Eremosparton songoricum (Litv.) Vass. is a clonal shrub that reproduces both asexually by under-ground rhizomes and sexually by seeds. It is now a rare species with a narrow distribution in fragmented habitat patches ...Eremosparton songoricum (Litv.) Vass. is a clonal shrub that reproduces both asexually by under-ground rhizomes and sexually by seeds. It is now a rare species with a narrow distribution in fragmented habitat patches in the Gurbantunggut Desert of Xinjiang, China. The objective of this study was to determine the spatial pattern or structure of genetic variation within population. The within-populations genetic structure of E. songoricum in a plot (10 m×10 m) was analyzed using inter simple sequence repeats (ISSR) markers. Correlograms of Moran's I showed significant positive value was about 7 m, but changed into a negative correlation with the increase of distance, indicating strong genetic structure. The natural character of clonal reproduction, restricted seed and pollen dispersal were the main factors of influencing the spatial pattern. The knowledge of clonal structures within populations was crucial for understanding evolutionary processes and ecological adaptation. This study provided basic data for the conservation and management of E. songoricum, especially for sampling strategies for ex situ conservation.展开更多
Eremosparton songoricum(Litv.) Vass is a dwarf clonal shrubby legume developed on the windward slopes of mobile or semi-fixed sand dunes of Central Asia. It is assumed that E. songoricum must possess a high degree of ...Eremosparton songoricum(Litv.) Vass is a dwarf clonal shrubby legume developed on the windward slopes of mobile or semi-fixed sand dunes of Central Asia. It is assumed that E. songoricum must possess a high degree of phenotypic plasticity for such a heterogeneous habitat. The variations of E. songoricum plants growing in two typical microhabitats(the upper slope and the lower slope of semi-mobile dune) were investigated. The morphological characteristics and the biomass allocation patterns were measured and compared at the clonal fragment level. Compared with the clonal fragment on the lower slope of dune,the clonal fragment on the upper slope of the dune(a) declined in total biomass and ramet height,(b) increased the length of rhizomes and the number of roots,(c) increased the degree of asym-metry,and(d) heightened allocation to the belowground biomass. Our results confirmed the hypothesis of high phenotypic adjustment capacity of E. songoricum to habitat moisture availability. Phenotypic plasticity of E. songoricum contributed to reduce the damage risk,led to an environmentally induced specialization in function of resources exploitation,resulted in its persistence in heterogeneous environments and was adaptive in sand dune environment.展开更多
基金supported by National Science Foundation program (30970547)Grant Project of Xinjiang Committee of Science and Technology (No.200933122)
文摘Eremosparton songoricum (Litv.) Vass. is a clonal shrub that reproduces both asexually by under-ground rhizomes and sexually by seeds. It is now a rare species with a narrow distribution in fragmented habitat patches in the Gurbantunggut Desert of Xinjiang, China. The objective of this study was to determine the spatial pattern or structure of genetic variation within population. The within-populations genetic structure of E. songoricum in a plot (10 m×10 m) was analyzed using inter simple sequence repeats (ISSR) markers. Correlograms of Moran's I showed significant positive value was about 7 m, but changed into a negative correlation with the increase of distance, indicating strong genetic structure. The natural character of clonal reproduction, restricted seed and pollen dispersal were the main factors of influencing the spatial pattern. The knowledge of clonal structures within populations was crucial for understanding evolutionary processes and ecological adaptation. This study provided basic data for the conservation and management of E. songoricum, especially for sampling strategies for ex situ conservation.
基金supported by the Key Knowledge Innovation Project of Chinese Academy of Sciences (KSCX2-YW-Z- 1020)the National Basic Research Program of China (2009CB825104)the National Natural Science Foundation of China (30970547)
文摘Eremosparton songoricum(Litv.) Vass is a dwarf clonal shrubby legume developed on the windward slopes of mobile or semi-fixed sand dunes of Central Asia. It is assumed that E. songoricum must possess a high degree of phenotypic plasticity for such a heterogeneous habitat. The variations of E. songoricum plants growing in two typical microhabitats(the upper slope and the lower slope of semi-mobile dune) were investigated. The morphological characteristics and the biomass allocation patterns were measured and compared at the clonal fragment level. Compared with the clonal fragment on the lower slope of dune,the clonal fragment on the upper slope of the dune(a) declined in total biomass and ramet height,(b) increased the length of rhizomes and the number of roots,(c) increased the degree of asym-metry,and(d) heightened allocation to the belowground biomass. Our results confirmed the hypothesis of high phenotypic adjustment capacity of E. songoricum to habitat moisture availability. Phenotypic plasticity of E. songoricum contributed to reduce the damage risk,led to an environmentally induced specialization in function of resources exploitation,resulted in its persistence in heterogeneous environments and was adaptive in sand dune environment.
