compound 1 exhibited inhibitory effect on Bacillus subtilis, Staphylococcus epidermidis and methicillin-resistant S. aureus with MIC value of 16.25 SymbolmA@ g·mL^-1, Micrococcus luteus and Actinomyces viscosity with MIC value of 7.812 5 SymbolmA@ g·mL^-1, and Staphylococcus aureus with MIC value of 31.25 SymbolmA@ g·mL^-1. Compound 2 displayed inhibitory effect on Micrococcus luteus with MIC value of 62.5 SymbolmA@ g·mL^-1, Bacillus subtilis, Staphylococcus epidermidis, methicillin-resistant S. aureus and Actinomyces viscosity with MIC values of 125 SymbolmA@ g·mL^-1, and Staphylococcus aureus with MIC value of 250 SymbolmA@ g·mL^-1. Three active strains were reported in the project. It is reported that Compound 1 shows the antibacterial activity for the first time. The result provides the basis for the antibacterial values of endophytic fungi of Aegiceras corniculatum.]]> 2023/12/2 12:35:43 1,3, YI Wangdi¹, XING Nannan², LIU Yonghong^1,3, GAO Chenghai^1,3, XIA Chenxi^1,3, CHEN Xianqiang^1,3*]]> LUO Zhihong^1,3, YI Wangdi¹, XING Nannan², LIU Yonghong^1,3, GAO Chenghai^1,3, XIA Chenxi^1,3, CHEN Xianqiang^1,3* 13true 2, with Kandelia obovata having the largest distribution area of 49.96 hm², followed by Avicennia marina, Sonneratia caseolaris, S. apetala, and Bruguiera gymnorhiza, with respective areas of 26.23, 8.90, 6.52, and 0.50 hm².(2)The total carbon storage of Kandelia obovata community was the highest, followed by Avicennia marina, Sonneratia caseolaris, S. apetala, and Bruguiera gymnorhiza the lowest. The carbon density in Sonneratia apetala and S. caseolaris community showed an increasing trend, and S. apetala community revealed the highest among the five dominant communities. The carbon density of Kandelia obovata community increased first and then decreased, while Avicennia marina community showed a downward trend consistently, and carbon density in Bruguiera gymnorhiza community did not vary significantly. In summary, the carbon storage of mangrove dominant communities in Futian did not change much from 2017 to 2023. The carbon sequestration capacity of mangrove in Kandelia obovata, Sonneratia apetala and S. caseolaris communities was stronger. The carbon density of Avicennia marina community decreased year by year, while that of Bruguiera gymnorhiza community was relatively stable. These results provide foundational data for evaluating the carbon sequestration capacities of different dominant communities in Futian mangrove, in tandem with scientific support for subsequent mangrove restoration and management.]]> 2024/9/4 0:00:00 1, TAN Min², LUO Qin², HUANG Zijian², XIANG Xuelian², LI Buhang², YU Shixiao², WU Zefeng¹, YANG Qiong¹, HU Ping^1*]]> HU Liuliu¹, TAN Min², LUO Qin², HUANG Zijian², XIANG Xuelian², LI Buhang², YU Shixiao², WU Zefeng¹, YANG Qiong¹, HU Ping^1* 12true 2024/9/4 0:00:00 1,2,3, SHI Xian^3,4, CHEN Quan^3,5, WU Lan^3,5, CUI Wei⁶, WANG Wenmei^1,2, SUN Zhongyi^3,5*, TAN Ke^7*]]> ZHENG Yinqi^1,2,3, SHI Xian^3,4, CHEN Quan^3,5, WU Lan^3,5, CUI Wei⁶, WANG Wenmei^1,2, SUN Zhongyi^3,5*, TAN Ke^7* 11true Laguncularia racemosa plantations gradually with native mangrove forests through thinning and pruning without clear-cutting of drastic habitat disturbance in the reserve, we took the exotic mangrove L. racemosa forests introduced in Hainan Dongzhai Harbor National Nature Reserve as the study area, and L. racemosa forests were thinning and pruning relying on the reserve. The purpose was to study the ecological effects of the thinning and pruning of L. racemosa forests on the restoration of native mangrove communities. The results were as follows:(1)Asexual reproduction of L. racemosa stump sprouting after thinning and pruning weakened the treatment effect, and there was no significant difference in the effects of L. racemosa stump sprouting between one intervention(50% intensity of thinning and pruning)and two interventions(50% intensity of thinning and pruning followed by an additional pruning).(2)Both intervention methods enriched native mangrove species and promoted their growth in the understory shrub layer, and the two interventions had a more significant promotion effect than the one intervention. However, there was no significant effect on the natural regeneration of mangrove seedlings in the herbaceous layer.