Grouping of Disease Resistant Sorghum Genotypes Based on Cluster Analysis Multivariate Tool
V. Pavithra *
Uttar Banga Krishi Viswavidyalaya, Pundibari, West Bengal, India.
K. V. Ashalatha
University of Agricultural Sciences, Dharwad, India.
B. Swathi
Department of Plant Pathology, KVK, Chintamani, India.
H. T. Vinay
Uttar Banga Krishi Viswavidyalaya, Pundibari, West Bengal, India.
Shridhar Ragi
Indian Agricultural Research Institute, New Delhi, India.
*Author to whom correspondence should be addressed.
Abstract
Sorghum ranks as the fifth leading cereal grain globally in terms of both production and cultivated area, following wheat, rice, maize, and barley. Disease incidence is a significant limiting factor for sorghum production, directly impacting crop yield. This study utilizes secondary data collected from the All India Co-ordinated Research Project (AICRP) on Sorghum, Dharwad Centre. A total of forty-four genotypes were assessed in Initial Advanced Hybrid Trials, and forty-three genotypes were evaluated in Varietal Trials to study disease incidence, specifically Downy mildew, Charcoal rot, and Rust. The disease scores obtained from all genotypes were subjected to Hierarchical Clustering analysis to cluster the genotypes based on their disease resistance. The clustering analysis, using between-group linkage and dendrogram construction, resulted in the division of the forty-four hybrids into two clusters, while the forty-three varieties were grouped into three clusters. Notably, CSV 22 and CSV 29 R demonstrated high resistance to charcoal rot and resistance to both downy mildew and rust. On the other hand, SPV2758 and SPV2746 exhibited high susceptibility to downy mildew, resistance to rust, and moderate resistance to charcoal rot. The identified genotypes in this study hold potential as valuable sources of multiple disease resistance for incorporation into breeding programs aimed at varietal or hybrid development.
Keywords: Cluster, dendrogram, hierarchical clustering, disease scores, genotypes