Davidia involucrata, a rare relic plant in China, exploring the responses of the antioxidant enzymes, malondialdehyde(MDA)and free proline, soluble protein to different concentrations Pb and Cd by pot experiment. The results were as follows:(1)The concentrations of MDA in D. involucrata seedlings were higher in different concentrations of Pb than that in the control group. The MDA concentrations of the different concentrations of Cd, except for the concentration was 10 mg·kg^-1, was significantly higher than that in the control group, indicating the increased degree of cell membrane lipid peroxidation of D. involucrata.(2)Free proline concentration of osmoregulation substances initially increased and then decreased with the increase concentrations of Pb and Cd, which was lower than that in the control group under treatment of Pb concentration ≥800 mg·kg^-1 and Cd concentration ≥20 mg·kg^-1, respectively. With the increase of Pb concentration, the soluble protein concentration also showed an initial increase and then decrease trend. The concentrations of soluble protein were higher in the treatment groups of Cd than that in the control group. The increase of soluble protein and free proline enhanced the stress resistance of D. involucrata to resist the damage. In addition, the high concentration of heavy metals inhibited the growth of D. involucrata.(3)Antioxidant enzyme activities also initially increased and then decreased with the increase of Pb and Cd concentrations, indicating that low concentrations of heavy metals(Pb concentration≤600 mg·kg^-1 and Cd concentration≤5 mg·kg^-1)could easily activate the antioxidant capacity of D. involucrata and it could deal with the harm, while high concentrations of heavy metals could inhibit the activities of antioxidant enzymes.(4)The correlation and principal component analysis showed that antioxidant enzymes and free proline in D. involucrata seedlings had important indicative effects on the stresses of the two heavy metals.]]> 2021/9/29 14:12:47 1, ZHANG Liuqing¹, YANG Yan^1,2*, HUANG Xing¹, LI Yunxiang^1,2, QUAN Qiumei^1,2, ZHU Xiaohua^1,2]]> LIU Chaorong¹, ZHANG Liuqing¹, YANG Yan^1,2*, HUANG Xing¹, LI Yunxiang^1,2, QUAN Qiumei^1,2, ZHU Xiaohua^1,2 12true -1 MnCl₂ solution decreased significantly, which was only 47.7% of the control treatment; The relative root elongation was also significantly reduced to 71.1% of the control treatment.(2)The content of Mn in root tips increased significantly after adding the polar auxin transport inhibitor NPA to the Mn solution, which was 1.5 times that of the control treatment.(3)After adding NAA into the Mn solution, the Mn content in root tip cell wall was not significantly different from that of the control treatment, but the relative root elongation was significantly reduced while the absorption amount of Mn in plants, the Mn content in root tips and the distribution ratio of Mn into cell sap of root tips were all significantly increased; The Mn content in the leaves of vitro rice plants immersed in the Mn solution at the stem base was also significantly increased after the addition of NAA; The expressions of OsYSL2, OsYSL6 and OsMTP8.1 in root tips of rice were significantly increased after the addition of NAA under Mn stress. These results indicate that excessive Mn can significantly inhibit root elongation and reduce the level of free auxin in rice root tips. Auxin was involved in the regulation of Mn absorption, transport and toxicity in rice.]]> 2021/9/29 14:12:47 1, LING Guizhi², XIAO Jinglin¹, QIN Mei¹, TANG Xinlian^1,2, LI Xiaofeng^1,2*]]> CUI Xinyue¹, LING Guizhi², XIAO Jinglin¹, QIN Mei¹, TANG Xinlian^1,2, LI Xiaofeng^1,2* 11true Taraxacum mongolicum and its parents were chosen as experimental materials, and eight physiological parameters such as malondialdehyde(MDA)contents were determined, as well as analysis of differentially expressed genes in the root under saline treatments of 0, 12 and 24 h through cDNA-RAPD technique. The results were as follows:(1)Except for MDA content and relative conductivity, contents of proline, chlorophyll and soluble protein, and activities of CAT, POD and SOD in leaves of the mutant ‘BINPU 1.' under different saline treatments were all higher than those of the parents in general.