Genetic similarity and origin of weedy rice in Yangzhong region of Jiangsu province

In order to reveal the genetic background of weedy rice in Yangzhong region of Jiangsu province at molecular level,39 rice materials(ten weedy rice in Yangzhong region,six weedy rice in other areas of Jiangsu province,four pond rice,two Ludao,three wild rice,fourteen japonica rice and indica rice) were analyzed by 63 pairs of SSR molecular markers evenly distributed on 12 chromosomes.92 polymorphic DNA bands were amplified with 36 pairs of SSR markers in 39 rice materials.Genetic similarity analysis showed that similar coefficients of different rice materials were between 0.35 and 1.00,with 0.62 as average.Clustering results revealed that 16 weedy rice were indica,and had high similarity with indica varieties 9311 and IR26.Ten weedy rice in Yangzhong region could be clustered into two groups,and the similar coefficient was 0.74.The two groups varied significantly in plant height,panicle length,and seed shattering(P0.05).The results suggested that the weedy rice in Yangzhong region probably originated from cultivated rice through gene recombination or reverse mutation.