(3)In the experiment of planting native mangrove seedlings in the three plots of non-thinning, thinning and pruning, and forest margin, the survival rates of Rhizophora stylosa and Kandelia obovata seedlings were promoted by the thinning and pruning. The effect of thinning and pruning on the growth of Rhizophora stylosa seedlings was close to the forest margin conditions, but the effect was limited. In conclusion, we suggest increasing the thinning intensity or pruning frequency based on 50% intensity thinning and pruning, carrying out artificial planting of native mangrove plants in the understory appropriately, and removing the sprouting branches from the stumps of Laguncularia racemosa, which is more conducive to the conversion of L. racemosa plantation to native mangrove community.]]> 2024/9/4 11:42:31 1,2, YANG Shan^1,2, LIU Qiang^1,2*, ZHOU Jiayi^1,2]]> CHEN Chunlian^1,2, YANG Shan^1,2, LIU Qiang^1,2*, ZHOU Jiayi^1,2 10true Ligustrum lucidum was used as the test material and the fertilization method of ingrown soil cores(volume 196.25 cm³)was used to conduct nitrogen and phosphorus addition experiments on the soil core of the soil surface layer(0-10 cm)of L. lucidum. Suppose the fertilization gradient was 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 20 g per hole. The effects of N and P nutrients on the functional traits of fine roots in the soil surface were studied. The results were as follows:(1)Compared with the control, when 3 g N was applied, the length, surface area, volume, root length density, root surface area density, and biomass of fine roots increased significantly, with the increases of 62.39%, 120.87%, 169.97%, 59.19%, 106.99% and 102.75%, respectively; when 5-11 g N was applied, the above indicators gradually decreased. When the amount of N was applied greater than 11 g, no root grew.(2)When 3 g P was applied, the total length, surface area, volume, root length density, root surface area density and biomass of the root system significantly increased, with the increases of 77.37%, 111.15%, 147.50%, 73.87%, 97.88% and 98.05%. When the amount of P was applied greater than 5 g, the above indicators of fine roots gradually decreased, but there was no rootless situation. Fertilization caused significant changes in the morphological indicators and biomass of fine roots, and plants improved the ability to acquire soil nutrients by changing the structure of fine roots. Therefore, applying 3 g of N or P respectively to the surface soil 1 m away from the trunk significantly can promote the growth of fine roots of L. lucidum.]]> 2024/9/4 11:42:31 1, LU Xinghui¹, ZHANG Yanyi¹, WANG Hongjiao¹,XIE Xian¹, JIANG Hong³, HAN Jingya¹, WANG Yihe¹, LIANG Jing^2*]]> WANG Zhibao¹, LU Xinghui¹, ZHANG Yanyi¹, WANG Hongjiao¹,XIE Xian¹, JIANG Hong³, HAN Jingya¹, WANG Yihe¹, LIANG Jing^2* 9true Syzygium hancei seedlings to environmental factors in three different habitats under natural regeneration conditions, the current year's S. hancei seedlings were collected as experimental materials that regenerated in naturally coastal environments of Guangxi, and then antioxidant enzyme activities, soluble sugar(SS)content, malondialdehyde content and photosynthetic pigments in leaves and roots were measured. The results were as follows:(1)Variance analysis(ANOVA)was conducted on multiple environmental factors, which indicated that light intensitIES had highly significant differences, soil surface temperature and water content had not significant differences between the three sample plots.(2)Various light densities resulted in the changes of physiological characteristics of seedling leaves and roots in different habitats. With the light density increasing, superoxide dismutase(SOD)activity, SS content, MDA content, and chlorophyll a/b contents in leaves, and peroxidase(POD)activity in roots of seedlings were significantly higher in Habitat B than those in Habitat A; while POD activity, chlorophyll a, chlorophyll b and total chlorophyll contents in leaves, and SOD activity, SS and MDA contents in roots were higher in Habitat A than those in Habitat B.