Introduction and application of the seed longevity model in the research of determining the longevity (storage) of seeds

Different seeds deteriorate after harvesting and during seed storage, and this deterioration of seeds will cause a decrease in seed quality, seedling establishment and eventually decrease in plant yield in the field. To predict the longevity of orthodox seeds, the longevity equation  p v  Ki  is used, and this model can be used to compare the longevity of different cultivars, investigate the effect of different treatments or types of packaging on seed longevity, and also be used in the gene bank, etc. This model is not well known among Iranian researchers. In this study, the seed viability model has been introduced. In order to introduce the seed viability model, the germination data of mountain rye seeds in different storage conditions were used. ν is the probit based on the probit after storage, Ki is the initial probit of the seed mass, p is the daily storage period and σ is the standard deviation of the seed death distribution per unit of time. Another component of this equation is the relation log10σ = KE-CWlog10m-CHt-CQt 2 , where σ can be calculated from the relation σ=10(KE-CW log10m-CHt-CQt2). KE, CW, CH and CQ are constant coefficients of seed longevity, which CW coefficient shows the relative effect of seed moisture content, CH and CQ the response of seeds to temperature during storage, and KE the potential coefficient of seed lifespan. These coefficients can be calculated with a series of storage experiments with a wide range of temperature and seed moisture content. A larger KE in comparison between seeds indicates a longer longevity.