Fenotipagem anatômica, morfo-fisiológica e desempenho de genótipos de arroz de terras altas com aplicação de bioinsumos

Abstract

Upland rice (Oryza sativa L.) cultivation plays a strategic role in global food security. However, its productivity is often limited by abiotic stresses, demanding sustainable technologies such as the use of bioinputs. This study aimed to investigate the effects of bioinput formulations (humic acids and soil conditioners) on the phenotypic, morphophysiological, and anatomical development of four elite upland rice genotypes (BRS Esmeralda, BRS A502, BRSMG Caçula, and CMG1590). The research was conducted in two complementary stages: field trials across two growing seasons (2023/24 and 2025/26) and in vitro cultivation in MS medium for histological and biometric analyses. Field results indicated that environmental variability between seasons was the determining factor for most phenological traits, such as the number of days to flowering and chlorophyll content. Despite climatic fluctuations, grain yield demonstrated high statistical stability, suggesting a robust adaptive capacity of the elite genotypes. The use of bioinputs did not promote significant changes in field variables, suggesting that macroclimatic effects can mask immediate responses to the application of these inputs in open-field environments. Conversely, controlled in vitro experiments revealed significant interactions between genotypes and bioinputs, demonstrating that treatment efficacy is strictly dependent on the genetic constitution of each line. The cultivar BRS Esmeralda stood out as the most responsive to treatment T5 (soil conditioner + Zinc), converting increases in the vascular cylinder area into actual gains in dry and fresh biomass. BRSMG Caçula exhibited the highest phenotypic plasticity, showing massive anatomical expansion of the shoot under treatment T7 and of the root system under T5. On the other hand, BRS A502 and CMG1590 presented greater phenotypic canalization, maintaining anatomical homeostasis under different treatments. Bioinputs modulated the hydraulic efficiency of the plants by increasing the number of metaxylem vessels (especially in treatments T3 and T5), which improves safety in water and nutrient transport. In conclusion, sustainable management of upland rice requires a precise combination of genotype and bioinput to optimize the crop's internal architecture and physiological resilience against environmental challenges.