Screening for drought stress tolerance in traditional mango (Mangifera indica L.): biochemical and physiological approaches

Abstract

This study assessed the ability of 34 mangoes (Mangifera indica L.) accessions and one control to tolerate drought by measuring several physiological and biochemical characteristics. There were notable variations in the relative water content among the accessions. KLM37, PTA01 and ALA23 had the highest values, suggesting that they had higher drought tolerance. Furthermore, KLM37, ALA15 and PTA01 exhibited the greatest saturated water content (SWC), indicating improved water retention during periods of drought. The analysis of specific leaf area (SLA) showed significant differences among the accessions studied. KLM37, ALA23, KLM12 and PTA01 exhibited the greatest SLA values. The accessions also showed a significant increase in epicuticular wax content (EWC). This indicates that they have improved drought adaptation by reducing water loss. The accessions exhibited an increased cell membrane stability index (CMSI), which further demonstrates their ability to withstand drought stress. The biochemical markers revealed that ALA27, ALA23 and KLM37 exhibited a noteworthy increase in proline concentration, suggesting their capacity for drought tolerance. PTA01, TVM02 and ALA27 exhibited high chlorophyll concentrations, indicating enhanced photosynthetic efficiency in drought conditions. Principal Component Analysis (PCA) revealed that RWC, CMSI and EWC are the primary characteristics that contribute to drought tolerance. PC1 accounts for 76.913% of the overall variation. The levels of proline and chlorophyll had a significant impact on the second principal component (PC2), explaining 10.556% of the variation. A drought study conducted as part of abiotic stress tolerance thus identified several mango accessions with superior drought tolerance traits, particularly KLM37, PTA01, ALA23 and KLM12. These mango accessions are promising candidates for breeding programs aimed at improving drought resilience in mangoes.