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 nivara 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1~10枚不等;雌蕊1~3枚不等;子房上柱头1~5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18.2%;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 hybridprogeny of a wild rice (O. nivara Sharma et Shastry) and a cultivar rice (O. sativa subsp. indica Kato). Theflorets of the mutant plant show long, leafy paleas/lemmas that result in open hulls. A single floret consistsof one to ten stamens, one to three pistils and one to five stigmas on the same ovary. Stamens/pistils-likestructures and bulged tissues near ovaries were observed. Low seed setting rate was another obviouscharacter of this mutant. According to statistical analysis, seed setting rate was 18.2%. The percentage ofpollen fertility was 62.46%. The process of floral organ morphogenesis was also investigated using scanningelectron microscopy (SEM), and genetic analysis indicated that mutant traits were controlled by singlerecessive gene (temporarily designated as lh). The possible relationships between this lh gene and otherfloral organ mutants reported earlier in rice are discussed. Furthermore, we deduced that this gene mightrepresent an example of a gene required for generating proper floral organ number and also be similar to B-like genes in Arabidopsis and Antirrhinum.