辣木的染色体制片优化及核型分析

以辣木分生组织为材料,采用酶解去壁低渗法制片,探讨不同取材部位、预处理方式和酶解时间对辣木染色体制片的影响,并对其进行核型分析,以期为辣木的起源、演化及遗传育种提供一定理论依据。结果表明:以辣木新枝茎尖为最佳取材部位,用饱和对二氯苯预处理2 h,再用4%纤维素酶和5%果胶酶混合物酶解4 h,制片所得染色体效果最佳。核型分析表明,辣木染色体属于小染色体,有28条,核型公式为2n=2x=2n=28m,属于1B类型,核型不对称系数60.29%,核型对称程度较高,这表明辣木在进化中可能处于比较原始类型。

Optimization of Chromosome Sectioning and Karyotype Analysis of Moringa oleifera

Chromosome mounting technique was optimized to explore the chromosome karyotype of Moringa oleifera, to provide important cytological evidences for the study of the evolution, evolutionary characteristics and genetic regularity of camphor plants. The effects of different sampling position, pretreatment methods and enzymatic hydrolysis time on the production of M. oleifera were discussed by the enzymatic dissociation wall low permeability method, microscope observation and photography. The observation showed that the best sampling position was the tips of new branches. Samples pretreated in p-dichlorobenzene for 2 h, dissociated in 4% cellulase and 5% pectinase for 4 h could achieve the optimal experimental results. Karyotype analysis showed that the chromosome number was 28, and the karyotype formula was 2n=2x=2n=28m. The results demonstrated that the asymmetry indexes was 60.29%, and the karyotype was 1B type, suggesting that M. oleifera was possibly relatively primitive in the evolution.