外来入侵植物胜红蓟的胚胎学观察及繁殖系统研究  

Embryological observation and reproductive system of invasive alien plant Ageratum conyzoides L.

作　　者：张玉环 郝建华[2] 吴海荣 陈学林[1] Zhang Yu-Huan;Hao Jian-Hua;Wu Hai-Rong;Chen Xue-Lin(Northwest Normal University,Lanzhou 730070,China;Changshu Institute of Technology,Changshu,Jiangsu 215500,China;Guangzhou Customs Technology Center,Guangzhou 510623,China)

机构地区：[1]西北师范大学,兰州730070 [2]常熟理工学院,江苏常熟215500 [3]广州海关技术中心,广州510623

出　　处：《植物科学学报》2020年第2期162-172,共11页Plant Science Journal

基　　金：国家自然科学基金(31370548);江苏省自然科学基金(BK20131192);中国出入境检验检疫局科技计划(JSCIQ_2014IK013)。

摘　　要：以采自我国广东江门和广州两个种群的胜红蓟(Ageratum conyzoides L.)种子为材料,采用流式细胞种子筛选技术(FCSS)和人工控制授粉实验,对胜红蓟的繁殖系统进行研究,并结合整体透明技术和微分干涉差(DIC)显微镜观察法,对其胚珠发育过程和花药结构进行细胞胚胎学观察。种子筛选结果显示,胜红蓟的种子既可以通过有性生殖产生,又可以通过不需要假受精的无融合生殖产生,属于兼性无融合生殖类型。开放性授粉和套袋处理之间的结实率均较高,分别为88%±1.2%和86.2%±1.2%,两者之间无显著差异;而去雄处理的结实率和开放性授粉、套袋这两种处理之间差异显著。胚珠的细胞胚胎学观察结果发现,胜红蓟的有性生殖胚囊发育方式为蓼型,无融合生殖胚囊的发育方式为山柳菊型。胜红蓟的花粉粒在花药内就开始萌发出花粉管,具有闭花受精特性。研究结果表明闭花受精和兼性无融合生殖等繁殖特性保证了胜红蓟在各种生存环境下的结实量,提高其在新生境中归化和入侵的可能性。Alien plant invasions are a serious threat to agricultural production and economic development.Understanding the reproductive characteristics of invasive alien plants can provide a theoretical basis for effective prevention and control.Ageratum conyzoides L.,an alien Asteraceae species,has invaded 23 provinces and administrative regions in China,where it has greatly impacted local agriculture and the economy.Here,flow cytometric seed screening(FCSS)and controlled pollination experiments were used to study the reproductive system of A.conyzoides.Cytoembryological development of the ovule and anther was observed by differential interference contrast(DIC)microscopy after the application of whole clearing technology.The FCSS results showed that the seeds were produced by both sexual reproduction and apomixis,i.e.,facultative apomixis.There were no significant differences in seed sets between open pollination and bagging treatment,but significant differences were found among seed sets under emasculation and the other two treatments,with relatively high seed sets under open-pollination 88%±1.2%and bagging treatments 86.2%±1.2%.Thus,A.conyzoides showed a high degree of self-compatibility.Embryo sac development under sexual reproduction was Polygonum-type,whereas the apomixis embryo sac was Hieracium-type,which was initiated by one or two nucellar cells at the chalazal end and development into an eight-nucleate embryo sac without meiosis.Embryo and endosperm were developed autonomously and without pseudogamy.Polyembryos were observed in some ovules.A.conyzoides showed precocious embryo formation,which began before flowering.Pollen germinated within the anther and cleistogamy occurred.Therefore,the reproductive traits of cleistogamy and facultative apomixis ensure A.conyzoides fecundity in different environments and increase the opportunity of naturalization and invasion in new habitats,which is closely related to its strong invasiveness.

关 键 词：胜红蓟 外来入侵植物 流式细胞种子筛选 细胞胚胎学发育 繁殖系统 

分 类 号：Q944.57[生物学—植物学]