超级杂交稻育种三步法设想与实践

 介绍了国内外水稻超高产育种的基本情况，提出了当前我国水稻超高产育种面临的新问题，即超级稻品种资源匮乏、部分超级杂交稻组合适应性较差、超高产水稻育种理论过于模式化等。针对当前形势，结合多年育种实践，提出了超级杂交稻育种三步法设想，即超级亲本选育——超级杂交组合选育——超级杂交制种，并详细阐述了各步骤的标准和实现其目标的技术路线。超级亲本要求综合性状优良，产量水平或库容量达到或基本达到各级区试对照杂交稻组合的水平。超级杂交稻组合的标准是品质优、适应性广、耐肥抗倒、对主要病虫害达中抗以上水平，产量水平较国家或省区试中对照增产8%左右。其选育的技术路线是通过双亲最佳组配方式，增加选择压力，注重理想株型和优良生理机能及其各性状间的高度协调。超级杂交制种产量水平根据不育系的类型来确定，其中早稻类型不育系杂交制种产量要求大面积达到3.75 t/hm2以上，中稻类型的不育系要求达到5.25 t/hm2以上。其技术路线是通过选择最佳的制种基地，选用库容量大和异交结实特性好的不育系，通过超大行比与超常规培育父本措施提高父本的花粉量，从而提高制种产量。按照超级杂交稻育种三步法的技术路线，成功选育了父本996和两用核不育系C815S两个超级杂交稻亲本，利用前者选育出适合长江中下游稻区作双季早稻种植的超级杂交早稻组合陆两优996，用后者选配出几个增产幅度大、极有应用前景的超级稻新组合。

Prospect and Practice of Three-Procedure Breeding on Super Hybrid Rice

The status of super hybrid rice breeding program in China and other countries were both reviewed. There were three main problems in super rice breeding in China, including: 1)the scarcity of super rice varieties, 2) poor adaptation of super hybrid rice combination, 3)current breeding theories put too much emphasis on the rice growth model, and lack in practicability for guiding rice breeding. According to the author′s experience on rice breeding, the breeding strategy, which involved in three procedures, were proposed. The objective of each procedure and the key technologies for achieving the goals were elucidated in detail. The super parent of hybrid rice should exhibit a comprehensive excellent performance, with the yield or sink capacity equal to the hybrid rice control in regional yield trial. The super hybrid rice combination should meet the following criteria, including high rice quality, wide adaptation, lodging resistance, main insects and diseases resistance, and a yield increase above 8% compared with the control varieties in regional yield trial. Through optimal combination of the parents, increasing selection pressure, and paying more attention to harmony on ideal type, excellent physiological function and all the agronomic traits, the goals of super hybrid rice should be achieved. The yield of hybrid rice seed production should reach 3.75 t/hm2 and 5.25 t/hm2 for early-season and middle-season type of male sterile line, respectively. The main technologies included selection of optimal ecological site, use of the male sterile line with large sink capacity and good outcrossing characteristics, and increased amount of the pollen by intensive cultivation of the male parent. According to the breeding technologies, two super rice parents, including a male parent 996 and a T(P)GMS C815S, were bred. The super hybrid rice combination, Luliangyou 996, which can be used as a double-season early rice variety in middle and lower reaches of Changjiang River, China, was bred by using the super rice variety 996 as the male parent. Several hybrid rice combinations, with higher yield than control varieties both in Hunan provincial and national regional yield trials, were bred with the T(P)GMS C815S as the male parent.