Genetics of fertility restoration of 'WA' based cytoplasmic male sterility system in rice (Oryza sativa L.) using basmati restorer lines

Abstract

Hybrid technology in basmati rice (Oryza sativa L.) is expected to make a quantum increase in production and boost the export of the country. The success in development of basmati hybrids largely depends on availability of effective restorers and precise basic knowledge on the genetics of fertility restoration of such lines. Study using five diverse restorers and Pusa 3A a 'WA' type cytoplasmic male sterile (CMS) line in basmati background, revealed the fertility restoration to be governed by two major genes with epistatic interactions that differed from cross to cross. Restorers PRR 78 and PRR 73 when crossed with Pusa 3A, segregated in the ratio of 9:3:4 and 1:1:2 in F2 and BCl generations, respectively for pollen and spikelet fertility indicating two major genes with recessive epistasis involved in fertility restoration. Crosses Pusa 3A1PRR 72 and Pusa 3A1IR 42266 showed a segregation ratio of 9:6:1 and 1:2:1 in F2 and BCl generations, respectively, indicating two major genes governing fertility restoration showing epistasis with incomplete dominance. Pusa 3A1IR 48749 gave segregation ratio of 12:3:1 in F2 and 2:1:1 in BCl generation showing digenic dominant epistatic interaction.