Genetic Diversity and Divergence in Populations of the Threatened Grassland PerennialVincetoxicum atratum(Apocynaceae-Asclepiadoideae) in Japan

Abstract

We examined the genetic diversity and structure in populations of the endangered grassland herb Vincetoxicum atratum using 11 polymorphic microsatellite loci. Although the populations were small and disconnected, our molecular data indicated that the species maintains relatively high levels of genetic diversity and connectivity among populations. Population clustering analyses detected 2 to 3 clusters and most of the populations of V. atratum comprised admixture of these genetic clusters. These admixtures likely formed during the process of colonizing habitats that had been disturbed by human activities. However, STRUCTURE clustering detected low-admixtures in populations occurring in rocky maritime sites, which may not be suitable for agriculture/rangeland activities. High genetic diversity and population connectivity suggested that loss of the remaining populations by grassland reduction might be an immediate threat for this species. Small grasslands populations managed by local farmers need appropriate conservation practices. Although our results showed genetic diversity and gene flow among populations of V. atratum were high, it is possible that this resulted from the historical continuous distribution of the species. To examine this hypothesis, further periodical monitoring of the genetic diversity and the genetic differentiation for the species is needed for a conservation action of the species.

Demographic history influences spatial patterns of genetic diversityin recently expanded coyote (Canis latrans) populations

“…Though similar to STRUCTURE, TESS additionally incorporates spatial information into clustering assignments and has been suggested to outperform STRUCTURE when populations are weakly differentiated (Chen et al 2007). To evaluate the optimal K value for the TESS analysis, the deviance information criterion (DIC) value was averaged over each independent run and plotted against K. Generally, the optimal K value corresponds to the plateau of the DIC curve (Durand et al 2009); however, clustering patterns at successive K values were also taken into account when selecting the optimal K (Yamashiro et al 2016). Output over each independent run was combined with CLUMPP prior to graphic representation.…”

Elucidation of genetic diversity base in Calotropis procera – a potentially emerging new fibre resource

“…This shows that the gene flow is not severely restricted and no intense genetic barrier separate these populations in the northern plains of India. The mean gene flow of 2.9 indicates the significant level of allele sharing and is higher than the other Apocynaceae species like Hancornia speciose and Vincetoxicum atratum (1.463), and Gymnema sylvestre (Jimenez et al ., 2015; Rathore et al ., 2016; Yamashiro et al ., 2016).…”

Genetic diversity of the critically endangered Ferula sinkiangensis K. M. Shen (Apiaceae) and the implications for conservation

“…Compared to other rare and endangered species, F. sinkiangensis showed a moderate to high level of genetic diversity, which was higher than Nuphar submersa (He = 0.42) (Shiga et al, 2017) and Ottelia acuminata var. jingxiensis (He = 0.441, I = 0.781) , and lower than Ruta oreojasme (He = 0.687) (Meloni et al, 2015), Vincetoxicum atratum (He = 0.67) (Yamashiro et al, 2016), Ammi seubertianum (He = 0.66, I = 1.28), A. trifoliatum (He = 0.67, I = 1.35) (Vieira et al, 2018), and Tapiscia sinensis (He = 0.6904, I = 1.4368) (Zhou et al, 2016). The moderate to high level of genetic diversity within F. sinkiangensis contradicted the general hypothesis that small and narrowly distributed species have low levels of genetic diversity (Frankham, 1997;Leimu et al, 2006;Flight, 2010).…”