The objective of this study was to evaluate the genetic diversity and population structure of natural subpopulations of Paspalum rawitscheri (Parodi) Chase ex G.H. Rua & Valls using inter-simple sequence repeat (ISSR) molecular markers. Four natural subpopulations from State of Rio Grande do Sul, Brazil, were evaluated, using six ISSR primers. A total of 131 fragments were amplified, 34 of which were polymorphic. The genetic diversity (h) for the subpopulations was considered low, with values ranging from 0.130 to 0.217. The Vacaria subpopulation presented the lowest diversity among populations. The Shannon (I) diversity indices were also low, with values ranging from 0.187 to 0.334, with the Vacaria subpopulation also presenting the lowest values. The molecular variance (AMOVA) analysis showed, in general, the highest variation occurred within subpopulations rather than between subpopulations. The Bayesian Inference analysis separated the individuals into four genetic clusters, mixing individuals from different municipalities in the clusters. The results indicate that the species has low genetic diversity and low population structure, requiring conservation plans. Ex situ conservation becomes a necessary effort, since populations of this species are found in grasslands remnants affected by fires and implantation of crops, and is not present in any protected area of the Brazilian Conservation Units system.

这项研究的目的是使用简单序列重复（ISSR）分子标记评估Paspalum rawitscheri（Parodi）Chase ex GH Rua＆Valls的自然亚种群的遗传多样性和种群结构。使用六种ISSR引物对巴西南里奥格兰德州的四个自然亚种群进行了评估。总共扩增了131个片段，其中34个是多态的。该亚群的遗传多样性（h）被认为很低，其值在0.130至0.217之间。Vacaria亚群的种群多样性最低。香农（我）多样性指数也很低，范围在0.187至0.334之间，瓦卡里亚（Vacaria）亚群也呈现最低值。分子变异（AMOVA）分析显示，一般而言，最大的变异发生在亚群内而不是亚群之间。贝叶斯推断分析将个体分为四个遗传簇，将来自不同城市的个体混合在一起。结果表明该物种遗传多样性低，种群结构低，需要保护计划。异地保护成为一项必要的努力，因为该物种的种群存在于受火灾和农作物植入影响的草地残留物中，并且在巴西保护单位系统的任何保护区中都没有。