Status of yellow leaf resistance in sugarcane germplasm and parental clones at Sugarcane Breeding Institute, India

Abstract

Yellow leaf (YL) caused by Sugarcane yellow leaf virus (SCYLV) was first reported in India during 1999 and in recent years it has attained epidemic proportions, seriously affecting sugarcane production in the country. In the absence of disease resistant varieties for cultivation, virus-free tissue culture seedlings derived through meristem culture are recommended to manage yellow leaf in sugarcane. Further, host resistance has not been exploited due to lack of information on resistance to the disease in the germplasm and the parents. Sugarcane Breeding Institute (SBI), Coimbatore houses one of the largest collections of sugarcane germplasm and hybrid collections. We have conducted detailed surveys on YL symptom incidence and severity for the last five seasons in the germplasm resources totalling ~ 4066 genotypes/varieties maintained by the Institute at Coimbatore and its research centres, Agali, Kannur (Kerala) and Karnal (Haryana). Both YL symptom incidence and severity on a ‘0’-‘5’ grade system were recorded in the sugarcane germplasm resources. Among the different centres / collections Agali centre recorded more severity to YL followed by National Hybridization Garden (NHG), National Active Germplasm (NAG) and ‘Co’ canes. However, Saccharum spp. clones maintained at Kannur recorded low YL symptom incidence and least severity for the disease symptoms. Overall, the study indicated that most of the parents used for breeding and hybridization were affected by YL to varying severities. High incidence of vector population and constitution of varietal / parental materials are suspected for the high disease incidence and intensity in the two collections. We have identified 463 resistant sources in the hybrid clones and 773 in Saccharum spp. Detailed surveys for the YL symptom incidence /intensity for the first time in a large varietal collections and germplasm of sugarcane have identified resistant sources for YL. The outcome of the study lays foundation for developing YL resistance in sugarcane progenies in the country.