摘要
在IR50成熟种子离体培养起源的R_3代一株系的群体(140株)中发现1株雌性不育突变。其主要特点如下: 1.突变体的雌蕊缺乏花柱及柱头,仅由子房组成。大多数子房不具真正的胚囊,“胚囊”中充满了薄壁细胞。大约30%的颖花具有两个以上的子房。突变体完全不能结实。 2.颖花内的花药部分退化或完全退化。在所观察的颖花中没有发现具有全部6枚花药的。1颖花内花药最多时仅为4枚(占全部观察的颖花的3.9%)。大多数的颖花只具有2枚花药(占33.7%)。而25.9%的颖花内完全没有花药。花药退化时雄蕊仅剩下花丝或瘦弱空瘪(不含花粉粒)的花药。但发育正常的花药内含有有功能的花粉粒,I-KI的着色率达90%以上。当以突变体的花粉给IR50及突变体的姐妹正常株“164N”授粉时,可以获得杂种。 3.突变体的颖花也不正常。其外颖过于发达而成为钩状,内颖近于退化而成为一片状物,因而颖花不能关闭,花药在抽穗后颖花开放前已裸露于颖花之外。 4.(IR50/164V)及(164N/164V)两组合的F_1植株表现完全正常,种子结实率为47.8—88.5%。半不育的植株也具有发育正常的雌蕊。F_1代分离出雌性不育的个体,χ~2测验表明突变体雌性不育受两对独立的隐性基因控制。 讨论了本突变产生的原因,水稻雌性不育的分类以及雌性不育在固定杂种优势中所具有的潜?
One female sterile mutant was found in a somaclone of R?generation which was derived from mature seed culture of IR50. The main characters of the female mutant were as follows:1. The pistil of the mutant had no stigma and style and consisted of ovary only. Most of ovaries in the mutant were without embryo sac, and the sac full of parenchyma cells. About 30% of spikelets possessed two or more ovaries. No seeds were set in the mutant plant.2. The anthers of the mutant were fully or partially degenerated. No spikelet possessed all 6 anthers. In a spikelet of the mutant, the maximum number of the anthers was 4 (making up 3.9% of the total number), most spikelets had two anthers (making up 33.7%) and 25.9% of spikelets were without any anther. In the case of no ambers, the staman consisted of 6 filaments only. The degenerated anthers were empty and no pollen grains were inside but in the normal anthers of the mutant, the pollen grains were functional and stained by IKI solution. The hybrid seeds were set when thee pollen of the mutant plant (164V as the male parent) was pollinated to IR50 (as female parent). 3. In the spikelets, the lemma was over-developed while the palea was underdeveloped and became a small piece. Therefore the spikelets did not close after flowering and the anthers were out of the spikelet before flowering.4. The hybrid F1 of two combinations, (1R50/164V and 164N/164V) expressed as fertile as the normal plant and the seed setting frequency was between 47.8-88.5%. In the F2 generation, female sterile plants were segregated and the result of x1 of the segregation ratio showed that the mutant was controlled by two ressesive genes.
基金
七.五攻关项目课题~~
关键词
籼稻
雌性不育
体细胞培养
突变
Female sterile, Somaclonal variation, Indica rice, Somatic cell culture
