Breeding system and its consequence on fruit set of a rare sand dune shrub Eremosparton songoricum(Fabaceae:Papilionoideae):implications for conservation  

作　　者：DaoYuan ZHANG Xiang SHI JianCheng WANG HuiLiang LIU John F GASKIN 

机构地区：[1]Key Laboratory of Biogeography and Bioresources in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China [2]Turpan Eremophytes Botanical Garden, Chinese Academy of Sciences, Turpan 838008, China [3]Forestry College, College of Agriculture in Shihezi University, Shihezi 832011, China [4]USDA Agricultural Research Service, Sidney, Montana 59270, USA

出　　处：《Journal of Arid Land》2011年第4期231-239,共9页干旱区科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (30970547,31070472);the National Basic Research Program of China (2009CB825104)

摘　　要：The breeding system and its consequence on fruit set of Eremosparton songoricum（Litv.） Vass.,a rare shrubby legume occurring in moving or semi-fixed sand dunes of Central Asian deserts,were examined by manipulative experiments and observational studies in natural populations during the period of 2007-2009.The results showed that E.songoricum exhibits a mixed mating system.It is self-compatible,but depends strictly on pollinators to set fruits.Only two effective pollinators were detected and they triggered the specialized pollination mechanism（a ＇brush type＇ and ＇tripping mechanism＇）.Geitonogamy becomes predominant in natural populations,because（74.5±1.3）% of visiting activity happened within or between inflorescences and（24.3±1.4）% occurred between ramets.As a result,inbreeding depression caused by geitonogamous selfing inevitably happened under natural conditions,showing 2.36 times less fruit set than was achieved by hand cross-pollination.The results explained the rarity of the species due to its breeding system,and will assist to develop suitable conservation strategies in severe desert environments.The breeding system and its consequence on fruit set of Eremosparton songoricum（Litv.） Vass.,a rare shrubby legume occurring in moving or semi-fixed sand dunes of Central Asian deserts,were examined by manipulative experiments and observational studies in natural populations during the period of 2007-2009.The results showed that E.songoricum exhibits a mixed mating system.It is self-compatible,but depends strictly on pollinators to set fruits.Only two effective pollinators were detected and they triggered the specialized pollination mechanism（a ＇brush type＇ and ＇tripping mechanism＇）.Geitonogamy becomes predominant in natural populations,because（74.5±1.3）% of visiting activity happened within or between inflorescences and（24.3±1.4）% occurred between ramets.As a result,inbreeding depression caused by geitonogamous selfing inevitably happened under natural conditions,showing 2.36 times less fruit set than was achieved by hand cross-pollination.The results explained the rarity of the species due to its breeding system,and will assist to develop suitable conservation strategies in severe desert environments.

关 键 词：GEITONOGAMY inbreeding depression inland sand dunes SELF-FERTILIZATION pollen brush tripping mechanism 

分 类 号：S812.2[农业科学—草业科学] TM561[农业科学—畜牧学]