(2)Totally 22 clear bands were amplified through cDNA-RAPD technique using 10 screened RAPD primers, of which, 10 different bands were found and the polymorphism was 45.4%.(3)Fragment size of amplification product ranged from 150 to 1 000 bp, mainly consisting of fragments of salt suppressor genes, indicating that the ability of salt-tolerant mutant ‘BINPU 1.' T. mongolicum was related to the protective effects caused by the increase of osmotic regulating substance such as proline and various of antioxidant enzymes activities, as well as some differentially expressed genes in roots. This study provides a theoretical support for further cloning salt-tolerant genes in T. mongolicum and breeding new salt-tolerant T. mongolicum cultivars through genetic engineering.]]> 2021/9/29 14:12:47 1, ZHANG Xiaodong^2*]]> CHEN Guiping¹, ZHANG Xiaodong^2* 10true Brevibacterium sp. and Bacillus mycoides respectively by 16S rRNA gene sequence analysis.(2)Both two strains could produce IAA, SID and ACC-deaminase activity. Strain TS22 showed high ACC-deaminase activity(264.69 nmol·α-KB mg^-1·h^-1), TS27 displayed higher IAA [(7.52±3.85)mg·L^-1] and SID(92%)production ability.(3)Under low temperature(10 ℃), these two isolated PGPB exerted different effects on the growth of Poa annua and Elymus sibericus. Inoculation of strain TS22 significantly improved the growth of Poa annua in plant height, root length, aboveground dry weight, underground dry weight, and showed greater plant growth-promoting activity than strain TS27. This study provides valuable strain resources and experimental basis for application of plant-microbe technique in vegetation restoration in Northern Tibetan Plateau.]]> 2021/9/29 14:12:47 *]]> HE Min, WANG Xiupu, LI Yan, DAI Zhicong, WANG Congyan, DU Hai, DU Daolin^* 9true 2 and particulate pollution, and to provide scientific support for the application of these trees in gardens. The photosynthetic parameters including the net photosynthetic rate(P_n), transcription rate(T_r), stomatal conductance(G_s), intercellular CO₂ concentration(C_i)and dust retention parameters(dust retention per unit leaf area, dust retention capacity of single leaf and dust rentention in crown per unit area)of each tree species in January were measured by LI-6400 portable photosynthesis analyzer could with the elution-mass method, and the results of each parameter were analyzed by cluster analysis. The results were as follows:(1)The P_n, T_r and G_s values of leaves from Ligustrum lucidum, Buxus sinica, Pittosporum tobira and Eriobotrya japonica were significantly higher than those of other eight species(P<0.01), and the C_i values of leaves from Cinnamomum camphora, C. septentrionale, Buxus sinica and Eriobotrya japonica were extremely significant(P<0.01)higher than those of other eight species. The mesophyll cells of Ligustrum lucidum, Pittosporum tobira and Photinia serratifolia maintained higher photosynthetic activities, but the activities of mesophyll cells of Cinnamomum camphora, C. septentrionale were significantly inhibited by low temperature and were weaker than those of other species.(2)7 d and 14 d after washing, the dust retention parameters of Eriobotrya japonica, Magnolia grandiflora and Osmanthus fragrans were significantly higher than those of other species(P<0.01). 14 d after washing, the dust retention amount of Eriobotrya japonica, Magnolia grandiflora and Osmanthus fragrans accumulated to more than 6.65 g·m^-2· crown^-1, and showed a strong dust retention capacity. In addition, the amount of Photinia serratifolia, Cinnamomum septentrionale, Ligustrum lucidum, Viburnum odoratissimum and Buxus sinica accumulated to more than 3.99 g·m^-2· crown^-1.