Biodiv Sci ›› 2010, Vol. 18 ›› Issue (2): 129-136.  DOI: 10.3724/SP.J.1003.2010.134

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Spatial genetic structure in five natural populations of Eremosparton songoricum as revealed by ISSR analysis

Liu Yan1,2, Zhang Daoyuan1,*()   

  1. 1Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011
    2Graduate University of the Chinese Academy of Sciences, Beijing 100049
  • Received:2009-07-07 Accepted:2009-11-16 Online:2010-03-20 Published:2010-03-20
  • Contact: Zhang Daoyuan

Abstract:

Spatial autocorrelation analyses have highlighted the importance of clonal growth in shaping the spatial genetic structure in Eremosparton songoricum, a woody rhizomatic clonal shrub distributed in drift sand dunes of the Gurbantunggut Desert of China. Spatial patterns of genetic variation in five populations of E. songoricum found in different community types and habitats were investigated using Inter Simple Sequence Repeat (ISSR) markers. Using GeneAlEx Genetic Analysis Software and the computer program of SAAP 4.3 and the polymorphic bands generated from eight ISSR primers, we calculated an autocorrelation coefficient with a frequency between 0.3 and 0.7. Equal geographic distance was considered when estimating spatial genetic distribution patterns. In this paper, populations B (located in hinterland desert), D (located in hinterland desert) and F (located in east of desert) occurred as a cline pattern, in which individual plants within distances of 7 m, 7 m and 9 m had significant positive correlation, respectively. Our results suggested that the natural properties of clonal reproduction were the main factors influencing the spatial distribution patterns of these three populations. Population G (located in north of desert) occurred as double cline pattern, in which individual plants within 3 m had significant positive correlation, respectively. Seed recruitment was successful in population G, while restricted seed and pollen dispersal, and intervention of human activities were main factors influencing the spatial genetic structure. Population A (located in hinterland desert) exhibited depression pattern. The small size of population A would increase the likelihood of self-fertilization (inbreeding) by pollination among ramets of the same genets, and would induce random genetic drift. Knowledge of spatial genetic structures within populations is crucial for understanding evolutionary processes and ecological adaptations, and provides a baseline for the conservation and management of E. songoricum, especially for ex situ conservation sampling strategies.

Key words: Eremosparton songoricum, spatial autocorrelation, spatial genetic structure, conservation genetics, Moran’sI index