Study On Genetic Diversity Of Mentha

Mint is a kind of important aromatic perennial herb. Mint is widely used in food, spices and other industrial, mint is also important traditional medicine. Regional test were carried out in this paper, Mint new varieties, the current world main cultivated adaptability in China climate zones, evaluation of resources of mint collection, in order to select the suitable planted in Hainan with high-yield and high resistant varieties to provide sufficient scientific argument and data support.From the external morphology, cell biology, physiology, molecular marker four aspects of evaluation on regional planting our Mentha germplasm resources in Hainan are evaluated, the results of this study:1) The morphological diversity of plant germplasm resources of MenthaOn14mint germplasm resources of140materials for morphological observation. R cluster analysis and Q cluster analysis have been used to examine the18characteristics, which is including inflorescence types, position of inflorescens of mint and so on. The results showed that most characters were independent of each other, only a few performanced related or close relationship. Through Q type cluster, the similarity of quantitative character between2.695to8.222. There has a great variation in the morphological characters of Mentha, and it can be divided into eight types.2) The cell biology of plant germplasm resources of MenthaThe leaf epidermal micromorphology of germplasm resources of Mentha were observed under the optical microscope. The research shows that different kinds of mint in stomatal size, stomatal density, distribution density of glandular hairs and non-glandular hairs are difference. With these characteristics clustering, it can be divided into five types. And Mentha aruensis clustered into one group separately. This is the same with the morphological classification and molecular classification.Because of the difference of structure determines the difference of drought resistance. So among14mini cultivars, the drought resistance of Mentha rotundifolia ’Variegata’was stronger than that of others, Mentha suaveolens xpiperita and Mentha didyma followed, but the drought resistance of Mentha pulegium was the weakest relatively, and Mentha piperita’Chocolate’followed.3) The physiology of plant germplasm resources of MenthaBy determining three kinds of POD, SOD, CAT enzyme activity, there have some differences between the different varieties of mint. And it infer that the resilience of Mentha requienii, Mentha’champagne’and Mentha rotundifolia’Variegata’may be the strongest, Mentha pulegium and Mentha gracilis were the weakest relatively.4) The molecular diversity of plant germplasm resources of Mentha Genetic diversity analysis of14Mint populations with ISSR markers. A total of276loci were generated from12ISSR primers. The polymorphic rate reached to98.32%. Results showed that these cultivars exhibited abundant genetic diversity. Cluster analysis indicated that all the cultivars could be divided into three groups with the similarity coefficient at0.65. And all the cultivars could be divided into six groups with the similarity coefficient at0.69. Mentha haplocalyx was more close to Mentha spicata. Mentha requienii was farthest to Mentha suaveolens xpiperita and Mentha didyma.