水稻长颖壳突变体的形态发生、解剖结构观察及其遗传鉴定

长颖壳花器官突变体从野生稻(Oryza ntvara Sharma et Shastry)和栽培稻(Oryza sativa subsp.indica Kato)杂交后代材料中获得.该突变体的内外稃变长、呈叶状,且顶端表现不同程度的开裂;每朵颖花的雄蕊l～10枚不等;雌蕊l～3枚不等;子房上柱头l～5个不等;有的颖花形成雄蕊/雌蕊嵌合体;子房处常附有瘤状物;此突变体结实率为1 8.2%;花粉可育率为62.46%.利用扫描电镜观察了该突变体花器官形态发生过程,并经遗传分析鉴定该突变性状由单隐性基因(暂命名为lh)控制.本文讨论了lh基因和以前鉴定的其他突变体基因之间的关系,通过表型分析推测,突变体基因可能影响花器官数目同时具有拟南芥B类基因的部分功能.

Morphogenesis, Anatomical Observation and Genetic Analysis of a Long Hull Floral Organ Mutant in Rice

The long hull floral organ mutant in rice (Oryza sativa L.) was firstly discovered in the hybrid progeny of a wild rice (O. nivara Sharma et Shastry) and a cultivar rice (O. sativa subsp. indica Kato). The florets of the mutant plant show long, leafy paleas/lemmas that result in open hulls. A single floret consists of one to ten stamens, one to three pistils and one to five stigmas on the same ovary. Stamens/pistils-like structures and bulged tissues near ovaries were observed. Low seed setting rate was another obvious character of this mutant. According to statistical analysis, seed setting rate was 18.2%. The percentage of pollen fertility was 62.46%. The process of floral organ morphogenesis was also investigated using scanning electron microscopy (SEM), and genetic analysis indicated that mutant traits were controlled by single recessive gene (temporarily designated as lh). The possible relationships between this lh gene and other floral organ mutants reported earlier in rice are discussed. Furthermore, we deduced that this gene might represent an example of a gene required for generating proper floral organ number and also be similar to B-like genes in Arabidopsis and Antirrhinum.