Partial conversion of elite maintainer genotype mas99 into new male sterile line suitable for aerobic and drought conditions through backcross breeding in rice

Abstract

Two populations were developed and advanced to BC3 generation using IR70369A and KCMS31A CMS lines as donors and MAS 99 as recurrent parent. In BC3F1 generation, the populations were evaluated with parents for morpho-floral traits under aerobic field condition. In both crosses, the mean values of number of tillers/plant (22 & 27), plant height at maturity (74 & 73cm), days to 50% flowering (95 & 97 days) were found comparable to the recurrent parent with superior floral traits such as pollen sterility (100%), stigma exertion (30% & 25%) and spikelet sterility (100%). IR70369A × MAS99 cross derived plants, A04, A35, A47, A65, A84 and KCMS31A × MAS99 cross derived plants, B06, B27, B30, B34 and B44 were identified as superior MAS99 converted CMS plants as indicated by morpho-floral traits and advanced to BC4F1. Between two crosses, IR70369A × MAS99 cross derived population was superior for days to 50% flowering and stigma exertion rate.

Keywords

• aerobic rice
• backcross
• conversion
• male sterility
• spikelet fertility