Biological effects of allelochemicals from barley

Abstract

The biological effects of allelochemicals from barley were investigated. A barley cultivar that contains high gramine concentrations (cv.Lara) was found to have adverse effects on the growth and development of larvae of the common armyworm, 'Mythimna convecta' (Walker). Larvae fed on cv.Lara had lower head width (by about 10%) and body weight (by about 30%) than larvae fed on cv.Schooner. Gramine concentration in leaves of cv.Lara was more than 200x that of leaves of cv.Schooner. There were no significant differences in the survival of larvae on the two cultivars. Gramine, when incorporated into artificial diets, was found to have no significant effect on the growth and development of 'M. convecta', although the concentrations of gramine present were higher than in leaves of cv.Lara. ... Studies on the effect of gramine and hordenine on biology of insect pests of barley may be valuable in breeding resistant cultivars. Reports in the literature show that high gramine concentration in barley affects the palatability of barley to grazing animals and hordenine also showed adverse effects on animals. Consequently, cultivars with very high gramine and hordenine content may be not desirable. Cultivars that contain lower gramine and hordenine concentrations may be useful when used in an integrated pest management program.