Interação genótipos × ambientes, adaptabilidade e estabilidade de variedades de alface crespa em ensaios multiambientes não-repetidos

Abstract

Lettuce is one of the most widely cultivated leafy vegetables in Brazil, with particular emphasis on the crisp lettuce segment. Due to its temperate origin, cultivation in tropical regions poses challenges related to adaptation and quality, making an understanding of genotype × environment (G × E) interaction essential for the development of better-adapted and more stable varieties. This study aimed to evaluate the adaptability and phenotypic stability of crisp lettuce varieties in non-replicated multi-environment trials and, additionally, to investigate environmental interrelationships to optimize experimental resources. Nine varieties were evaluated across ten strategic environments, with quantitative traits (head weight, head diameter, and number of leaves) and qualitative traits (basal arrangement, lateral shoot development, shoulder shape, and overall rating) assessed. The data were analyzed in two stages by integrating the multivariate additive main effects and multiplicative interaction (AMMI) approach with the univariate standardized variables sum index. In addition, biplots were generated to characterize the interrelationships among environments and varieties, as well as radar charts to describe the performance profiles of the varieties. Genotypes AF 09, AF 07, and AF 08 were identified as the most promising for recommendation across the experimental network. AF 09 stood out for its high productive potential combined with adaptability, whereas AF 07 and AF 08 exhibited high phenotypic stability, ensuring consistent and predictable performance across different growing environments. Potential mega-environments were identified, revealing informational redundancy among environments such as Mogi das Cruzes, Salesópolis, Ibiúna, and Bragança Paulista. To optimize the experimental network, priority should be given to environments with contrasting profiles, such as Brasília, characterized by a broad diurnal temperature range and favorable mild nighttime temperatures; Conchal, characterized by high solar radiation stress; Colombo, characterized by low temperatures and limited radiation; and Piedade, which proved to be the most discriminating environment under intensive crop management and strong positional selectivity.