文献类型： 会议论文

第一作者： Guangjun Ren

作者： Guangjun Ren ¹ ; Fangyuan Gao ¹ ; Xianjun Lu ¹ ; Zhihua Li ¹ ; Guangchun Liu ¹ ; Shuxia Sun ¹ ; Haojie Li ¹ ;

作者机构： 1.Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China

关键词： hybrid rice;cytoplasmic male sterile line;rice quality;aroma;intermediate amylose content;preharvest sprouting;outcrossing rate

会议名称： International symposium on hybrid rice

主办单位：

页码： 1-13

摘要： Improving the quality of hybrid rice varieties, especially the quality of indica hybrids, is one of the most important goals in rice production for many rice-producing areas of the world. In our breeding program, two cytoplasmic male sterile(CMS) lines, Chuanxiang-29A (Ch-29A) and Chuanmei-102A, as well as some good-quality maintainer lines were developed by combining classical breeding with molecular marker-assisted selection (MAS) to obtain desirable alleles. We introduced the aromatic trait from Xiangsimiao-2, an aromatic rice landrace native to southern China, into the CMS maintainer line II-32B by crossing. From the progenies, we obtained an elite CMS maintainer line named Chuanxiang-29B(Ch-29B) and the corresponding sterile line, Ch-29A, which had a high-quality appearance, large panicles, and high general combining ability (GCA). Subsequently,we generated a series of hybrid rice combinations to be released for production. Of all the combinations, ten aromatic hybrid rice combinations were developed and released by Sichuan, Chongqing, Fujian, Anhui, and Guangxi Provincial Variety Examination Committees. Moreover, a total of three combinations were approved by the National Variety Examination Committee during the past five years. Having early flowering and pollination times, a high percentage of exserted stigmas, and a high outcrossing rate, Ch-29A also proved to be a new CMS line that could yield about 4.5 t ha–1 in hybrid rice seed production.Further linkage analysis between simple sequence repeat (SSR) markers and the aroma locus for aromatic F2 plants mapped the Ch-29B aroma gene to a chromosome 8 region flanked by SSR markers RM23120 at 0.52 cM and RM3459 at 1.23 cM. In an effort to specifically improve the rice quality of the CMS line, G46A, Lemont was used as a donor parent to introduce resistance to preharvest sprouting (PHS), a low percentage of chalkiness, and intermediate amylose content (AC) into G46B, the maintainer line of G46A that was used as a recurrent backcross parent. Based on the evaluation of agronomic traits and grain quality, MAS with the SSR markers RM3754, RM447, and 484/485 (linked to PHS and AC, respectively) was used for screening the plants in the backcross population between G46B and Lemont. Some elite lines obtained from the backcross generation were then backcrossed to G46A to improve breeding of the CMS lines. A new CMS line, Chuanmei-102A, was successfully developed using a strategy similar to that employed to generate G46A, but this line was specifically improved in PHS, AC, grain shape, and chalkiness. Furthermore, we used major maintainer lines currently used in rice production (II-32B,F-32B, Bo-B, Ch-29B, Zhong-9B, and IR58025B) as recurrent parents, and Basmati370, KDML 10, and Lemont as donor parents to develop more than 2,000 maintainer lines with intermediate AC, good appearance quality, and a high percentage of exposed stigmas. These lines could be useful for developing new CMS lines and good-quality hybrid rice in the future.

分类号： Q781`S334