澳洲坚果花芽分化的形态学观察

Morphological Observation on Flower Bud Differentiation of Macadamia(Macadamia spp.)

据对澳洲坚果的花芽分化形态学观察结果:花芽分化初期正常,小花分化是从外往内。其生殖器官属于适于异花传粉的雌雄蕊异长型;花芽分化过程中在花托中部、花被、药隔周围等均出现了大量的后含物;花序发育过程中出现了大量脱落的小花;花粉囊结构正常,花粉母细胞为连续性减数分裂;四分体解体后绝大多数单核花粉粒异常,花粉囊内仅约1/9花粉粒正常发育,另有约1/9花粉粒死亡;剩余的7/9花粉粒均为残片,残片周围均环有胼胝质壁。后期花粉囊有大量中空败育的花粉粒,从形态解剖学的角度来看,这是澳洲坚果结实率低的最重要的原因之一。

Observation on flower bud differentiation of macadamia integrifolia has shown that its structure is normal at the beginning and all bud differentiation of little flowers on inflorescence starts from the outside to the inside. The plant＇s reproductive organs are heterogony that can be avallably adapted cross-pollination. It can be found there are much ergastic substance in the middle of the receptacle, the surrounding perianth and connectivum during the flower bud differentiation. Many shedding of flowers are found on the slices in inflorescence＇s developing. Their meiosis mode of the microspore mother cells arc continuous in the pollen sac which structure are normal. The vast majority of microspore after which pollentetrad separate are anomalous, only 1/9 pollen granule can be normally developed while 1/9 pollen granule died, and 7/9 of them are only fragment which are surrounded by their callose wall. At the same time we watched there are a wealth of hollow abortive pollen in the later period of the anther development. From the morphological point of view, we thought that it is one of the major reasons that cause pollen abortion.