Evaluation of Population Structure, Genetic Diversity and Origin of Northeast Asia Weedy Rice Based on Simple Sequence Repeat Markers

Weedy rice exerts a severe impact on rice production by competing for sunlight, water and nutrients. This study assayed the population structure, genetic diversity and origin of Northeast Asia weedy rice by using 48 simple sequence repeat markers. The results showed that weedy rice in Northeast Asia had a high genetic diversity, with Shannon's diversity index (I) of 0.748 and the heterozygosity (He) of 0.434. In each regional population, I value varied widely. The widest range of I (0.228-0.489) was observed in the weedy rice of Eastern China, which was larger than that of Northeast China and Korea (0.168-0.270). The F-statistics of regional populations (Fis, Fit and Fst) also showed higher values in the weedy rice of Eastern China than those of Northeast China and Korea. All weedy rice accessions were grouped into two clusters in the unweighted pair group method with arithmetic mean cluster analysis dendrogram, namely Eastern China branch and Northeastern China plus Korea branch. There was significant differentiation in genetic characteristics in weedy rice of northeastern and eastern Asia, especially in Eastern China.