文献类型： 外文期刊

作者： Li, Shaoxiang ¹ ; Ding, Mingliang ¹ ; Li, Hongsheng ¹ ; Liu, Kun ¹ ; Yang, Zhonghui ¹ ; Gu, Jian ¹ ; Yang, Mujun ¹ ;

作者机构： 1.Yunnan Acad Agr Sci, Food Crops Res Inst, Natl Wheat Improvement Ctr, Yunnan Branch, Kunming 650205, Yunnan, Peoples R China

关键词： hybrid wheat; two-line system; thermo-photo sensitive genic male sterility; Yunnan

期刊名称：CHINESE SCIENCE BULLETIN-CHINESE （ 影响因子：1.1； ）

ISSN： 0023-074X

年卷期： 2022 年 67 卷 26 期

页码：

收录情况： SCI

摘要： Wheat is one of the most important food crops in Yunnan Province. Drought and yellow rust are the main limiting factors to wheat productivity. Utilization of heterosis is expected to be a promising way to increase resistance to stress and yield potential. In 1992, photo-thermo sensitive genic male sterile wheat "ES" and thermo-photo sensitive genic male sterile wheat "C49S" were developed by Hunan Agricultural University and Chongqing Academy of Agricultural Science, respectively, which provided a new way for heterosis utilization in China by conducting two-line hybrid wheat breeding. ES and C49S were sterile under low-temperature and short-day conditions, and fertile under high-temperature and long-day conditions. During 1993-2000, ten sterile lines of ES and C49S were introduced into Yunnan for sterility identification, while only C49S-87 from Chongqing showed stable sterility in three special locations of Yunnan when sowed in middle October, with 15-20 d of sterile heading duration (bagged seed-set rate <1%). In 2002, hybrid cultivar Yunza 3 from C49S-87 was released in Yunnan and increased yield by 11.4% over the inbred CK in regional tests, but was planted only 12400 ha in Yunnan due to the loss of resistance to yellow rust after 2004. Given that C49S-87 was poor in out-crossing ability (40%-50%) and susceptible to yellow rust, an improved sterile line K78S was developed from C49S-87 in 2001. K78S had 26-44 d of sterile heading duration in all regions with altitudes from 1530 to 2400 m when sowed from middle October to early November, as well as better out-crossing ability (70%-80%) and higher resistance to yellow rust. In 2004 and 2005, Yunza 5 and Yunza 6 developed from K78S were separately released in Yunnan. Both cultivars showed higher yield increase by >15% in regional tests. Meanwhile, high cross-pollination ability of K78S markedly raised the yield of hybrid seed production from 1500-1800 kg/ha of Yunza 3 to 3900-4500 kg/ha of Yunza 5 and Yunza 6 when the same techniques of mechanized seed production were applied. These cultivars have been totally planted about 700000 ha in Yunnan and parts of Vietnam till now. However, since 2005, no hybrid cultivar has been released in Yunnan. The main reasons are as follows: (1) Only two sterile lines were practically used for test-crossing before 2020 but became susceptible to yellow rust ten years ago, which greatly reduced the opportunities of creating high heterotic hybrids although thousands of restorers were test-crossed. In 2020, 24 elite sterile lines were developed by using doubled haploid (DH) breeding, and have been used in hybrid wheat breeding now. (2) Most restorers were "by-products" of developing inbred cultivars, thus the combining ability between the sterile line and the restorer was never tested during the developing of restorers, resulting in completely random or accidental emergence of heterotic hybrids. Therefore, it might be necessary to re-construct the restorer breeding program by using dwarf-male-sterile wheat with reference to maize inbred line breeding. In addition, exploitation of nucleo-cytoplasmic heterosis might be another way to increase heterosis both in yield potential and resistance to stress, as suggested by Kihara in 1979. Generally, some promising progress in two-line hybrid wheat breeding based on thermo-photo sensitive genic male sterility has been achieved in Yunnan during past 30 years. However, more efforts should be made in breeding and basic research to efficiently create hybrids with higher yield increase and better resistance to drought and diseases, and this will improve the current system and promote the wider application of hybrid wheat in Yunnan.