Chloroplast DNA Microsatellite Analysis Of Wild Hop (Humulus Lupulus L.) In Xinjiang

This thesis mainly analysed 137 wild hops from nine pupulations and three hop cultivated species using molecular markers of chloroplast DNA microsatellites, to reveal the genetic variation and population genetic structure of Xinjiang wild hops at the molecular level, as well as the genetic differentiation and genetic diversity within and among wild hops populations. The research results will provide some theoretical and practical basis to the hop's protection and breeding. The main results are highlighted in the following:1. With the method of low pH extraction medium and high salt concentration , hops chloroplast had been isolated completely from young leaves of hops, and a higher quality of chloroplast DNA were extracted. Chloroplast DNA concentration were 140-4470 ng/ul; chloroplast DNA extraction were 0.56-17.88 ug/g; used 1% agarose gel electrophoresis test, the chloroplast DNA size was about 23 kb, the bands were clear, no degradation and no tailing; the PCR reaction of two chloroplast DNA universal primers can be amplified specific bands.2. A total of 46 alleles were observed at the 20 microsatellite loci from 137 wild hops of nine populations, in which there were two unique gene, two sporadic gene, nine widespread gene and 33 essential gene.3. The observed number of alleles (A) ranged from 2 to 3 with an average of 2.3000. The effective number of alleles(Ae) was 1.6246 on average and ranged from1.0606(HlGT17) to 2.2190(Hl-AGA6).The expected heterozygosity(He) exhibited a range of variation from 0.5493 (Hl-AGA6) to 0.0517 (HlGT17) with the mean of 0.3568. The observed heterozygosity(Ho) averaged 0.4256 and ranged from 0.0588 (HlGT17) to 0.9225 (ccmp10).4. Fis, Fit and Fst were -0.3409, -0.2054 and 0.1010 on average, respectively, which suggested that an obvious genetic deviation from Hardy-Weinberg equilibrium occurred within and among populations,and the genetic variation among populations was10.10%, whereas the genetic variation within population for 89.90%. The gene flow (Nm) was 2.2241, indicated that gene flow among populations was more frequently.5. From the level of populations, the number of polymorphic loci(Np) ranged from 16(Population TY, AB, AC,YH) to 20(Population AD); the percentage of polymorphic loci(P) ranged from 80% to 100%; the observed number of alleles(A) varied from1.8500 (PopulationAC,YH) to 2.1500 (PopulationAD) and the effective number of alleles(Ae) varied from1.4220 (PopulationYH) to 1.7539(PopulationAD); the expected heterozygosity(He) exhibited a range of variation from 0.2451 (Population YH) to 0.4056 (Population AD) and the observed heterozygosity(Ho) exhibited a range of variation from0.3468 (Population YH) to 0.5212 (Population AD); the highest Shannon's Information index (I) was found in PopulationAD(I=0.6069), and the lowest was found in PopulationYH(I=0.3809). This indicated that the maximum genetic diversity was in Population AD and the minimum in Population YH. 6. The genetic distance among nine wild hop populations was 0.0499 on average, the genetic similarity coefficient among nine wild hop populations averaged 0.9541; the genetic distance among nine wild hop populations and three cultivated species was 0.4092 on average, the genetic similarity coefficient among nine wild hop populations and three cultivated species averaged 0.6688. The cluster analysis among populations divided nine wild hop populations and three cultivated species into six groups, three cultivated species and populations TE were becoming an independent group, respectively; populations TY, AC, YH AE and populations AA, YX, AD AB clustering into a group, respectively. The cluster analysis among samples divided 137 wild hop samples and three cultivated species into ten groups, most of the samples were clustered in Group1, a small number of samples clustered in Group 2, and Group3, 4, 5, 7,8consisted of 3, 2, 4, 4, 2 samples, respectively; AB8, CV1 and CV2 were becoming an independent group, respectively; and CV3 clustering in Group 5. This indicated that: the genetic variation among nine wild populations was small, and the genetic differentiation was low, and the differences with the three cultivated species were significant.