穿龙薯蓣大小孢子发生与雌雄配子发育  

Sporogenesis and Gametogenesis in Discorea nipponica

作　　者：张雨晴 高润梅[1] 李聪 李进 党裳霓 李红月 ZHANG Yuqing;GAO Runmei;LI Cong;LI Jin;DANG Shangni;LI Hongyue(College of Forestry,Shanxi Agricultural University,Taigu,Shanxi 030800,China)

机构地区：[1]山西农业大学林学院,山西太谷030800

出　　处：《江西农业大学学报》2022年第2期319-328,共10页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家自然科学基金项目(31400536);山西省林业科技创新资助项目;林业重点研发计划专项(LYCX201961);山西省基础研究计划项目(20210302123391)。

摘　　要：【目的】为探讨薯蓣属植物亲缘关系及薯蓣科植物系统地位,丰富药用植物穿龙薯蓣(Discorea nipponica)的生殖特征研究,并为后续栽培育种等工作提供基础资料。【方法】利用快速石蜡制片技术分别对穿龙薯蓣雌雄花进行制片,对其大小孢子发生及雌雄配子体发育过程进行系统地显微观察。【结果】穿龙薯蓣为单性花、雌雄异株。雄蕊6,花药4室;小孢子胞质分裂为同时型;小孢子四分体主要为四面体形,兼有左右对称形和交叉(十字)形;成熟花粉为2-细胞型花粉。花药壁由外到内依次为表皮、药室内壁、中层和绒毡层;中层细胞自小孢子母细胞时期逐渐分解扁平,绒毡层细胞在小孢子四分体时期开始解体;花粉囊开裂时中层、绒毡层消失,药室内壁纤维状增厚,表皮仅有干枯的残迹;花药壁发育类型为单子叶型,绒毡层发育类型为腺质型。雌花子房下位,3室,中轴胎座,每室生2枚倒生胚珠;胚珠具双珠被,厚珠心;大孢子母细胞由造孢细胞发育而来;大孢子四分体线性排列,珠孔端3个退化,仅合点端一个发育;成熟胚囊为7胞8核,中央细胞的形成早于卵器和反足细胞的细胞化;胚囊发育类型为单孢子蓼型,成熟雌配子体中助细胞体积小于卵细胞;反足细胞形成后不再进行分裂,在胚囊成熟时期逐渐退化。【结论】穿龙薯蓣部分生殖生物学特征较为原始,倾向于双子叶植物;穿龙薯蓣助细胞体积较小可能与胚珠发育异常有关。[Objective]This study aims to discuss the genetic relationship of Dioscorea and the phylogenetic status of Dioscoreaceae,thus enriching the research into the reproductive characteristics of the medicinal plant Dioscorea nipponica and collecting information for the subsequent cultivation and breeding of the plant.[Method]This study adopted rapid paraffin section technique to examine the microsporogenesis,microgametogenesis,megasporogenesis and macrogametogenesis of the plant.[Result]Dioscorea nipponicawas unisexual and dioecious.The male flower had 6 anthers,and each anther had 4 pollen-embryo sacs.Meiosis of the microspore mother cells was of simultaneous type.Microspore tetrads were mainly tetrahedral,with both left-right symmetry and cross shape.The mature pollen grains were two-celled.The anther wall from outside to inside were epidermis endothecium,middle layer and tapetum.The middle layer began to disintegrate and became flattened at the microspore mother cell stage.At the microspore tetrad stage,the tapetum began to disintegrate.When the pollen sacs cracked,the middle layer and tapetum completely disappeared,the endothecium became fibrotic,and the epidermis disappeared except dry remnants.The anther wall development followed the monocotyledonous type,the tapetum was of glandular type.The femal ovary was hypogynous,and axial placentation.There were 3 loculus with 2 anatropous ovules in each.The ovule was bitegmic and crassinucellate.The megaspore mother cells were developed from sporogenous cells.Macrospore tetrads were linearly arranged,three of them were degenerated at micropylar end,only one chalazal megaspore became the functional megaspore.The mature embryo sacs were 7-celled and 8-nucleated,The formation of central cells preceded the cellularization of eggs and antipodal cells.The female gametophyte was of the Polygonum type,the synergid in the mature embryo sacs were smaller than egg cells.After the formation of antipodia cells,they ceased to divide and degenerated gradually during embryo sacs maturat

关 键 词：穿龙薯蓣 薯蓣属 大孢子发生 小孢子发生 雄配子体 雌配子体 

分 类 号：Q944.58[生物学—植物学] S567.239[农业科学—中草药栽培]