摘要
为了解桂花两性株孢子发育和花器形态的关系,对早籽银桂(Osmanthus fragrans‘Zao Zi Yin’)大小孢子发育过程和花器外部形态进行了观察。。结果表明,圆珠期花芽突然膨大时,小孢子母细胞减数分裂启动,至花芽顶壳期进入四分体时期,四分体多数呈四面体型,少数呈十字交叉型,也有介于二者之间的排列方式;柃梗期时小孢子发育至单核靠边期;香眼期至盛花期形成二细胞型花粉并发育成熟;花药长度由0.3 mm增加至1 mm,颜色由无色透明变为鲜黄色。雌蕊柱头二裂,子房2室,每室2胚珠,胚珠横生,单珠被,薄珠心,珠柄不明显。二细胞花粉时期,大孢子母细胞减数分裂形成大孢子,至盛花期胚囊发育为成熟的8核蓼型胚囊。雄蕊发育早于雌蕊,花开后雌、雄蕊趋于同熟。大小孢子细胞学发育时期与花器形态建成密切相关,根据花器形态特征可判断大小孢子发育时期。
In order to understand the relationship of spore development with morphology of floral organ in Osmanthus fragrans,the changes in morphology of floret organ during micro-and megaspores development of'Zao Zi Yin'bisexual plant were observed.The results show that the meiosis of microspore mother cell started when flower bud at ball-shaped stage suddenly expanded,and it came into tetrad stage at top bract stage.Majority of microspore tetrads were tetrahedral,minority were decussate,and others between the two ways.Flower bud was at the bud-pedicel stage,microspore develop to the late uninucleate stage,and flower bud from bud-eye stage to full blooming stage,microspore form2-celled pollen and mature,the anther length increased from0.3mm to1mm,color changed from colorless transparent to bright yellow.Pistil stigma two lobed,ovary2rooms,each room2ovules,amphitropous ovule,unitegmic,tenuinucellate,and funicle was not obvious.During two-cell pollen period,the megaspore mother cell goes on meiosis to form megaspore.To flowering stage,the8-nuclear sac was mature with polygonum type.The development of stamen was earlier than that of pistils,they tend to mature at the same time after flowering.So,the micro-and mega-sporogenesis had high relation with morphology of floret organs.It was suggested that the micro-and mega-spore development period could be judged according to morphological characters of floral organs.
作者
董立格
丁雨龙
DONG Li-ge;DING Yu-long(College of Biology and the Environment;Nanjing Flower Park Management Office, Nanjing 210037, China;Southern Modern Forestry Collaborative Innovation Center;Bamboo Research Institute, Nanjing Forestry University, Nanjing 210037, China)
出处
《热带亚热带植物学报》
CAS
CSCD
北大核心
2017年第3期299-308,共10页
Journal of Tropical and Subtropical Botany
基金
江苏省优势学科建设工程项目(PAPD)资助~~
关键词
桂花
孢子发育
花器
Osmanthus fragrans
Spore development
Floral organ
