Evaluation of mango (Mangifera indica L.) germplasm for phenotypic diversity and breeding potential in Pakistan

Abstract

Mango (Mangifera indica L.) is a globally significant tropical fruit crop, widely cultivated across South and Southeast Asia, with Pakistan recognized as a major center of production and varietal diversity. However, the genetic potential of mango in Pakistan remains underutilized due to limited morphological characterization of its diverse germplasm. This study assessed the morphological diversity of 89 Mangifera indica L. genotypes at the Mango Research Station (MRS), Shujabad, Pakistan. The germplasm included indigenous varieties, hybrids, and exotic genotypes originated from diverse eco-geographical regions. A total of 43 qualitative and 14 quantitative traits related to tree, leaf, inflorescence, fruit, and stone were recorded and analyzed. The Shannon–Weaver diversity index indicated high variability in traits such as canopy shape, young leaf color, fruit shape, blush color (ripe and unripe), and stone fiber texture. Quantitative traits including fruit weight, stone weight, tree height, and trunk diameter exhibited high diversity with a coefficient of variation exceeding 35%. Significant differences were observed among genotypes for all the quantitative traits. Some of the promising genotypes were identified for commercial cultivation and breeding initiatives. Correlation analysis helped to identify associations among key traits, facilitating the selection of superior germplasm for breeding. Principal component analysis revealed four principal components for quantitative traits and seventeen for qualitative traits, each with eigenvalues greater than 1, contributed over 75% of the total variation. Cluster analysis grouped genotypes into five clusters based on quantitative traits and six clusters based on qualitative traits, reflecting both geographical origin and morphological similarities. This study highlights the rich phenotypic diversity of a large collection of mango germplasm in Pakistan and provides valuable insights for its conservation, genetic improvement, and sustainable utilization in future mango breeding programs in the region.