该实验以黄果龙葵和龙葵的根尖为实验材料,进行不同的预处理、固定和解离,确定出各种材料适合于核型分析的制片方法.结果表明:龙葵于15℃条件下经0.05%秋水仙素预处理2.5 h,固定后用1 mol/L HCl酸解后,染色观察,得到的染色体分散,易于染色体计数和形态观察.用此方法对黄果龙葵和龙葵进行核型分析,结果发现:黄果龙葵和龙葵都属于小型染色体,黄果龙葵为四倍体,核型公式为K(4n)=48=4sm+44m,核型不对称系数为56.22%,属于2B核型.龙葵为六倍体,核型公式为K(6n)=72=72 m,核型不对称系数为55.89%,属于1B核型.%In this test,the experimental materials are root tips of Solanum nigrum var.suaveolens and So-lanum nigrum .In order to determine pretreatment methods of the most suitable for karyotype analysis,we optimized processing the root tips by different pretreatment,fixed and different dissociation.Root tips of Solanum nigrum L.are pretreated with 0.05% colchicine for 2.5 h at 15℃.Then root tips were hydro-lyzed or 6 min in 1 mol/L HCl at 60 ℃.The results showed the chromosome clearer.S .nigrum var. suaveolens and S .nigrum are both belong to small chromosomes,S .nigrum var.suaveolens is tetraploid, the karyotype formula is K (4n)=48=4sm+44m,karyotype asymmetry belongs to 2B.The karyotype a-symmetry coefficient was 56.22%.S .nigrum L.is hexaploid,the karyotype formula is K (6n)=72 =72m,karyotype asymmetry belongs to 1B and the karyotype asymmetry index was 55.89%.
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