Screening the resistance to aphid of spring wheat germplasm

From 2002 to 2004,three highly resistant accessions and nine resistant accessions to the aphid were screened out from 521 spring wheat germplasms by the method of aphid index,which accounted for 2.29% of all the varieties.Moreover,these three highly resistant accessions and five highly susceptible accessions were screened by artificial infestation during the grain filling stage and the result indicated that the resistance screened by artificial infestation on panicle was the same as that by the method of aphid index,and the result also showed that antibiosis was one of the resistant mechanism of the two highly resistant accessions C272 and 04-9284 but,as a highly resistant accession,C151 showed low antibiosis to the aphids.So we concluded that non-preferrence might be the main resistant mechanism of C151.