Fujian Provincial Key Laboratory of Crop Breeding by Design,Fujian Agriculture and Forestry University
Program of China (NO.2017YFD0100100)； Regional Development Project of Fujian, China (NO. 2018N3011)；Key Sci-Tech Project of Fujian (NO.2018N006)
以优质两系不育系Y58S 与携有多个抗病基因的优质保持系M215B 杂交，F1 抽穗期再与优质两系抗病不育系 RGD-7S 复交，通过分子标记辅助选择技术和系谱法育种相结合，选育出同时携有Pi-2、Pi-1、Pi-Kh、Xa21 和Xa23 的两系不 育系禾9S。稻瘟病抗性表明，禾9s 田间鉴定平均叶瘟发病率为仅为2.5%（感病对照为83.0%），病情指数为0.60（感病对照 为52.9），表现抗苗瘟；穗颈瘟平均发病率为38.3%（感病对照为88.5%），病情指数为8.0（感病对照为62.3），表现中抗穗 颈瘟；室内鉴定抗菌株率为87.5%（感病对照为6.25%），表现为抗稻瘟病；田间和室内鉴定综合评价为中抗稻瘟病。白叶枯 接菌鉴定表明，禾9S 在用PXO99、ZHE173 和GD1358 3 个菌株接菌14 天后的病斑长度分别为0.1 cm，0.1 cm 和0.4cm，与 抗性供体亲本M215B 相近（病斑长度分别为0.1 cm，0.1 cm 和0.3cm，明显短于对照品种RGD-7S（病斑长度分别为2.2 cm， 7.4cm 和7.8cm）和Y58S（病斑长度分别为1.3cm，5.1 cm 和5.5cm）的病斑长度。主要特征特性观察表明，禾9S 具育性转 换起点温度低（23℃左右）、可繁性好、柱头外露率高、米质优等特点，目前利用禾9S 已配组出禾两优676 等10 多个杂交稻 新品种，其中禾两优676 和禾两优639 表现生育期适中、产量高、抗性好、稳产性好等特点，已分别于2019 年5 月和2020 年6 月通过福建省作物品种审定委审定，另有多个品种已进入各级续试或生产试验，表明该不育系具较好的推广应用前景。
A good-quality two-line male sterile line (Y58S) was crossed with a good-quality maintainer line (M215B) that carry multiple disease resistant genes. The obtained F1 hybrids were crossed with RGD-7S, which is a good-quality and disease-resistant male sterile line at the heading stage, a two-line male sterile line (He-9S) that contained five resistance genes ,Pi-2, Pi-1, Pi-Kh, Xa21 and Xa23 was bred by marker-assisted selection in combination with pedigree breeding. The average incidence rate of leaf blast in the field identification of He-9 S was only 2.5% (83.0% for the susceptible control), and the disease index of leaf blast was only 0.60 (52.9 for the susceptible control). The incidence rate of panicle neck blast of He-9 S was 38.3% (88.5% for the susceptible control) and the disease index of panicle neck blast was 8.0 (62.3 for the susceptible control) . The Frequency of resistance of He-9S in indoor artificial inoculation was 87.5%(6.25 for the susceptible control).Tests for rice blast resistance under greenhouse condition and field conditions showed moderate resistant to rice blast in He-9S. Furthermore, inoculation with three respective isolates (PXO99, ZHE173 and GD1358) showed that the diseased lesion length of He-9S was variable between 0.1-0.4 cm, similarly to the resistant donor parent, M215B, the lesion length of which were 0.1 cm, 0.1 cm and 0.3 cm respectively. On the contrast, the lesion length of both control varieties RGD-7S and Y58S were variable from 1.3 cm to 7.8 cm. Attractively, He-9S showed low fertility conversion temperature (about 23 °C), good versatility, high stigma exsertion rate and excellent rice quality. Up to date, >10 hybridization combinations have been produced by taking use of He-9S. For example, two elite variety Heliangyou 676 and Heliangyou 639, which exhibited moderate growth period ,high yield, good resistance and good stability, had been approved and released to farmers in May 2019 and on June 2020 respectively in Fujian province, and there are more than 3 varieties are in second-year tests or production test. Taken together, this study released an elite sterile line with a predictable potential in breeding for elite rice hybrids.