Characterization and genetic mapping of a novel recessive genic male sterile gene ms305 in maize (Zea mays L.)

The male sterility system shows tremendous value for the long-term utilization of hybrid crop breeding. In this study, a male sterile mutant, K305ms, was derived from the M3 progeny of maize (Zea mays L.) inbred line K305 exposed to 60Co-γ irradiation. Male sterile K305ms plants did not show any obvious differences from their sibling male fertile plants (K305F) during the vegetative stage, but failed to produce functional pollen at the reproductive stage. Microscopic observations determined that the dyads and tetrads from the pollen of K305ms plants developed abnormally, and subsequently the microspores were shriveled. Genetic analysis indicated that the male sterility of K305ms was controlled by a single recessive genic gene. Gene mapping showed that the responsible gene was located between two simple sequence repeat markers on chromosome 2L in a region of 10.3 cM, bnlg469b and bnlg1940, with genetic distances of 2.9 and 7.4 cM, respectively. According to the microscopic and mapping characteristics, our ...