棉花胚珠纤维发育的研究

将未受精的棉花胚珠漂浮培养在加有不同植物激素的BT培养基上,培养48小时或96小时后,用扫描电镜观察纤维发育情况,以及测定胚珠内IAA氧化酶活性变化及内源ABA的含量变化,并和同一时期的大田生长的胚珠进行比较。结果表明:IAA+GA_3是最佳激素组合。在这种激素组合的培养基中培养的未受精胚珠,在纤维发育、酶活性变化等方面,均与大田生长的胚珠相似。这一激素组合还能抑制离体胚珠内源ABA的增长,但同一时期的大田生长的胚珠,其内源ABA含量却相对要高。

THE STUDY OF COTTON FIBER DEVELOPMENT

Unfertilized cotton ovules were removed aseptically from ovaries on the morning of anthesis and cultured by floating on the sur- face of the liquid Beasley's medium in which different phytohormones were added.When indol-3-acetic acid (IAA) or gibberellic acid (GA) was added in the medium,no effects or a few on fiber development were observed. But when IAA plus GA was added in the medium,fiber development was apparently promoted.Further,the observing results with electron scanning telescope showed:If IAA and GA were added in the medium,the sur- face of the ovules would be similar to that of the ovules cultivated in the field,i.e.,the surface was covered with close and numerous elongating fibers,In the meantime,the deter- mination of IAA oxidase activity and inter- nal abscisic acid (ABA) contents showed that the best hormones combination (IAA+ GA) could enhance the enzyme activity and decrease the accumulation of internal ABA. Besides,the determination of IAA oxidase activity and internal ABA contents was also done with the ovules taken from the cotton plant growing in the field.