Analysis of Genetic Diversity and Environmental Factor Correlation of Heterodera glycines in Northern China
Heterodera glycines is one of the most serious diseases that damages the yield and quality of soybean in China and even in the world.To clarify the genetic structure of the geographical popula-tions of H.glycines,130 cysts of 13 populations from 5 provinces in northern China were analysed us-ing Inter-Simple Sequence Repeats(ISSR)markers.The results showed that the percentage of poly-morphic loci within 13 populations ranged from 9.52％-33.33％,the number of alleles(Na)was 1.095 2-1.333 3,the effective number of alleles(Ne)was 1.053 3-1.217 7,the average heterozygos-ity(He)was 0.033 0-0.126 8.The Shannon information index(Ⅰ)of 13 populations was 0.050 3-0.188 1,which showed a high level of genetic homogeneity within every population.The percentage of polymorphic loci in the fragments amplified by three ISSR primers was 80.95％(30/42 fragments),with a genetic differentiation coefficient(Gst)of 0.732 5 and a gene flow(Nm)of 0.182 6,indicating the existence of extremely low gene flow and high-level genetic differentiation among populations.The pairwise Nei's genetic identity among 13 populations ranged from 0.630 5(HLJM and JLCC)to 0.960 6(HLDQ and HLAD),the genetic distance ranged from 0.040 2(HLDQ and HLAD)to 0.461 3(HUM and JLCC),the dendrogram separated the 13 populations into two main groups at the genetic similarity coefficient of 0.65.The correlation analysis between genetic diversity index and ecological factors showed that the monthly average maximum temperature during soybean planting period was moderately or strongly correlated with genetic diversity index,indicating that the higher the tempera-ture was,the higher the genetic diversity of SCN was in a certain temperature range.There was no significant correlation between other factors.The genetic consistency and genetic distance between two populations were weakly correlated with geographical distance(R2=0.005 8,R2=0.009 6).All of these results showed that there was obvious differentiation and high level of genetic diversity among 13 H.glycines populations in northern China.
万方数据
维普
