Pollen Fertility and Agronomic Performance of Sorghum Hybrids with Different Male-Sterility-Inducing Cytoplasms

Effects of three sources of male-sterility-inducing cytoplasm in sorghum [Sorghum bicolor (L.) Moench] were compared in crosses with 217 male parents. Hybrids of these parents and A2 Redbine 58\u27, \u27A3 Combine Kafir 60\u27, and \u27A4 Martin\u27 female parents were evaluated for percentage stained pollen, seed set of bagged panicles, plant height, and days to midbloom. Additionally, hybrids of 12 of the inbreds crossed to each female parent were evaluated for grain yield and other agronomic traits in comparison with hybrids in A1 male-sterility-inducing cytoplasm. Twenty-one inbreds restored pollen fertility to hybrids with A2 cytoplasm, 11 restored pollen fertility to hybrids with A3 cycoplasm, and four rescored fertility co A4 hybrids. All inbreds chat restored male fertility to hybrids with A2 or A3 cytoplasm were known restorers (R-lines) for Al cytoplasm. Three R-lines to Al cycoplasm restored male fertility to hybrids with A4 cytoplasm, but the inbred N34, a nonrestorer (B-line) for hybrids with A 1, A2, or A3 cytoplasm, also restored pollen fertility to A4 hybrids. The inbred KS 19 was cheonly genotype that restored pollen fertility to A2, A3, and A4 hybrids. Collectively, the performance of hybrids in A2, A3, or A4 cytoplasm was not consistently or markedly different for grain yield, the components of yield, and ocher agronomic traits from that of counterpart hybrids in A1 cytoplasm. Greater use of A2 and A3 cytoplasms in breeding and seed production studies seems warranted