Genetic Diversity of Solidago canadensis Correlates Negatively with the Number of Buds and Positively with Species Number of Plant Community

The genetic diversities of 5 populations of Solidago canadensis were studied using intersimple sequence repeat markers method (ISSR). Genomic DNA was extracted by a modified NaOH method from samples collected in Zejiang province, China. Meanwhile, the generative organs (buds and rhizomes) of S. canadensis and plant species number in its grown site were investigated. Our results indicated that among 5 populations, the polymorphic percentages ranged from 78.08 to 91.03. Neis gene diversity index and Shannon diversity index were more than 0.25 and 0.38 respectively. The 5 populations displayed some genetic differentiations (Gst=0.3208), showing Jiaxing population and Zhoushan population in one group, while Hangzhou population, Wenzhou population and Quzhou population in another group. We found that the number of buds varied greatly among the 5 populations, genetic diversity of S. canadensis displayed significant negative correlation with the number of buds and significant positive correlation with plant species number in its grown site. S. canadensis population has higher genetic diversity index and less buds, when grown with more other species, than with less other species. The result implied that increased competition from other species of plant community could reduce fecundity of S. canadensis.