Analysis Of Genetic Diversity Of Humulus Lupulus L. In Xinjiang

Abstract: This thesis mainly studied the genetic diversity and genetic structure in 7 natural local populations of Humulus lupulus L. in Xinjiang by the genetic markers of random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR). The research results will provide some basic data to the hop's research and development of hop industry. The main results are highlighted in the following:1. With the method of low pH extraction medium and high salt concentration , we can successfully extract total DNA from the leaf tissues of H.lupulus. By a series of tests, we obtained an effective RAPD reaction system for adapting to H. lupulus RAPD markers. The optimized system included 2.0mM Mg²⁺, 200μM dNTP, 0.5uM primers, 1.5U Taq DNA polymerase.2. A total of 70 individuals representing 7 natural populations of H. lupulus in Xinjiang were surveyed with 12 RAPD primers, which generated 121 loci.,of which 119 loci were polymorphic and accounted for 98.35%. The higher PPB was in pop.AC and lower in pop.AD. By Shannon phenotypic diversity index, it was found that 63. 55% of molecular variation existed within populations while 36. 46% of which among populations. The result with Nei's index also identified it. And the differentiation coefficient was 0.3435, which showed the genetic differentiation had occurred among populations of H. lupulus. The largest genetic distance was 0.2591 between pop.AA and pop.TT, and the smallest was 0.1392 between pop.TA and pop.YY. The genetic average distance among seven populations of H. lupulus was 0.2009.3. A total of 70 individuals of H. lupulus were investigated by used of 3 pairs of SSR primers. The result showed that percentage of polymorphic bands in the species lever was 100%. The higher PPB was in pop.YY and lower in pop.AK. By Shannon phenotypic diversity index from SSR data, it was found that 64. 05% of molecular variation existed within populations while 35.95% of which among populations. And the differentiation coefficient was 0.3212. The largest genetic distance was 0.3152 between pop.AA and pop.AC, and the smallest was 0.0197 between pop.AD and pop.AK. The genetic average distance among seven populations of H. lupulus was 0.1346.4. The study indicated that the genetic diversty of H. lupulus had the remarkably positive correlation with soil organic matter ,which showed organic matter might play a role in maintaining the genetic diversity of H. lupulus. Furthermore, we observed that the frequencies of some alleles of H. lupulus individuals were highly related with the corresponding ecological factors. It showed that the differentiaton within ecological factors might play a role in maintaining the genetic variation of H. Lupulus. No significant correlation between genetic distance and spatial distance was found.