| In this experiment,30 wild Cynodon dactylon germplasm resources were collected from Hunan province as research material. The genetic diversity of these materials had been studied from morphological and molecular level. The main research fruits wents as follows:1.13 morphological characters of experiment materials have been shown great variability. The observations whose variability have reached more than 30%, are the width of leaves, root depth, color of the leaves, length of leaves-hair and the area of leaves. Correlation analysis showed that:The higher the leaf layer, the more narrow leaves, smaller leaf area, leaf color is also more shallow, and the greater the length of inter-node; The more longer the Cynodon dactylon leaves, the more greater of leaf area, so is the length of leaves-hair; Cynodon dactylon which have large width of leaves, also have greater area of leaves; The longer the inter-node length, stem bermudagrass color and leaf color is also more shallow; The more greater the node diameter, which leaves hair more often not obvious; Cynodon dactylon whose section length of stolon is long, the color of its leaves would be less; The longer leaves-hair the Cynodon dactylon have, they Stem color will be more shallow. If the color of the Stem is deeper, the color of the leaves is also deeper.3 Cynodon dactylon germplasm resources have been selected as quality lawn grass in Changsha.2. The main external morphological characters have been cluster analysised, these 30 Cynodon dactylon materials were divided into five major categories. The external phenotype of Cynodon dactylon in every category is related with the natural environment where they grown, especially with the altitude, the relationship between latitude and longitude. With the elevation of the Cynodon dactylon, leaf color and stem color trend has deepened. In the good hydro-thermal conditions region, even if the elevation of acquisition region is high, Its color of leaves tends to similar wth the Cynodon dactylon which grown at lower elevations.3. In this experiment, based on the previous studies, a set of simple, rapid and accurate technique has been explored for Cynodon dactylon DNA extraction and purification, and a best experimental system for the molecular markers of Cynodon dactylon has been established, that is:the optimal reaction system of ISSR is the 20.0μL system containing 20.0 ng template DNA,0.4μmol/L random primers,0.5 mmol/L Mg2+ 0.05 mmol/L dNTPs,0.2 U TaqDNA polymerase; and 2.0μL 10×buffer; and that the optimized annealing temperature is 55℃. The PCR procedure is:pre-denaturizing at 94℃for 5 min, denaturizing at 94℃for 45 s, annealing at 55℃for 45 s, extension at 72℃for 1.5 min, reaction of 35 cycles and re-extension at 72℃for 7 min.4. In this paper, The level of genetic diversity and population genetic structure of 12 wild populations of Cynodon dactylon have been researched by ISSR molecular markers. A total of 10 primers amplified 167 loci, of which 165 for the polymorphic loci, accounting for 98.80%. POPGENE analysis showed that:Cynodon dactylon has a wealth of genetic variation (At the species level, H=0.1883,I=0.3137; At the groups level, PPL=24.60%, H=0.0947,1=0.1404). Nei's genetic diversity analysis showed that, Among different groups have a certain degree of genetic differentiation(Gst=0.4963). The lowest level of genetic diversity of the groups in Changzhutan (CZT), the highest level of genetic diversity of the groups in Zhangjiajie (ZJJ), shows the overall basic changes as Changzhutan(CZT) |
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