Genetic Diversity Of Wild Bluegrass Based On Morphological AFLP Markers

Poa L., which is the most widely used cool-season turf grass in turf establishment innorthern China, has the advantages of ornamental effect and strong resistance. Wild Poa L.plants are widely distributed in China, so they can be the material sources of turf grassbreeding research with their rich genetic background. The research of germ plasm resourcesgenetic diversity can provide the theoretical basis for turf grass breeding, at the same time, itis of great significance in plant origin, evolution, classification and the screening of excellentgene. In order to comprehend the genetic background, diversity and the differences betweendifferent materials, the research used morphological marker to analyze the genetic diversity of23wild Poa L. germ plasm resources from Gansu Province, and use AFLP marker to analyzethe genetic diversity of43wild Poa L. germ plasm resources from Gansu Province QinghaiProvince, so that can provide a reference for breeding of Poa L.. The main findings are asfollows:1. Through observed and measured the morphological index of23wild Poa L. germplasm to research their morphological diversity. The results indicated that the morphologicalindex of wild Poa L. germ plasm resources had a rich diversity, the average diversity indexwas1.60, and the average coefficient of variation was52.40%. Using principal componentanalysis to evaluate the morphological character of23wild Poa L. germ plasm, the resultshowed that the principal component of the tested materials were obvious, the first fourprincipal components represented90.07%of the morphological diversity of wild Poa L. germplasm, principal component analysis can be used to evaluate the genetic diversity.2. Clustering analysis based on morphological characters,23tested materials clusteredinto four germ plasm types. Type1contained10materials, including6Poa pratensis L.materials,1Poa tibetica L. material,1Poa micrandra L. material,1Poa poophaqorum L.material and1Poa sphodylodes L. material. Type2contained8materials, including4Poasphodylodes L. materials,2Poa poophaqorum L. materials,1Poa micrandra L. material and1Poa crymophila L. material. Type3contained3materials, including2Poa pratensis L.materials and1Poa alpigena L. material. Type4contained2materials, which were both Poaannua L.. Among them, the advantages of materials in Type1and Type3were outstanding. 3. Modified CTAB method was used to extract the genomic DNA of wild Poa L..Germplasm resources and obtained the high purity, good quality and RNA-freed DNA, in linewith the requirements of the AFLP technique.4. In the system optimization of AFLP, optimal AFLP system of Poa L. was established,in the system, optimal digestion time was3.5h, appropriate dilution factor preamplificationwas10×, in20μL selective amplification system, optimal concentration of primers was EcoRI primer (50ng/μL)1.0μL and Mse I primer (50ng/μL)1.0μL.5.10pairs of primer with high polymorphism were screened out from64pairs ofcommon AFLP primer,480informative AFLP markers were generated and scored as binarydata, which showed a polymorphic band ratio of81.71%.The AFLP polymorphism of all thetested materials was rich, high polymorphic detection efficiency of wild Poa L. can obtainedby AFLP markers.6. Genetic diversity analysis showed that the genetic distance between tested materialswas between0.0371-0.8542, genetic similarity coefficients was between0.9556-0.3778, highgenetic diversity existed in wild Poa L..7. Data of AFLP marker was analyzed by cluster analysis, UPGMA phylogenetic treewas built,43material can be clustered into seven categories in0.6611, genetic differencebetween tested materials was closely related to their origins. Type1contained14materials,including13Poa pratensis L. materials from Gansu and1Poa alpigena L. material. Type2contained6materials, including2Poa sphondylodes L.materials,2Poa micrandra L.materials and2Poa annua L. materials. Type3contained2Poa micrandra L. materials,1Poa sphondylodes L. material and1Poa annua L. material. Type4contained16materials,including8Poa sphodylodes L. materials,4Poa poophagorum L. materials,1Poa attenuateL. material,1Poa pratensis L. material,1Poa crymophila L. material and1Poa anqustifoliaL. material. Type5, Type6, Type7were all contained one material, which was Poamicrandra L.(Xiahe), Poa tibetica L.(Tianzhu) and Poa annua L.(Xiahe).