Correlation and Path Coefficient Analysis of Yield and Yield Attributing Traits in Pigeonpea [Cajanus cajan (L.) Mill Sp]

Abstract

Background: Pigeonpea [Cajanus cajan (L.) Millsp.] is a diploid species (2n = 2x= 22), often cross-pollinated, with a genome size of 833.1 Mbp. The inheritance of quantitative traits is often affected by variation in other traits, resulting from pleiotropy or genetic linkage. Understanding the relationships between yield and its components is crucial for developing effective selection strategies. Aim: This study aimed to conduct correlation and association analyses for grain yield and yield-contributing features in order to select genotypes with acceptable attributes for use in crop improvement programs. Methodology: The experiment was conducted in a Randomised Complete Block Design (RCBD) with three replications. The experiment was conducted at the Agricultural and Horticultural Research Station, Kathalagere, during Kharif 2024. The experimental material comprised 13 pigeonpea genotypes along with three checks (TS-3R, BRG-5, PRG-175). These were evaluated for ten characters namely days to 50 per cent flowering, days to maturity, plant height (cm), number of primary branches per plant, number of secondary branches per plant, number of pods per plant, number of seeds per pod, pod length (cm), 100 seed weight (g), protein content (g/100g) and seed yield per plant (g). Correlation and path analysis were estimated. Data was recorded and statistical analysis was carried out using R software. Results: Association studies showed that seed yield per plant had a significant positive correlation with the number of pods per plant and was most strongly correlated with plant height, followed by days to 50% flowering, days to maturity, number of secondary branches per plant, and protein content. Direct selection for days to 50 per cent flowering, number of seeds per pod, pod length, number of pods per plant and plant height may be advantageous for selecting the high-yielding genotypes in pigeonpea. Indirect effects of the number of seeds per pod on seed yield via the days to 50 per cent flowering, 100 seed weight, protein content, plant height and number of secondary branches per plant. Therefore, this trait appears to be a key contributor to seed yield and should be a focus in selection programs aiming to increase seed yield. Conclusion: Through this study, it is clear that yield improvement programs could prioritise traits like the number of secondary branches per plant, number of seeds per pod, number of pods per plant, plant height and seed yield per plant in breeding programmes.