Of the genus Craigia,widespread in the Tertiary,only two relict species survived to modern times.One species is now possibly extinct and the other one,Craigia yunnanensis,is severely endangered.Extensive surveys have ...Of the genus Craigia,widespread in the Tertiary,only two relict species survived to modern times.One species is now possibly extinct and the other one,Craigia yunnanensis,is severely endangered.Extensive surveys have located six C.yunnanensis populations in Yunnan province,southwest China.Using fluorescent amplified fragment length polymorphism(AFLP),the genetic diversity and population structure of these populations were examined.It was found that genetic diversity of C.yunnanensis was moderate at the species level,but low at regional and population levels.Analysis of population structure showed significant genetic differentiation between Wenshan and Dehong regions,apparently representing two geographically isolated for long time refuges.There are also clear indications of isolation between populations,which,together with anthropogenically caused decline of population size,will lead to general loss of the species genetic variation with subsequent loss of adaptive potential.To conserve the genetic integrity of C.yunnanensis,we recommend that ex-situ conservation should include representative samples from every population of the two differentiated regions(e.g.Wenshan and Dehong).The crosses between individuals originated from different regions should be avoided because of a high risk of outbreeding depression.As all the extant populations of C.yunnanensis are in unprotected areas with strong anthropogenic impact,there is no alternative to reintroduction of C.yunnanensis into suitable protected locations.展开更多
基金funded by the National Science Foundation of China (NSFCU1302262)the Department of Forestry of Yunnan Province, project name "Rescue and conservation of PSESP species Craigia yunnanensis"supported by the Science and Technology Research Program of Kunming Institute of Botany, the Chinese Academy of Sciences (KIB2016005)
文摘Of the genus Craigia,widespread in the Tertiary,only two relict species survived to modern times.One species is now possibly extinct and the other one,Craigia yunnanensis,is severely endangered.Extensive surveys have located six C.yunnanensis populations in Yunnan province,southwest China.Using fluorescent amplified fragment length polymorphism(AFLP),the genetic diversity and population structure of these populations were examined.It was found that genetic diversity of C.yunnanensis was moderate at the species level,but low at regional and population levels.Analysis of population structure showed significant genetic differentiation between Wenshan and Dehong regions,apparently representing two geographically isolated for long time refuges.There are also clear indications of isolation between populations,which,together with anthropogenically caused decline of population size,will lead to general loss of the species genetic variation with subsequent loss of adaptive potential.To conserve the genetic integrity of C.yunnanensis,we recommend that ex-situ conservation should include representative samples from every population of the two differentiated regions(e.g.Wenshan and Dehong).The crosses between individuals originated from different regions should be avoided because of a high risk of outbreeding depression.As all the extant populations of C.yunnanensis are in unprotected areas with strong anthropogenic impact,there is no alternative to reintroduction of C.yunnanensis into suitable protected locations.
