利用花培与辐照诱变培育粳型两系不育系江79S

为创制新的两系不育系,并将其应用于强优势杂交水稻品种培育,综合利用花培和诱变技术培育了粳稻两系不育系江79S。取培矮64S/粳稻H179的F₁幼穗,利用花药培养技术培育获得一个粳型光温敏不育系S79;后采用高能碳离子束处理S79干种子,在其后代中选育了一个熟期突变体GS79(江79S),其在长日照和短日照条件下始穗表现不同,分别较S79早7 d左右和迟5 d左右。观察江79S的育性转换特性,发现其在嘉兴种植时,每年9月8日左右开始出现可育花粉并开始结实;在陵水种植时,植株正常结实且结实率达80%以上。人工气候箱光温敏特性鉴定结果表明,江79S在长日照条件下育性转换温度低于23.5℃。稻米品质和抗性鉴定结果为江79S米质达农业部(现农业农村部)部颁三级优质米标准,苗叶期抗稻瘟病。对江79S进行全基因组测序,分析发现其携带源自农垦58S的光敏不育基因pms1和pms3,且含携带抗稻瘟病基因pi21、Pia、Pid3和Pita,与其高抗苗瘟的特性相一致。以江79S配制的亚种间杂交水稻品种江两优7901通过了国家主要农作物品种审定。本研究结果为综合运用花培和辐照诱变技术培育新两系不育系材料提供了研究方法。

Breeding of the Photoperiod/Temperature-Sensitive Genic Male Sterile Line Jiang 79S by Using Anther Culture and Irradiation Technology

To generate new two-line male sterile lines which can be used to breed elite hybrid varieties, a japonica photoperiod/temperature-sensitive male sterile (PTGMS) line Jiang 79S was generated by anther culture and irradiation. Firstly, a japonica PTGMS line S79 was generated through another culture of F₁ hybrids derived from Peiai 64S and japonica line H179. Then its dry seeds were treated by high energy carbon ion beam, a mutant line GS79 (Jiang 79S) with changed heading date was obtained. Under the long-day condition, Jiang 79S started heading ~7 days earlier than S79, while under the short-day condition, Jiang 79S headed ~5 days later than S79. Jiang 79S showed partial to complete fertility after the September 8 and set seeds in Jiaxing. While in Lingshui, Jiang 79S showed normal fertility with seed set rates higher than 80%. A photoperiod/temperature sensitivity test in phytotron showed that the fertility transition temperature was lower than 23.5 ℃ under long-day condition. The whole genome sequencing of GS79 showed that besides the photosensitive male sterile genes pms1 and pms3 derived from its progenitor Nongken 58S, it also carries rice blast resistance genes pi21, Pia, Pid3 and Pita, which corroborates its high seedling blast resistance. The inter subspecific hybrid rice “Jiangliangyou 7901” from Jiang 79S has completed the national new variety trial test and been nationally approved. The results provide methods for breeding new two-line male lines by comprehensive use of anther culture and irradiation mutation technology.