Genetics of corn leaf aphid (Rhopalosiphum maidis) resistance in barley.
A study was undertaken to determine the genetics of corn leaf aphid (CLA) resistance in barley under controlled conditions with artificial inoculation at adult plant stage. Inheritance of CLA resistance was investigated in five resistant barley genotypes (EB921, EB2507, Manjula, DL529 and K144) in crosses with susceptible parent Alfa93 in F1, F2, F3 and backcross (BCF1) generations. The aphid inoculation was done using the brush method as well as the detached leaf method. Individual plants were classified in resistant, moderately resistant, susceptible and highly susceptible categories base on number per shoot as well as multiplication of CLA on any of the fresh, young leaf. The plants scored as resistant or moderately resistant were observed twice more at 10 days interval to confirm their reaction. Resistance was governed by a single dominant gene in EB921, DL529 and K144, while it was monogenic recessive in Manjula and EB2507. These diverse sources may be used in breeding for CLA resistance in barley improvement programme.