【摘要】 <正> 在一般被子植物中,影响胚胎发育最重要的部分,为双受精后所形成的胚乳。关于这种胚与胚乳的关系,已成为近年研究胚胎培养的中心问题,并且也已十分注意到胚乳(如椰子汁)对于营养体细胞培养中的促进作用(全面详细的评述可参考Steward and Ram,1961)。但是在裸子植物的种子内,生理上相当于被子植物胚乳的结构,乃是在卵受精以前即更多还原

【Abstract】 Four kinds of cultures were provided for comparing the growth rate and development between excised embryos and those within intact megagametophyte,namely:a) embryos in intact megagametophyte grown in culture medium supplemented with 5% sucrose;b) same as a),grown in culture medium without sugar;c) excised embryos grown in "double tube",with the upper tube containing 5% sucrose,but none in the lower; d) excised embryos grown in "double tube",with the lower tube containing 5% of sucrose,but none in the upper tube. Results from a series of aseptic cultures,substantiated with certainty that there is no dormancy factor either in the embryo itself or in those enclosed in the megagametophyte, whereas the stony seed coat is the only inhibiting factor.If the seed coat was removed and embryo in the intact megagametophyte was grown in the sterile culture medium without sugar under aseptic techniques (b),some "seeds" exhibited initial germination within one week.After three weeks in culture,the percentage of germination increased rapidly and the seedling growth continued vigorously.Hence,they could be transplanted into pods. In instances where the embryos within the megagametophyte were grown in a culture medium containing 5% sucrose (a),however,the germination rate declined markedly and there was no expansion of the cotyledons as seen in the culture (b). Growth of the excised embryo in type c double tube continued as usual,yet the rate of growth was way below that enclosed in the megagametophyte.When the excised embryos were cultured as in type d,they exhibited a pale,feeble appearance.Furthermore, root development usually failed to occur and seedlings ceased to grow. Finally some of the morphological changes of the excised embryos and those within the intact megagametophyte were discribed.更多还原