J Syst Evol ›› 2019, Vol. 57 ›› Issue (1): 66-74.DOI: 10.1111/jse.12428

• Research Articles • Previous Articles     Next Articles

Enhanced genetic diversity of weedy rice populations associated with latitude decreases revealed by simple sequence repeat fingerprints

Zhe Wang1, Min-Jie Fu1, Hai-Ge Zhu1, Yue Zhu1, Xiang-Xiang Zhao2, and Bao-Rong Lu1*   

  1. 1Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, Department of Ecology and Evolutionary Biology, Fudan University, Shanghai 200433, China
    2Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huaian, Jiangsu 223300, China
  • Received:2018-03-05 Accepted:2018-05-17 Online:2018-07-10 Published:2019-01-10


Weedy rice (WR, Oryza sativa L. f. spontanea) is a noxious agricultural weed, infesting rice fields worldwide and causing tremendous yield losses of cultivated rice. However, little is known about the relationship between genetic diversity and distribution of WR populations across a wide latitudinal gradient, in addition to its reasons for genetic differentiation. To determine the distribution of genetic diversity and differentiation, we analyzed 20 WR populations collected from wide geographic ranges of rice-planting regions across Northeast, Jiangsu and Guangdong provinces of China, and Sri Lanka, based on 20 simple sequence repeat loci. Our results indicated a significant negative correlation (R = 0.84, P < 0.01) between genetic diversity and latitudinal locations of WR populations. The Mantel test (R2 = 0.49, P < 0.01) showed distinct groupings of WR populations from different rice-planting regions, fitting an isolation-by-distance pattern. In addition, the STRUCTURE analysis and principal coordinates (PCoA) analysis indicated considerable genetic differentiation of WR from different rice-planting regions, which was associated with the types of co-occurring rice cultivars. We conclude based on the above results that WR genetic diversity is affected by the latitudes where WR populations are located. The genetic differentiation of WR populations is determined by their spatial distances and co-occurring rice cultivars. Such a pattern of genetic diversity and differentiation across different regions may facilitate the design of effective WR control, in addition to understanding adaptive evolution of this weed.

Key words: conspecific weed, differentiation, genetic polymorphism, introgression, latitude variation, Oryza sativa f. spontanea.