尖叶牛樟染色体制片优化与核型分析

本研究以尖叶牛樟根尖为材料,采用酶解去壁低渗法制片,探讨不同预处理方式和酶解时间对牛樟根尖染色体制片的影响,并对其进行核型分析,以期为牛樟的起源、演化及遗传育种提供一定的理论依据。结果表明:于9:00-11:00进行取材,用0.002 mol/L 8-羟基喹啉液预处理2 h,4%果胶酶和5%纤维素酶酶解5 h,能获得较佳的染色体制片。核型分析结果表明:尖叶牛樟的染色体数目为24条,核型公式为2n=2x=24=22m+2sm,第10对染色体带有随体,属于2B类型,核型不对称系数55.81%。核型对称程度较高,这表明尖叶牛樟可能进化程度较低,属于比较原始的物种。

Optimization of Chromosome Mounting Technique and Karyotype Analysisi of Cinnamomum kanehirae Hay of Sharp Leaves

In order tooptimize the chromosome mounting technique and explore the chromosome karyotype of C. kanehirae Hay, and to provide important cytological evidences for the study of the evolution, evolutionary characteristics and genetic regularity of camphor plants, the effects of differentpretreatment methods and enzymatic hydrolysis time on the production of C. kanehirae were discussed by the enzymatic dissociation wall low permeability method. The observation showed that pretreated in 0.002 mol/L 8-hydroxyl for 2 h, dissociated in 4% cellulase and 5% pectinase for 5 h could achieve the optimal experimental results. The karyotype analysis showed that the chromosome number was 24, with a karyotype formula 2n=2x=24=22m+2sm. The results demonstrated that the asymmetry index was 55.81%, the karyotype was 2B type, suggesting that C. kanehirae Hay maybe a relatively primitive species.