Studies On Genetic Diversity Of Perilla L. Germplasm Resources

Perilla frutescens (L.) Britt. (Labiatae) is a annual herb of Labiatae which originates in the Himalayan mountains and central of southern China. According to the Flora Reipublicae Popularis Sinicae, there are one specie and three varietal species in genus Perilla.the Perilla is not only a traditional Chinese herb, spice and vegetable, but also valuable oil plant with long cultivation history in Asia. As the studies have advanced, Genus perilla has been given more and more attentions for its important roles in medical treatment,health care, food and chemical fields. There is no excellent variety for medicinal and oil at present, the wild plant resource has been widespread used. so, classification of Perilla and the choice of excellent germplasm is one of urgent problems that needs to be solved. Genetic diversity of 26 Perilla L. accessions from different areas in China was analyzed by morphology, cytology and molecular markers technique, in order to make sure the taxonomic position, development and utilization and material basis for Perilla breeding. The primary results were as follows:1. In order to assess genetic diversity of 26 Perilla L. accessions, a total of 15 morphological descriptors were studied. The results showed the average of variation coefficient is 46.41%, they ranged from 22.25% in grain color to 89.17% in surface of the leaf based on qualitative descriptors and from 10.90% inpetiole length to 65.31% in thousand seed weight based on the quantitative deseriptors. The first principal component of variance contribution rate was 37.94% in principal component analysis, the first four principal components of accumulated variance contribution was 74.68%, all of the original information can be represent basically. In this study, the 26 Perilla L. accessions were clustered into 4 groups based on the morphological data, hierarchical cluster analysis were mainly in accord with different variations.2. SRAP molecular markers was firstly used for the assessment of genetic diversity of Perilla genus.11 pairs of primers was used to detect DNA polymorphism among 26 Perilla L. accessions from different regions,116 of the generated 188 bands were polymorphic bands, with an average of 10.5 maker bands per pair of primers. The dendrogram generated by UPMGA showed there was no obvious genetic diversity with different variations, which indicated that there was a geographic differentiation in 26 Perilla L. accessions. The 26 accessions showed abundant genetic diversity with comprehensive analysis of two marker systems, the morphological and molecular markers between var. arguta and var. frutescens are quite different, which indicated that var. frutescen should be classified as an independent variation.3. The observation results showed that the chromosome number of all Perilla L. aecessions is 2n=40. P. frutescens var. arguta belonging to "2A" type, and the other three varietals belonging to "2B" type, indicated that P. frutescens var. arguta is in a low phyletic evolution levels.4. FISH (fluorescence in situ hybridization) analysis of 45S rDNA and 5S rDNA on metaphase chromosomes showed that all materials used in this study have one pairs of 45S rDNA strong sites localized in the terminal region of short arms of chromosomes. the 5S rDNA sites was varied, rang from 1-3 pairs. Karyotype analysis revealed that P. frutescens var. arguta have 2 pairs of 5S rDNA sites, one localized on the short arm of chromosome 8 and the other localized on the centromere of chromosomes 3; P. frutescens var. frutescens has 45S rDNA localizing on chromosome 11 and has 3 pairs of 5S rDNA sites, localizing on the short arm of chromosomes 5,8 and 15 respectively.This study suggested that there is abundant genetic diversity in genus perilla from China, The genetic relationship between var. arguta and var. frutescens is relatively distant, var. arguta is is more primitive types. This study provided reference data for their characteristics of genetic mutations and classification and utilization of germplasm resources in perilla.