摘要
小麦成熟胚囊卵细胞中存在较多围核分布的淀粉粒和少量散布的脂类颗粒;两个助细胞中积累很多脂类,未见有淀粉粒存在;中央细胞中存在中等量均匀分布的淀粉粒和脂类颗粒。受精时期,胚囊内各细胞中淀粉粒变化不大。精卵核融合时,卵细胞和中央细胞中的脂类分别存在一个积累高峰。合子与相应时期游离核胚乳中的脂类颗粒均较少。原胚初期,每个原胚细胞及胚乳原生质中均积累较多脂类。珠孔附近的内珠被细胞中脂类颗粒较多,并存在一个有规律的变化。在观察的所有发育时期的胚珠中,均未发现贮存蛋白质。胚珠中脂类的一系列变化可能与雌性细胞的营养。
In a mature embryo sac of wheat (Triticum aestivum) the egg contained numerous perinuclear starch grains and fewer diffused lipid globules. The synergids contained a lot of lipids but no starch grains whereas the central cells contained only a moderate amount of diffused starch grains and lipids.There was little change of starch grain contents in all cells of an embryo sac during fertilization. The lipid globules increased sharply in the egg and central cells at the time of fusion of sperm and egg nuclei.Zygote and the corresponding free nuclear endosperm contained fewer diffused lipid globules. At early proembryo stage the proembryo cells and endosperm contained numerous lipid globules in their cytoplasm. The lipid content exhibited a regular change in the inner integument cells of an ovule. No cytoplasmic storage protein was detected in ovules at all observed stages.The changes of lipids in ovules might be associated with the nutrient of the female cells and early proembryo, and the chemotropic growth of pollen tubes.
基金
国家自然科学基金