Assessment of Variability, Genotype × Growth Stage Interaction of Physiological Traits, and Their Association with Grain Yield in Finger Millet [Eleusine coracana (L.) Gaertn.] Evaluated under Natural Blast Disease Incidence
Sujata Bhat
Department of Studies in Botany, Davangere University, Shivagangothri, Davangere – 577002, Karnataka, India.
K. B. Palanna
Project Coordinating Unit, ICAR-AICRP on Sorghum and Small Millets, University of Agricultural Sciences, GKVK, Bengaluru-560065, Karnataka, India.
R. Madhusudhana
Project Coordinating Unit, ICAR-AICRP on Sorghum and Small Millets, University of Agricultural Sciences, GKVK, Bengaluru-560065, Karnataka, India.
N. Anuradha
Agricultural Research Station, Acharya NG Ranga Agricultural University, Vizianagaram- 535001, Andhra Pradesh, India.
TSSK Patro
Agricultural Research Station, Acharya NG Ranga Agricultural University, Vizianagaram- 535001, Andhra Pradesh, India.
N. Marappa
Project Coordinating Unit, ICAR-AICRP on Sorghum and Small Millets, University of Agricultural Sciences, GKVK, Bengaluru-560065, Karnataka, India.
H. S. Padmashri
University of Agricultural Sciences, GKVK, Bengaluru-560065, Karnataka, India.
D. N. Vinutha
Project Coordinating Unit, ICAR-AICRP on Sorghum and Small Millets, University of Agricultural Sciences, GKVK, Bengaluru-560065, Karnataka, India.
I. S. Tilak
Project Coordinating Unit, ICAR-AICRP on Sorghum and Small Millets, University of Agricultural Sciences, GKVK, Bengaluru-560065, Karnataka, India.
M. Thippeswamy *
Department of Studies in Botany, Davangere University, Shivagangothri, Davangere – 577002, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
Aim: Blast disease is one of the most destructive biotic stresses limiting finger millet production, particularly in semi-arid regions. It adversely affects crop productivity by reducing photosynthetic efficiency across growth stages and can cause substantial grain yield losses. This study evaluated variability in physiological traits, genotype × growth stage interactions, and associations between these traits and grain yield among finger millet genotypes under natural blast disease incidence.
Study Design: Thirty finger millet genotypes were evaluated in a Randomised Complete Block Design with three replications.
Place and Duration of Study: The study was conducted at the ICAR–All India Coordinated Research Project on Small Millets, University of Agricultural Sciences, Bengaluru, Karnataka, during Kharif 2025.
Methodology: Genotypes were grown in two 3 m rows at a spacing of 30 × 10 cm. One blast-resistant, high-yielding cultivar and two susceptible checks were included. An infector-row technique under natural epiphytotic conditions was used to promote uniform blast disease pressure. Blast severity, grain yield per plant, days to maturity, and major physiological traits were recorded.
Results: Significant genetic variation was observed among the finger millet genotypes for all evaluated traits. Genotypes GE 16, GE 4805, and GE 5155 exhibited high grain yield, favourable blast responses, and favourable physiological performance. The genotype × growth stage interaction was highly significant for SPAD chlorophyll content, leaf area index, net photosynthetic rate, stomatal conductance, and transpiration rate. Susceptible genotypes recorded higher proportions of unfilled grains than the resistant check. Net photosynthetic rate, stomatal conductance, and transpiration rate showed significant positive associations with grain yield.
Conclusion: GE 16, GE 4805, and GE 5155 were identified as promising genotypes combining high grain yield, favourable blast responses, and physiological efficiency. Photosynthetic traits may serve as useful selection criteria when breeding high-yielding, blast-tolerant finger millet cultivars.
Keywords: Finger millet, grain yield, blast disease, physiological parameters, variability, trait association