Genotypic diversity and genetic structure of populations of the distylous aquatic plantNymphoides peltata(Menyanthaceae) in China

Abstract

Nymphoides peltata is a distylous aquatic plant. In order to explore the relative importance of clonal growth and sexual reproduction within populations and also to reveal the origin of the commonly occurring one style morph populations in China, we studied the clonal diversity and population genetic structure of this species. By using seven single sequence repeat primer pairs, a total of 192 multilocus genotypes (MLGs) were identified among the 472 samples from the 21 populations analyzed; each population had two or more MLGs. The number of MLGs was lower for the one style morph populations than distylous populations. Analysis of molecular variance showed that a smaller proportion of genetic variation resided among populations (36.8%). A neighbor‐joining tree indicated that there was no significant geographical structure of the genetic variation among populations of N. peltata. The Bottleneck tests indicated that there had been significant bottlenecks in most of the studied populations. The successful sexual recruitment from seeds may have contributed to the high clonal diversity in distylous populations of N. peltata in China. Demographic stochasticity or bottleneck should account for the one style morph population with several MLGs. And also the bottleneck effects or demographic changes caused by human activities occurring randomly in populations should account for the finding of no significant geographical structure of the genetic variation among the investigated populations of N. peltata.

Population genetic structure in six sympatric and widespread aquatic plants inhabiting diverse lake environments in China

“…The genetic diversity of N. peltata measured in this study was considerably lower than that found by Liao et al. (), which may be related to the differences in molecular markers and sample size between the two studies.…”

“…The values of within‐population genetic diversity ( H S = 0.154–0.211) of the six species found in the present work were within the range of the reported values of plant genetic diversity and similar to those of the widespread aquatic species (Chen, Li, Yin, & Li, ; Chen et al., , ; Liao et al., ; Nybom, ; Wang et al., ). The genetic diversity of N. peltata measured in this study was considerably lower than that found by Liao et al.…”

“…For N. peltata and M. spicatum only, individuals could be generally divided into plateau (Caohai and Erhai Lakes) and plain (Honghu and Liangzihu Lakes) groups (excluding Taihu Lake individuals) via PCA analysis. Previous studies on these species in China have yielded similar findings (Liao et al., ; Wu et al., ). Noticeable local differentiation was observed in each of the six species because samples originating from each lake tended to cluster together, like that in Potamogeton maackianus in the middle reaches of the Yangtze River (Li, Xia, Li, & Wang, ) and the seagrass Halodule wrightii from Christmas Bay (Angel, ).…”

“…Noticeable local differentiation was observed in each of the six species because samples originating from each lake tended to cluster together, like that in Potamogeton maackianus in the middle reaches of the Yangtze River (Li, Xia, Li, & Wang, ) and the seagrass Halodule wrightii from Christmas Bay (Angel, ). Local differentiation may attribute to divergent environmental pressures and demographic factors such as population size and lake isolation (Li et al., ; Liao et al., ; Wang & Bradburd, ). Hydrologic connectivity seems not appear to significantly contribute to genetic similarities between lakes because genetic distances were not consistently closer between Yangtze River‐connected lakes than between unconnected lakes.…”

The phylogeographic structure of Hydrilla verticillata (Hydrocharitaceae) in China and its implications for the biogeographic history of this worldwide-distributed submerged macrophyte

“…As vegetative reproduction is common in aquatic plants, modest variations within populations have also been observed in other species, e.g., Ranunculus bungei [ 29 ], Podostemum ceratophyllum [ 47 ], and Hippuris vulgaris [ 48 ]. Moreover, certain studies based on nuclear markers suggested that founder effects played an important role in the establishment of populations in aquatic plants [ 26 , 49 , 50 ]. To explore the role of founder effects in shaping population structure of hydrilla, further studies using nuclear markers are needed.…”