Study On The Screening Of Bemisia Tabaci Resistant Materials And Bemisia Tabaci-Resistant Mechanism Of Cucumber

Cucumber is a kind of high nutritional value and much loved vegetable, it has an important role in the supply of vegetables. Bemisia tabaci is one of the major pests of cucumber, with the rapid development of modern agricultural facilities provides more favorable conditions for anniversary breeding of bemisia tabaci, which causes heavy losses to the production of cucumbers. At present, the plants to the resistance of Bemisia tabaci is one of the hot spots in he field of biological research. In the process of comprehensive control of bemisia tabaci, breeding and planting bemisia tabaci-resistant cucumber varieties are one of the most economical and effective measures to control bemisia tabaci. In order to further breed new cucumber varieties with high resistance to bemisia tabaci, and provide theoretical basis for the identification of cucumber bemisia tabaci-resistance. In this experient, the “Daqingba” cucumber(an ordinary cucumber) was used as the control of less anti-bemisia tabaci ability, while the glabrous cucumber was used as the control of anti- bemisia tabaci. We took 370 home and abroad cucumber germplasm resources as materials to the anti-bemisia tabaci screening, and were inoculated bemisia tabaci to the cucumber materials with different levels of anti-bemisia tabaci ability. By studying the contents change of the enzyme activities of peroxidase(POD), phenylalnine ammonialyase(PAL) and polyphenol oxidase(PPO) and some secondary metabolites including flavone, tannins, total phenol, lignin, flavonoids in the leaves before and after inoculation of bemisia tabaci, we explored the relationship of the enzymes and related secondary metabolites with bemisia tabaci resistant ability. The main results of the study were listed as the following:1. The 370 home and abroad cucumber germplasm resources were taken as test materials, we obtained 4 anti-bemisia tabaci meterials. From strong to weak the anti-bemisia tabaci materials were No.4, No.13, No.19, and No.76.2. The related enzyme activities before and after bemisia tabaci inoculation were tested. In seedling period the activities of POD and PPO in the leaves of NO.4 cucumber, which was the highest anti-bemisia tabaci material,were higher than those of the other anti-bemisia tabaci materials. The activity of PAL in the leaves of NO.13 cucumber, which was the high anti-bemisia tabaci material, was higher than that of the other anti-bemisia tabaci materials. In fruiting period the activity of POD in the leaves of NO.4 cucumber, was higher than that of the other anti-bemisia tabaci materials. The activities of PAL and PPO in the leaves of NO.13 cucumber, were higher than those of the other anti-bemisia tabaci materials. The enzyme activity had a little difference at seedling period and fruiting period, because external environment in different period made enzemes activity change slightly. So the bemisia tabaci resistance ability was not determined by a single indicator, but several indicators and the results of multiple factors together.3. The secondary metabolites before and after bemisia tabaci inoculation were tested. In seedling period the contents of flavone, tannins, lignin and flavonoids was the highest in the leaves of NO.4 anti-bemisia tabaci material. The content of total phenol was the highest in the leaves of NO.13 anti-bemisia tabaci material. In fruiting period the contents of tannins, total phenol and flavonoids was the highest in the leaves of NO.4 anti-bemisia tabaci materials. The content of lignin was the highest in the leaves of NO.13 anti-bemisia tabaci material. The content of flavonoids was the highest in the leaves of NO.19 anti-bemisia tabaci materials. It was significantly higher than other insect-resistant materials. The secondary metabolites had a little difference at seedling period and fruiting period, because the external environment changed a lot in different periods. Thus the bemisia tabaci resistance ability was not determined by a single factor, it was closely to the combined action of one or several substance.