Contribution of Leaf Tissue Parameters for Leaf Rust Resistance in Bread Wheat ( Triticum aestivum L.)

Abstract

In an attempt to understand the contribution of morpho-physiological parameters of leaf tissue in leaf rust resistance, histological analysis was made on resistant as well as susceptible bread wheat genotypes. On average, the resistant genotypes had epidermal cell layer thickness of 17.93 ^m, epidermal cell number of 36.20 per mm2 and laminar thickness of 148.79 (im; while the corresponding
susceptible genotypes had epidermal cell layer thickness of 15.50 |im, epidermal cell number of 33.40 per mm2, and laminar thickness of 145.05 nm. All the three histological parameters had significant negative correlation with leaf rust score (Average Coefficient of Infection) values. The result revealed that resistant genotypes had thicker epidermis, more number of epidermal cells, and thicker leaf lamina than the susceptible genotypes. These leaf morpho-physiological traits might be useful for selection against leaf rust resistance in wheat.