INVITRO SELECTION FOR RUSSIAN WHEAT APHID (DIURAPHIS-NOXIA) RESISTANCE IN WHEAT (TRITICUM-AESTIVUM)

The Russian wheat aphid (Diuraphis noxia) is a pest on wheat (Triticum aestivum) in many regions of the world. The aphid injects a phytotoxi n when it feeds. Identification of somaclonal variants with phytotoxin resistance may shorten development time for resistance. Wheat calli f rom the susceptible cultivar 'Stephens' were exposed to an extract fro m the aphid. Five plants were regenerated from 100 treated calli. Resi stance to the aphid was observed in both the R2 and R3 generations. On e of the six R3 populations had improved resistance for leaf curling a nd leaf folding, while another had improved response for chlorosis dam age. These results indicate that the use of aphid extract on wheat cal lus offers an alternate method for development of resistance to the Ru ssian wheat aphid.