A new gene for hybrid sterility from a cross between Oryza sativa and O. glaberrima

With 4 figures and 2 tables Abstract Oryza glaberrima is a valuable and potential source of useful genes of interest for rice improvement. However, hybrid sterility between O. sativa and O. glaberrima is a main reproduction barrier when favourable traits/genes are transferred from O. glaberrima to O. sativa. Understanding of the nature of hybrid sterility is critical and will contribute to overcome this problem. In this study, a new gene from O. glaberrima was mapped as a Mendelian factor controlling hybrid sterility in an advanced backcross population derived from one accession of O. glaberrima as a donor parent and ‘Danjing 5’ (a japonica cultivar from Liaoning) as recurrent parent. Sterile plants as female parent from F1 were observed after six backcrosses. The BC6F1 population containing 47 plants was screened with 142 simple sequence repeat (SSR) markers on all 12 chromosomes to analyse the pollen fertility. As a result, one locus qSS‐2 on chromosome 2 was distinct from all previously reported ones. A new locus designated as S36(t) was identified and mapped to interval between two SSRs RM208 (0.5 centiMorgans, cM) and RM482 (0.8 cM) on rice chromosome 2.