(3)The result of cluster analysis indicated that Buxus sinica, Ligustrum lucidum and Pittosporum tobira had the strongest leaf photosynthetic properties, followed by Viburnum odoratissimum, Magnolia grandiflora, Eriobotrya japonica, Photinia serratifolia and Parakmeria lotungensis; Magnolia grandiflora, Osmanthus fragrans and Eriobotrya japonica had strong dust retention abilities, followed by Ligustrum lucidum, Viburnum odoratissimum, Photinia serratifolia and Cinnamomum septentrionale. Therefore, the six evergreen tree species including Ligustrum lucidum, Magnolia grandiflora, Eriobotrya japonica, Viburnum odoratissimum, Buxus sinica, and Photinia serratifolia, could be used as the priority tree species for greening because they have strong capacity on ecological regulation through improving the air quality and dust retention in northern cities in winter.]]> 2021/9/29 14:12:47 *, MA Yongtao, ZHANG Jiangtao]]> YAN Zeng, ZHAO Penghui, YANG Shuhong^*, MA Yongtao, ZHANG Jiangtao 8true Pleioblastus amarus, we determined the contents of leaf C, N and P for 1-3-year-old bamboo from stand at three different altitudinal gradients [low altitude,(200±10)m; middle altitude(400±10)m; high altitude,(800±10)m], and analyzed their stoichiometries and allometric growth. The results were as follows:(1)Bamboo age had great influences on the contents of leaf C, N and P and its stoichiometrics. With the increasing of bamboo age, the contents of leaf C, N, P and N:P ratios decreased overall, while ratios of C:N and C:P increased.(2)Altitude had significant effects on the contents of leaf C, N and P and its stoichiometrics. With the increase of altitudinal gradient, leaf carbon increased remarkably and then deceased sharply, while leaf N and P decreased overall, and leaf C:N, C:P and N:P increased generally.(3)There were significant differences existing in the contents of leaf C, N, P, C:N and C:P at different altitudinal gradients. Leaf N:P ratios of stands from the middle and high altitudes were higher than those of the low altitude. There was significantly positive allometric growth between leaf C, N and P. With the increase of altitudinal gradient, allometric exponent for leaf C-N and C-P increased remarkably, but that for N-P decreased dramatically. The results indicate that the P. amarus stand at the high altitude had the highest utilization efficiency of N and P, but its carbon content was lower and P limitation increased. While the P. amarus stand at the middle altitude had higher utilization efficiencies of N, P and the highest C content, therefore, it is the preferred altitude of high-yield cultivation for P. amarus forest.]]> 2021/9/29 14:12:47 1, XIE Yanyan², YANG Liting², CHEN Shuanglin², GUO Ziwu^2*]]> LIN Hua¹, XIE Yanyan², YANG Liting², CHEN Shuanglin², GUO Ziwu^2* 7true Fritillaria unibracteata is mainly distributed in alpine areas with an elevation above 3 000 m. Unsustainable harvesting of this species has greatly destroyed its natural habitats and made it more valuable. Among all factors affecting its growth, altitude is the most obvious one. To explore the effects of altitude on leaf traits of F. unibracteata, three altitudinal sites(low site, medium site and high site)were set up on the north-facing slope of Kaka Mountain in the upper reaches of Min River, and plant transplant experiments were carried out between low site and high site, which was 108.5 d. Then leaf traits including leaf lifespan, stomatal density and length, single leaf area and specific leaf area in each site were measured. In these experiments, some meaningful results were produced. The results were as follows:(1)From low site to high site, leaf lifespan shortened, and there were significant differences among sites. Leaf lifespan at low site was 121.3 d, about 13 d was shortened more than that at high site, which was 108.5 d. Along with altitude rise, stomatal density increased.