Variability of reproductive seed quality in <i>Сlarkia amoena</i> (Lehm.) A. Nelson & J.F. Macbr)) depending on storage duration under ex-situ conditions

Abstract

This paper presents the results of assessing the reproductive seed quality of Clarkia amoena (Lehm) A. Nelson & J.F. Macbr) seeds during storage under laboratory conditions (temperature 20–22°C). The seeds were stored in paper bags for eight years. The authors selected seed samples from pods of varying degrees of maturity (open and closed) and different positions on the mother plant (branches of other orders). The authors set up three groups based on their location on the mother plant: 1) Sixty-four seed samples were formed on the main stem (firstorder branches); 2) Sixty-four seed samples were created on second-order branches; 3) Sixty-four seed samples were created on third-order branches and two groups based on fruit maturity: open and closed pods. In total, 192 seed samples were evaluated. Seed quality assessment was conducted annually in April, following GOST 24933.081 standards for flower crop seeds. The initial laboratory germination of seeds ranged from 69% for samples taken from closed pods on third-order branches to 97% for samples taken from open pods on the main stem. It decreased with an increase in the seed storage period according to a linear regression equation: Y = 7.673–0.064X, where Y is the storage duration, and X is the seed germination rate. Over eight years of storage, the 1000-seed mass decreased by 37.2% for samples from the main stem's open pods and 30.3% for samples from closed pods, by 43.6% and 46.8% for second-order branches, and by 46.1% and 50.9% for third-order extensions, respectively. On average, the 1000-seed mass decreased by 0.2 g for all samples over eight years of storage. Regression and correlation analyses (Pearson's coefficient) revealed significant negative relationships between storage duration and seed germination energy (r = –0.849), germination rate (r = –0.853), and 1000-seed mass (r = –0.790). A strong positive correlation was observed between seed mass and viability (r = 0.886). Over eight years of storage, seeds from the main stem lost their germination rate to 18–23%, significantly lower than the initial rate. In contrast, second-order branch seeds decreased by half, and roots from third-order branches completely lost viability. A multidimensional model of the interaction of factors—storage duration and branch order—on seed viability under ex-situ conditions was constructed, demonstrating that the overall viability of Clarkia amoena seeds is maintained for 4–5 years.