Effects of altitudes on the growth performance and fruit quality of Renong No. 1 mango

【Objective】To explore the effects of altitude on the growth and fruit quality of Renong No. 1 mango, in order to provide a reference for determining the most suitable cultivation altitude range and supporting its production.【Methods】The 33 indicators for growth characteristics and fruit quality were determined and analyzed at 4 different altitudes in Huaping, Yunnan.【Results】(1) With the increase in altitude, there was no significant change in the flower bud differentiation period, initial flowering period, and annual shoot number in Renong No. 1 mango. However, the full flowering period and final flowering period were delayed by approximately 10 days at altitudes H3 and H4. For every 200-meter increase in altitude, the fruit maturity period was correspondingly delayed by 5-10 days. (2) Altitude showed a significant positive correlation with the trunk circumference, north- south crown width, leaf width, and petiole thickness. Leaf length and petiole length were the highest at altitude H3 (1 503.54) and showed a significant difference compared with altitude H1 (1 148.00). (3) None of the 11 fruit appearance indicators, including single fruit weight, fruit longitudinal diameter, transverse diameter, and peel color, showed a significant correlation with altitude. (4) Among the 9 fruit quality indicators, 6 had a significant or extremely significant correlation with altitude. Peel thickness was significantly positively correlated with altitude; total acid and crude fiber were extremely significantly positively correlated with altitude; soluble solids, total sugar, and crude fat were extremely significantly negatively correlated with altitude; and flesh recovery, ascorbic acid, and protein had no significant correlation with altitude. There was no significant difference in peel thickness or edible rate of Renong No. 1 mango among different altitudes. The crude fiber content was the highest at 1700 m, showing a significant difference from other altitudes, and increased with the rise of altitude. Soluble solids and crude fat decreased with increasing altitude. The contents of ascorbic acid, total acid, total sugar, and protein first increased and then decreased with increasing altitude. (5) Principal component analysis (PCA) was conducted on 10 indicators that were significantly correlated with altitude (trunk circumference, north- south crown width, leaf width, petiole thickness, peel thickness, soluble solids, total acid, total sugar, crude fiber, and crude fat). The results showed that the cumulative variance contribution rate of the first 4 principal components reached 88.216% . Based on the principal component scores, assignment and comprehensive evaluation were performed on the performance of growth and fruit quality of Renong No. 1 mango at 4 altitudes. The results indicated that Renong No. 1 mango grown at 1100 m had the best comprehensive performance.【Conclusion】Changes in altitude comprehensively affect the plant growth and fruit quality of Renong No. 1 mango. In general, altitude has a relatively small impact on fruit morphology but a greater impact on internal quality. Renong No. 1 mango grown at an altitude of 1100 m shows the best comprehensive performance.