Correlation of leaf trichome density and stomatal parameters of some commercial sugarcane genotypes to orange rust incidence and severity

摘要

Abstract Orange rust is one of the important diseases of sugarcane in tropics causing huge losses in susceptible genotypes which could be managed by deploying resistant genotypes. The present study evaluated the field resistance of seventeen commercial sugarcane genotypes in Andhra Pradesh to orange rust and correlated the stomatal parameters and trichome density to orange rust incidence and severity. Seventeen sugarcane genotypes were planted in an augmented design during May, 2019 and rust infection was allowed to occur naturally. Stomatal characters and trichome density were recorded by tissue imprinting method. Results revealed that disease incidence and severity was high in the sugarcane genotypes, 2006 A 64, 2006 A 102 and 2009 A 107. Stomatal density/mm2, polar diameter, equatorial diameter and trichome density/mm2 ranged between 142.50 and 234.50 stomata/mm2, 33.36–46.70 μm, 12.09–22.10 μm and 56.50-148.50 trichomes/ mm2, respectively. The analysis of data for rust incidence showed significant correlation with trichome density on lower surface of sugarcane leaves.