| Cornus officinalis which has been used generally to subdue blood sugar,treat germs, treat cancer, treat disease of cardiovascular system, prevention and cureAIDS and strengthen immunization and so on, is a tradition Chinese crude drug. It isan important component of many kinds of Chinese patent medicine and clinicalformulary. Furthermore, its fruit has been used to develop health food and drink, andits vegetation used to develop afforestation and beautify the landscape. However, itleads to uneven in quality and sell seconds at best quality prices in medicine marketfor C. officinalis, because of starting late to study and research germplasm resources,lagging behind to collect, preserve, evaluation studies for C. officinalis, and lacking ofmanagement experience and cultivar consciousness to pell-mell plant for farmers.Therefore, in order to avoid or abate destruction for tradition medicinal germplasmresources of C. officinalis, protect its genetic resources and xenogeneic diversity,develop and utilize well germplasm resources of C. officinalis, we must be badly inneed of solve the above-mentioned problem from germplasm.In this paper, the genetic diversity of C.officinals, which was collected fromXixia, Neixiang were analyzed on the traditional morphological markers combinedwith technology is mature and stable economy with high levels of applicable andpolymorphism of ISSR markers. It provide a theoretical basis for C.officinalsbreeding and germplasm conservation.1. Cornus officinalis material on43of10phenotypic analysis showed that thecoefficient of variation：Mutation frequency of germplasm phenotypic traits are thereflects of quantitative genetic diversity. In general, the coefficient of variation greaterthan10%, it indicat that the large difference between the germplasm traits ofindividuals, there is a big variation in this trait of individuals in the sample populationand preserving genetic resources of the trait well. The results showed that coefficient of variation of fruits length, fruits diameter, carpopodium length, seeds length,100-fruit weight,100-seed weight, flesh dry weight, medicine rate were higher than10%. It explained that there were large differences and rich in diversity amongindividual traits. While the coefficient of variation of seeds diameter and percentageof fresh flesh were less than10%, which indicated that the variation of these traits wassmall and the phenotypic traits were stable between individuals. The coefficient ofvariation of flesh dry weight is highest(33.61%). While the coefficient of variation ofthe percentage of fresh flesh is lowest(4.23%). It illustrates that there are large geneticdifferences in the external phenotype between different individuals in the growthcycle of Cornus officinalis,so it offers the possibility of breeding varieties of highyield and quality Cornus officinalis.2. Cornus officinalis material on43of10phenotypic analysis showed that thecoefficient: There is high degree of correlation between most of phenotypic traits ofCornus officinalis. However, the correlation between the different phenotypic traitsare not the same. For example, the correlation coefficient of fruit diameter and100-fruit weight is0.881, the correlation coefficient of flesh dry weight and100-fruitweight is0.881. The fruits length and fruits diameter had a higher correlation with100-fruit weight (0.788and0.881, P <0.01) and the flesh dry weight (0.646and0.649, P <0.01). The results indicated that fruit100seed weight and fruit dry weightwere affectted by fruits length and fruits diameter. There was significant correlationbetween percentage of fresh flesh (0.605, P <0.01), medicine rate (0.536, P <0.01)and flesh dry weight, which suggested that it was a key factor that flesh dry weightaffected percentage of fresh flesh and medicine rate.3. The improved CTAB method is the best one with fewer steps, easy to handleand stable. The average OD260/2801.805；the average yield was100.7μg/g. Theextraction is suitable acting as template DNA for ISSR-PCR amplification.4. The optimal ISSR-PCR reaction system was determined. Each20uL reactionsystem should contain60ng template DNA,0.8mmol/L primer,10.0μL2×Taq PCRMasterMix. The amplification program as follows：predenature at94℃for10min,followed by denature at94℃for45s; annealing at55.2℃(depend on primer) for1min, extend at72℃for1min,40cycles; and then extend at72℃for10min, finalstore at4℃for ever.5.12stable polymorphisms primers were selected from50ISSR primes,43Cornus officinalis on genomic DNA was amplified to a total out of98sites per primer locus8.2a,90polymorphic sites per primer locus7.5a, the percentage ofpolymorphic loci was91.84％, the number of alleles Na=1.9184, the effective numberof alleles Ne=1.6890, gene diversity h=H=0.3777, Shannon information indexI=0.5455shows that between43Cornus officinalis material there is a high geneticvariation.6. Population genetic structure analysis shows that：Cornus officinalis group genediversity Htwas0.2957, gene diversity within populations Hcwas0.1909, coefficientof gene differentiation Gst was0.3225. that indicating only32.25％of the variationcomes from the population between the main genetic variation among individualswithin populations and gene flow Nm to1.0504>1, indicating that there was geneflow among populations. The genetic distances were significantly small betweensamples from populations1and population2and5, were0.1263and0.1191, and theNei’s genetic identity were high to0.8814and0.8877. It indicate that the kinships thesamples population1were close with the samples from populations2and5. Thegenetic distances were significantly large between samples from populations4andpopulation1and5, were0.2392and0.2535, and the Nei’s genetic identity were lowto0.7872and0.7761. It indicate that the kinships the samples population4were farwith the samples from populations1and5. The coefficient of variation for eachgenetic distance between populations was27.62%. The correlation coefficientbetween genetic distance and geographic distance among populations was only0.233.It indicate the correlation between genetic distance and geographic distance amongpopulations were not significant. |
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