2018/4/2 10:37:04 *]]> ZHANG Qiuxia, LI Debao, XIA Shunying, OU Xiaokun^* 8true Bidens pilosa from three habitats and their relations with soil nutrients were analyzed through field sampling and laboratory measuring. Furthermore, the relative growth rate and nutrient utilization strategy under these habitats were also analyzed. The results were as follows:(1)Total nitrogen(TN)and available nitrogen(AN)contents in soils under all three habitats were low, while organic carbon(C)and total phosphorus(TP)were abundant. TN and TP contents of soil, in habitat I and Ⅱ were significantly less than those of the other two habitats, respectively, and both TN and TP in soil of habitat Ⅲ were significantly more than those of the other two habitats.(2)P content of leaf in low-N habitat was more than that of root, which implied that P was more distributed to aboveground of plants. P content of root in habitat with rich-N and -P was more than that of leaf, which showed that more P distributed in the root of plants.(3)There were different growth rates for aboveground part and root of B. pilosa under three habitats. The N/P and C/P values of leaves in low-N habitat were less than that of other two habitats, indicating that B. pilosa in low-N habitats had higher growth rates and more competitive advantage for aboveground part. The N/P and C/P values of leaves in low-P habitat were more than those of other habitats, showing that B. pilosa in low-P habitats has slower relative growth rates. The N/P and C/P of root in both rich-N and rich-P habitat were less than that of two habitats, implying that the root of B. pilosa in these habitats has higher growth rates, and further enables plants to increase competition for belowground part.(4)There was insignificantly negative correlation between leaf N/P and root N/P of B. pilosa, therefore, between aboveground and the underground part of plant were allometry. There are different nutrient utilization and allocation strategies for B. pilosa under different habitats to ensure plants more competitive and invasive.]]> 2018/4/2 10:37:04 1, WANG Juhong^2*, PENG Yujiao³, WU Xiaorong², ZHANG Shurou², WANG Cuili², MA Yiting²]]> CHEN Wen¹, WANG Juhong^2*, PENG Yujiao³, WU Xiaorong², ZHANG Shurou², WANG Cuili², MA Yiting² 7true 2018/4/2 10:37:05 1,2, ZHU Shuangshuang^1,2, CHEN Yuqing^1,2, GUO Xiaoming^1,2, WANG Ruijiang^1*]]> JIANG Aolin^1,2, ZHU Shuangshuang^1,2, CHEN Yuqing^1,2, GUO Xiaoming^1,2, WANG Ruijiang^1* 6true Solidago canadensis(Solidago), the total flavonoids and phenolic contents in its ethanol extract(70%), and different ploarity extracts were investigated by AlCl₃ assay and Folin-Ciocalteu assay, respectively, and the in vitro antioxidant activities of them were also studied by several methods including ABTS, DPPH, FRAP and ORAC assay, with Vc and BHT as positive control. The results showed that the ethyl acetate extract possessed the highest amount of total flavonoids(202.45 mg·g^-1)and phenolic(485.94 mg·g^-1), and it had the strongest antioxidant activity than other extracts, even higher than Vc(P<0.05). Thus, the ethyl acetate extract of S. canadensis can be regarded as a kind of potential resource of high-efficiency and natural antioxidants. This will provide the references for further exploiting and utilizing the S. canadensis.]]> 2018/4/2 10:37:05 1,2, WANG Zhenxing^1,3, CHEN Liqiong^1,2, GUAN Jiayi^1,2, ZOU Zhengrong^1,2*]]> SHEN Xiao^1,2, WANG Zhenxing^1,3, CHEN Liqiong^1,2, GUAN Jiayi^1,2, ZOU Zhengrong^1,2* 5true Alternanthera philoxeroides were studied by homogeneous garden cultivation experiment. The results were as follows:(1)Both clonal integration and connection or disconnection had significant effects on the phenotypic characteristics, gender phenotypic traits, gas exchange properties and other physiological characteristics of A. philoxeroides.(2)Clonal integration significantly reduced the phenotypic characteristics of hermaphroditic plant and carpelloid plant of two sexes, and the gender characteristics of offsprings were apparently correlated with vegetative phenotype.(3)Clonal integration signicantly increased growth and gas exchange in barren sandy substrates, but did not show significant effect on both of these characteristics in abundant organic bog substrates.(4)Connection between ramets reduced both gas exchange and phenotypic responses to local conditions. Connection between ramets reduced both gas exchange and phenotypic responses to local conditions in different soil matrixes. At the same time, ramet gender was consistent with mother plant regardless of environmental conditions during clonal integration, while ramet gender was affected by environment in unconnected condition that cultivated in sand or bog alone. Therefore, clonal integration facilitates the stability of gender trait of A. philoxeroides.]]> 2018/4/2 10:37:05 1, 2, Li Wenqi^{1, 2}, JIANG Chu^{1, 2}, OUYANG Xuejun^{1, 3}, DENG Rufang¹, LIU Wei^1*]]> QUAN Huimin^{1, 2}, Li Wenqi^{1, 2}, JIANG Chu^{1, 2}, OUYANG Xuejun^{1, 3}, DENG Rufang¹, LIU Wei^1* 4true Wedelia trilobata and its associated species of Synedrella nodiflora and Dicliptera chinensis were utilized by potted plant method in greenhouse to compare the effects of soil microorganism on the growth of three plants. The plant height, biomass, leaf number, photosynthetic electron transport rate of three plants were determined after cultivated in the Wedelia trilobata invaded soil for 96 d. The soil sterilized by high temperature and high pressure, or adding fungicide and bactericide sterilization. The experiment indicated that the growth of the three plants described above was different in disparate soil. The strongest growth inhibition was W. trilobata in sterilization soil. Compared with the growth of plants in untreated soil, the plant height was decreased by 17.59%, the number of leaves decreased by 38.10%, biomass was reduced by 56.00%. The growth inhibition of Synedrella nodiflora was the greatest in anti-fungal soil. Compared with the plant in untreated