Oxygen interacts with priming, moisture content and temperature to affect the longevity of lettuce and onion seeds

Abstract

Lettuce (Lactuca sativaL.) and onion (Allium cepaL.) seeds have relatively short longevity during storage and their germination is sensitive to environmental stress. Seed priming (controlled hydration followed by drying) can improve seed germination under stressful conditions, inducing faster and more uniform germination over broader temperature ranges, but it can also reduce seed longevity in storage. Controlled deterioration (CD) tests are often employed to study longevity by ageing seeds rapidly at elevated temperature and moisture content, and primed seeds are particularly sensitive to CD conditions. As reactive oxygen (O2) species are thought to be involved in seed deterioration, we tested whether storage under reduced O2atmospheres (0 and 2% O2) would extend the longevity of primed and non-primed seeds under low relative humidity (RH) (33% RH+37°C) and CD (75% RH+50°C) storage conditions. The longevity of both non-primed and primed lettuce seeds in low RH storage was extended by anaerobic environments, but the effect of O2was much less under CD conditions. In onion, only primed seeds exhibited a beneficial effect of low O2atmospheres under both types of ageing conditions. In both species, storage under anaerobic conditions was beneficial for extending the longevity of primed seeds, but was not able to ameliorate fully the negative effect of priming on storage life.

The Seed Water Sorption Isotherm and Antioxidant-Defensive Mechanisms of <i>Hordeum vulgare</i> L. Primed Seeds

“…The results indicated that hydro-priming technique affected to seed vigorous especially speed of germination and germination uniformity. These results were supported by previous reports that hydro-priming technique can advance germination or could improve germination rate [16] [41] [42]. Vitor et al [43] reported that seed hydro-priming technique could reduce time to germination, resulted in rapid and uniform seedling emergence, high seed vigor, better and uniform seedling stand establishment.…”

Abscisic acid-determined seed vigour differences do not influence redox regulation during ageing

“…Seed WC appears to be decisive for seed responsivity to O 2 during ageing. At higher WC O 2 may promote seed longevity by allowing O 2 -mediated metabolism, whereas decreasing O 2 levels increases seed survival at slower ageing rates (3,5,37,40). The minor effects of O 2 levels on viability loss observed here (Fig.…”

“…Seeds age during storage, and the resulting loss of seed vigour and viability can impact on crop yields and sustainable agricultural production. Seed deterioration rates are accelerated by elevated storage temperatures and seed water contents (WC), which can also be influenced by the O 2 content of the storage environment (1)(2)(3)(4)(5). Vigorous germination, resulting in rapid and uniform seedling establishment, is an important agronomic trait (6).…”

Genetic and Epigenetic Stability in Rye Seeds under Different Storage Conditions: Ageing and Oxygen Effect

“…In the present work, the effect of oxygen on seed ageing was studied by storing seeds under air or vacuum. Previous studies with dry seeds have reported either neutral or positive effects of anoxic storage on seed longevity [4,5,44,45]. However, negative effects of reduced oxygen were observed upon seed storage at relatively high seed moisture levels [46].…”