植物细胞质雄性不育系育种的反向核置换技术分析

Breeding of Elite CMS Lines by Reverse Nuclear Substitution

通过不育细胞质为选择背景,在田间事先鉴定出杂种后代的优异完全不育株,用花药培养或诱导孤雌生殖使其纯合,测定其配合力,可以筛选到优良的目标不育系。以下3种方法则可能通过目标不育系而获得其同型保持系:一是通过体细胞变异(花药培养)产生;二是在不育系孕穗期高温或低温处理使其转换成可育,选择仍具有不育保持能力的作为保持系,或作为轮回亲本,将其细胞核换到可育细胞质中;三是用原生质体融合的方式向不育系导入已杀死细胞核的可育细胞质而获得配套保持系。它可以使杂种优势利用变得有预见性,可能提高现有杂种优势水平。在创造雄性不育新质源,排除微效可育基因,进行不育系的定向改造,选育高配合力不育系,以及加速育种进程等方面具有重要价值。

It was very difficult to specifically identify the maintainability of a plant line unless it isgenetically stable and its whole nuclear genome has completely replaced in the CMS (cytoplasmic malesterile) line. To overcome this problem, a breeding method was proposed in this paper. The breedingprocedure includes: (1) screening elite male sterile plants from segregating populations using malesterile cytoplasm as background selection; 2) getting genetically stable CMS lines via anther culture orparthenogenesis; (3) selecting target CMS lines with good combinability, restorability, outcrossinghabit, grain quality and resistance to pests and diseases; (4) converting target CMS lines into maintainersby the following approaches: (a) to obtain fertile mutants of target CMS lines by further anther culture;(b) to make the target CMS line fertile by high temperature treatment at young panicle stage, then toselect maintainers through screening their offspring, or through nuclear substitution using their off-spring as male recurrent parent; (c) to irradiate to the obtain hybrids between CMS cells and radiatednormal cells via protoplast fusion and screen fertile plants as new maintainers.