(3)With light intensity decreasing, seedlings that regenerated in Habitat B represented significantly higher SOD activity and MDA content in leaves, and POD activity in roots than those regenerated in Habitat A; however, these seedlings that regenerated in Habitat A represented significantly higher POD activity and SS content in leaves compared with those regenerated in Habitat B; chlorophyll a, chlorophyll b, total chlorophyll, and SS and MDA contents in roots were significantly higher in Habitat A than those in Habitat B firstly, and then changed to Habitat B being significantly higher than Habitat A; chlorophyll a/b content and SOD activity in roots were significantly higher in Habitat B than those in Habitat A firstly and then changed to Habitat A being significantly higher than Habitat B. Comprehensive analyses show that the physiological and biochemical characteristics of all the three habitats showing different adaptation abilities, in the meanwhile, photoinhibition occurrs in Habitat B with the lowest canopy density, hence, some manual adjusting practices are needed to create a moderate light environment, and to provide a suitable condition for promoting the natural regeneration of seedlings.]]> 2024/9/4 11:42:31 1, ZHAO Lijun^1,2*, ZHU Liqiong³, MO Ruoguo¹, WANG Yanling¹]]> ZHAO Xiaoyu¹, ZHAO Lijun^1,2*, ZHU Liqiong³, MO Ruoguo¹, WANG Yanling¹ 8true Staphylococcus aureus, S. epidermidis, S. aureus and Acinetobacter baumannii)were screened with Kirby-Bauer method. The results were as follows:(1)A total of 42 culturable bacteria were isolated, belonging to 14 genera and 13 families, which included Streptomyces, Vibrio, Bacillus, Shewanella, Microbacterium, Brevibacterium, Staphylococcus, Sphingomonas, Rothia, Psychrobacter, Pseudonocardia, Photobacterium, Halomonas, and Shigella. The genus Streptomyces was the dominant bacterium.(2)Antibacterial activity showed that six bacteria exhibited strong inhibitory activity against at least two or more human pathogenic bacteria, which included Vibrio(1 strain), Rothia (1 strain), and Streptomyces(4 strains). The studies show that the rhizosphere soil microbial resources of halophytes in the seagrass bed in Fangchenggang sea area are novel and unique, and Streptomyces has a strong antibacterial activity, which provides a new source for the research and development of new antibiotics drugs.]]> 2024/9/4 11:42:31 1,2,3, LI Mi^1,2, LI Fangting^1,2, GAO Chenghai^1,2*]]> CHEN Wang'an^1,2,3, LI Mi^1,2, LI Fangting^1,2, GAO Chenghai^1,2* 7true Kandelia obovata produces a certain number of new twigs in different seasons within a year. To gain a deeper understanding of the growth status and seasonal dynamics of new twigs of K. obovata, this study investigated the growth traits of the stems and leaves of new twigs. Statistical methods such as analysis of variance, multiple comparisons, and principal component analysis(PCA)were used to comprehensively evaluate the growth performance of the twigs in different seasons and to explore the growth and survival strategies of mangrove plants, represented by K. obovata. The results were as follows:(1)The 14 trait indicators characterizing the growth status of the twigs showed significant variation, with a coefficient of variation ranging from 13.856% to 56.469%, and a strong correlation between the indicators.(2)The growth traits of the twigs varied significantly in different seasons(P<0.05), with the overall performance being July>May>March>October. Additionally, the importance of the growth traits was ranked as leaf traits > biomass > stem configuration.(3)The importance of growth traits was ranked as leaf traits(55.050%)>biomass(35.480%)>stem configuration(9.470%). The total weight proportion of the seven trait indicators such as leaf density, leaf and stem biomass ratio, leaf number, leaf biomass, big leaf area, stem length, and leaf area ratio was 87.146%, which were the key indicators characterizing the growth status of the twigs of K. obovata. In conclusion, the growth status of the twigs reflects the adaptation strategy of the tree to resource levels, influenced by external factors such as light and temperature, as well as internal factors such as growth strategies. These research results provide insight into the response of the twigs to environmental changes in different seasons and offer a reference basis for the protection and sustainable development of K. obovata population.]]> 2025/9/30 10:22:28 *]]> XU Bingyan, LI Jian, HONG Tao^* 6true Cassytha filiformis, Chromolaena odorata, Wollastonia biflora, Leucaena leucocephala, Bidens pilosa and Tridax procumbens, mainly distributed in Yongxing Dao, Dong Dao, Chenhang Dao, and Shanhu Dao.