Evaluation of plant resistance in progenitors of wheat against foliage feeding aphids

Among different aphid species attacking wheat crop, bird cherry oat aphid Rhopalosiphum padi L. and corn leaf aphid R. maidis Fitch. appear every year in Punjab and severely threaten wheat production. One hundred sixty two progenitors of wheat including Aegilops tauschii, Ae. speltoides, Triticum dicoccoides, T. monococcom, T. boeoticum and synthetic wheats were screened for three years against foliage feeding wheat aphids. The majority of wheat accessions were found susceptible or highly susceptible to aphids. In the first year of screening (201213), four resistant (R) and 29 moderately resistant (MR) wheat accessions were identified. Re-evaluation of R and MR accessions in succeeding year (2013–14) yielded one R and six MR accessions. Further screening was done in 2014–15 to confirm some potential resistance sources. In the third year, seven promising accessions showed same reaction and confirmed the results of 2013–14 screening. Overall, the three years of screening identified one resistant (Aegilops tauschii 14096) and six moderately resistant accessions (Aegilops tauschii 14135, 14232, 14339, 14348, 14576 and 3733) against foliage feeding wheat aphids. Morphological/phenological investigations of resistant and susceptible genotypes indicated that characters like dark green colour and higher panicle length offer conducive conditions for the population build of aphids in wheat.