水稻花器官数目突变体mf2的鉴定和基因定位

水稻的花器官发育影响着水稻的产量与品质。本研究通过~(12)C重离子诱变航恢7号获得一个水稻花器官突变体multi-floret 2(mf2),其稃片、浆片、雄蕊、雌蕊增多,多数小穗内具2~3朵类似小花。mf2内外稃不能很好勾合,而且形状和维管束的数目都产生了一定程度的变化。电镜扫描幼穗发现花器官的变异在幼穗分化期的各花器官原基分化时就已形成。另外,该突变体的抽穗期推迟,株高降低,穗数增多,表明其营养生长也受到一定的影响。遗传分析表明mf2突变体表型受单隐性核基因控制。利用SSR、InDel分子标记将MF2定位于第1染色体的标记SSR39108和InD39210之间,区间大小约为102 kb。

Identification and Gene Mapping of a Floral Organ Number Mutant mf2 in Rice (Oryza sativa)

A rice floral organ mutant mf2 (multi-floret 2) was identified from Hanghui 7, an indica restorer line in rice (Oryza sativa L.), which was treated with heavy ion irradiation. The glumes, lodicules, stamens, pistil of the mutant increased, and most of the spikelets had 2-3 flowers. The palea and lemma of mf2 mutant were dehiscent, the shape and number of vascular bundles were different from those of the wild-type. Scanning electron microscope analysis revealed that the flowers variation of mf2 had been formed in the differentiation of the primordium during the spike differentiation stage. The heading date of the mf2 mutant was delayed, the plant height was decreased, but the number of panicles was increased, showing that the vegetative growth of the mutant was also affected. Genetic analysis showed that the mf2 mutant phenotype was controlled by a recessive nuclear gene. There are 321 recessive individuals from the F₂ segregation population were used to fine map MF2. Finally, MF2 was located in a 102 kb physical interval between markers SSR39108 and InDel39210 on chromosome 1.