Abstract:

This study aimed to solve the bottleneck issue of high yield but poor quality in hybrid rice. The complex hybridization was conducted by utilizing the high-combining ability and high-outcrossing rate maintainer line Bo B, the high-quality Simiao rice variety Mi 31 from South China, and the high-quality, disease-resistant early rice variety Zhe 9248 from the lower reaches of the Yangtze River. The methods of shuttle planting to increase the ecological pressure for phenotypic identification and indoor analysis for quality assessment were employed. A high-quality cytoplasmic male sterile line and its corresponding maintainer line, Taifeng A/B, with slender grain shape, high head rice recovery, low chalkiness, and good taste, have been bred. By the end of 2023, 92 hybrid rice varieties, including Taifengyou 208, Taiyou 1002, Taiyou 390, and Taiyou 398, have been bred using Taifeng A, of which 80.4% meet the national (ministerial) high-quality standard of Grade 3 or above. Among them, 18 varieties/times have won gold and silver awards in national or provincial high-quality rice taste evaluations, and 2 varieties have been recognized as super rice. This has effectively solved the problem of “high yield but poor quality” in hybrid rice. In addition, we have analyzed the genetic characteristics controlling the important quality traits of Taifeng A/B and found that the GS3, GW5^TFB, Wx^TFB, and GW7^TFB genes located on chromosomes 3, 5, 6, and 7, respectively, or the chromosomal segments where they are located, are the critical genetic basis for the excellent quality of Taifeng A/B.

Key words: hybrid rice, male sterile line, maintainer line, Taifeng A/B, grain quality, genetic basis

摘要：

针对杂交稻“高产难优质”的瓶颈问题，基于杂种优势群与优势模式，选择华南地区高配合力、高异交率保持系博B和优质丝苗米亲本米31以及长江流域优质抗病早稻浙9248作为育种亲本进行复合杂交，通过穿梭种植生态加压表型鉴定与室内品质鉴定相结合的方法，育成了粒型细长、整精米率高、食味佳的“三高一优”不育系及其保持系泰丰A/B。截至2023年，用泰丰A配组育成泰丰优208、泰优 390、泰优1002和泰优398等优质杂交稻共计92个。其中，80.4%的米质达到国（部）标优质3级以上标准，18个品次获得国家或省级优质稻食味鉴评金奖和银奖，2个品种被农业农村部认定为超级稻，较好解决了杂交稻“高产难优质”的“卡脖子”问题。此外，对控制泰丰A/B重要品质性状的QTLs（基因）进行了分析，发现位于第3、5、6和7号染色体上的gs3、GW5^TFB、Wx^TFB和GW7^TFB基因或其所在的染色体区段是泰丰A/B品质表现优异的重要遗传基础。

关键词: 杂交稻, 不育系, 保持系, 泰丰A/B, 稻米品质, 遗传基础