R. Bras. Zootec.27/fev/2025;54:e20240111.
Productive and morphological responses of Megathyrsus maximus hybrids subjected to water deficit and waterlogging
Eduardo Moreira Barradas de Souza
, Domingos Sávio Campos Paciullo
, Carlos Augusto de Miranda Gomide
, Wadson Sebastião Duarte da Rocha
, Rafael Bolina da Silva
, Ângela Maria Quintão Lana
, Leandro Sâmia Lopes
ABSTRACT
This study aimed to characterize the response mechanisms and evaluate the resistance of Megathyrsus maximus hybrids to water deficit and waterlogging. The experiment was conducted in a greenhouse using a randomized block design with an 8 × 3 × 2 factorial arrangement. Treatments were a combination of eight genotypes of M. maximus, three water conditions (control, waterlogging, and water deficit), and two harvest times (20 days of water stress and 12 days post-recovery). Productive and morphological traits were evaluated at the end of the stress period and after the recovery period. All hybrids subjected to water deficit showed reduced aerial and root mass. However, a survival response was observed post-stress, with recovery of approximately 28.4% of the aerial part and 16.3% of the root system in all genotypes. Hybrid PM409 showed potential for adaptation to waterlogging, as suggested by the observed greater root production (41.2%) compared with the average production of other genotypes. In addition, there was no reduction on leaf and stem mass production compared with the control condition. The results suggest that no material showed to be resistant to water deficit. On the other hand, hybrid PM409 showed promising traits for waterlogging stress resistance.
Palavras-chave: biomass production; root recovery index; root to shoot ratio; root volume