Influence of rootstocks on scion leaf mineral content in mango tree (Mangifera indica L.)

Grafting is an important practice in mango (Mangifera indica L.) orchard management for propagating elite germplasm but there is limited information on the effect of rootstock-scion interactions on the mineral nutrition of mango. Here, we analyzed the variations in leaf nutrients of commercial ('B74' and 'Kensington Pride' [KP]) and newly developed cultivars from the National Mango Breeding Program (NMBP) ('NMBP1243', 'NMBP1201', and 'NMBP4069') grafted onto six different rootstocks ('B', 'KP', 'Mallapunyah', 'SabahBRF', 'Vellaikulamban', and 'Watertank') to determine the influence of the rootstock on the scion leaf nutrient content. Deviation from the optimum percentage (DOP and sigma DOP indexes) was calculated to compare nutrition status/balance among the different rootstocks. Leaf nutrient concentrations and their DOP index were affected by the rootstocks and scions. None of the rootstocks or scions had consistently higher or lower nutrient levels, and interaction effects between rootstock and scion factors were insignificant. The DOP index indicated an imbalance of nutrients in the leaves, but scions grafted onto rootstocks 'Vellaikulamban' and 'SabahBRF' were more nutritionally balanced, indicating that they are preferred rootstocks for propagation. Principal component analysis showed a clear separation among rootstocks according to their differences in nutrient concentrations, such that 'Vellaikulamban' and 'SabahBRF' (Group 1) were different from 'Watertank' and 'B' (Group 2) as well as from 'KP' and 'Mallapunyah' (Group 3). Scions were clustered based on their similarities with 'B74' and 'NMBP1201' in Cluster 1, 'NMBP 4069' in Cluster 2, 'NMBP 1243' in Cluster 3, and 'KP' in Cluster 4. This study provides valuable information to understand the potential impact of the rootstock on the nutritional status of scions as well as for the selection of rootstock-scion combinations for variety improvement.

Automated summary

The study found that different rootstocks have an impact on the leaf nutrient content of scions, with insignificant interaction effects between rootstock and scion factors. 'Vellaikulamban' and 'SabahBRF' rootstocks provide better nutrient balance for the scions, making them preferred for propagation. Principal component analysis revealed clear differences in nutrient concentrations among rootstocks, leading to clustering of scions based on similarities.