秋英属植物核型分析

Karyotype analysis of different varieties of Cosmos

采用常规压片法,以秋英属2种植物为研究材料进行核型分析,旨在为波斯菊和硫华菊种质资源的开发利用和良种培育提供细胞学依据.结果表明:波斯菊的染色体数目为2n=2x=24和2n=4x=48,染色体数目出现异常,首次发现48条染色体.硫华菊染色体数目是2n=24.2种植物在染色体类型中均含有m、sm和st类型.核型类型有1A、2A、3A、2B和3B型.最长与最短染色体比值为1.27~2.37,臂比大于2∶1的染色体占染色体总数的0~58.33%.核型不对称系数为58.12%~67.69%,核型不对称程度较高,说明秋英属2种植物的进化程度较为进化,其中CC(纯粹SensationPurity)最原始,KL(凯莱SensationGloria)最进化.秋英属不同品种的核型特征均有差异,说明不同品种之间具有染色体遗传多样性.

The karyological analysis on two cultivars of Cosmos were studied by conventional pressed slice method. The purpose was to utilize and breed germplasm.The results showed that:the chromosome number of Cosmos bipinnata for the test are 2 n=2x=24 and 2 n=4x =48, the chromosomes was abnormal,and forty-eight chromosomes were identified for the first time.The chromosome number of Cosmos sulphureus are 2 n =24.The chromosome types of Cosmos included m,sm and st.The karyotype types contained 1A,2A,3A,2B and 3B. The ratio of the longest chromosome / the shortest chromosome was from 1.27 to 2.37,the percentage of chromosomes of arm ratio >2 is 0-58.33%.The karyotype asymmetry index of nine cultivars were from 58.12% to 67.69%,which implied the karyotype of Cosmos was asymmetric and evolutive.Among the cultivars,the karyotype of CC(Sensation Purity) was the most primitive,and the karyotype of KL(Sensation Gloria)was the most evolutive.The karyotype characteristics of different cultivars were different,indicating that there are chromosomal genetic diversity among different cultivars.