Dry ageing: A physiologically realistic alternative to accelerated ageing for phenotyping seed longevity in soybean

Seed longevity is a vital trait that influences germplasm storability and seed quality maintenance. The accelerated ageing test (AAT) is often used to measure longevity, but its high-temperature and humidity conditions do not truly represent natural seed ageing. This study aimed to develop a dry ageing (DA) method as an alternative to the AAT for phenotyping soybean (Glycine max L.) seed longevity. Fifteen soybean genotypes differing in seed coat colour were evaluated under controlled dry conditions at moderate temperature and humidity (41 ± 0.3 °C and 50 % relative humidity (RH)). Germination and vigour traits, including total germination (TG %), normal seedlings (NSL %), shoot length (SL), root length (RL) and seed vigour index (SVI-I) were recorded to compare AAT and DA. Significant variations were observed among genotypes, ageing periods and their interactions. While AAT caused rapid deterioration (TG % from 97.5 to 0.3 % in 10 days), DA showed a slower and more natural decline (TG % from 97.8 to 57.7 % in 214 days). Genotypes TGX 855-32E and B 252 showed less than 30 % reduction in most of the traits. Correlation analysis revealed that DA maintained and strengthened trait relationships over time, unlike AAT, which disrupted them. Dry ageing also separated tolerant and sensitive genotypes more clearly, capturing the natural variation in seed longevity that AAT often compresses or masks. Overall, the DA method provides a simple, less stressful and more realistic alternative to accelerated ageing for screening soybean genotypes for seed longevity under conditions that better represent natural ageing.