罗汉果与三种苦瓜属植物的核型比较分析

Comparative Analysis of Karyotype Between Siraitia Grosvenorii and Three Species of Momordica

以罗汉果、苦瓜、木鳖子、云南木鳖种子根尖为实验材料,采用去壁低渗法进行染色体制片和核型分析,为罗汉果的分类归属及品种选育、倍性育种提供细胞遗传学资料.结果表明:罗汉果染色体28条,为二倍体,基数为14,核型公式为2n=2x=28=10m+6sm+6st+2t+4T,核型类型为3A型;苦瓜染色体22条,为二倍体,基数为11,核型公式为2n=2x=22=2M+20m,核型类型为1A型;木鳖子染色体28条,基数为14,核型公式为2n=2x=28=2m+22sm(2SAT)+4st,核型类型为3A型;云南木鳖染色体24条,基数为12,核型公式为2n=2x=24=22m+2sm,核型类型为1A型染色体数目和核型类型表明罗汉果和木鳖子的亲缘关系比较近,在分类系统上比较进化;苦瓜和云南木鳖亲缘关系比较近,在分类系统上比较原始.核不对称系数也表明木鳖子和罗汉果在分类系统上比较进化,苦瓜和云南木鳖比较原始.

The seed root tips of four species of cucurbit plant,including Siraitia grosvenorii,Momordica charantia,Momordica cochinchinensis,Momordica dioica,were used as explants,chromosome preparation and karyotype analysis were carried by wall degradation and hypotonic treatment,which provided the cytogenetic data for the classification,attribution,variety selection and polyploid breeding of S.grosvenorii.The results showed that S.grosvenorii had 28 chromosomes,diploid,and the basic number of chromosome was 14,the karyotype formula was 2n=2x=28=10m+6sm+6st+2t+4T,and the karyotype type was 3A;M.charantia had 22 chromosomes,diploid,and the basic number of chromosome was 11,the karyotype formula was 2n=2x=22=2M+20m,and the karyotype type was 1A;M.cochinchinensis had 28 chromosomes,and the basic number of chromosome was 14,the karyotype formula was 2n=2x=28=2m+22sm(2SAT)+4st,and the karyotype was 3A;M.dioica had 24 chromosomes,and the basic number of chromosome was 12,the karyotype formula was 2n=2x=24=22m+2sm,and the karyotype type was 1A.The chromosome number and karyotype indicated that the phylogenetic relationship between S.grosvenorii and M.cochinchinensis was relatively close,and they were relatively evolved in classification systems.The relationship between M.charantia and M.dioica was relatively close and primitive in classification system.The index of asymmetric of four species gave the same results.