水稻光温敏不育系“六圃法”提纯保真原种繁殖体系的建立与应用

Establishment and Application of “Six-Nursery Method” System for Seed Purification and Multiplication of PTGMS Lines in Rice

【目的】水稻光温敏不育系的提纯保真繁殖对于两系法杂交水稻的发展和应用具有十分重要的意义。现有提纯繁殖技术多以防止起点温度漂移为目的,而忽视了生物学性状的提纯保真。为解决这些问题,本研究结合光温敏不育系Y58S的多年大规模原种生产实践,建立了水稻光温敏不育系"六圃法"提纯保真原种繁殖体系。【方法】该技术体系基本步骤如下:首先,直接从生产上大规模制种使用的不育系种子中取样,种植"典型单株筛选圃",进行典型单株初选;其次,通过"起点温度鉴定圃"筛选不育起点温度基本一致的核心单株,进行起点温度纯化;然后,通过"群体观察圃"、"配合力鉴定圃"和"制种试验圃"来确保光温敏不育系的遗传背景基本纯合和表型整齐一致,从而决选保真核心株系,进而获得保真核心种子;最后,建立连续稳定的品种"专一性原种繁殖圃"来实现原原种和原种的高纯度生产。【结论】实践证明,该技术体系可确保获得育性稳定、表型整齐,且遗传背景来源基本一致的光温敏不育系原种,大幅度提高水稻光温敏不育系繁殖的安全可靠性和生产效率。2008年以来,应用该技术体系生产了249万kg Y58S生产用种,基本消灭了同形可育株,纯度全部达到99.5%以上。目前这些Y58S生产用种已经全部销售给各种业公司进行杂交制种,生产的杂交种子推广1474万hm2以上。

[Objective] Guaranteeing the seed purity of photo-thermo-sensitive genic male sterile （PTGMS） lines is extremely important for developing and using two-line hybrids. Problems still remained in existing technologies which put too much emphasis on preventing the threshold temperature drift and neglect maintaining not only high seed purity but authenticity. To solve these problems, a new set of ＂Six-Nursery Method＂ purification and multiplication system of PTGMS lines in rice has been established based on years of multiplication practices of PTGMS line Y58S in large scale commercially. [Method] Key technologies of this system are as follows., initial separating typical monoclonal in screening nursery which is sampled directly from commercial foundation seeds in mass multiplication, and then genetically purifying critical temperature inducing male sterility in critical temperature identification nursery; integrating evaluation results in 3 nurseries, such as group observation nursery, combining ability identification nursery and outcrossing testing nursery, to the final selection for purified genetic background and uniformed phenotype, in order to screening authentic core lines and to obtaining original seed; establishing a specifical original seed multiplication base to achieve the high purity original seed; multiplying original seed to produce breeder seed and multiplying breeder seed to produce foundation seed of PTGMS lines. [Conclusion] Practices have proved that application of such a set of techniques could guarantee stable sterility and identical genetic background of PTGMS line and greatly improve the safety and reliability of two line hybrids in commercial production. Since 2008, 2.49 million kg foundation seeds of Y58S with the purity over 99.5% have been produced by applying this purification and multiplication system, and been provided to seed companies for hybrid seed production, which have produced a large number hybrid seeds for planting 14.74 million hectare in farmer＇s field.