(2)Compared with low site with only 48.5 stomas per square milimeter, stomatal density in high site increased by 42.8%.(3)Contrary to stomatal density, stomatal length decreased along with the increase of altitude. Compared with low site with 82.4 μm, stomatal length at high site with 71.3 μm reduced by 13.5%.(4)As to single leaf area and specific leaf area, they both showed a rising trend from low site to high site. At low site with 1.61×10^-4 m², single leaf area at high site reached 2.20×10^-4 m², 36.6% more than that at low site; similarly, specific leaf area at high site was 12.5×10^-4 m²·kg^-1, 62.3% higher than that at low site with 7.7×10^-4 m²·kg^-1. At the same altitudinal site, the control plants and transplants did not differ significantly.(5)For those transplanted plants, they always performed in accordance with control plants at the same altitudinal site after transplant experiment, but did not show characters of control plants at different altitudinal sites before transplant experiment. It can be concluded that altitude exerts an evident influence on leaf traits of F. unibracteata, and that leaf traits of F. unibracteata is of great plasticity when environment conditions change.]]> 2021/9/29 14:12:47 *, CAI Pingyuan]]> CHEN Wennian^*, CAI Pingyuan 6true Psammochloa villosa in different ecological environments, we observed the fruiting of 137 populations of P. villosa, and found that the fruiting could be divided into seedless, filled and unfilled seeds. Based on them, we analyzed the correlation between the populations of P. villosa and 22 geographical and climatic factors by applying cluster analysis, Kruskal-Wallis test and canonical correspondence analysis(CCA). The results were as follows:(1)A total of 137 populations of P. villosa were clustered into three groups according to different geographical and climatic factors.(2)Kruskal-Wallis test showed that there was no significant differences in fruiting among three groups of P. villosa (P=0.269). That is, the fruiting of populations was not direct related with geographical and climatic factors.(3)Meanwhile, the CCA analysis showed that there was no significant differences in fruiting among populations(P>0.05). However, there was a significant correlation between geographical and climatic factors and plumpness of seeds and seedless feature. Among them, altitude and bio12-bio19 were positively correlated with filled seed, while longitude, latitude, bio4 and bio7 were negatively correlated with filled seed, but the seedless feature was only positively related to the mean temperature of wettest quarter(bio8). In summary, geographical and climatic factors are more important to the sexual reproduction(with seeds)than the asexual reproduction(without seeds)in the natural population of P. villosa, which proves that the environmental factors that restrict the sexual reproduction of P. villosa are complex, and its asexual reproduction may be a stable adaptive performance of the population.]]> 2021/9/29 14:12:47 1,2,3, MA Zilan^1,2,3, LIU Tao^2,4, LÜ Ting^2,4, LIANG Ruifang^1,2, SU Xu^1,2,3, ZHOU Yonghui⁵, LIU Yuping^1,2*]]> LIU Feng^1,2,3, MA Zilan^1,2,3, LIU Tao^2,4, LÜ Ting^2,4, LIANG Ruifang^1,2, SU Xu^1,2,3, ZHOU Yonghui⁵, LIU Yuping^1,2* 5true Sorbus rhamnoides and Rhododendron moulmainense, two canopy herbs Coelogyne punctulata and Pleione hookeriana, two trunk herbs Polygonatum punctatum and Cautleya gracilis, were surveyed to study the stomatal characteristics and plasticity in leaves of vascular epiphytes and their responses to light change in evergreen broad-leaved forests in the Ailao Mountains of Yunnan Province. The results were as follows:(1)The stomatal area(SA), stomatal density(SD), potential stomatal conductance index(PCI)and epidermal cell density(ECD)of the two canopy epiphytic trees responded significantly to light change. The canopy epiphytic herbs had the largest SA and the smallest SD among all the studied epiphytes. The response of the SD and ECD of epiphytic trees to light change was consistent with those of terrestrial plants, while epiphytic herbs showed interspecific variations.