文献类型：期刊文献

英文题名：Analyses of genetic diversity, differentiation and geographic origin of natural provenances and land races of casuarina equisetifolia based on EST-SSR markers

作者：Zhang, Yong[1] Hu, Pan[2] Zhong, Chonglu[1] Wei, Yongcheng[1] Meng, Jingxiang[1] Li, Zhen[1] Pinyopusarerk, Khongsak[3] Bush, David[3]

第一作者：张勇

通信作者：Zhong, Chonglu|[a0005737689b43f937cf1]仲崇禄;

机构：[1] Research Institute of Tropical Forestry, Chinese Academy of Forestry, Longdong, Guangzhou, 510520, China; [2] Experimental Centre of Forestry in North China, Chinese Academy of Forestry, Beijing, 102300, China; [3] CSIRO Australian Tree Seed Centre, GPO Box 1600, Canberra, ACT, 2601, Australia

年份：2020

卷号：11

期号：4

外文期刊名：Forests

收录：EI(收录号：20202008671669);Scopus(收录号：2-s2.0-85084669526)

语种：英文

外文关键词：Biomarkers - Genes - DNA sequences - Forestry

摘要：Research Highlights: High variation of genetic diversity and differentiation among 27 seed sources within 14 natural provenances and 13 land race samples of Casuarina equisetifolia were found. High proportions of monoecious individuals may be present in some populations, as indicated by severe heterozytote deficiency and inbreeding found in many provenances and land races. The most probable origins of the land races were inferred according to the values of pairwise provenance differentiation and Nei's genetic distances. Targeted introductions and testing of unrelated new accessions of C. equisetifolia fromthe Pacific and Philippines was proposed to identify Ralstonia-resistant genotypes. Background and Objectives: Casuarina equisetifolia was introduced to China a hundred years ago and has become a critically important tree species in coastal protection since the 1950s. Despite its importance, patterns of genetic variation, genetic relationships among natural provenances and probable origins of the land races remain unresolved. This has become a concern in China where Ralstonia solanacearum bacterial wilt has devastated plantations that are known to be from a narrow genetic base that urgently needs to be broadened. Materials and Methods: Fourteen natural provenances from Australia, Pacific islands and Southeast Asia, and 13 land race samples from parts of Asia and Africa outside the natural range were genotyped using 13 SSR (Simple Sequence Repeats) markers to characterize their allelic variation and genetic relationship. Results: Significant genetic diversity and differentiation among 27 seed sources within 14 provenances and 13 land race samples of C. equisetifolia was indicated. Significant heterozygote deficiency and inbreeding was indicated for a number of provenances, perhaps indicating a high proportion of monoecious parents in these populations. The most probable origins of the land races of the introduced countries were suggested according to the values of pairwise provenance differentiation (FST) and Nei's genetic distances. Conclusions: We found significant genetic diversity and genetic differentiation among seed sources of C. equisetifolia. While individual land races do not appear to lack diversity, we were able to infer the origins of some, allowing targeted introductions of unrelated material to be made. In the case of the Chinese land race, targeting and testing new accessions from the Pacific and the Philippines may be a good strategy to identify Ralstonia-resistant genotypes. ? 2020 by the authors.