低温预处理对水稻花药培养中花药壁褐变的结构影响

Effects of Cold Pretreatment on the Structure of Anther Wall Browning in Japonica Rice during Anther Culture

摘要:

药壁褐变是影响花药离体培养效率的因素。研究了粳稻品种台中65（Oryza satva L．）花药培养前低温预处理对药壁褐变的影响，观察了花药褐变前后药壁各层的变化及褐变对小孢子发育的作用。结果表明：药壁褐变主要发生在表皮与药室内壁。10℃低温预处理在花药培养前期可有效延缓表皮与药室内壁膜结构的降解速度，减缓褐变发生；花药经低温处理后，药壁中层细胞膨大，绒毡层降解速度减缓，有利于花粉脱分化。药壁褐变会影响药腔内小孢子的活力和继续发育，但不是制约花粉愈伤组织形成的关键因素。

Abstract:

Anther wall browning in variety Taichung 65 of japonica rice （Oryza sativa L.） was studied through cold pretreatment of anthers at late uninucleate stage. Some microstructural and ultrastructural changes in the anther wall were found during anther culture. Anatomical observation showed that anther wall browning took place mainly in epidermis and endothecium. Cold pretreatment of anthers at 10℃ could effectively reduce the browning rate during the early culture period and delay degradation of the membrane structures of epidermis and endothecium, and thus postpone browning in anther wall. Meanwhile, cold pretreatment contributed to stimulating cell enlargement in the middle layer and delaying tapetum degradation, which produced positive effects on the microspore dedifferentiation. Although anther wall browning favored microspore in vigor and development, it was not the key factor in reducing the ability of pollen callus induction.