RESISTANCE MECHANISM OF WHEAT TO APHIDS

A brief survey is presented about the damages caused by the aphids fee ding on wheat, and also the resistance factors. They cause considerabl e reductions in grain yield by actual feeding and transmitting a virus . Rhopalosiphum padi L. has the widest range of food-plants and it is the most harmful species among the cereal aphids. This species is domi nant in cereal crops in Hungary, and is an important vector of the bar ley yellow dwarf virus (BYDV) in the world. Resistance to aphids is in fluenced by the quantity and quality of plant extracts being the hydro xamic acids (DIMBOA-aglucone, DIMBOA-glucoside), free amino acids, fre e phenols and sugars.