荒漠十字花科植物粗果庭芥的核型分析

目的]分析新疆荒漠十字花科植物粗果庭芥(Alyssum dasycarpum Steph.ex Willd.)的核型特征.方法]以粗果庭芥根尖细胞为实验材料,采用常规压片法对细胞染色体数目、大小核型及倍性进行分析.结果]该物种的染色体数目为2n=16,基数=8,二倍体；全部为中着丝粒染色体(m),染色体长度比为2.283,臂比＞2的染色体比为0,核型公式为2n=2x=16 =16 m,染色体组型属Stebbins核型分类中的“1B”类型,不对称系数为57.07;,低于60;,对称性高；核型分析过程中,未观察到随体存在.结论]推测粗果庭芥在系统演化上可能属于较原始的种类.

Karyotype Analysis of the Desert Cruciferous Plant Alyssum asycarpum Steph.ex Willd.

Objective]To analyze the karyotype characteristics of cruciferous plant Alyssum dasycarpum Steph.ex Willd.from the desert area in Xinjiang.Method]The somatic cells of root - tips from this species as experimental materials were used to observe the chromosome number,karyotype and ploidy characteristic by root - tip squashing method.Result]The chromosome number is 2n = 16;The basic chromosome number is confirmed to be x =8;And this species is diploid;All of them are metacentric(m) chromosomes;The ratio of the longest chromosome to the shortest chromosome(Lc/Sc) is 2.283;The percentage of chromosomes with arm ratio(P.C.A) >2 is 0;the karyotype formula of this species is 2n = 2x = 16 = 16m,which belongs to "IB" type of Stebbins karyotype classification;And the index of the karyotype asymmetry(As.K%) is 57.07%and is lower than 60%,so the karyotype symmetry of this species is higher;The satellite on the chromosome of this species is never found in the process of the karyotype analysis.Conclusion]These results revealed karyotype of Alyssum dasycarpum is symmetrical to a higher degree,indicating that Alyssum dasycarpum belongs to a relatively primitive type and relatively old or the original plant in evolutionary processes.