摘要
Use of cytoplasmic male sterility (CMS) in hybrid breeding requires effective male fertility-restoring lines. In sorghum, very few restoring lines that can restore fertility in A_3 CMS have been reported. To identify the reasons for this deficiency, F_1 and F_2 hybrids of an A_3 CMS line crossed with the line IS1112C, a donor of fertility-restoring (Rf) genes for A_3 cytoplasm, and testcrosses of fertile plants to A_3CMS lines were grown under contrasting water availability regimes in dryland and irrigated field plots. In the irrigated plots the frequency of fertile plants in testcrosses was twice that in dryland plots (P < 0.05). Fertile plants from the F_2 family grown in the irrigated plots showed significantly higher restoration ability than fertile plants from the same family grown in dryland plots. F_3 plants from the F_2 family grown in irrigated plots yielded on average a sixfold higherfrequency of fertile plants in testcrosses than F_3 plants derived from dryland plots (P < 0.01).Fertility of testcross hybrids correlated negatively with air vapor pressure deficit (VPD) at flowering (r = - 0.96; P < 0.01) suggesting that VPD is a trigger for downregulation of Rf genes for A_3 cytoplasm.
Use of cytoplasmic male sterility (CMS) in hybrid breeding requires effective male fertility-restoring lines. In sorghum, very few restoring lines that can restore fertility in A_3 CMS have been reported. To identify the reasons for this deficiency, F_1 and F_2 hybrids of an A_3 CMS line crossed with the line IS1112C, a donor of fertility-restoring (Rf) genes for A_3 cytoplasm, and testcrosses of fertile plants to A_3CMS lines were grown under contrasting water availability regimes in dryland and irrigated field plots. In the irrigated plots the frequency of fertile plants in testcrosses was twice that in dryland plots (P < 0.05). Fertile plants from the F_2 family grown in the irrigated plots showed significantly higher restoration ability than fertile plants from the same family grown in dryland plots. F_3 plants from the F_2 family grown in irrigated plots yielded on average a sixfold higher
frequency of fertile plants in testcrosses than F_3 plants derived from dryland plots (P < 0.01).Fertility of testcross hybrids correlated negatively with air vapor pressure deficit (VPD) at flowering (r = - 0.96; P < 0.01) suggesting that VPD is a trigger for downregulation of Rf genes for A_3 cytoplasm.
基金
partially supported by the Russian Foundation for Basic Research (Nos. 13-04-01404, 16-04-01131)
