Upland rice tolerance to drought

Abstract

Water deficiency stress can seriously damage the upland rice crop, mainly reducing its yield. Therefore, the selection of genotypes better adapted to drought is relevant. This study aimed at evaluating agronomic traits and leaf temperature, in F₇ upland rice lines under two irrigation conditions (with and without water deficit stress), in order to allow the selection of lines more tolerant to this abiotic stress. In 142 recombinant inbred lines and their two parents, Bico Ganga Curto and Chorinho, the leaf temperature (ºC), days to flowering, number of tillers and panicles per linear meter, spikelet sterility (%), plant height (cm), one thousand spikelets weight (g) and yield (kg ha^-1) were evaluated. The experimental design used was a 12x12 triple lattice, with or without water stress. Fifteen lines were selected by using the Drought Susceptibility Index and compared with their parents by the Tukey test. An increase was observed in the number of days to flowering and spikelet sterility, under water deficit stress. Under the same condition, there was a reduction for plant height and number of tillers and panicles per linear meter. Among all lines, the 51 distinguished itself by presenting a high yield, concerning both environments.