The influence of aerated hydration seed treatment on seed longevity as assessed by the viability equations

• Published in: Journal of experimental botany Vol. 51; no. 353; pp. 2031 - 2043
• Main Authors: Powell, Alison A., Yule, Louise J., Jing, Hai‐Chun, Groot, Steven P.C., Bino, Raoul J., Pritchard, Hugh W.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.12.2000; OXFORD UNIVERSITY PRESS
• Subjects: 4C DNA; Agronomy. Soil science and plant productions; Biological and medical sciences; Brassica - physiology; Brassica oleracea var. botrytis; Cauliflower; Cell cycle; controlled deterioration germination; DNA; DNA repair; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; Germination; Longevity; Oxygen; Plant Research International; Preservation, Biological; rate of deterioration (1/σ); Regulation of Growth, Development and Whole Organism Physiology; Seed science; Seed storage; Seeds; Seeds - physiology; Seeds and other planting stocks; Viability; Water; β‐tubulin; Brassica oleracea var. botrytis; Genetic selection; Temperature; Seeds; Hydration; Germination; Environmental factor; Longevity; Ambient humidity; Aeration; Storage; Tubulin; Cruciferae; Dicotyledones; DNA; Angiospermae; Spermatophyta; Application method; Intraspecific comparison; Repair
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jexbot/51.353.2031

Aerated hydration (AH) treatments of cauliflower seeds for 12 h (12AH) and 28 h (28AH) at 20 °C resulted in improved or reduced storage potential of low or high vigour seeds, respectively. Seeds were stored at their initial seed moisture content (mean 5.5% mc) or at 12% mc at 10 °C for 12 months and at 20 °C for 4 months. The improved longevity of low vigour seeds was associated with increased Ki (initial seed viability) and a reduced rate of deterioration (1/σ) whereas the Ki of high vigour seeds fell after 28AH and the rate of deterioration increased such that the time to lose one probit of viability decreased from 28.7 to 5.3 months at 10 °C and from 10.4 to 1.2 months at 20 °C. The improved Ki of low vigour seeds could be explained by the reduction in the extent of deterioration after AH, as indicated by the increase in germination after cotrolled deterioration (CD), and the possible activation of metabolic repair during treatment. In contrast the reduced germination after CD of AH‐treated high vigour seeds was indicative of deterioration as a result of treatment. Both high and low vigour seeds contained constitutive levels of β‐tubulin which increased during AH treatment, the increase being greater in high vigour seeds. High vigour seeds also showed an increase in the proportion of nuclear DNA present as 4C DNA, from 3% (untreated seeds) to 26% (28AH), indicative of germination advancement from the G1 to G2 phase of the cell cycle during treatment. This higher proportion of 4C DNA is correlated with the increased sensitivity of seeds to drying and/or storage after AH, leading to their reduced Ki and storage potential. In contrast, there was little change in %4C in low vigour seeds. Priming in polyethylene glycol (PEG, –1.0 MPa) for 5 d or 13 d also improved the longevity of low vigour seeds stored at their initial and 12% mc at 10 °C for 8 months, as reflected in their laboratory and CD germination. In this case, however, the improved longevity of the low vigour seeds following 13 d priming was associated with an increase in 4C DNA from 4% (dry control) to 56% after treatment. The germination of both untreated and primed high vigour seeds remained high throughout the storage period. Increases in the rate of germination (decreased mean germination time) observed after all AH and PEG treatments were not consistently associated with an increase in the proportion of nuclei containing 4C DNA.