Altitudinal effect on sugar contents and sugar profiles in dried apricot (Prunus armeniaca L.) fruit

Genetic component influencing sugar contents and sugar profile in apricots is well documented. This study aims to evaluate influence of altitude on sugar contents and sugar profile in dried-apricots. Fruits from 108 genotypes were collected from six locations from 3006 to 3346 m asl in trans-Himalaya. The geographical elevation had a marked influence on the fruit sugar contents. Linear relationship between total sugar contents and increasing altitude was observed (R2 = 0.877, p ≤ 0.01). For every 100 m increase in altitude, total sugar increased by 64.8 mg/g DW. Sucrose was the highest individual sugar (57.8%), followed by glucose (19.4%), fructose (14.3%) and sorbitol (8.4% of total sugar). The relative proportion of sorbitol increased significantly with increasing altitude in fruits with brown seed coat (R2 = 0.849, p ≤ 0.01). Linear relationship between sucrose contents and increasing altitude was observed (R2 = 0.767, p ≤ 0.05). For every 100 m increase in altitude, sucrose contents increased by 49.1 mg/g DW. Fruit sorbitol contents showed linear relationship with increasing altitude (R2 = 0.899, p ≤ 0.01). Glucose levels increased with increasing altitude, while fructose contents showed inverse relationship with altitude. Therefore, results from the present study suggested that apricots growing at higher altitude contain higher sugar, sucrose and sorbitol. Knowledge from the present study provides useful guide for selecting orchard location towards improving fruit quality.