核不育芝麻小孢子败育机理的细胞学研究

Cytological Studies on the Mechanism of the Abortion of Microsporogenesis in Nucleic Male Sterile (NMS) Sesame (Sesamum indicum L.)

核不育芝麻小孢子败育发生在四分体形成之后的无液泡小孢子期,败育在很短的时间内完成。败育前小孢子大量液泡化,其线粒体异常膨大与质体的基质化可作为小孢子开始败育的标志。败育小孢子缺少花粉外壁上的覆盖层。芝麻花药绒毡层的异常,包括有机物贮量的降低;细胞内含物的异位分布及迅速减少与消失;不能及时或缺乏分泌胼胝质酶和花粉外壁来源的乌氏体等,是芝麻小孢子败育的直接原因。

Microsporogenesis in normal and NMS lines of sesame was studied. Almost all the NMSlines have normal microspore ontogeny until the tetrad stage, when the abnormality of thepollen organelles are a sign of the abortion that contain largely emerged vocuole,anomalously dilated mitochondria and the sharp decrease in the content of plastids. Theabortion takes place rapidly and thoroughly in a very short duration at the earlynon--vacuolate microspore stage when the content of proteins, polysaccarides and DNA inthe anther are very low as compared with the normal lines. The degenerative microspore isdeficient in tectorial layer. The abortion is closely related to the lask of nutrition supply. Thecomposition of the tapetum plays a decisive role in the anther abortion, which is associatedwth early maturation of the tapetum, reduced storage of organic compounds, decreased con-tent of the tapetal cell, and lack of callose enzyme and the Ubish body.