Elemental Variation of Berry Mineral Nutrient Content in Early Maturing Grapes Genotypes Grown Under Sub-tropical Climate

Abstract

Cultivar development in grapes with increased mineral nutrient composition relies on the selection of genetically unique and complementary breeding lines. The objective of this study was to assess the peel, flesh and seed minerals composition of diverse grape collections of exotic and indigenous origin to select promising parents to develop a breeding population. Twenty-nine genetically diverse grape genotypes were field evaluated using a randomised complete block design with three replications under subtropical climatic conditions of New Delhi, India. The peel + flesh and seed mineral contents were determined using standard procedure. Analyses of variance showed significant (P < 0.05) effects of genotypes on the accumulation of 10 mineral nutrients in grape berry peel + flesh and seeds. The twenty-nine genotypes showed considerable variation for the following ten mineral contents: Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium(Mg), Iron (Fe), Copper (Cu), Zinc (Zn), Manganese (Mn) And Sodium (Na), and varying from 0.96 to 3.30 %; 0.14 to 0.22 %; 0.91 to 2.11 %; 0.23 to 0.38 %; 0.02 to 0.16 %; 27.58 to 77.69 ppm; 8.23 to 19.60 ppm; 14.60 to 64.10 ppm; 1.38 to 11.61 ppm and 0.00 to 0.24 ppm, respectively in berry peel and flesh together. Further, the seed mineral content also varied significantly among the genotypes. It was not assessed in the seedless genotypes due to a lack of seeds. Therefore, nineteen genotypes were tested for 10 mineral elements in their seed samples after drying. It was found significantly variable for nitrogen (0.88 to 2.12 %), phosphorus (0.18 to 0.34 %), potassium (0.35 to 0.87 %), calcium (0.26 to 0.92 %), magnesium (0.19 to 0.42 %), iron (33.02 to 96.94 ppm), copper (14.53 to 24.16 ppm), zinc (18.46 to 80.43 ppm), manganese (12.13 to 34.98 ppm) and sodium (0.01 to 0.12 ppm). The selected grape genotypes are useful genetic resources for population and cultivar development for nutrient composition.