Development of practical photoperiod-sensitive cytoplasmic male sterility lines for hybrid wheat breeding

在长日照（≧15 h）条件下，利用长叶草（Aegilops crassa）细胞质产生的光周期敏感雄性不育（PCMS），提出了一种生产普通小麦（Triticum aestivum）杂交品种的新方法。在短日照条件下，PCMS系通过自交授粉维持，而在长日照条件下，PCMS系与传粉者的异交可以产生杂交种子。本研究的目的是为杂交小麦育种开发实用的PCMS品系。2002年，利用2001年杂交的农林26号的FI杂交种，选育了不含Rf基因的4个优良品系，即“Chugoku 143”、“fukuoome”、“Chugoku 131”和“Chikugoizumi”。2003年，对Norin 26 / Fujimikomugi BC1系和这4个优良系进行了调查，在短日条件下筛选出10个Norin 26 / Fujimikomugi /2^* Chugoku 143和Norin 26 / Fujimikomugi /2^* fukuoome为高自交种育性和高杂交种育性的PCMS系。2004年，从Norin 26 / Fujimikomugi /3^* fukuoome的BC2系中筛选出2个短日条件下种子育性高、长日条件下雄性不育性高的实用PCMS系。

A two-line system using photoperiod-sensitive cytoplasmic male sterility (PCMS) caused by Aegilops crassa cytoplasm under a long-day photoperiod (≧15 h) has been proposed as a new means of producing hybrid varieties in common wheat (Triticum aestivum). The PCMS line is maintained by self-pollination under short-day conditions, and hybrid seeds can be produced through outcrossing of the PCMS line with a pollinator under long-day conditions. The objective of this research is to develop practical PCMS lines for hybrid wheat breeding. In 2002, using FI hybrid of Norin 26 crossed in 2001, we selected four elite lines, Chugoku 143, Fukuotome, Chugoku 131, Chikugoizumi, which has no Rf gene. In 2003, BC1 lines of Norin 26 / Fujimikomugi and these four elite lines were investigated and 10 lines of Norin 26 / Fujimikomugi /2^* Chugoku 143 and Norin 26 / Fujimikomugi /2^* Fukuotome were screened as PCMS lines with high selfed seed fertility and high crossed seed fertility under short-day condition. In 2004, among BC2 lines of Norin 26 / Fujimikomugi /3^* Fukuotome, two lines were screened as practical PCMS lines with high seed fertility under short-day condition and high male sterility under long-day condition.