Towards Resilient Cotton: Morphological and growth responses of three INIFAP cotton cultivars under salt stress in hydroponics

Resumen

Objective: To evaluate the aerial and root morphological response in seedlings from three cotton cultivars under moderate and severe sodicity conditions.

Design/methodology/approach: Nineteen growth traits were analyzed in seedlings of INIFAP cotton cultivars Cian 95, Cian Precoz, and Juárez 91, grown for 21 days in a hydroponic system with nutrient solutions supplemented with NaCl at two electrical conductivity levels: 12 and 19.6 dS/m.

Results: Sodicity significantly affected all evaluated traits, with more pronounced effects on aerial growth than on root development. The only significant genotype × sodicity level interaction was observed in leaf area, with Juárez 91 being the most sensitive. Root growth displayed a bimodal pattern: it was maintained under moderate sodicity but was significantly inhibited under severe conditions. The multivariate functional value (MFV) index effectively integrated the morphological data into a single metric, allowing for the ranking of relative tolerance among cultivars.

Limitations on study/implications: This study provides a morphological basis for understanding adaptive strategies in early developmental stages. The MFV index proved to be a valuable tool for characterizing the overall response to sodicity and may be incorporated into cotton breeding programs focused on salinity tolerance.

Findings/conclusions: Although the cultivars showed similar responses, Cian Precoz exhibited greater stability under both sodicity levels and was classified as tolerant. Cian 95 and Juárez 91 were moderately tolerant, with Cian 95 standing out due to its lower variation under high sodicity conditions.