热研4号王草和桂闽引象草的核型分析

摘要

The present study investigated the chromosome number and karyotype of Pennisetum purpureum× P .americanum cv.Reyan No.4 and P .purpureum cv.Gui minyin using the conventional compression method to provide theory basis of Pennisetum germplasm resources diversity protection and genetic breeding research. The results showed that their basic chromosome number was 7.Reyan No.4 was triploid and the chromosome number was 21,the karyotype formula was 2n=3x=21=21m (3SAT),the formula of chromosome relative length was I.R.L=9S+3M1+3M2+6L,three of chromosomes have trabant.Gui minyin was tetraploid and the chromosome number was 28,the karyotype formula was 2n=4x=28=18m (2SAT)+10sm (2SAT),the formula of chromosome relative length was I.R.L=10S+6M1+4M2+8L,four of chromosomes have trabant. For Reyan No.4 and Gui minyin,index of the karyotypic asymmetry was 60.15% and 62.19%,the karyotype was 1B type and 1C type,respectively.The results indicated that their karyotype belong to primitive types .%采用常规压片法,对热研4号王草(Pennisetum purpureum×P.americanum cv.Reyan No.4)和桂闽引象草(P .purpureum cv.Guiminyin)的染色体数目和核型进行分析,以期为狼尾草属种质资源多样性保护利用和遗传育种研究提供理论依据.结果表明,两者染色体基数均为 x＝7.其中,热研4号王草为三倍体,有21条染色体,核型公式2n＝3x＝21＝21m(3SAT),染色体相对组成 I.R.L＝9S＋3M1＋3M2＋6L,3条染色体含有随体；桂闽引象草为四倍体,有28条染色体,核型公式2n＝4x＝28＝18m(2SAT)＋10sm(2SAT),染色体相对组成 I.R.L＝10S＋6M1＋4M2＋8L,4条染色体含有随体.热研4号王草和桂闽引象草核型不对称系数分别为60.15％和62.19％,属于1B型和1C型,其核型都属于比较原始的类型.