Hybrid plants preserve unique genetic variation in the St Helena endemic trees Commidendrum rotundifolium DC Roxb. and C. spurium (G.Forst.) DC

详细信息    查看全文

• 作者：Alan Gray ; Annika Perry ; Stephen Cavers ; Antonia Eastwood…
• 关键词：Allelic variation ; Genetic conservation ; Rarity ; Breeding programme ; Endemic plants
• 刊名：Conservation Genetics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：18
• 期：1
• 页码：241-246
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Conservation Biology/Ecology; Ecology; Biodiversity; Evolutionary Biology; Plant Genetics & Genomics; Animal Genetics and Genomics;
• 出版者：Springer Netherlands
• ISSN：1572-9737
• 卷排序：18

文摘

The island of St Helena in the South Atlantic Ocean has a rich endemic flora, with 10 endemic genera and 45 recognised endemic species. However, populations of most endemic species have undergone dramatic reductions or extinction due to over-exploitation, habitat destruction and competition from invasive species. Consequently, endemic species are likely to have lost genetic variation, in some cases to extreme degrees. Here, the entire extant wild populations and all planted trees in seed orchards, of two critically endangered species in the endemic genus Commidendrum (Asteraceae), C. rotundifolium and C. spurium, were sampled to assess levels of genetic variation and inbreeding. Six new microsatellite loci were developed from next-generation sequence data, and a total of 190 samples were genotyped. Some seed orchard trees contained alleles from both wild C. rotundifolium and C. spurium indicating they could be hybrids and that some backcrossing may have occurred. Some of these trees were more similar to C. rotundifolium than C. spurium both genetically and morphologically. Importantly, allelic variation was detected in the putative hybrids that was not present in wild material. C. rotundifolium is represented by just two individuals one wild and one planted and C. spurium by seven, therefore the seed orchard trees comprise an important part of the total remaining genetic diversity in the genus Commidendrum.