Screening Of A.gossypii Resistant Germplasm Materials Based On EPG Technology

Aphis gossypii Glover(Hemiptera: Aphididae)is an important pest that seriously damages cotton yield and quality.In the absence of effective aphid resistance gene,screening and establishing a method for identification of A.gossypii resistance from cotton germplasm materials can provide theoretical basis for breeding and field control of A.gossypii resistant cotton materials.This paper took 8 known anti-aphid cotton varieties as the research object,indoor survey statistics and analysis of growth and reproduction parameters such as the survival rate,number of offspring and R0 of A.gossypii,collected the relevant parameters of A.gossypii feeding behavior on different cotton materials.Through the main component analysis of A.gossypii growth,reproduction and EPG parameters,five EPG parameters were selected as the evaluation indicators of cotton resistance to A.gossypii.Based on the five main EPG indexes,80 germplasm cotton materials were screened for aphid resistance,which laid a theoretical foundation for indoor EPG technology for screening aphid-resistant cotton materials.The changes of A.gossypii feeding behavior over time were systematically studied,aiming to clarify the A.gossypii feeding behavior and provide scientific basis for spraying pesticides in the field.1.The probing and feeding behavior of A.gossypii on 8 cotton varieties showed different resistance to aphids in the field were clarified.The results showed that the cotton aphid resistance grade identified in the laboratory was consistent with those identified in the field.The total number of Np,total number of E1,time to 1st probe,duration of 1st E1,and time to 1st E2 were selected,combined with survival rate,number of offspring and R0 of A.gossypii on leaves.These five main EPG parameters can be used as preliminary indicators for cotton resistance to A.gossypii,provide important theoretical basis and technical support for cotton anti-aphid identification method.2.Based on the parameters such as the survival rate,number of offspring and R0 of A.gossypii on different cotton germplasm materials,combined with EPG-related indicators,80 cotton germplasm materials were screened for resistance to A.gossypii.The results showed that the materials with high resistance were: “Taiyuan 02-25”,“402”,“MS-66”,“Taiwan Recovery 3” and “Liaomian 1” > “Brazil 017” and “Yishuhong” > “Brazil 014” and “Donglannanhengdahua” > “PD9364” and “Lu R1297” et al.Materials that are relatively sensitive to aphids were: “Jinmian 21” > “Jinnongdayuan 2-3”,“Bangxu-lu”,“Fuchuangshibadahua” and “Jimian 1” > “AC239” > “PD0111”,“Soviet 143”,“Blanco” and “Jisheng 03H16” et al.Other cotton materials were in an intermediate aphid-resistant state.3.The change of feeding behavior of A.gossypii in one day was clarified.The results showed that between 10:00~12:00 and 17:00~19:00,the duration of Pd,E1 and E2 was long,and A.gossypii probe mesophyll cells,saliva secretion,passive sucking juice and other oral needle activity were strong.If a pesticide with dual functions of contact and stomach poisoning is used to control A.gossypii,considering the application conditions of the pesticide itself,it is recommended to spray pesticides between 10:00~12:00 and 17:00~19:00,which can more fully play the dual role of contact and stomach poison.