甜荞长花柱长雄蕊突变体lpls大小孢子发生和雌雄配子体的发育  

Megasporogenesis and Microsporogenesis and Development of Female and Male Gametophytes in Mutants lpls with Long Pistil and Long Stamen from Fagopyrum esculentum Moench

作　　者：王旋 刘志雄[1] WANG Xuan;LIU Zhi-Xiong(College of Horticulture and Gardening,Yangtze University,Jingzhou 434025)

机构地区：[1]长江大学园艺园林学院,荆州434025

出　　处：《植物研究》2021年第6期921-927,共7页Bulletin of Botanical Research

基　　金：国家自然科学基金(31771867;31571736)。

摘　　要：采用石蜡切片技术对甜荞长花柱长雄蕊突变体lpls大、小孢子的发生和雌、雄配子体发育进行观察,结果显示:甜荞花药4室,花药囊壁由4层细胞构成,小孢子四分体为四面体型,少数四分体中的小孢子具有2个核,成熟花粉多为2细胞型,少数为3细胞型;直立胚珠、双珠被、厚珠心,大孢子四分体直线型,合点端为功能大孢子、雌配子体发育方式为蓼型。雄蕊原基比雌蕊原基起源早,雄蕊花药前期发育相对较快,后期相对较慢,主茎第4片真叶开始发育时,小孢子四分体开始解体形成单核或二核小孢子,主茎上第7片真叶开始发育时,小孢子发育成熟;雌蕊胚囊前期发育慢,后期相对较快,小孢子四分体形成时,胚珠中出现大孢子母细胞;当雄蕊花药中2细胞型花粉形成时,雌蕊胚囊中形成功能大孢子;随着主茎上第7片真叶的发育,雄蕊花药中花粉壁加厚和发育成熟,少数2细胞型花粉粒中的生殖核进一步分裂1次形成3细胞型花粉,功能大孢子迅速经过3次有丝分裂形成8核7细胞胚囊。The Mega-and Micro-sporogenesis and development of female and male gametophytes in mutant Buckwheat with long pistil and long stamen were investigated by the paraffin section.The results showed that anthers were tetradymous and the anther wall was composed of four layers of cells.The meiosis of microspore mother cells was followed by simultaneous cytokinesis and resulted in tetrahedral tetrads.A few microspores with two nuclei were observed in tetrahedral tetrads.Most of mature pollen grains were 2-cell type,while a few 3-cell mature pollen grains were also observed in anther sac.Orthotropous and bi-integument ovule,as well as thick nucellus was found in embryo sac.The megaspore mother cells underwent meiosis and were divided into liner type tetrads,and the megaspore in the chalazal end was functional one.The embryo sac was Polygonum type.The stamen primordia emerged before the appearance of gynoecium primordia.Single or tow-nucellus microspores were released from tetrahedral tetrads when the forth leaf arose from the main stem,and the mature pollen grains were observed when the seventh leaf arose from the main stem.Megaspore mother cells emerged when the tetrahedral tetrads formed,while the functional megaspore appeared until 2-cell pollen grains formed.2-cell and 3-cell mature pollens coexisted after development of the seventh leaf on the main stem,while the mature embryo sac with 8 nucellus and 7 cells resulted from continuous mitosis of the functional megaspore.

关 键 词：甜荞 长花柱长雄蕊突变体 大、小孢子发生 雌、雄配子体发育 

分 类 号：S517[农业科学—作物学]