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本文对普通栽培稻不同品种类型间杂种小穗败育的细胞学基础及雌性败育的过程进行了研究,结果表明:(1)引起杂种小穗败育的原因有胚囊败育、花粉败育、开花时花药不开裂和雌雄异熟。其中胚囊败育而丧失受精能力是引起低结实率的最重要的因素,开花时花药不开裂和雌雄异熟在一定程度上形成了雌雄性细胞时间和空间的隔离屏障。(2)杂种植株的所有大孢子母细胞都能进行正常的减数分裂,形成四个大孢子,败育主要发生在靠近合点端的功能大孢子分化形成胚囊的早期,有的功能大孢子在进行第一次有丝分裂前便萎缩解体,多数走向败育的功能大孢子能完成一次或二次有丝分裂,形成二核或四核败育胚囊。败育的共同特征是无液泡的分化,细胞质少或退化,在败育胚囊残迹部位,解体的珠心细胞和萎缩的胚囊残渍混杂垛叠。已受精的杂种子房没有观察到胚及胚乳发育的异常。籼粳杂种胚囊败育频率较高。
In this paper, the cytology and abortion process of hybrid spikelet abortion in different cultivars of common cultivated rice were studied. The results showed that: (1) The abortion of hybrid spikelet was caused by embryo sac abortion, Fertility, flowering anthers do not crack and dioecious. The embryo sac abortion and loss of fertility are the most important factors that cause low seed setting rate. Flowering anthers do not crack and dichogamy to a certain extent, forming a barrier of space and time of male and female cells. (2) All megaspore mother cells of hybrid plants can undergo normal meiosis and form four megaspores. Abortion mainly occurs in the early stage of differentiation of megaspores which function close to the confluent point to form embryo sacs. Some megaspores Before the first mitosis will atrophy disintegration, most of the function of the abortion megaspore to complete one or two mitosis, the formation of two or four nuclear abortion embryo sac. The common feature of abortion is the absence of vacuolar differentiation with less or reduced cytoplasm. In the aborted part of the embryo sac, the disintegrated abacus and the atrophied embryo sac are mixed with each other. Fertilized hybrid ovary did not observe abnormal embryo and endosperm development. Indica japonica hybrid embryo sac abortion frequency higher.