LEAF AREA TO CLUSTER WEIGHT RATIO ON FRUIT VISUAL COLOR, CONTENTS OF TOTAL ANTHOCYANIN AND INDIVIDUAL ANTHOCYANINS OF RELIANCE GRAPES (Vitis hybrid)

Abstract

Fruit color parameters including fruit red color, total anthocyanin content, and individual anthocyanins content in response to leaf area to cluster weight ratio (LACWR, cm2/g), were investigated using Reliance grapevines grown in the field. Non-linear parametric models were used to describe the relationship between LACWR and fruit color parameters. The critical levels in LACWRs required for maximum fruit red color, total anthocyanin content, delphinidin-3-glucoside, cyanldin-3-glucoside, petunidin-3-glucoside, peonldin-3-glucoside, malvidin-3-glucoside, and cyanldin-3-(p-coumarin)-glucoside contents, were 7.85, 8.09, 7.85, 8.19, 8.52, 8.52, 9.25, 7.92, respectively. Delphinidin-3-glucoside (critical LACWR, 7.85) or cyanldin-3-(p-coumarin)-glucoside (critical LACWR, 7.92) showed much closer association with fruit red visual color than cyanldin-3-glucoside (critical LACWR 8.19). Much higher LACWRs were required for the evolution of petunidin-3-glucoside, peonidin-3-glucoside, or malvidin-3-glucoside than for the fruit visual color. This indicates that petunldin-3-glucoside, peonldin-3-glucoside, or malvidin-3-glucoside contributed much less to fruit red visual color than delphinidin-3-glucoside, cyanidin-3-glucoside, or cyanldin-3-(p-coumarin)-glucoside.