玉米隐性核不育双杂合保持系的选育:Ⅱ.提高保持系生活力的研究

试验采用两种方案选育不同自交系背景的隐性核不育双杂合保持系。不同保持系在成株率、双杂合体比例、花粉败育率等特性上有明显差异,表明不同自交系对染色体重复缺失承受力的差异,将双杂合结构转育到更多自交系背景中,有可能筛选出农艺性状优良、生活力强的保持系。通过同一自交系双杂合体互交或不同自交系双杂合体杂交,改良保持系农艺性状已初见成效。 ms~2|双杂合保持系保持雄性不育株率99.72%,符合生产杂交种子的要求。文章还讨论了两种选育方案的效果和保持系的应用前景。 Abstract:Recessive enic male-sterile double heterozygous maintainers in various inbred line backgrounds were eveloped using two different breeding procedures.The maintainers showed significantly differences in plant viability percentage,double heterozygote percentage,abortive pollen percentage and other traits.This implied different tolerances of various inbred lines to Dp-Df chromosome complement.Maintainers possessing good viability can be selected when double heterozygous constitution was transferred to more inbred lines.The agronomic traits and viability was improved by sibcrossing among double heterozygotes with the same inbred line background or crossing among different double heterozygotes.The maintainers could maintain 99.72% progeny plants to be male-sterile,this satisfies essential reguirement for production of commercial hybrid corn.The merits and demerits of two approaches for breeding double heterozygous maintainers and the applied prospect of maintainers are discussed.     

玉米隐性核不育双杂合保持系的选育:Ⅱ.提高保持系生活力的研究

试验采用两种方案选育不同自交系背景的隐性核不育双杂合保持系。不同保持系在成株率、双杂合体比例、花粉败育率等特性上有明显差异,表明不同自交系对染色体重复缺失承受力的差异,将双杂合结构转育到更多自交系背景中,有可能筛选出农艺性状优良、生活力强的保持系。通过同一自交系双杂合体互交或不同自交系双杂合体杂交,改良保持系农艺性状已初见成效。 ms~2|双杂合保持系保持雄性不育株率99.72%,符合生产杂交种子的要求。文章还讨论了两种选育方案的效果和保持系的应用前景。 Abstract:Recessive enic male-sterile double heterozygous maintainers in various inbred line backgrounds were eveloped using two different breeding procedures.The maintainers showed significantly differences in plant viability percentage,double heterozygote percentage,abortive pollen percentage and other traits.This implied different tolerances of various inbred lines to Dp-Df chromosome complement.Maintainers possessing good viability can be selected when double heterozygous constitution was transferred to more inbred lines.The agronomic traits and viability was improved by sibcrossing among double heterozygotes with the same inbred line background or crossing among different double heterozygotes.The maintainers could maintain 99.72% progeny plants to be male-sterile,this satisfies essential reguirement for production of commercial hybrid corn.The merits and demerits of two approaches for breeding double heterozygous maintainers and the applied prospect of maintainers are discussed.