Phenotypic and enzymatic analyses of upland rice lines seeds under no-tillage

Abstract

Over 40% of the agricultural area in Brazil corresponds to no-tillage farming. Although it is evident the importance of obtaining upland rice cultivars adapted to this cropping system, researches in this sense are still incipient and breeders do not have cultivars available to recommend with enough security. The aim of this study was to evaluate phenotypic characters favorable to the no-tillage system in order to establish the basis for upland rice breeding programs interested in this cropping system. The seeds of twenty elite inbred lines from the Upland Rice Breeding Program from the Brazilian research institutions UFLA, EMBRAPA and EPAMIG were evaluated at the Central Seeds Lab from the Agriculture Department of UFLA following a randomized block design with four replicates. The characters evaluated were seedlings emergence (SE), green matter yield (GM), dry matter yield (DM), photosynthetic activity (PA), and superoxide dismutase activity (SOD). The quality parameters evaluated were obtained by a germination test (GT), germination first count (GFC), emergence test (E), initial stand (IS), and alpha-amylase expression. The lines CMG 2074, CMG 1967, CMG 2017, BRSMG Caravera and CMG 2097 showed higher SOD content in the enzymatic analyses, and consequently higher tolerance to abiotic stresses that could be caused by no-tillage. Considering the evaluation of agronomic traits, the line CMG 1967 showed the best performance in no-tillage soil and, therefore, should receive higher attention in Upland Rice Breeding Programs.