Karyotype Analysis of Four Species in Caragana Fabr.

Peashrub is popular name of Caragana Fabr.and up to now there are about 67 species of Peashrub were recorded in China,which are mainly distributed in arid and semiarid areas of North China.All species of peashrub developed typical biological features,which are highly drought-tolerant and good shrubs for dune-fixation,animal feeding,and biological resources for fuel energy and fiber material.They are valuable plants in eco-environment construction of North China.It is very important to analyze the karyotypes of Caragana Fabr.and reveal their genetic diversities for further protecting their idioplasmatic resources and utilizing for human.The Karyotypes of four species in Caragana were analyzed in this paper.Present results indicated that four species had different chromosome number and karyotypes.The number of chromosome was 16,16,18 and 20 in C.purdomi Rehd.,C.microphylla Lam.,C.intermedia Kuang et H.C.Fu and C.arborescens Lam.;While their karyotypes were 2n=16=16 m(4 SAT),2n=16=14 m(2 SAT)+2M,2n=18=16 m(4 SAT)+2 M and 2n=20=20 m(4 SAT).It can be inferred that the C.intermedia Kuang et H.C.Fu may be the hybrid or intermediary genotype between C.microphlla Lam.and C.arborescens Lam.,or between C.purdomi Rehd.and C.arborescens Lam.;either may be the different species with progressive increasing haploid chromosome number.