Study On Grape Phylloxera Resistance Of Several Grape Varieties

Grape phylloxera is one of the most destructive pests on grapes. Thus, it will be very important to screen resistant germpilasm and develop resistant varieties. The evaluation methods of pest-resistance and the morphological, biochemical and genetics mechanism of the resistance of grape to phylloxera were studied. The main results are as follows:In this study, laboratory bioassays and pot trials were carried out for evaluation on 9 grape varieties. The results showed that, in laboratory identification, Kangzhen No.3 and Kangzhen No.5 were highly resistant to grape phylloxera, just as the highly resistant rootstock SO4 and 5BB, on which the larva of grape phylloxera died quickly or stopped their development at the first stage. And there were not any nodosities and the larva on them in the pot identification. Kangzhen No.1 was low resistant to grape phylloxera, it was non-harm by the grape phylloxera in the potted vine observations. However the grape phylloxera population proliferated 2.4 times on Kangzhen No.1, the infection rate could reach 36.0%. Kangzhen No.6 was susceptible to grape plhylloxera. The danger degree of Kangzhen No.6 were higher than Koyho in laboratory and the results were similar in the pot trials. The results showed that there were no obvious difference between two methods. The evaluation method in vitro was faster and less environmental influence than the evaluation under yield conditions.Infection rate of phylloxera on grape root was significant negative correlated with the content of water, reducing sugar, soluble sugar and starch, but it was significant positive correlated with the content of lignin, dannin, flavonoid and total phenol. The volume of cork layer cells becomes smaller in order, and the number of cork layer cell layers becomes larger in order, the arrangement of cortex cells becomes firmer in order, meanwhile, the same tend as the volume and arrangement of cortex cells, at the same time, the resistance to grape phylloxera becomes stranger with these changes in anatomical structure.Labortary bioassays were carried out for evaluation on the progenies'resistance and inheritance of 6 cross combinations. The resistance to phylloxera belonged to quantitative inheritance, There are demonstrated continuous genetic segregation of resistance in progenies of cross combinations. Specifically, a few hybrids showed higher heredity than resistant parents in the resistance to phylloxera.