(2)The stomatal and epidermal cell characteristics, and phenotype plasticity of epiphytes showed no significant differences between herbs and trees, evergreen and deciduous plants, and canopy and trunk epiphytes.(3)Their plasticity indexes of stomatal and epidermal cell characteristics were lower than those of terrestrial plants. Our results indicate that epiphytes have relatively weak adaptability to light change in subtropical forests. Epiphytes are able to adapt to high light intensity by increasing SD and ECD with different degrees, and to cope with low light stress by increasing potential photosynthetic capacity with trade-offs between SD and SA.]]> 2021/9/29 14:12:47 1,2, WANG Pengcheng³, LI Su^1*, LU Zhiyun^1,4, SONG Yu⁵]]> PU Xiaoyan^1,2, WANG Pengcheng³, LI Su^1*, LU Zhiyun^1,4, SONG Yu⁵ 4true Eucalyptus urophylla and Dalbergia odorifera plantation(MP)was taken as our object, and the adjacent pure second-generation E. urophylla plantation(PP)was taken as the control(CK). We used phospholipid fatty acids(PLFAs)as biomarkers to assess soil microbial community composition and measured soil enzyme activity as an indicator of soil microbial function. We focused on the effects of mixing N-fixing species with E. urophylla on soil microbial community composition and function in subtropical China. The results were as follows:(1)Soil organic carbon(SOC), total nitrogen(TN), ammonium nitrogen(NH₄⁺-N), nitrate nitrogen(NO₃^--N)and pH in MP were significantly or extremely significantly increased by 61.92%(P<0.05), 60.12%(P<0.05), 72.87%(P<0.01), 488.49%(P<0.01)and 15.97%(P<0.05)compared with that in PP, respectively.(2)The ratios of fungal-to-bacterial biomass(F/B)were significantly lower in MP than that in PP. However, there were no significant differences between the PP and the MP in total PLFAs and the ratios of gram-negative bacteria to gram-positive bacteria(G^-/G⁺).(3)The soil microbial community structure was significantly differed between MP and PP, and we found that the soil microbial community structure is strongly influenced by the variations of pH, NH₄⁺-N and ratios of organic carbon to total nitrogen in litter(C/N_litter).(4)The activities of β-glucosidase(BG)and N-acetyl-glucosidase(NAG)involved in soil carbon and nitrogen transformation were significantly higher, but the activities of peroxidase(PER)were lower in MP than that in PP. Nevertheless, the differences in phenoloxidase(PO)and acid phosphatase(ACP)activities were not significant between MP and PP. The results indicate that interplanting of nitrogen-fixing species in Eucalyptus plantations may be an effective management measure to improve soil quality in subtropical region.]]> 2021/9/29 14:12:47 1, TAN Xumai¹, LI Meng¹, XU Haocheng¹, MO Xueqing¹, XIAO Na¹, YOU Yeming^1,2, HUANG Xueman^1,2, WEN Yuanguang^1,2, ZHU Hongguang^1,2*]]> CHEN Yongkang¹, TAN Xumai¹, LI Meng¹, XU Haocheng¹, MO Xueqing¹, XIAO Na¹, YOU Yeming^1,2, HUANG Xueman^1,2, WEN Yuanguang^1,2, ZHU Hongguang^1,2* 3true Pinellia ternate photoreaction system to daily variations of light intensity and temperature, we simulated the low temperature(10-18 ℃), moderate temperature(20-28 ℃)and high temperature(28-38 ℃)under the diurnal variation of the same light intensity(0-1 600 μmol·m^-2·s^-1)for three consecutive days, and the chlorophyll fluorescence parameters of Photosystem Ⅱ(PS Ⅱ)and Photosystem I(PS Ⅰ)were measured. The adaptation of photosynthetic system to diurnal changes of light intensity and temperature in P. ternata was researched by detecting the changes of PS Ⅱ and PS Ⅰ photosynthetic activity and electron transfer capacity. The results were as follows:(1)Minimal fluorescence intensity at actinic light(F_o')and photochemical efficiency of PS Ⅱ in the light(F_v'/F_m')was decreased with increased light intensity, and the low temperature further led to the F_v'/F_m' decrease and the F_o' increase.