Resistance to Cereal Leaf Beetle in Wheat: Density and Length of Leaf‐surface Pubescence in Four Wheat Lines¹

Abstract

Measurements of leaf hair length and quantity of leaf hairs were made from seedlings of four wheat ( Triticum aestivum L. em. Thell.) cultivars to develop bench marks for certain genotypes and to determine the effect of leaf size on hair density. Length was measured from photographs of cleared leaf material; density was determined directly from cleared material with the aid of a compound microscope. The superior resistance of Cl 9321 to oviposition of Oulema melanopus (L.), compared with that of ‘Selkirk,’ occurred because of the greater hair density of Cl 9321. The hair length of Selkirk was probably the main factor responsible for the greater resistance of this cultivar compared with that of ‘Chris.’ The importance of choosing leaves of similar growth stages for pubescence studies was demonstrated.