Avaliação de genótipos de arroz de terras altas quanto a tolerância à deficiência hídrica

Abstract

Rice (Oryza sativa L.) is a plant of great importance in the Brazilian economy and food, and it is also cultivated, and consumed all over the world. Under high lands conditions, water deficiency is seen as the greatest threat to the climate due to a number of problems, that, significantly, affect the development and productivity of the plant. The objective of this study was evaluate upland rice genotypes aiming at tolerance to water deficiency. The experiment was carried out in the dry season at the water deficit tolerance phenotyping site at the EMATER experimental station in Porangatu, GO, with two water treatments, with and without stress. The presentation of the stress test, due to water deficiency, began after 45 days of emergency. After the statistical analysis of the data for the two environments, with and without water stress, an accuracy of 0.87% and 0.90% was obtained, indicating good experimental precision. The general grain yield test for the two conditions, with and without water stress, was 330.13 kg/ha and 1223.20 kg/ha, respectively, with differentiated responses of the genotypes, ranging 104.26 kg/ha to 802,70 kg/ha, in the environment under water stress. This indicates the existence of variability between the evaluated genotypes and the possibility of success with the selection of drought tolerance. There were significant differences between genotypes. Under water deficiency, five genotypes produced more than the best control, and can be considered as a high potential for lineage extraction, or used in crosses as water deficit tolerance donors.