Characteristics of the root system in two Brazilian upland rice varieties which exhibit contrasting behavior towards drought tolerance

Autor: Cristiana Maia de Oliveira, Renan Pinto Braga, Orlando Carlos Huertas Tavares, Sônia Regina de Souza, Leilson Novaes Arruda, Manlio Silvestre Fernandes, Leandro Azevedo Santos, Leandro Martins Ferreira
Rok vydání: 2020
Předmět:
Zdroj: Semina: Ciências Agrárias. 41:421-434
ISSN: 1679-0359
Popis: Root system architecture plays a fundamental role in the adaptation of rice to environments subjected to abiotic stresses. This study aimed to characterize the root architecture and morphology of two Brazilian upland rice varieties which display contrasting behavior towards drought tolerance: the tolerant Catetao and susceptible Mira varieties. Two experiments were carried out under greenhouse and growth chamber conditions. The experimental design was completely randomized in a 2 × 2 factorial scheme (varieties × drought stress conditions) with four replicates. Rice varieties were subjected to control and drought conditions for 14 days. Drought stress was applied either by withholding water until the desirable soil tension was achieved or by addition of 20% polyethylene glycol 6000 (PEG) to the nutritive solution. After harvest, the dry weight, root architecture, as well as physiological and root features were assessed. Under drought stress, a higher root biomass was recorded in Catetao compared to Mira. A higher ratio of deep rooting (RDR) was observed for Catetao, while Mira remained stable in response to drought stress. The evaluated physiological features showed that the Catetao variety is less likely to compromise membrane integrity and lipid peroxidation during drought stress. Moreover, analyzed root features exhibited a significant increase in lateral root emission and root density for Catetao in response to drought treatment, which may be considered an important feature when selecting for superior genotypes.
Databáze: OpenAIRE