Major plant characteristics associated with resistant sugarcane hybrids to Deltocephalus menoni, the vector of Sugarcane White Leaf Disease

Sugarcane is affected by a wide range of insects causing more than ten percent yield loss. Deltocephalus menoni (Hemiptera: Cicadellidae, Subfamily: Deltocephalinae) is one of the sap-sucking insects serves as the vector of Sugarcane White Leaf Disease (WLD) in Sri Lanka.  WLD is a major threat to sugarcane cultivation resulting severe reduction of cane yield, juice volume, and pure obtainable cane sugar (POCS) while increasing fiber in canes. Effective management of WLD vector is important to limit the spread. This study aims to develop an approach to screen sugarcane varieties for resistance against D. menoni to manage WLD in sugarcane. Principal Component Analysis (PCA) was used to identify key vector-related traits associated with varietal resistance.  Aggregation, amount of feeding and adult longevity were identified as indicators for assessing resistance. Plant morphological traits such as number of leaves, leaf length, and distance between leaves contributed to resistance differentiation among varieties. In addition, PCA of leaf colour, epicuticle wax, arrangement of trichomes, stomata, leaf nutrition, moisture and chlorophyll content also can be used to confirm the resistance status. Resistant sugarcane varieties were characterized by short leaves, lower leaf angle, and thin leaves with higher distance between leaves, leaves with higher red and green colour composition, a higher level of epicuticle wax, shorter trichomes, and thin stomata, a smaller number of thin vascular bundles, thick phloem fiber layer, and a higher distance from the epidermis to vascular bundle. By leveraging these traits, breeders can develop sugarcane varieties with enhanced resistance to D. menoni and WLD, contributing to sustainable pest and disease management in sugarcane cultivation.