小麦温光敏雄性核不育系K78S在云南的生态适应性研究

Ecological Adaptability of Thermo-Photo-Sensitive Genic Male Sterile Wheat K78S in Yunnan Province

自1992年我国育成C49S和ES系列小麦温光敏雄性核不育系以来，温光敏两系法杂交小麦即成为我国小麦杂种优势研究与利用的主要途径之一。利用C49S-87组配的云杂3号（C49S-87／98YR5）2002年首先在云南通过审定并投入生产应用，2001年育成了改良的第二代温光敏雄性核不育系K78S，以其组配的云杂5号于2004年通过审定，云杂6号正进入大面积生产示范。为确定K78S的安全制种范围，2001--2004年在云南不同海拔的5个生态区对K78S的育性进行了研究，结果表明，K78S在上述5个生态区均可安全制种，10月中旬至11月上旬播种，其套袋不育度均达98％以上，不育期18～43d，较C49S-87至少长18d，育性稳定。初步研究表明，K78S的不育临界温度和临界光长分别比C49S-87高2．1qC和长0．93h，因此K78S的安全制种区域比C49S-87更广，适应性更好。

Two-line hybrid wheat （Triticum aestivum L. ）, created with Thermo-Photo-Sensitive Genic Male Sterile （TPSGMS） line, has become one of the main ways studied in China in heterosis utilization of wheat since 1992, as TPSGMS wheat CA9S and ES series were bred. In 2002, first hybrid wheat combination Yunza 3 （C49S-87/98YR5） was registered and released in Yunnan. Simultaneously, the improved second generation of TPSGMS lines K78S derived from C49S-87 was developed in 2001, Yunza 5 （released in 2004） and Yunza 6 were also developed subsequently. In order to determine the suitable hybrid seed production region of K78S, the investigation of fertility was conducted in 5 different ecological regions with altitude of 1 530- 2 400 m from 2001 to 2004 in Yunnan. The results showed that K78S was adaptable in all theses areas with the sowing period from middle October to early November, bagged sterile rates 〉 98 %, and sterile duration of 18-43 d （18 d longer than C49S-87）, indicating that the hybrid seeds could be produced safely in these areas. Observation of abortive pollen in Kunming indicated that K78S was better in pollen sterile rate and fertility stability than CA9S-87, and for 19 times of observation from Jan. 31 to Apr. 1, 95.96% of abortive pollens in K78S were round or typical abortion types, only 4.04% the stainable abortion; while in C49S-87, the figures were 77.68% vs 22.32%, which meant the pollen abortion in K78S was more complete than that in CA9S-87. Preliminary analysis of the critical sterile thermo-photo values for fertility alteration indicated that K78S was 2.1 ~C higher in critical temperature and 0.93 h longer in daylength than CA9S-87, which proved that K78S has wider adaptability and broader planting area suitable for hybrid seed production in Yunnan.