同域分布的两种荒漠春季十字花科草本植物的花部特征与花气味差异性比较  

Comparison of the floral trait and scent from two sympatric desert spring flowering Brassicaceae herbs

作　　者：刘丹 祝洪波 石靖宇 马菡泽 陈亚丽[2] 黄代红 LIU Dan;ZHU Hongbo;SHI Jingyu;MA Hanze;CHEN Yali;HUANG Daihong(College of Life Science,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China)

机构地区：[1]新疆农业大学生命科学学院,新疆乌鲁木齐830052 [2]中国科学院新疆生态与地理研究所,新疆乌鲁木齐830011

出　　处：《草业科学》2023年第5期1315-1325,共11页Pratacultural Science

基　　金：国家自然科学基金(31760139);新疆维吾尔自治区自然科学基金面上项目(2022D01A195);贵州省林业局科技项目(黔林科合[2020]09)。

摘　　要：卡拉麦里山自然保护区是我国著名的荒漠有蹄类野生动物自然保护区,春季开花植物是该保护区荒漠植被的重要组成部分,也是食草野生动物赖以生存的优良牧草。西伯利亚离子芥(Chorispora sibirica)和扭果花旗杆(Dontostemon elegans)是广泛同域分布在该区域砾质荒漠上的两种十字花科春季开花草本植物。为了比较这两种草本植物的花部特征与花气味的差异性,对两物种的花部性状进行野外观测和测量,同时收集并分析其花气味挥发物的组成。结果表明:(1)两种草本植物的花均具有典型的虫媒花特征,如较大的花冠直径、鲜艳的颜色和芳香的气味,并且两物种的主要花部性状存在着显著的差异,尤其表现在花冠的颜色、直径、花瓣宽以及雌雄蕊长上。(2)两种草本植物的花气味中共分离出41种挥发物,主要以萜类化合物为主,其中西伯利亚离子芥花气味的主要成分为顺-β-罗勒烯,而扭果花旗杆的花气味中α-蒎烯和苯乙醛的含量最高。主成分分析表明两物种花气味的化学组成表现出明显的种间差异性。同域分布中的两种荒漠草本植物具有相似的花部特征和花气味,可吸引共享传粉者,促进两物种进行异交,从而增加开花植物的后代适合度;推测共享传粉者可以利用两草本植物之间的这种差异性来区分出各物种,进而分别为其传粉,从而可以保障两草本植物的种间生殖隔离,维持了该区域内的物种多样性,也对该区域野生动物的保育具有重要意义。Mt.Kalamaili Nature Reserve is a famous nature reserve of desert ungulates in China.Desert spring flowering plants are an important part of the desert vegetation in this reserve and an excellent source of forage for herbivorous wild animals.Chorispora sibirica and Dontostemon elegans are the two kinds of Brassicaceae desert spring-flowering herbs that are widely sympatrically distributed on the gravelly desert in this region.To compare the differences in the floral characteristics and scent between the two desert herbs,we observed and measured the floral characteristics of the two species in the field and collected and analyzed the composition of their volatile floral scent.The results showed that:(1)both desert herbs showed typical entomophilous flower traits,such as a larger corolla diameter,bright colors,and a strong floral fragrance.The two herbs exhibited significant differences in the main floral characteristics,especially in their corolla color and diameter,petal width,and stamen length.(2)A total of 41 volatiles were isolated and identified from the floral scents of the two desert herbs,mainly terpenoids.Among them,(Z)-β-Ocimene was the main component of the floral scent of C.sibirica,while the highest amounts ofα-pinene and phenylacetaldehyde were detected in the floral scent of D.elegans.The principal component analysis indicated that there is obvious interspecific variation in the chemical composition of the floral scents among the two desert herbs.The two sympatric desert herbs can attract their pollinators through obvious floral characteristics and scents in spring,to promote their own outcrossing,which may increase the offspring’s fitness.Shared pollinators may use this difference between the two species to distinguish between them and then separately pollinate each species to ensure the interspecific reproductive isolation between the two species,maintaining the species diversity in this region;this would be significant for the conservation of wild animals in this region.

关 键 词：卡拉麦里山自然保护区 同域分布 砾质荒漠 西伯利亚离子芥 扭果花旗杆 花部特征 花气味 

分 类 号：Q948[生物学—植物学]