Analysis of Genetic Variation in Anti-aphid Generations of Germplasm Resources

In the present study,the synthetic wheat line 98-10-35 is resistant and the synthetic wheat line 1376 is susceptible to S.avenae in greenhouse and field tests.Several related populations including F1,F2,F3 and BC1 bred from 98-10-35/1376 are analyzed by genetic model,combining ability,gene frequency and genotypic frequency.Results indicated that: backcross population of BC1 was a single normal distribution,BC2,two normal distribution,then the proportion of the 1 ∶1 segregation ratio,the performance of a single dominant gene.The gene and genotype frequencies were:P(A)=46.7%,P(a)=53.3%,P(AA)=21.8%,P(Aa)=49.8%,P(aa)=28.4%.The combining ability analysis showed that the general combining ability 0.006 16,specific combining ability-0.220 41;The phenotypic identification results from the field showed that 98-10-35 and F1 were resistance to aphid,and the resistance analysis of their F2 segregation populations showed that both segregation ratios were corresponding with the expected Mendelian segregation ratio of 3 ∶1 by Chi-square value(x2=1.667,P=0.168)suggested that the aphid resistance in wheat lines 98-10-35 to 1376 was controlled by a single dominant gene respectively.In order to provide theoretical support and guidance for practical work for the wheat aphid resistance breeding,we analyzed genetic variation in anti-aphid generations of germplasm resources.