慈姑属4种同域分布植物的人工种间杂交

Artificial interspecific hybridization of four sympatric species in Sagittaria

泽泻科(Alismataceae)是现存最原始的单子叶植物类群之一,慈姑属(Sagittaria)是泽泻科相对进化的分类群,地域分布广泛,其物种大多集中分布于北温带,且有种间同域分布现象。为了探究同域分布物种之间的杂交可能性,我们通过选取同域分布且在系统进化树上具有代表性的冠果草(S.guayanensis subsp.lappula)、小慈姑(S.potamogetonifolia)、利川慈姑(S.lichuanensis)和野慈姑(S.trifolia)为研究对象,调研中国数字植物标本馆(CVH)的标本信息和已有文献,分析这4种慈姑的地理分布格局,并分别以这4种慈姑为母本进行人工授粉实验以检验种间杂交的可能性。基于对1172份4种慈姑属腊叶标本的分析,表明这4种慈姑在福建省武夷山地区存在同域分布情况。通过对4种慈姑之间的人工授粉实验结果分析表明,冠果草、小慈姑、利川慈姑和野慈姑异种授粉后均出现心皮膨大现象,所有异种授粉产生的种子均不可育,败育胚种子比例各不相同,且该比例与父本和母本在系统进化树上的位置有关。

Alismataceae is one of the most primitive groups of monocots in existence.Sagittaria is a relatively evolved taxan of Alismaaceae.It has a wide geographical distribution.Most of its species are concentrated in the northern temperate zone,and there is a sympatric distribution among species in the genus Sagittaria.In order to explore the possibility of hybridization between sympatric species,we selected the representative species of S.guayanensis subsp.lappula,S.potamogetonifolia,S.lichuanensis and S.trifolia from the phylogenetic tree of the genus as our research targets.Through investigating the specimen information of the China Virtual Herbarium(CVH)and existing literature,the geographical distribution pattern of these 4 species of Sagittaria were analyzed,and these 4 species of Sagittaria were used as female parents for artificial pollination to test the possibility of interspecies hybridization.Based on the analysis of 1172 dehydrated specimens of 4 species in Sagittaria,it is shown that these 4 species of Sagittaria have the same geographical distribution at Wuyishan area of Fujian Province.The results of the artificial pollination experiments among the 4 species of Sagittaria show that the carpels of S.guayanensis subsp.lappula,S.potamogetonifolia,S.lichuanensis and S.trifolia expand after heterogeneous pollination and all seeds produced by heterogeneous pollination are infertile.In addition,the proportion of aborted embryos varies,and the proportion is related to the position of the male parent and the female parent on the phylogenetic tree.