Molecular markers reveal low genetic diversity in Casuarina equisetifolia clonal plantations in South China
- PDF / 961,826 Bytes
- 15 Pages / 439.37 x 666.142 pts Page_size
- 77 Downloads / 177 Views
Molecular markers reveal low genetic diversity in Casuarina equisetifolia clonal plantations in South China Wei Yu1 · Yong Zhang1 · Xiuyu Xu2 · Chonglu Zhong1 · Yongcheng Wei1 · Jingxiang Meng1 · Yu Chen1 · Zhen Li1 · David Bush3 Received: 12 February 2019 / Accepted: 21 September 2019 © Springer Nature B.V. 2019
Abstract Casuarina equisetifolia is planted extensively in clonally-established coastal shelterbelts in South China. During the last decade, the plantations have been severely attacked by Ralstonia solanacearum bacterial wilt, causing widespread decline and mortality. It has been thought that lack of genetic diversity, both within individual sites and at a regional scale, may render the plantations particularly susceptible to attack. Analysis of samples from 109 separate plantations in three provinces, Hainan, Guangdong and Fujian, using microsatellite molecular markers, revealed that only 22 separate clones are in use. Analysis of coancestry among the clones further revealed that many are closely related, consistent with selection of new clones from the sexually-reproduced offspring of existing ones, or selection of multiple clones from individual seedling families. Comparison with wild materials from throughout the species’ natural range indicated that the origins of the South China clones are most likely from within the Southeast Asian region. We recommend diversifying the genetic base of planting material in South China and planting a more-diverse mix of unrelated clones at local and regional scales. Keywords Casuarina equisetifolia · Microsatellite · Coastal shelterbelt · Genetic relatedness
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s1105 6-019-09752-7) contains supplementary material, which is available to authorized users. * Yong Zhang [email protected] * Chonglu Zhong [email protected] * David Bush [email protected] 1
Research Institute of Tropical Forestry, Chinese Academy of Forestry, Longdong 510520, Guangzhou, People’s Republic of China
2
Guangdong Academy of Forestry, Longdong 510520, Guangzhou, People’s Republic of China
3
CSIRO Australian Tree Seed Centre, GPO Box 1600, Canberra, ACT 2601, Australia
13
Vol.:(0123456789)
New Forests
Introduction The family Casuarinaceae comprises four genera and 96 species occurring naturally from Australia to the Pacific islands and in Southeast Asia (Turnbull 1990). Casuarina are nitrogen-fixing trees of considerable importance in many tropical and subtropical regions of the world. Over two million hectares of Casuarina plantation, most of them Casuarina equisetifolia subp. equisetifolia (hereafter referred to as C. equisetifolia), have been planted for wood production, coastal shelterbelts, land rehabilitation and for ornamental purposes around the world (Zhong et al. 2011). Research on genetic diversity, reproductive biology and breeding system, and genetic improvement of C. equisetifolia have been carried out in many countries (Nagarajan et al. 2006; Huang et al. 2009;
Data Loading...
