|GENNA, NICHOLAS - University Of Florida
|PEREZ, HECTOR - University Of Florida
Submitted to: Seed Science Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2020
Publication Date: 6/1/2020
Citation: Genna, N., Perez, H., Walters, C.T. 2020. Viability and vigour loss during storage of Rudbeckia mollis seeds having different mass: An intra-specific perspective. Seed Science Research. 30(2):122-132. https://doi.org/10.1017/S0960258520000161.
Interpretive Summary: Seeds within a heterogeneous seed lot lose viability at different times. This presents a problem of genetic erosion during storage for genebanks, since the cause for variation in aging rate may be related to an inherited trait like phenology, dormancy or seed coat coverings. This paper compares aging rates of seeds within the same seed lot that differ in mass. Correlations with mass are important because it might reflect relationships with dry matter accumulation in seeds or surface area to volume ratios allowing differences in rates of water migration. Results here are inconclusive. This paper presents a new method to potentially measure vigor changes in stored seeds that otherwise show no symptoms of aging.
Technical Abstract: Recent evidence points to relationships between intra-specific seed mass variation and viability loss in response to aging stress. However, little is known about how seed quality may change temporally in response to such stress. Here we examined seed-water relations of mass separated Rudbeckia mollis seeds to better understand physiological status among mass classes. We then evaluated seed viability and vigour changes in response to various storage conditions or post-storage vigour tests (a 41°C, 75% RH stress for up to 45 days). We found similar pre-storage physiology among mass classes. However, seeds of lower mass deteriorated up to 1.5-fold faster than heavier seeds under certain conditions. Stressing seeds after storage resulted in distinct vigour differences among mass classes. For example, vigour in lower mass seeds tended to decline more compared to heavier seeds following storage in a climate-controlled room. Alternatively, vigour loss varied among mass classes following storage in a non-climate-controlled shed. Our results highlight the importance of distinguishing between pre-sowing storage and post-storage vigour effects when quantifying relative levels of viability loss among seeds of different mass. Furthermore, differential responses to storage and aging stress among mass classes may have important implications for post-storage regeneration and subsequent population dynamics.