Abstract:

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.

Key words: Moringa oleifera, chromosome sectioning, karyotype analysis, stem tip