Resistance and susceptibility of various wheat varieties to Sitobion avenae (Hemiptera: Aphididae) in Iran

The English grain aphid, Sitobion avenae (Fabricius), is a severe pest of wheat plants in temperate countries. Therefore, we carried out primary screening to assess the resistance or susceptibility of 23 commonly grown wheat varieties to this aphid at greenhouse and laboratory conditions in Iran. Also, population attributes of this aphid were evaluated on six wheat varieties, namely Saysonz, Arta, Moghan3, Zagros, Sardari and Shirodi. The aphids were colonized on the Hirmand wheat variety in a growth chamber at 20 +/- A 1A degrees C, 60 +/- A 5% R.H. and a photoperiod of 14:10 (L:D). The tested varieties were grouped into three major classes including A (e.g., Shirodi, Falat and Moghan2), B (e.g., Sardari, Zagros and Tagan) and C (e.g., Arta, Saysonz, Moghan3 and Pishtaz). Also, the results of the life history traits showed that the developmental time of nymphal stage ranged from 7.5 days on Zagros to 10.8 days on Saysonz. The intrinsic rate of increase (r (m) ) of S. avenae varied from 0.133 (day(-1)) on Saysonz to 0.210 (day(-1)) on Shirodi. Jackknife estimates of other population parameters on these varieties were evaluated. As a result, our findings showed that the varieties Saysonz, Arta and Moghan3 were partially resistant against S. avenae, whereas Shirodi, Zagros and Sardari were relatively susceptible.