苏丹草与高粱染色体核型比较研究

Analysis on karyotype of Sorghum sudanense and Sorghum bicolor

采用去壁低渗火焰干燥法对4个苏丹草和6个高粱品种的核型进行比较研究。结果表明,苏丹草和高粱体细胞染色体数均为20(2n=20);苏丹草品种均为1A核型,并具有1对随体染色体,其中1、2号品种的第2对染色体为近中间着丝点染色体,3、4号品种为中间着丝点染色体;高粱品种除5号为1A核型、中间着丝点染色体外,其余的5个品种为2A或2B核型,且都有1或2对近中间着丝点染色体,9号品种还出现1对近顶端着丝点染色体;高粱8、9号品种各观察到1对随体染色体。染色体数量分析表明,第1到第10对染色体长短臂的绝对长度、相对长度以及绝对全长在苏丹草和高粱2类间的差异均不显著(P>0.05)。因此,苏丹草和高粱的遗传差异不在染色体长度上。

The karyotypes of 4 S. sudanense varieties and 6 S. bicolor varieties during mitosis were investigated by using the method of wall degradation and hypotonic treatment of making chromosomal preparations. The resuits showed that the numbers of chromosome are 20 in S. sudanense and S. bicolor. The karyotypes of S. sudanense varieties were 1A, and their karyotype formulas were shown as follows. No. 1 and No. 2 2n= 18m＋2sm（2SAT）, No. 3 2n= 18m＋2sm（2SAT）, No. 4 2n=20m（2SAT）. Their karyotypes were not all same among S. bicolor varieties. Only No. 5 was 1A, and all the other varieties were 2A or 2B. The karyotype formulas of S. bicolor varieties were： No. 5 2n=20m, No. 6 2n=16m＋4sm, No. 7 2n=18m＋2sm, No. 8 2n=18m （2SAT）＋2sm, No. 9 2n=16m＋2sm（2SAT）＋2st, No. 10 2n=16m＋4sm. There were not different significantly between S. sudanense and S. bicolor in short arm, long arm and absolute total length（P〉0. 05）.