Related Effects of Climate Change on Root System Dynamics and Symbiotic Activity in Local Bean Varieties (Phaseolus vulgaris L.) in the Humid Tropics of Costa Rica

Climate change poses an increasing challenge to tropical agriculture, particularly for heatsensitive crops such as local varieties of beans (Phaseolus vulgaris L.).This study evaluated the effects of induced passive heat on the root architecture and symbiotic interactions of two local genotypes, Tayní and Bruncas, using Open Top Chambers under field conditions.Both varieties were included in the analysis and exhibited consistent qualitative responses to warming, with no contrasting cultivar-specific trends detected.Both varieties developed more roots and greater root area compared to the control, while mycorrhizal colonization increased up to 80% under warming.Soil temperature emerged as the main environmental factor influencing root expansion.These findings highlight the adaptive plasticity of local bean varieties under induced passive heat.