Analysis of evolutionary relationships provides new clues to the origins of weedy rice

Weedy rice (Oryza sativa f. spontanea) is considered to be a pest in modern rice production systems because it competes for resources, has poor yield characteristics, and subsequently has a negative effect on rice grain yield. The evolutionary relationships among weedy rice, landrace rice, improved rice cultivars, and wild rice are largely unknown. In this study, we conducted a population genetic analysis based on neutral markers and gene haplotypes in 524 rice accessions and a comparative transcriptomic analysis using 15 representative samples. The results showed that weedy rice populations have the highest level of genetic diversity (He=0.8386), and can be divided into two groups (japonica-type and indica-type). The japonica-type weedy rice accessions from HLJ, JL, LN, and NX provinces clustered with the landraces grown in these same provinces. The indica-types from JS province also clustered with the indica-type landraces from JS province. Comparative transcriptome analysis of weedy ...