濒危物种灰叶胡杨的大孢子发生和雌配子体发育  

Megasporogenesis and Development of Female Gametophyte of Endangered Species Populus pruinosa

作　　者：李志军[1,2,3] 焦培培[2] 王玉丽[1,2] 李健强[3] 

机构地区：[1]塔里木大学植物科学学院,新疆阿拉尔843300 [2]新疆生产建设兵团塔里木盆地生物资源保护利用重点实验室,新疆阿拉尔843300 [3]中国农业大学农学与生物技术学院,北京100193

出　　处：《西北植物学报》2011年第7期1303-1309,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金资助项目(30060007);国家重点基础研究发展计划资助项目(2009CB426303);新疆生产建设兵团塔里木盆地生物资源保护利用重点实验室开放课题(BRZD1001)

摘　　要：用石蜡切片法对濒危物种灰叶胡杨的大孢子发生和雌配子体发育过程进行观察研究.结果显示,灰叶胡杨雌蕊由三心皮构成,侧膜胎座,胚珠为倒生型,有18～21列;发育早期的胚珠为双珠被,厚珠心;当外珠被发育至与内珠被处于同一水平时,内珠被便开始退化,故成熟胚珠为单珠被;孢原细胞1个,并且自表皮下2层处分化;大孢子母细胞由孢原细胞分裂后形成的造孢细胞直接发育而来;大孢子四分体直线形排列,合点端的大孢子为功能大孢子,蓼型胚囊;在胚囊发育过程中珠孔端的珠心组织退化.根据开花物候不同阶段花的形态特征,可以初步判断灰叶胡杨大孢子发生和雌配子体的发育进程.The megasporogenesis and development of female gametophyte of endangered species Populus pruinosa Schrenk.were studied using method of paraffin section.The results indicated that the pistil of P.pruinosa was composed of three carpels,parietal placenta,with 18 to 21 rows of anatropous ovule.At the early developmental stage,the ovule showed crassinnucellate and bitegminous,the inner integument degenerated when the outer integument developed into the same level with inner integument,the mature ovule was unitegmic.One archesporial cell differentiated from two layers beneath the epidermises.The megaspore mother cell directly developed from the archesportial cell which formed after the archesporial cell division.The megaspore mother cell undergoes meiosis to form a linear tetrad,the chalazal megaspore functions,polygonum-type embryo.During the developing of embryo,nucellus tissue of micropylar end degradated.According to the flower morphological character of flowering phenology at different growing stage,it is possible to estimate primarily the process of megasporogenesis and development of female gametophyte of P.pruinosa.

关 键 词：灰叶胡杨 大孢子发生 雌配子体 

分 类 号：Q944.58[生物学—植物学]