Evaluation Of Pepper For Resistance To Polyphagotarsonemus Latus(Banks)

Pepper is one of the main vegetable crops in China. So, how to manage the pest and disease during its growth has been attracting attention.. Polyphagotarsonemus lotus is one of the major pests of pepper. The widespread existence of Polyphagotarsonemus latus harms more than 30 families 70 genuses plants. If the plants have been harmed by the mite, it will result in the decline for the quality and production of pepper. So, it is necessary to find an effective way to control the mite. However, the Polyphagotarsonemus latus is very small in shape, so it is very hard to find it. For these feature of the mite, if the common pesticide is used to control the mite, it will be very hard to control the harm of the Polyphagotarsonemus latus. Therefore, it has caused the difficulties to the control of pests of pepper.Cultivating the resistant cultivars is one of major methods for the Integrated Pest Management (IPM) program of Polyphagotarsonemus latus. The evaluation of disease resistance of the germplasm resources, screening, study the mechanism of anti-mite, it is the major measure of the anti-mite breeding.As the study of the resistance evaluation and mechanism of Polyphagotarsonemus latus on 11 kinds of chili materials, the results showed as below:1. Using four resistant methods below: mite density ratio, mite population density investigation, harm of leave index and unit area chlorophyll as resistant appraisal standards, the resistance of 11 kinds of chili to Polyphagotarsonemus latus (Banks) was evaluated. Paojiao No.1 is the highest resistance.We also found 2 other kinds of high sensitivity material, which are Tiaojiaoxinxiu and American green peppers respectively.2. A new method to identify resistance was explored by the 11 kinds of pepper as experiment material. Comparing the four resistance identification methods, which were the method of mite density ratio, method of harm of leave index, method of unit area chlorophyll, method of mite population density investigation, the results were identical. As a result, the coincidence between the method of mite population density investigation and the method of mite density ratio was 54.6%, while 72.7% between the method of harm of leave index and the method of mite density ratio, 54.6% between the method of unit area chlorophyll and the method of mite density ratio. From the linear correlation coefficient, the method of harm of leave index and the method of mite density ratio proved to be positively correlated, the correlation coefficient was up to r=0.9419 (y=0.1917x+0.0968), the method of mite population density investigation and the method of mite density ratio proved to be positively correlated, the correlation coefficient was up to r=0.9915 (y=2.3835x+0.1195), the method of unit area chlorophyll rate and the method of mite density ratio proved to be negative correlation, the correlation coefficient was up to r=-0.8855 (y=-0.1319x+1.1319).3. The physical resistance mechanisms of the different pepper cultivar to the polyphagotarsonemus lotus were analyzed. The unit area villus density, villus length, mite density rate of the 11 kinds of pepper were analyzed by the linear correlation analysis. The mite density rate and the units area villus density proved to be the negative correlation, the correlation coefficient was up to r=-0.845 (y=-84.03x+2229.65) , and there had no correlation with the villus length.4. The Bio-chemical mechanism of the different pepper cultivar to the Polyphagotarsonemus latus was analyzed, with the linear correlation analysis of the unit area chlorophyll rate and the mite density rate. It was showed as below: All the value proved to be significant negative correlation, with the correlation coefficient up to r=-08855(y=-0.1319x+1.1319). the mite density and the content of the soluble sugar of the plant had exist sigmficant positive correlation, with the correlation coefficient up to r=-0.6720(y=-6.0813x+58.081). it was showed that the protein content and the plants did not have a significant resistance correlation, with the correlation coefficient up to r=0.029(y=0.1199x+9.3766). It is proved that there is significantly negative correlation between the mite density ratio and the content of the free aspline acid gluline. Forther more there was no obvious correlation between the mite density ratio and lysine. However, there was a high positive correlation between the mite density ratio and the content of alanine(Y=1.883-4.89X_Asp**-6.94X_Glu**+1.523X_Ala*-5.51X_Lys).