Resistance to sorghum midge (Contarinia sorghicola Coquillet) in grain sorghum

Abstract

Standardized levels of infestation of sorghum midge Contarinia sorghicola Coquillet were used to compare the levels of resistance in sorghum cultivars (Sorghum bicolor) in glasshouse experiments at Biloela in Central Queensland. Sorghum heads were reduced to 250 florets and ten female midges were caged over each head on three consecutive days during anthesis. Two breeding lines from the U.S.A., IS 12608C and IS 12664C were superior (P < 0.01) to Alpha and KS 19 in percentage seed set and number of midge progeny produced. The percentage seed set was 50, 54, 22, 12 for IS 12608C, IS 1664C, Alpha and KS 19, respectively. The Indian line Q 13828 was susceptible. Testing with a standardized level of infestation is a useful technique for screening parents in a breeding program aimed at incorporation of midge resistance into agronomically useful hybrid cultivars.