Water deficit on germination and vigour in seeds of the Jambu

Abstract

Water availability influences plant metabolism during the various stages of development, especially in the period between germination and seedling emergence. The aim of this study was to evaluate the effect of water deficit during the germination process on seeds of A. oleracea. The experiment was carried out in a completely randomised design, with four replications of 50 seeds. The treatments were arranged in a 5 x 2 factorial scheme, with the first factor consisting of the osmotic potentials (-0.2, -0.4, -0.6, -0.8 and distilled water for the potential 0.0 MPa) and the second factor consisting of two lots of seed. The germination test was carried out on substrates moistened with solutions of mannitol and polyethylene glycol (PEG 6000) at the various potentials, in a Biochemical Oxygen Demand (BOD) germinator at a temperature of 30°C and under constant light. The test was evaluated daily for 14 days, considering the seeds that had a root length equal to or greater than two millimetres as having germinated. The variables under analysis were germination, germination speed index, seedling length and seedling dry weight. The germination process of A. oleracea is compromised at water potentials of -0.2 MPa and -0.4 MPa when submitted to PEG and mannitol respectively. Seeds from Lot 1 were more tolerant to the water deficit than were those from Lot 2.

Synthetic seeds of Acmella oleracea (Asteraceae) from micropropagated plants in different concentrations of 6-benzylaminopurine

“…The leaf composition of this plant includes 24.01% proteins, 1.54% lipids, 63.38% carbohydrates, besides calcium, magnesium and copper (Seal et Acmella oleracea is preferably cultivated in hot and humid conditions, typical of the Amazon region, with temperatures above 25°C, annual rainfall greater than 2,500 mm and relative humidity of 80% (Spinozzi et al 2022). Water availability is one of the factors that most in uence the germination of A. oleracea seeds and the rehydration intensi es respiration and the degradation of reserve tissues, producing energy and nutrients necessary for the growth of the embryonic axis (Sarmento et al 2019). On the other hand, very hot environments with low relative humidity reduce the water potential and, consequently, the speed, percentage and vigor of germination of A. oleracea seeds (Botelho and Perez 2001;Ávila et al 2007).…”