-Black oat seeds exhibit dormancy when newly harvested, which is normally broken in the interval between harvest and the sowing season. Dormancy, however, becomes a limiting factor in the estimate of the physiological quality of the seeds soon after harvest, requiring the use of methods for breaking dormancy, which delays making decisions in regard to the destination of seed lots. Given this situation, the aim of the present study was to evaluate the possibility of reducing the period for obtaining results in the germination test of newly harvested black oat seeds, studying variations on the recommended methods for breaking dormancy. Five seed lots of newly harvested seeds of cultivar IAPAR 61 (Ibiporã) were used, for which the following determinations were done: moisture content, germination test, and tetrazolium test. The following methods were tested for breaking dormancy: pre-cooling at 5 -10 ºC for three and five days; and pre-drying at 33 ºC for five and seven days. Based on the results obtained, it was concluded that there is the possibility of reducing the period recommended for estimating the germination of newly harvested black oat seeds through the use of pre-drying of the seeds for five days or of pre-cooling for three days.Index terms: Avena strigosa Schreb., dormancy, pre-drying, pre-cooling.Redução do período para avaliação da qualidade fisiológica de sementes recém-colhidas de aveia preta RESUMO -As sementes de aveia preta apresentam dormência quando recém-colhidas, sendo normalmente superada no intervalo entre a colheita e a época de semeadura. A dormência, porém, torna-se um fator limitante na estimativa da qualidade fisiológica das sementes logo após a colheita, necessitando do emprego de métodos para superação da dormência, o que torna demorada a tomada de decisão quanto ao destino dos lotes. Diante disso, o presente trabalho objetivou avaliar a possibilidade de redução do período para obtenção de resultados no teste de germinação de sementes recém-colhidas de aveia preta, estudando variações dos métodos recomendados para superação da dormência. Utilizaram-se cinco lotes de sementes recém-colhidas, da cultivar IAPAR 61 (Ibiporã), que foram submetidas às seguintes determinações: teor de água; teste de germinação e teste de tetrazólio. Para superação de dormência foram testados os seguintes métodos: pré-esfriamento a 5 -10 ºC por três e cinco dias; e pré-secagem a 33 ºC durante cinco e sete dias. Com base nos resultados obtidos, concluiu-se que há possibilidade de redução do período recomendado para estimar a germinação de sementes recém-colhidas de aveia preta, mediante o emprego da pré-secagem das sementes por cinco dias ou do pré-esfriamento por três dias.Termos para indexação: Avena strigosa Schreb., dormência, pré-secagem, pré-esfriamento.

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In plants, water deficit causes morphological, molecular and physiological responses, including stomata closure, photosynthesis reduction and accumulation of cellular osmoprotective compounds such as proline. This amino acid influences important biological functions, for instance by helping the stabilization of proteins and intracellular membranes and by mitigating the negative effects of reactive oxygen species. The present work had the objective to evaluate the performance of two transgenic events (Ev.6 and Ev.8) of Swingle citrumelo (Citrus paradisi Macfad. cv. Duncan x Poncirus trifoliata L. Raf.) rootstock transformed with the mutant Vigna aconitifolia P5CS-F129A gene, which encodes the key enzyme Δ1-pyrroline-5-carboxylate synthetase (P5CS) for proline biosynthesis, under the control of the stress-responsive RD29A promoter. Under greenhouse conditions, plants were left without irrigation up to reach severe stress level and then rehydrated after 31 days without watering. The event 8 (Ev.8) displayed significant increments of proline and higher photosynthesis, transpiration and stomata conductance rate throughout the stress period. Thus, because of its overall drought response, the plant 1329 of the Ev.8 was selected for multiplication and future field competition tests under our citrus rootstock breeding program, aiming to select a Swingle citrumelo genotype more tolerant to water deficit.