RESISTANCE OF BARLEY VARIETIES TO THE APHID RHOPALOSIPHUM PADI (L.)

Abstract

Forty-nine of one hundred and thirty-six barley varieties tested in the greenhouse showed some resistance (antibiosis or tolerance) to the aphid Rhopalosiphum padi (L.). When the 49 varieties were retested in the field, 14 demonstrated both antibiosis and tolerance. There was no significant difference in antibiosis among these 14 varieties. No varieties tested were completely immune to the aphid. The varieties Rojo C.I. 5401 and C.I. 3906-1, which showed antibiosis and tolerance to infestations of the aphid in both greenhouse and field, are known to be resistant to the barley yellow dwarf virus. The varieties C.I. 2376, Velvon 11 C.I. 7088, Compana C.I. 5438, Club Mariout C.I. 261 and Kindred C.I. 6969 showed some resistance to the aphid, and are also known to show varying degrees of resistance to the virus, indicating that there may be some correlation between vector resistance and virus resistance in barley plants.