###### Abstract  
Agriculture depends on the ability of seeds to survive until the next planting season under ambient conditions that may be averse to seed quality even when the seed is in a quiescent state. Seed priming invigorates seeds, but the impact on the longevity of seeds has limited its adoption. This study investigated the effect of the storage of primed rice seed on seed viability, vigor, and longevity. Three seed priming methods were employed on the rice cultivar New Rice for Africa (NERICA 4) seeds. Subsequently, the seeds were stored for 120 days at 25 \({}^{\circ}\)C and 65% relative humidity, simulating the ambient seed storage conditions of the tropics and sub-tropics. The primed seed recorded increased vigor compared to the non-primed seed until 90 days of storage. However, seed storage for 120 days reduced seed vigor and viability for all the seeds. The results indicated a significant reduction in seed vigor, increased solute leakage, generation of hydrogen peroxide, and accumulation of malondialdehyde after storage. Priming enhances cell membrane integrity and maintains seed vigor in storage at near ambient conditions long enough before reversal of its performance by the storage conditions. This assures that primed seed can either be stored until the following planting season or remain viable in the soil during delayed germination. imbibition damage; NERICA; seed aging; seed longevity; seed priming; seed storage; solute leakage +
Footnote †: journal: Medical  
Agriculture depends on the ability of seeds to survive until the following sowing season under ambient conditions. In the tropics and sub-tropics, the grain temperatures typically remain between 25 \({}^{\circ}\)C and 35 \({}^{\circ}\)C [8; 9]. The ambient temperature is 25 \({}^{\circ}\)C [10], with 65% relative humidity [11], which is usually sufficiently adverse for seed storage [12] and accelerates aging [13]. However, seeds must be stored for a period in readiness for use by farmers as a general practice while preserving the initial seed quality [14]. [PERSON] [12] suggested that good-quality seed of the major sub-tropical and tropical crops could be stored satisfactorily from harvest to the next planting season for up to 9 months at 20 \({}^{\circ}\)C and 60% relative humidity for cereal seed, with seed moisture contents ranging to a maximum of about 13%. Furthermore, rice was arbitrarily classified as a good storer under ambient conditions in warm-humid areas, maintaining good germination even up to 3 years under favorable conditions [11]. Various seed-priming techniques have been applied to rice [6; 15; 16; 17; 18] to improve seed vigor, uniform emergence, persistence, and performance over a range of abiotic stresses [19; 20; 21]. The technique involves partial hydration of seeds to initiate metabolic processes necessary for germination without the emergence of the radicle [3]. It stimulates seeds and alleviates environmental stresses and has been attributed to various mechanisms. Hydropriming makes water available for metabolic activation [22]; partial seed rehydration initiates activation of early germination events in the seed, including activation of the reactive oxygen species (ROS) antioxidant mechanism [21]. Furthermore, nitrates in potassium nitrate (KNO\({}_{3}\)) stimulate seed germination [23] by reducing seed dormancy, promoting antioxidant defenses, and increasing water uptake [24]. In addition, polyethylene glycol (PEG) delays water entry [25], limits ROS-mediated oxidative injury; increases the activities of antioxidant enzymes; increases the accumulation of free amino acids, proline, and soluble sugars; reduces malondialdehydedehyde (MDA) accumulation; and stabilizes the cell [26; 27]. These result in increased stress tolerance under drought or excessive soil moisture conditions. Despite the documented seed invigoration, seed priming tends to reduce the longevity of high-vigor seeds [16; 22; 28; 29], which usually deteriorate quickly, losing the beneficial effects of priming during subsequent storage [7; 29].