(2)PS Ⅰ donor end heat dissipation efficiency [Y(ND)] increased with the increase of light intensity and high temperatures, PS Ⅰ acceptor end heat dissipation efficiency [Y(NA)] decreased with the increase of light intensity and high temperatures.(3)Effective photochemical quantum yield of PS Ⅱ [Y(Ⅱ)] and the quantum yield of PS Ⅰ [Y(I)] were inhibited by high light(> 900 μmol·m^-2·s^-1),and the low temperature further significantly decreased Y(Ⅱ)and Y(I).(4)The increasing electron transport rate ETR(I)of the PS Ⅰ under the high light initiated the ring electron transfer(CEF), and the higher CEF stabilized the electron transfer rate ETR(Ⅱ)of the PS Ⅱ at high temperatures.(5)The non-photochemical quenching coefficient(NPQ)increased with the increase of light intensity, low NPQ keeps the quantum yield of non-regulated energy dissipation in PS Ⅱ [Y(NO)] on its highest level at low temperature. These results suggest that high temperature will reduce the photo-inhibition of P. ternata under high light by enhancing NPQ and CEF, accelerating the electron transfer and stability of the light reaction, in sharp contrast of low temperature. Therefore, low temperature can aggravate the damage of photoreaction system, and moderate temperature promotes the adaptation of plant photoreaction system to high light.]]> 2021/9/29 14:12:47 1,2,3, CHEN Junwen^1,2,3, XIE Shiqing^1,2,3, ZHANG Jinyan^1,2,3*]]> DONG Yi^1,2,3, CHEN Junwen^1,2,3, XIE Shiqing^1,2,3, ZHANG Jinyan^1,2,3* 2true Pinus massoniana plantations are unclear. To determinate the trends of needle leaves, roots, and soils and relationships between the three parts in these plantations, we selected total eight stands [including four age stands(young stand, half-mature stand, mature stand, and over-mature stand)and four density stands(low density, medium density, high density, and over-high density)] as the research object and measured C, N and P concentrations of needle leaves, roots, and soils in Zhenlong forest farm of Hengxian county, Nanning, Guangxi Zhuang Autonomous Region. The results were as follows:(1)N:P ratios of needle leaves in all stands were higher than 16.(2)The C concentrations of needle leaves increased and then decreased, and the C:N ratios, C:P ratios, and N:P ratios slightly(insignificantly)increased with the increasing stand ages, but the N and P concentrations were opposite. The C and P concentrations and C:N ratios of roots increased with the increasing stand ages, but the N concentrations, C:P ratios, and N:P ratios were the highest in young stand. Additionally, the C and P concentrations of needle leaves were the highest in mature stand, but the two parameters of roots were and relatively the highest in this stand.(3)Moreover, the highest P and relatively the highest C and N of needle leaves were found in medium density stand, as well as lowest C:P ratios and N:P ratios and relatively lowest C:N ratios. Simultaneously, the C, N, and P concentrations of roots were higher in medium density stand than in other stands, but the C:N ratios, C:P ratios, and N:P ratios of roots were opposite.(4)Root nutrients(especially P)of P. massoniana dramatically changed further than those of needle leaves in different age and density stands, as well as the relationships between root and soil nutrients. Our results suggest that P. massoniana is limited by P, and then, fertilization and management of phosphate in young stand and the appropriate density stand(medium)will be beneficial to relieve the P limitation in southern Guangxi.]]> 2021/9/29 14:12:47 1, PAN Fujing^2*, MA Jiangming³, YANG Zhangqi⁴, LING Tianwang⁵, LI Mingjin⁵, LU Shaohao⁵, ZHONG Fengyue⁵]]> LIANG Yueming¹, PAN Fujing^2*, MA Jiangming³, YANG Zhangqi⁴, LING Tianwang⁵, LI Mingjin⁵, LU Shaohao⁵, ZHONG Fengyue⁵ 1true