soil, the height, the number of leaves, biomass, the electron transfer rate of S. nodiflora was decreased by 42.28%, 38.89%, 16.99%, 7.41%. The growth inhibition of S. nodiflora was also the greatest in anti-bacteria soil, compared with the growth in untreated soil, the plant height was decreased by 36.64%, the number of leaves was decreased by 38.89%, biomass was reduced by 33.67%, the electron transport rate was increased by 11.11%. The soil without microbes had strong inhibitory effect on the growth of Wedelia trilobata. The growth of fungi and bacteria in the soil of Synedrella nodiflora had obvious inhibitory effects. The soil invaded by Wedelia trilobata was not only suitable for W. trilobata's growth, but also for its associated species of Synedrella nodiflora's growth. However, it had little effect on the Dicliptera chinensis. The invasion of alien plants into the new habitat, under appropriate conditions, spread, resulting in the loss of local biodiversity. In the whole process, soil microbes played a bridge role. The effects of different soil microbial communities on plant growth and feedback function, explained the ecological effects of soil microbes in the invasion process, and revealed the significance of the mechanism for the invasion. Explained study aimed at different groups of soil microbes including the effects on the growth of invasive plant Wedelia trilobata and associated species Synedrella nodiflora and Dicliptera chinensis. The index of the three kinds of plants were exploratory experiment, in order to find the influence of different kinds of microbes associated with the growth of invasive plants. And further analysis on vegetation and soil microbial community mutual relations, explored the mechanism of exotic plant invasion from the below ground plants on the ecological point of view. This study provides effecient ways for the effective prevention and control of alien invasive plants, and maintaining the stability of the ecosystem.]]> 2018/4/2 10:37:05 1, CHEN Xuelin¹, WANG Juhong^2*, CHEN Wen³, LI Zhangwei⁴]]> ZHANG Lina¹, CHEN Xuelin¹, WANG Juhong^2*, CHEN Wen³, LI Zhangwei⁴ 3true Mikania cordata(Asteraceae), a native plant in China, and to test the possible hybridization scenario between M. cordata and its invasive congener M. micrantha from a cytological perspective. Chromosome number and chromosome morphology of four populations in M. cordata were investigated. These included Hualian, Miaoli, Yilan and Taipei populations from Taiwan, China. The chromosome number 2n=36 was determined for all four populations. Their karyotypes, all formulated as 2n=18m+18sm, were characterized by having a remarkably larger, submedian centromeric chromosome pair with a secondary constriction in the middle of the long arms. All the karyotypes were Stebbins's 2B type. The intrachromosomal asymmetry index(A₁)varied from 0.38 to 0.39, and the interchromosomal asymmetry index(A₂)varied from 0.30 to 0.32. This is the only report of the chromosome number for M. cordata from China, and also the first karyotype report for this species. Our results, together with previous reports, indicate that there is aneuploid variation within this species, but 2n=36(diploid based on x=18)is the only number currently known from the populations in Taiwan, China. The karyotypes of M. cordata resemble those reported for other Mikania species in the secondary constriction of the first chromosome pair, which could be considered a cytological marker for this genus. Mikania cordata and M. micrantha have the same chromosome number and ploidy but different karyotypic characteristics. However, intermediate karyotype was not found within populations where the two came into close contact. No intermediates between the two species were observed during field work, and ISSR analyses also failed to detected hybrid individuals. Therefore, the above evidence suggest that the successful invasion of M. micrantha in China is not associated with hybridization and introgression between this invasive species M. cordata and its only indigenous congener in China. After comparing past herbarium records with results of recent field surveys, we found that the distribution range of M. cordata in China has undergone a great reduction. We infer that habitat destruction and invasion of M. micrantha may be the main causes for the gradual disappearance of M. cordata in Taiwan, China.]]> 2018/4/2 10:37:05 1, ZHANG Yanwu¹, GUO Qiang¹, LIU Ying², LI Chunmei^2*]]> JIANG Lu¹, ZHANG Yanwu¹, GUO Qiang¹, LIU Ying², LI Chunmei^2* 2true Phragmites australis and alien invasive plant Amaranthus retroflexus under two kinds of water conditions(dry and wet). The results were as follows:(1)Relative yield and total relative yield of Phragmites australis and Amaranthus retroflexus were all less than one, indicating that there was interspecific competition between the two plant species.(2)Growth of the two plant species was inhibited by interspecific competition leading to lower plant height and biomass with the increasing density of the competitor.(3)Aboveground and belowground nitrogen concentration of the two plants had the same trend as plant height and biomass, and there were differences under different water conditions.(4)Phragmites australis and Amaranthus retroflexus had higher competitiveness under wet and dry condition, respectively, while they also had higher competitiveness in higher planting density. In conclusion, both water condition and planting density have important effects on interspecific competition beween Phragmites communis and Amaranthus retroflexus. Therefore, in wetland with Amaranthus retroflexus distribution, its competitiveness can be restricted in plant initial growth by increasing water content of soil and/or increasing planting density of Phragmites australis and other native plants, so as to prevent the growth, population building, and furthermore diffusion and invasion of Amaranthus retroflexus in wetland.]]> 2018/4/2 10:37:05 1, GU Xiaozhi^2*]]> BAI Xiang¹, GU Xiaozhi^2* 1true