Studies On Resistance Of Pepper Varieties To Frankliniella Occidentalis

Frankliniella occidentalis damaged many plants including solanaceae,cucurbitaceae,leguminosae,cruciferae,and so on.The current control was mainly dependent on chemical pesticides.While there not only polluted the environment,but also coud caused residue of chemical pesticide,and increased resistance to pests.So screening and cultivating insect-resistant varieties was the most effective methods to solve these problems.In this paper,5 pepper varieties in Ningxia were chosen to study thrips selectivity and biochemical substance change of peppers damaged by F,occidentalis.The main results were summarized as follows:1.The population dynamics on five pepper varieties were single peak.In the slow growth period and rapid growth period,the population on Hangjiaowuhao were higher than other varieties,on 74-82 were always the lowest.Resistance identification showed that:Hangjiaowuhao,Yangdashuai were the susceptible varietes.Taikongla was the most susceptible variety.Jiaolong was resistant variety,and 74-82 was the most resistant variety.There were some differences in the survival curves.Hangjiaowuhao was belongs to type A,Yangdashuai,Taikongla were belong to type B,Jiaolong,74-82 were belong to type C.Through the analysis of population parameter showed that Yangdashuai,Taikongla,Hangjiaowuhao the most preferred,and Jiaolong,74-82 varieties were not conducive to the growth of thrips.2.There were correlation between the wax content,color selective,smell selective,chlorophyll content and thrips-resistance.This method could be used as an resistance evaluation index in the future,The wax content as resistance evaluation standard,the order was 74-82>Jiaolong>Taikongla>Yangdashuai>Hangjiaowuhao.The color selective as resistance evaluation standard,the order was Taikongla>Jiaolong>74-82>Yangdashuai>Hangjiaowuhao.The smell selective as resistance evaluation standard,the order was Jiaolong=74-82>Taikongla>Yangdashuai>Hangjiaowuhao.3.Soluble sugar,tanninsin and total phenols were correlation with thrips-resistance.In the process of damage,tannins and total phenols content of 74-82,Jiaolong was significantly higher than Hangjiao-wuhao varieties.The tannin content increased firstly and then decreased with the time of injury.The total phenols content decreased with the damage time.4.T he thrips on three kinds of protective enzymes SOD,POD,PPO activity has induced effect,the activities of three protective enzymes can be used as resistance evaluation index.Jiaolong,74-82 varieties of enzyme activity was significantly higher than other varieties,and the trend in the POD and PPO reflect more obvious.