棉花变异体(CHV1)的花形态特征分析

棉花体细胞培养再生植株存在大量的生理变异和可遗传变异,从中分离到一个性状稳定的花器变异体(CHV1)。从花器官形态特征和表面显微特征分析,该变异体的所有花器官都变成了苞叶状器官,但中央数片叶状器官的基部有胎座和胚珠着生。变异体每朵花有苞叶3-7片,苞叶状器官19-41片。苞叶状器官在花梗上的排布介于“轮”与“螺旋”状之间。据花器发育理论和变异体花的生长特性推测,该变异体中控制花器发育的A、B和C功能皆失活。对造成该变异的可能机理和棉花花发育模式进行了分析。该变异材料对研究棉花花发育和体细胞无性系变异的机理有一定价值。

ANALYSIS OF FLORAL MORPHOLOGY OF A COTTON HOMEOTIC VARIANT(CHV1)

Physiological and genetic variations exist frequently in the cotton plants regenerated from somatic embryos. A stable homeotic variant (CHV1) was identified from these regenerated plants. Morphological analysis suggested that all the floral organs of the CHV1 plants convert into bract leaf-like organs, this was confirmed by close inspection of floral organs surface using scanning electron microscope. However, there are placenta and ovules bearing at the basal region of central leaf-like organs. A flower of the variant consists of three to seven bracts, nineteen to fourty one bract leaf-like organs. Arrangement of the leaf-like organs is intermediate between spiral and whorl. The mechanisms responsible for the CHV1 phenotype are analyzed. The variant (CHV1) may be useful in the research of cotton flower development and the mechanism of somaclonal variation.