Camelina germination under osmotic stress - trend lines, time courses and critical points

Abstract

Camelina [Camelina sativa (L.) Crantz] is native species of Eurasia, which is gaining interest world wide due to its better cold, heat, and drought tolerance, and less susceptibility to disease and pests than oilseed rape (Brassica napus L.). Furthermore, studies conducted in Canada and USA reported that as far as yield is concerned, camelina could be competitive against other Brassicas. Water shortage during germination is one of the major constraints that induces irregular and delayed seed germination and emergence, leading to poor plant establishment. Camelina has relatively low water requirement and high tolerance to drought, at all stages of development, even at germination and early seedling growth. Aiming at understanding the response of camelina germination under osmotic stress and the identification of critical soil moisture levels for successful establishment, two spring cultivars, developed at the Institute of Field and Vegetable crops Novi Sad, were compared (NS Slatka and NS Zlatka) under 9 levels of osmotic stress, ranging from 0 MPa to -1.6 MPa. Seeds were kept at 20°C and 8/16 h light/dark cycle. Osmotic potential of solution was obtained by using polyethylene glycol. Seeds were considered germinated when radicle was at least 2-mm-long. Germination was surveyed daily, while final germination was determined when no germinated seeds were recorded for 3 consecutive d, or after 15 d of incubation.