Evaluation of Genetic Variability, Heritability and Correlation among Mandarin (Citrus reticulata Blanco) Genotypes

Abstract

The present investigation was conducted at the Agricultural Research Station, Sri Ganganagar, Rajasthan, utilizing seven mandarin genotypes—Mudkhed seedless, Nagpur Seedless, Nagpur mandarin, Kinnow Mandarin, Coorg Mandarin, Khasi Mandarin, and Darjeeling Mandarin—grafted onto Rough lemon rootstock laid out in a randomized block design featuring three replications. Data collected over a four-year period were analyzed to evaluate genetic variability, heritability, and phenotypic correlations among various morphological and fruit-quality traits. Notable variation was detected among the genotypes concerning plant height, canopy volume, stem girth, fruit weight, fruit yield, total soluble solids (TSS), and the TSS/Acidity ratio, indicating a significant level of genetic diversity. High genotypic (GCV) and phenotypic (PCV) coefficients of variation were observed for fruit weight and fruit yield, corroborated by exceptionally high heritability estimates (H² > 0.98), implying that these traits are primarily influenced by additive gene action and can be effectively enhanced through selection. Moderate variability along with high heritability was noted for TSS and the TSS/Acidity ratio, suggesting reliable inheritance to subsequent generations. Correlation analysis indicated strong positive relationships between fruit yield and fruit weight (r = 0.983) as well as TSS (r = 0.921), indicating that simultaneous enhancement of yield and quality traits is achievable. In summary, Kinnow Mandarin demonstrated outstanding performance in terms of canopy volume, fruit weight, TSS, and overall productivity, underscoring its potential as a high-yielding genotype in semi-arid environments.