早发生胚水稻小孢子发生及花粉的萌发生长

实验结果表明，早发生胚水稻（PDER）品系小孢子的发生发育与常规水稻品种相同，常规I-KI镜检显示其成熟花粉育性达87．4％．开花后，少量花粉在柱头上能正常萌发，并以短管形式进入柱头．大部分花粉在柱头上发生了异常行为：不萌发花粉管，但排放出大量内容物；花粉管细小或畸形；在枝头内或柱头外花粉管前端破裂；花粉管在柱头上绕行不进入柱头；花粉管在柱头内逆行生长；花粉管进入柱头后又穿出柱头；花粉管壁上粘有颗粒或被有一层膜等．文中就PDER的来源讨论了这些现象，并提出“萌败”这一新概念．

MICROSPOROGENESIS AND POLLEN GERMINATION IN PRE-DEVELOPED EMBRYO RICE

Microspore development and pollen gendnation in vivo in predeveloped embryorice (PDER) were observed using light and scanning electron microscope. The results showedthat the procedure of ndcrospore development in PDER was the same as that inconventional rice strains, in which mature pollen grains were filled with starch grains. Whenflowering, only part of mature pollen could gerndnate well and get into stigmatic tissue byshort tube, and most of them behaved abnormally: (1) Pollen did not gendnate, butexpel1ed mass of pollen content from the gerndnal aperture. (2) Pollen tube was very small.(3) Pollen tube swelled or broken outside or inside the stigma. (4) Pollen tube entered thestigma and then got out of it. (5) Pollen tube crawled (twisted) at the stigmatic surface. (6)Pollen tube was coated with pollen content. (7) Pollen tube growth direction was reverseinside the stigma. These abnormal phenomena were discussed.