【摘要】 本研究由桔子、柿子(包括有核品种与单性结果品种)及南瓜(有籽品种)在开花前后的子房中提取出酸性乙醚溶解物质,并用小麦芽鞘垂直生长法测定其活性。结果表明。在所测定的各品种中开花前子房中的生长促进物与生长抑制物的活性都很高。但在有核种中如果不经过授粉,则在花后1～3日内子房中促进物质的水平即迅速降低而抑制物质水平则仍然保持很高。授粉引起了子房中促进物质水平的迅速增高与抑制物质水平的显著降低。天然单性结果品种与有核品种的主要区别在于开花后1～3天内前者的子房中在不授粉情况下也具有较高的促进物活性,而抑制物活性则大为降低。人工用外源生长物质诱发南瓜单性结果时,也同样引起内源促进物的急增而抑制物则完全消失。 这些结果说明了授粉受精的作用不仅在于引起子房中生长促进物的活化,而且也消除或对抗了生长抑制物的作用。座果与果实的继续发育受到生长促进物与抑制物间一定平衡状态的控制。本文对生长抑制物质的生物学意义也进行了讨论。更多还原

【Abstract】 Acidic ether-soluble substances were extracted from ovaries of orange,persimmon (of both parthenocarpic and seedcd cultivars) and squash(seeded cultivar) during the period of anthesis and bioassayed by the wheatcoleoptile straight growth method. The results showed that both the activitiesof growth-promoting and growth-inhibitiog substances were relatively high be-fore anthesis in ovaries of all cultivars tested. However, a marked decrease inpromoting substances and a concomitant increase in inhibiting substances wereobserved in non-pollinated ovaries of seeded cultivars of orange and squash 1--3days afer anthesis. Pollination caused a rapid increase in level of promoting sub-stances and a prominent decline in the level of inhibiting substances. The majordifference between the naturally parthenocarpic and the seeded cultivars was thatthe activities of promoting substances were higher and these of inhibiting subst-ances were lower in the parthenocarpic than in the seeded cultivars 1--3 days afteranthesis. The results indicated that the function of pollination and fertilizationwas not restricted to the activation of growth promoting systems but also to eli-minate or antagonize the effect of growth-inhibiting substances. It is suggestedthat fruit-set and its subsequent development may be controlled by a certain be-lance among the levels of growth-promoting and growth-inhibiting substancesrather than by any single factor. The biological significance of growth-inhibi-ting substances is also discussed.更多还原