Genetic Studies of Variability, Correlation and Path Analysis in Potato (Solanum tuberosum L.) Genotypes for Yield and Yield Attributing Traits

Potato (Solanum tuberosum L.) breeding requires quantitative information on variation and relationships among traits associated with tuber yield. A field study was conducted at Assam Agricultural University, Jorhat, Assam, during the rabi season of 2021–2022 to evaluate 33 potato genotypes in a randomised block design with three replications. Seventeen traits related to plant growth, tuber characteristics and yield were measured. Analysis of variance indicated significant genotypic differences for all traits. The phenotypic coefficient of variation exceeded the corresponding genotypic coefficient for each trait. Tuber volume had the highest genotypic and phenotypic coefficients of variation (46.69% and 49.63%, respectively). Broad-sense heritability was highest for non-marketable yield per hectare (97.70%), followed by leaf area index (93.00%), whereas the number of stems per hill had the lowest value (31.10%). Genetic advance as a percentage of the mean was also highest for non-marketable yield per hectare (92.98%). Total yield per hectare showed positive associations with marketable yield, tuber yield per plant and average tuber weight at both the genotypic and phenotypic levels. Path analysis identified marketable yield per hectare as having the largest positive direct effect on total yield. Mahalanobis D² analysis grouped the genotypes into three clusters containing 22, 10 and one genotype, respectively. These findings identify variation and trait associations that may inform selection and parental choice within the evaluated material.