EVALUATION FOR RESISTANCE TO APHIDS OF WHEAT GERMPLASM RESOURCES IN CHINA

Host plant resistance plays important roles in controlling pests and protecting of natural enemies in an agroecosystem, and the effect of insect resistant varieties in reducing damage is conspicuous. Fuzzy recognition technique evaluation were used to determine sources of resistance in wheat to populations of the wheat aphids in five field experiments over 2 years in wheat-producing areas of China. Results showed that the majority of wheat varieties identified were susceptible to aphids, and no immune and highly resistant varieties was observed. The mean percentage from the wheat varieties with resistant, lowly susceptible, moderately susceptible and highly susceptible to aphid were 9.30%, 23.15%, 42.32%, and 25.23% in whole wheat varieties respectively. 5 wheat varieties (Lantian18, Lantian20, Lantian22, Lantian00-30 and Shanmai175) were moderately resistant in Jiangyou in 2009, other resistant sources were low levels for aphid-resisant. And more importantly, 2 wheat varieties (Lantian20, Lantian22) with the continuous resistance to wheat aphid in the five experimental fields over 2 years were found. Although resistance of wheat varieties had a close relation to their genetics and inheritance, we also found that the evaluation result of the same wheat varieties were varied in different place. The results indicated that the resistance to aphid could be affected by geographical environment.These evaluations on reaction to aphid metapopulation that could be crucial when germplasm is used in crosses to improve wheat cultivars. This research is part of program to evaluate germplasm for useful traits and make this information available to the germplasm system.