Study On The Resistance Of Different Tea Varieties To Toxoptera Aurantii Boyer

Tea aphid,Toxoptera aurantii Boyer,belong to Hemiptera,Aphididae.The main feeding and harmful tea tree is one of the important pests of tea trees,which are distributed both at home and abroad.A large area of tea aphid damage to the tea garden in spring and autumn,harm symptom clusters in tea shoot buds,leaves on the back of the sucking sap,saliva to plant endocrine,destroy normal physiological metabolism of tea,resulting in leaf bud atrophy,growth arrest,thus affecting the yield and quality of tea.In this paper,the selectivity of tea aphid to different tea varieties was studied.The feeding behavior of tea aphid on different tea varieties was analyzed by EPG technology.The relationship between morphological structure and biochemical components of different tea varieties and insect resistance was analyzed.The main results are as follows:1 Selectivity of tea aphid to different tea varietiesThe tea aphid has a certain selectivity for different tea varieties and can reproduce and grow on it,the population of the aphid was on the rise,and the difference between the varieties was significant.The order of selective strength and weakness of tea aphid to different tea varieties was as follows: Qianmei 601 > Qianfu4 > Qiancha 1 > Qiancha 8 > Fuding Dabaicha.The aphid resistance of different tea varieties was graded according to the ratio of aphid quantity: Qiancha 8 and Fuding Dabaicha are medium resistant varieties;Qiancha 1 and Qianfu 4 are susceptible varieties;Qianmei 601 is a highly susceptible variety.2 Feeding behavior of tea aphid on different tea varietiesTime to 1st probe from start of EPG and total duration of np of Fuding Dabaicha were longer than those of other varieties.The total duration of C wave of Qiancha 8was significantly longer than that of other varieties.The time from 1st probe to 1st Ey wave of Qianmei 601 was significantly shorter than that of other varieties.The number,time and individual proportion of F and G waves on Qiancha 8 and Fuding Dabaicha were higher than those of other varieties.The results showed that themechanical resistance of the tea aphid in Qiancha 8 and Fuding Dabaicha was high.The duration of 1st E wave of Qianmei 601 was significantly longer than that of other varieties.The contribution of E1 to phloem phase wave of Qiancha 8 and Fuding Dabaicha was significantly higher than that of other varieties.The total duration of E2 wave of Qianmei 601 was significantly longer than that of other varieties,however,the total duration of E2 of Qiancha 8 and Fuding Dabaicha is the shortest.The percentage of E2 wave in total time was Qianmei 601 58.96% > Qianfu4 36.68% > Qiancha 1 35.71% > Fuding Dabaicha 16.71% > Qiancha 8 10.58%.It shows that the tea aphid likes to eat in the Qianmei 601 for a long time;and does not like to eat in Fuding Dabaicha and Qiancha 8,and the time of feeding is short.The cluster analysis divided the different tea varieties into 3 types.The first class Qiancha 8 and Fuding Dabaicha varieties have strong resistance to the tea aphid,the second class Qiancha 1 and Qianfu 4 are in the middle,and the third type Qianmei601 resistance is the weakest.3 Analysis of the morphological structure and biochemical components of the resistance of different tea varieties to tea aphidThere was no significant correlation between the leaf color and leaf thickness of tea varieties and the ratio of tea aphids.There was a significant positive correlation between the stomatal density and the ratio of tea aphid in tea varieties,hair density and aphid ratio were negatively correlated.In the relationship between the morphological structure of tea varieties and the host selectivity of the tea aphid,the stomatal density is the main factor affecting the resistance of tea varieties to aphid resistance.The correlation between the content of amino acid and the ratio of tea aphid was not significant.There was a significant positive correlation between the soluble sugar content of tea varieties and the ratio of tea aphid,there was a significant negative correlation between the content of tea polyphenols and caffeine and the ratio of aphid.In the relationship between the biochemical components of tea varieties and the host selectivity of the tea aphid,caffeine content is the main factor affecting theresistance of tea varieties to aphid resistance.