雅江点地梅（报春花科）3个居群的核型和倍性变化

首次报道了雅江点地梅（Androsace yargongensis)3个居群的染色体数目和核型，对倍性也进行研究。3个居群的染色体数目（2n)，核型公式（KF），染色体相长度组成（C．RL），核型不对4称系数（As,K%)和核型类型（KT）分别为：野牛沟居群2n=40,KF=36m(1SAT) 2SM 2ST b,C,RL=2L 14M2 22M1 2S 2bS,As.K=54.75%,KT=2A;巴颜喀拉山居群2n=40,KF=36m 2sm 2st 1b,C.RL=4L 16M2 18M1 2S 1bS,As.K=56.31%,KT=2B；达坂山居群2n=60,KF=40m 14sm 6st,C.RL=4L 24M2 26M1 6S,As.K=59.56%,KT=2B。根据3个居群的染色体和核型不对称性与居群所在地的地理位置，认为雅江点地梅核型和倍性的演化与高海拔生态环境和寒冷、干旱的气候加剧有密切关系。

Variation of karyotype and ploidy of Androsace yargongensis (Primulaceae) in three population in Q-Z Plateau

The karyotype and ploidy of Androsace yargongensis in three populations distributed on Q Z Plateau have been analysed and studied.The chromosome number and karyotype are reported here for the first time.Their chromosome number (2n),karyotype formula (KF),chromosome component in relative longth (C.RL),the index of karyotype asymmetry (As.K%) and karyotype type (KT) are each presented as follows:Yeniuguo population 2n=40,KF=36 m(1SAT)+2 sm+2 st+2 b,C.RL=2L+14 M 2+22 M 1+2S+2bS,As.K%=54.75,KT belongs to 2A;Bayanharshan population 2n=40,KF=36 m+2 sm+2 st+1 b,C.RL=4 L+16 M 2+18 M 1+2S+1 bS,As.K%=56.31,KT belongs to 2B;Dabanshan population 2n=60,KF=40 m+14 sm+6 st,C.RL=4 L+24 M 2+26 M 1+6 S,As.K%=59.69,KT belongs to 2B.On the bases of relationship between karyotype asymmetry with geographical locality in three populations of Androsace yargongensis ,may consider that the evolution of karyotype and ploidy are close relative with ecological environment of high altitude and cold and dry climate to be intensified.