Ionome balance analysis of mango fruit from orchard with and without resin canal discolouration
Resin canal discolouration (RCD) NDASH a quality defect that appears during fruit ripening, reduces the market price and consumer appeal of mango fruits. Abiotic and biotic factors such as fruit maturity, time of harvest after rainfall event and opportunistic bacteria are implicated in RCD incidence. No study been has been conducted elucidating the possible contribution of nutrients on RCD. In this study, we analysed the nutrient contents of developing mango fruits from an orchard with high RCD incidence (RCD+) and fruits from an orchard without RCD incidence (RCD-). Fruit samples were collected from upper, lower, sunny (west) and more shaded (east) side of the tree, oven-dried, ground and analysed for macronutrient (N, P, K, Ca, Mg, S) and micronutrient (B, Cu, Fe, Mn, Zn) content. Nutrient balance was determined based on compositional data analysis using isometric log ratio (ilr) transformation. Results showed that fruit from RCD+ orchard had higher variations in Ca/K and Ca/Fe ratios while RCD- fruit had higher variations in Ca/Cu and Ca/Zn ratios. Principal component analysis indicated a distinct separation of nutrient content between mango fruit from RCD+ and RCD- orchards. Moreover, dendrogram of fruit ionome showed an imbalance of Ca/Cu, B/Mn and Fe/Zn ratios. These variations in nutrient ratios may indicate a possible role of nutrient imbalances to RCD. Further analysis is needed to confirm the usefulness of the balance approach to diagnose susceptibility of mango to RCD and develop a remediation program.
Asis, C.A., Meschiari, L. and McConchie, C. (2019). Ionome balance analysis of mango fruit from orchard with and without resin canal discolouration. Acta Hortic. 1244, 221-228
ionome balance, isometric log ratio, mango nutrition, resin canal discolouration