(3)The severity of pernicious plants was closely related to the total number of plant species and area of the island. The life form of pernicious plants in the Xisha Islands was mainly terrestrial herbs, accounting for 57.7%. The pernicious plants mainly came from the Americas, with a similar proportion of natural spread, unintentional introduction, intentional introduction sources. Based on the above results, it is suggested to conduct long-term monitoring of pernicious plants in the Xisha Islands, and formulate scientific prevention and control strategies for pernicious plants that have caused serious harm, including strengthening inspection and quarantine, physical removal, chemical control, alternative control, and publicity and education, etc. The research results provide important basic data, scientific and technological support for the protection, health and sustainable development of the vegetation and ecosystems in the Xisha Islands.]]> 2025/9/30 10:22:28 1,2, PU Lin¹, TONG Shenghong^1,3, CHEN Quan⁴, LIU Dongming¹, JIAN Shuguang^1*]]> CAI Hongyue^1,2, PU Lin¹, TONG Shenghong^1,3, CHEN Quan⁴, LIU Dongming¹, JIAN Shuguang^1* 5true Halophila ovalis and its environmental factors, this study systematically analyzed response relationship of H. ovalis biomass to multiple environmental factors using literature data(1990 — 2025)from the South China coast. Structural equation modeling(SEM)and linear mixed-effects model(LMM)were employed to quantify direct and indirect factors, such as water temperature, salinity, nutrients, suspended solids, and pH on biomass. The results were as follows:(1)Suspended solids in water significantly inhibited biomass accumulation and represented a widespread limiting factor across the region.(2)Water temperature, salinity, and nutrients [including dissolved inorganic nitrogen(DIN)and reactive phosphate in water(PO₄^3-)availability] were key environmental factors leading to biomass differences.(3)Nitrogen and phosphorus nutrients, particularly ammonium nitrogen(NH₄⁺-N), imposed critical constraints on biomass accumulation in each province(region), but dominant factors varied regionally. This study emphasizes that in the future, it is necessary to pay attention to the interaction effects of multi-scale environmental factors and formulate regional adaptive protection strategies based on environmental threshold management. The results of this study provide a scientific basis for the protection and restoration of the seagrass bed of H. ovalis.]]> 2025/9/30 10:22:28 1,2, DAI Hongtao³, GUO Yuming³, PAN Yuanfang^2,4, WU Liguang³, HUANG Liangliang¹, QIU Guanglong^2,4*]]> LIU Feiwu^1,2, DAI Hongtao³, GUO Yuming³, PAN Yuanfang^2,4, WU Liguang³, HUANG Liangliang¹, QIU Guanglong^2,4* 4true NAC gene, KoNAC25(GenBank accession number PP860407), was identified from the genome of the mangrove Kandelia obovata. To investigate whether the KoNAC25 gene of K. obovata is involved in the response to salt stress conditions, this study cloned the KoNAC25 gene from the cDNA of K. obovata leaves via RT-PCR and performed sequence characterization, phylogenetic evolution, subcellular localization, and gene expression analyses. The results were as follows:(1)The open reading frame(ORF)of the KoNAC25 gene was 858 bp in length and encoded 285 amino acids, with a molecular weight of 32.9 kDa and a theoretical isoelectric point of 8.53. KoNAC25 was a hydrophilic protein and contained no signal peptide or transmembrane structure, and its secondary structure was predominantly random coils(58.95%).(2)Amino acid sequence homology alignment showed the N-terminus of the KoNAC25 protein had a NAM superfamily structural domain, which consisted of five conserved substructural domains(ABCDE)and belonged to the NAM subfamily.(3)The phylogenetic tree revealed that the KoNAC25 transcription factor of K. obovata was similar to the transcription factors of Ricinus communis, Manihot esculenta, and Hevea brasiliensis.(4)The subcellular localization test confirmed that the protein was localized in the nucleus, which was consistent with bioinformatics prediction.(5)qRT-PCR analysis result revealed that the expression of the KoNAC25 gene was significantly greater in leaves than in flowers and could be induced to upregulate its expression by NaCl(200 mmol·L^-1)and abscisic acid(ABA)(100 μmol·L^-1), which peaked under 12 h treatment and 6 h treatment, respectively; however, the expression level of this gene was not induced by salicylic acid(100 μmol·L^-1)and methyl jasmonate(100 μmol·L^-1). In summary, KoNAC25 is involved in the related regulation of the salt stress response in Kandelia obovata, which provides a reference for further research on the function of KoNAC25 gene and its expression regulatory mechanism under salt stress in K. obovata.]]