栝楼雄花发育的研究

栝楼雄株在花期常是一具长梗的单生花和—总状花序并生于叶腋。花部按花萼、花冠、雄蕊、退化心皮的顺序依次发生。花的各轮基部并合。在花芽的幼期,雄蕊原基三个,二大一小,大的发育成的花药具二药室,小的具单药室。当花芽高约1.1—1.2cm时,花药内的小孢子为四分体时期。成熟的花粉粒近球形,二核,具三孔沟。三个退化心皮边缘的联合处形成三个突起物,发育的初期与雌花同,但其内维管束数目不固定,不发生离心的弯曲,不发生胎座,亦不形成柱头和花柱。退化心皮联合处上方,有三个长条状蜜腺,蜜腺常二长一短,贴生于花管与雄蕊花丝基部互隔排列.

STUDIES ON THE DEVELOPMENT OF STAMINATE FIOWFRS IN TRICHOSANTHES KIRILOWII MAXIM

The staminate flower of Trichosanthes Kirilowii Maxim usually grows on a long shoot.The slitary flower and the inflorescence (rccenae) both are formed at a leaf axil during the summer months Each inforescence bears 3-15 floral buds.The developmental sequence of the staminate flower is similar to that of the pistillate flower. During the early stage of flower development, the three staminate primodia are not equal in size. Later on the two large ones develop into two bithecal, and the small one into one monthecal stamen. At the base of the hypanthium 15 bundles are present, of these the test outer bundles pass alternately as traces for sepals and petals, of the remaining five intefnai trace bundles one remains free and the other four run in 2 pairs, Each pair of bundles fuses at some higher level of the hypanthium. Each of the two fused bundles passes info filamenf of a bithecal stamen whereas the odd one supplies the monthecal stamen. Higher up in the anther region the fused bundles bifurcate again.As the thecae are thrice fplded, 6 + 6+3 thecal sections and five anther wall layers of each thecal section are found in a transver section of a floral bud. Each theca becomes two lobed and each lobe-contains a microsporangium. The type of tapetum is glandular. The formation of spore tetrads is found in floral buds about 1.1--1.2cm in length. Most of them are the tetrahedral and isobilateral. The decussate tetrands are also fouad. The pollen grains are tricolpate The carple primordia of the staminate flower develop as a unit as normal. But they do not develop further and differente into the secretory tissue of the necteries.