SELEÇÃO DE GENÓTIPOS DE SEMENTES DE ARROZ DE TERRAS ALTAS SUBMETIDOS AO ESTRESSE HÍDRICO

• DOI: https://doi.org/10.22533/at.ed.9762517097

• Palavras-chave: arroz de terras altas; estresse hídrico; vigor de sementes

• Keywords: upland rice; water stress; seed vigor

• Abstract: Rice (Oryza Sativa L.), although it shows high susceptibility to water stress, about 59% of Brazilian rice is cultivated in the upland ecosystem, without irrigation. In Maranhão, the reality of producers is characterized by the use of rustic varieties and the absence of technology in the production system. Thus, for the farmer to succeed in rice cultivation, it is necessary to use high-quality seeds adapted to climatic variations to provide better productivity rates.The purpose of this study, it is to avaluate the fisiological potential in order to classificate upland rice lots tolerant to water stress and with and high vigor. The experimente was conducted in the seeds analysis laboratory of the Universidade Estadual do Maranhão - UEMA. Ten upland rice seeds lots produced in the State of Maranhão were sown in substrate with osmotic potentions of 0.0; -0.2; -0.4 and -0.6 Mpa. Were avaluated the water contente, germination test, firs count and germination rate index and seedlings aerial and root length. The physiological potential of upland rice seeds and seedlings, becoming sensitive to water deficit induced by PEG 6000 from the osmotic potential -0.4 Mpa. Germination tests, first germination counts, germination speed index, and shoot and root lengths are efficient in assessing the physiological potential of upland rice seed lots, providing sufficient information for the classification of lots the level of vigor. Rice genotypes respond differently to water stress, with lot 2 being the most tolerant to water restriction.