> 2025/9/30 10:22:28 1,2, JIANG Wenjun¹, WANG Yongfeng³, WANG Jianqiang⁴, DONG Chao⁴, DU Zhaokui^1,2*]]> YANG Dang^1,2, JIANG Wenjun¹, WANG Yongfeng³, WANG Jianqiang⁴, DONG Chao⁴, DU Zhaokui^1,2* 3true Streptomyces sporoverrucosus 33510 in Guangxi. Silica gel column chromatography, ODS reversed phase column chromatography, and hemi-preparative high performance liquid chromatography combined with various chromatographic techniques were used to separate and purify the fermentation extract of actinomyces No. 2 medium of this strain. The structures of monomeric compounds were identified by spectral analysis and literature comparison. In addition, the antifungal activity of these monomeric compounds were tested by disk diffusion assay. The results were as follows:(1)Ten monomeric compounds were isolated from fermentation cultures of Streptomyces sporoverrucosus 33510 and identified as cyclo(L-isoleucyl-L-prolyl-L-leucyl-L-prolyl)(1), matsudipeptide B(2), cyclo(L-Leu-L-Pro)(3), cyclo(Leu-Ile)(4), N-acetyltyramine(5), isoleucine(6), p-hydroxybenzoic acid(7), 3-hydroxy-4-methoxybenzoic acid(8), 2-minaline(9), 2-hydroxybenzaldehyde(10). Compounds 1, 2, 4, 5, 7, 8, and 10 were all isolated for the first time from this strain.(2)The activity test results indicated that Compound 6 exhibited high sensitivity against the Cryphonectria parasitica at a concentration of 0.2 mmol·L^-1, and the effect was superior to that of the positive control group. In this paper, the activity of Compound 6 against C. parasitica was reported for the first time. This study further enriches the structural types of secondary metabolites produced by the mangrove-derived actinomyces Streptomyces sporoverrucosus 33510 in Guangxi. The antifungal components of strain 33510 are identified, providing a theoretical basis for the subsequent development and utilization of antifungal pesticides.]]> 2025/9/30 10:22:28 1, LIU Ying¹, ZHANG Tangjie¹, YANG Shuyu², WU Jincheng¹, LIU Hongcun², MENG Juan³, JIANG Mingguo², YANG Lifang^1*]]> WENG Jie¹, LIU Ying¹, ZHANG Tangjie¹, YANG Shuyu², WU Jincheng¹, LIU Hongcun², MENG Juan³, JIANG Mingguo², YANG Lifang^1* 2true Burkholderia, Pantoea, Sphingomonas and Providencia, among which 20 strains belonged to the genus Burkholderia, which widely formed symbiosis with fungal hosts. According to the identification of ITS, 29 pairs of symbiont host fungi belonged to 2 phyla, 4 classes, 7 orders, 11 families, 12 genera and 22 species.(2)The endosymbiont bacteria were isolated from the symbiont GXIMD14377 derived from the soil of Hibiscus tiliaceus in Qinzhou via the hyphal fragmentation method and identified as Pantoea dispersa through 16S rRNA gene sequencing.(3)The wild nematodes fed on P. dispersa were isolated and cultured from the soil of Hibiscus tiliaceus in Qinzhou, and were identified as Caenorhabditis elegans.(4)It was found that fermentation broths of some symbionts exhibited antagonistic effects on wild nematodes. Among them, the symbiont GXIMD14385(Fusarium solani-Burkholderia territorii)showed the strongest antagonistic effect on wild nematodes, with an corrected mortality of(84.25±3.61)%. Furthermore, the symbiont GXIMD14377(Fusarium oxysporum-Pantoea dispersa)showed antagonistic effects on wild nematodes, which had predation relationships with symbiotic bacteria. In conclusion, the results indicate that the mangroves in the Beibu Gulf have a rich diversity of fungal-bacterial symbionts. There is a tripartite relationship exists between symbionts, endosymbiotic bacteria, and wild nematodes in the soil habitat of mangroves. This study is the first to explore the ecological relationship between fungal-bacterial symbionts and wild nematodes in mangrove habitats. This study lays the foundation for investigating the fungal-bacterial symbiotic interactions and their ecological relationships with wild nematodes in mangrove soils.]]> 2025/9/30 10:22:28 1,2, LI Mi^1,2, CHEN Xinyi^1,2, XU Landi^1,2, YI Xiangxi^1,2, GAO Chenghai^1,2*]]> XU Shufen^1,2, LI Mi^1,2, CHEN Xinyi^1,2, XU Landi^1,2, YI Xiangxi^1,2, GAO Chenghai^1,2* 1true