Multivariate Analysis of Okra [Abelmoschus esculentus (L.) Moench] Genotypes and Hybrids based on Mineral Content

Abstract

Background: In 2021, the world production of okra [Abelmoschus esculentus (L.) Moench] was over 10.8 million tonnes which is led by India (about 60%). The objective of this study was to determine mineral content of genotypes and hybrids of okra identified by our in-house heterosis breeding programme. Methods: The samples were digested in a heating block using nitric acid and hydrogen peroxide and analyzed using inductively coupled plasma mass spectrometry (ICP-MS) for mineral profiling of okra samples. Result: The results were evaluated using multivariate analysis. The genotype EC169474 was with the highest concentration of minerals Na (184.91 μg/g), K (14613.52 μg/g) and Fe (268.76 μg/g), while, EC169477 was found to have highest concentration of Mg (6530.76 μg/g) and Ca (273.58 μg/g). Comparatively, in hybrids, EC 169470 x EC169474 contains highest concentration of minerals Na (177.27 μg/g) and Ca (253.01 μg/g), EC169474 x EC169477 contains highest Mg (6301.74 μg/g) and hybrid EC169468 x EC169477 contains highest K (14412.99 μg/g) and Fe (246.51 μg/g). Principal component analysis (PCA) reveals that the element that contributed most for the variability between the genotypes and hybrids was K, moderate contribution by Ca, Fe and Na, while, Mg being the least. Score plot of principal components reveals EC169470 and EC169477 among the most variable genotypes and EC169470 x EC169477 was the most variable hybrid. Hierarchical cluster analysis (HCA) tends to separate all analyzed samples in two major clusters. However, the genotypes EC169474 and EC169477 were grouped in hybrid cluster, while, hybrid EC169470 ´ EC169477 grouped with genotype cluster. The multivariate analysis revealed a systematic difference in the mineral content of okra. The results presented in this study are of great value for nutritionally dense breeding programmes for okra that provides important nutritional diversity by hybrids.