Cereal Leaf Beetle 1 Plant Resistance: Antibiosis in an Avena sterilis Introduction 2

Abstract

A large portion of the USDA World Collection of Small Grains has been evaluated in the field for resistance to cereal leaf beetle ( Oulema melanopus (L.)) larval feeding damage. The best resistance was found in wheat ( Triticum spp.) with intermediate levels in some barley ( Hordeum vulgare L.) lines and lower levels in oats ( Avena spp.). In 1975, P.I. 311677, an Avena sterilis L. line was noted to have superior resistance to larval feeding damage in comparison with other oat lines in the cereal leaf beetle plant resistance nursery. It was also noted that this line had an unusual amount of leaf surface pubescence. The purpose of this research was to obtain more information about the resistance of this line and to measure relative levels of antibiosis in seedlings of this oat line and other selected oat, barley, and wheat lines in larval weight experiments. The weight of larvae confined to seedlings of P.I. 311677 was significantly lower than the weight of larvae confined to other oat lines. Of the lines tested, antibiosis was greatest in wheat, intermediate in the oat line, and lowest in barley.