Resistance Analysis To Sitobion Avenae(F.) Of Southern Shaanxi Wheat Landrace And Analysis Of The Resistance Related Gene To Aphid In Lanmai

Wheat aphid poses a serious threat to the yield and quality of wheat. Sitobion avenae(F.)were detected accounting for more than 95% of the total wheat aphid in China. The over-reliance on pesticides to combat wheat aphids which not only kill their natural enemies of wheat and pollute the natural environment, but also lead to wheat aphid resistance to pesticides. Therefore, more and more attention has been paid to select and promote the anti-aphid species. Using wheat endogenous resistance genes can reduce chemical pesticide use and help to increase the quantity and quality of wheat. In this study, 34 wheat landraces collected from Southern Shaanxi as materials, the resistance to Sitobion avenae(F.) of them, the relationships between the morphologic characters and the resistance to Sitobion avenae(F.) in wheat landraces were analyzed. A resistance aphid related gene Tt LOX2 from Lanmai S849 was isolated and its DNA sequence structure and conserved domain of encoding protein with basic properties were determined using bioinformatics analysis. The main results are as follows:The resistance to Sitobion avenae(F.) in 34 wheat landraces collected from Southern Shaanxi were analyzed at adult stage. 26(76.47%) wheat landraces showed resistance to Sitobion avenae(F.). Amomg them, T. turgidum line Lanmai(Shaanxi Zhashui)(S849) were high resistance to Sitobion avenae(F.), and S1111, S1124, S1125, S1148, S1181, S992 and Mazhaimai were moderate resistance to Sitobion avenae(F.), as well as 18 landraces were low resistance to Sitobion avenae(F.).The agronomic traits of 34 wheat landraces were investigated using analysis of variance,correlation, principal component. The results showed that there was a greater range of variation in eight agronomic traits, the coefficient of variation were from 10.64% to 34.53%.Base on the principle elements analysis, four principle elements were obtained, which variance contributes were 30.06%, 21.55%, 17.30% and 10.40%, respectively. The variation interval of the Euclidean distance was 1.32-51.03 with an average of 19.07. The 34 wheat landraces could be divided into 3major groups at the Euclidean distance of 17.00. The first group contained three landraces, S1017, S571 and S591.The second group contained a single landrace S652. The third group consisted of 30 wheat landraces. The result based oncorrelation analysis indicated that the resistance of these wheat landraces was significant correlations with flag leaf width and flag leaf area, respectively.An EST JK716074 was from suppression subtractive hybridization library made from seedling leaf cDNA library induced by Sitobion avenae(F.) of Lanmai(Shaanxi Zhashui)S849. A full length cDNA(3643 bp) was obtained using rapid amplification of cDNA ends,which encoded the lipoxygenase superfamily gene and was designated as TtLOX2. ORF region of the gene is 321 bp, the putative protein contains of 106 amino acids with a molecular weight of 12.17 kD and a theoretical pI of 9.68. Multiple sequence alignment of the amino acid sequence between LOX and other homologs from several plants were analyzed by MEGA 5 and shows that the TtLOX2 has high identity with LOX4 genes from Brachypodium distachyon. The identities is 84% with a deduced amino acid sequence of highly conserved functional domain.