Marker-Assisted Selection for Stv-bi Gene Controlling Resistance to Rice Stripe Disease

Rice stripe disease caused by rice stripe virus (RSV) is vectored by the small brown planthopper (Laodelphax striatellus Fallen). The resistance gene Stv-bi has been fine mapped on chromosome 11 of rice (Oryza sativa L.). The objective of this study was to develop a practical marker-assisted method with the help of molecular markers closely linked to Stv-bi. A total of 26 pairs of markers were tested, of which 8 pairs were polymorphic between the parents Shengdao 13 and Zhendao 88. These polymorphic markers consisted of 3 pairs of simple sequence repeat (SSR) markers and 5 pairs of sequence-tagged site (STS) markers. Three markers, H21, H11-8, and H11-12, were subsequently used in marker-assisted selection. The individual seedlings from 3 compound breeding populations, F30718 (Shengdao 13/Zhendao 88), F50701 (Wuyou 34/T022//Shengdao 806), and F60702 (V6/T022//Zhendao 88), were genotyped with the 3 markers. The resistant lines examined by marker-assisted selection were also investigated in field. The consistency between field performance and the marker genotypes was 99.3%, 87.7%, and 91.8% in the 3 compound breeding populations, respectively. These results indicate that the molecular markers can be applied for selecting candidate lines with resistance to RSV.