Fouad Meradsi

Natural resistance of broad bean against the Black bean aphid Fouad Meradsi

The level of resistance of fourteen cultivars of broad bean, Vicia faba was screened in the field against the main aphid pest of faba bean, the Black bean aphid, Aphis fabae Scopoli during January to April 2011 in Biskra region (in the east of Algeria). Among the cultivars tested, six cultivars (1, 9, 12, 13, 14 and 15) were the most resistant in the three counts, while three cultivars (4, 6 and 11) were showed a high susceptibility against this aphid at least once. The relationship between the level of resistance and morphological characters of cultivars indicated that the resistant cultivars have a longer leaflet than the high susceptible cultivars. Tests for antixenotic, antibiotic tolerance resistance of apterous A. fabae were investigated among the five cultivars (1, 4, 12, 13, and 14) at 17 ± 5°C, 70 ± 10% RH and a photoperiod of 14: 10 (L: D)h. The chemical analysis showed that the cultivar 12 had a lowest level of flavonoids than the other cultivars. However, the content of total phenols among the five cultivars did not differ significantly. The cultivars 12 and 1 had a high level of antixenosis and a moderate level of antibiosis. The cultivar14 had a high resistance level.