籼稻体细胞克隆雄性不育系54257/162-5及其保持系

SOMACLONAL MALE STERILE LINE 54257/162-5 AND ITS MAINTAINER

本文报道了籼稻雄性不育系54257/162-5的基本特性,其母本54257及父本162-5均为离体培养起源的体细胞无性系,分别来自 IR_(54)及IR_(52)。 不育系54257/162-5已回交8代,不育株率100％,自交不结实。花粉败育方面,部分个体表现为典败,部分个体表现为染败,或典败与染败兼而有之。试验表明,不育系54257/162-5个体间这种花粉败育的“分离”并非父本不纯所致,乃该不育系固有的特点。 以114恢、测64、IR_(24)、3550、测222及丰桂6号等6个野败型不育系之恢复系与野败不育系及 54257/162-5测交,恢复程度有较大差异。只有3个(114恢、测64及测222)能使54257/162-5的育性恢复;2个(IR_(24)及3550)只能达到半恢复;有1个(丰桂6号)不仅不能恢复,而且保持了其雄性不育。这表明,不育系54257/162-5与野败不育系在细胞质上可能既有相似的一面,也有相异的一面。 讨论了保持系体细胞克隆162-5的基因型,认为它是由恢复系IR_(52)经离体培养直接变为保持系。这在体细胞无性系变异中尚属首例。

The characters of male sterile (MS) line 54257/162-5 were described , both the female 54257 and male 162-5 parents of which were Somaclones derived from IR54 and IR52 respectively. The MS line 54257/162-5 being stable was produced in the 8th generation by backcross-ing. The frequency of MS plant in the population wsa 100% , the pollen was abnormal and seedless in the condition of self pollation. Although all pollens were abortive, the pollens about 30% of the individuals were non-stainable, 50% stainable and 20% partial stainable by I-KI. six restoters of WA (wild abortive) type male sterile lines (114 Hui, Test 64, IR24, 3550, Test 222 and Fenggui 6) were used as male parents to test crossing with MS line 54257/162-5. Three of these restorers tested (114 Hui , Test 64 and Test 222) could fully restore the fertility of 54257/162-5, two (IR24 and 3550) were half-restored and one (Fenggui 6) maintained its sterility . These results indicated that the cyoplasm of MS line 54257/162-5 might be somewhat different to that of the WA MS line. The variety IR52 is possessed of restoring ability for WA type MS lines . However, the so-maclone 162-5 derived from IR52 turns to be its maintainer, which means the fertility of the mutant changed from restorer to maintainer via in vitro culture. This might be the first example of this phenomenon in somaclonal variation in rice. The genotype of the mutant was also discussed.