Identification of Resistance to Tetranychus turkestani and Analysis of Leaves Surface Wax of Different Cotton Varieties (Lines) in Xinjiang

Objective] Based on the representative 236 cotton varieties in Xinjiang, the resistance of cotton to mites was identified, and the waxy content and waxy components of leaves were analyzed to lay a foundation for cotton breeding. Method] In the cotton seedling stage, the waxy content of the leaves of different cotton varieties was determined, and the waxy components of the leaves were analyzed by gas chromatography-mass spectrometry. Result] Most cotton varieties are sensitive to the damage of cotton mites. There were 2 high resistance varieties, 3 resistant materials, 22 medium resistant materials, 207 sensitive materials and 2 high-sensitivity materials in 236 cotton materials. The waxy content on the surface of cotton leaves was significantly negatively correlated with leaf damage levels. The waxy components of cotton leaves were mainly alkane compounds, containing a small amount of esters, ethers and fatty acids. The content of alkanes and esters in waxy leaves of high-resistance cotton germplasm materials was higher than that of high-sensitivity materials. The compound with the largest difference in content are C₂₄H₅₀, C₃₅H₇₂ and C₁₇H₃₆. Conclusion] These results lay a foundation for further study on the effects of waxy content on host selection and mite resistance of cotton mites.