Comparative Correlation Analysis in M\(_2\) Populations of Horse Gram (Macrotyloma uniflorum [Lam.] Verdc.) Generated Using Ethyl Methane Sulphonate (EMS) and Sodium Azide (SA)
Chetangouda G Patil *
Department of Genetics and Plant Breeding, College of Agriculture, Bangalore – 560065, UAS Bangalore, Karnataka, India.
Bangaremma S Wadeyar
AICRP on Pearl Millet, RARS, Vijayapur-586101, UAS Dharwad, Karnataka, India.
Soregaon C D
AICRP on Sorghum, RARS, Vijayapur-586101, UAS Dharwad, Karnataka, India.
Ashvathama V H
AICRP on Sorghum, RARS, Vijayapur-586101, UAS Dharwad, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: Horse gram (Macrotyloma uniflorum) an underutilized legume valued for its drought tolerance and nutritional richness suffers from limited improvement due to its narrow genetic base and self pollinating nature. The present study aimed to determine the correlations between seed yield and its component traits in EMS and SA induced M2 populations with the goal of influential yield components for indirect selection and breeding strategies.
Study Design: The experiment was conducted using an augmented design with four blocks and five checks whereM2 populations were raised from chemical mutagenic treatments and evaluated alongside checks.
Place and Duration of Study: The study was carried out during late Kharif 2023–2024 at the College of Agriculture, Vijayapur, University of Agricultural Sciences, Dharwad, Karnataka, India.
Methodology: Seeds of the horse gram variety GPM-6 were treated with ethyl methane sulphonate (EMS: 0.1–0.4%) and sodium azide (SA: 0.03–0.1%) to generate M2 populations. Data were collected on nine morpho-physiological traits like, days to germination (GD), days to maturity (DM), plant height (PH), number of pods per plant (NOP), pod length (PL), number of seeds per pod (NSPP), test weight (TW) and seed yield per plant (SYPP). Phenotypic correlation coefficients were estimated and significance was tested using standard statistical methods. Analyses were performed in RStudio software.
Results: In EMS derived populations, SYPP showed a very strong positive correlation with NOP (r = 0.92) and moderate positive associations with NSPP, PL and PH while GD was negatively correlated. In SA derived populations SYPP was strongly associated with NOP (r = 0.94), PH, NSPP and PL but TW showed negative associations with both SYPP and NOP. These mutagen specific insights highlighted the importance of correlation analysis for designing effective breeding strategies in horse gram improvement.
Conclusion: The study identified NOP, NSPP and PL as the most reliable yield contributing traits for simultaneous consideration during selection. Therefore, the generated two M2 populations may be advanced through further breeding programs to develop high yielding varieties of horse gram.
Keywords: Horse gram, ethyl methane sulphonate, sodium azide, M2 mutants, correlation, yield components