Evaluation of the Resistance of Different Tea Cultivars to Tea Aphids by EPG Technique

In order to investigate the resistance of tea plant to tea aphid, the feeding behavior of tea aphids on six different tea cultivars was monitored by (EPG) technique. The result showed that the duration of E1, E2 as well as (E1+E2) which was feeding waveforms of Toxoptera aurantii (Boyer) in tea phloem was significantly different by variance analysis (P<0.05) and so did the duration of the probing of T. aurantii in all the tea tissues. And the six tea cultivars were classified into three groups with cluster analysis, based on the six major parameters which were durations of np, C, E1, E2, F, and G waveforms, then the six major parameters of these three groups were detected by variance analysis, and the rank of six different tea cultivars' resistance to T. aurantii from strong to weak was Zhongcha 108, Sucha 1, Anjibaicha, Longjing 43, Xicha 5, and Sucha 120. As this result was in accord with the investigation into the tea field, we concluded that EPG technique was one of the most important means to examine tea plant resistance to T. aurantii and the durations of waveform E1, E2 and (E1+E2) were important parameters for evaluating resistance of tea plants to tea aphids.