DEVELOPMENT OF A TRITICALE RESISTANT TO THE GREENBUG - AN HISTORICAL-PERSPECTIVE

A greenbug [Schizaphis graminum (Rondani)] resistant strain of rye (Se cale cereale L.) 'Insave F.A.' from Argentina was crossed with 'Chines e Spring' wheat (Triticum aestivum I,.) and also with 'Elbon' and 'Bal bo' cultivars of common rye. Juvenile plants of the primary wheat X ry e hybrid were treated with colchicine. Partially fertile amphidiploids were obtained that are resistant to greenbug Biotypes B and C. F-1 an d F-2 populations of seedling plants derived from crosses of 'Insave F .A.' with 'Elbon' and 'Balbo' rye were tested for reaction to the gree nbug to determine the genetic basis of inheritance. The results confir med previous reports that resistance in 'Insave F.A.' is conditioned b y a single dominant gene.