Priming and re-drying improve the survival of mature seeds of Digitalis purpurea during storage

Abstract

† Background and Aims Most priming studies have been conducted on commercial seed lots of unspecified uniformity and maturity, and subsequent seed longevity has been reported to both increase and decrease. Here a seed lot of Digitalis purpurea L. with relatively uniform maturity and known history was used to analyse the effects of priming on seed longevity in air-dry storage. † Methods Seeds collected close to natural dispersal and dried at 15 % relative humidity (RH), 15 8C, were placed into experimental storage (60 % RH, 45 8C) for 14 or 28 d, primed for 48 h at 0, 21, 22, 25, 210 or 215 MPa, re-equilibrated (47 % RH, 20 8C) and then returned to storage. Further seed samples were primed for 2 or 48 h at 21 MPa and either dried at 15 % RH, 15 8C or immediately re-equilibrated for experimental storage. Finally, some seeds were given up to three cycles of experimental storage and priming (48 h at 21 MPa). † Key Results Priming at 21 MPa had a variable effect on subsequent survival during experimental storage. The shortest lived seeds in the control population showed slightly increased life spans; the longer lived seeds showed reduced life spans. In contrast, seeds first stored for 14 or 28 d before priming had substantially increased life spans. The increase tended to be greatest in the shortest lived fraction of the seed population. Both the period of rehydration and the subsequent drying conditions had significant effects on longevity. Interrupting air-dry storage with additional cycles of priming also increased longevity. † Conclusions The extent of prior deterioration and the post-priming desiccation environment affect the benefits of priming to the subsequent survival of mature seeds. Rehydration-dehydration treatments may have potential as an adjunct or alternative to the regeneration of seed accessions maintained in gene banks for plant biodiversity conservation or plant breeding.

Priming of pioneer tree Guazuma ulmifolia (Malvaceae) seeds evaluated by an automated computer image analysis

“…These findings were confirmed by other authors that showed increased drying sensitivity of seeds primed for longer periods that were submitted to accelerated aging (Chojnowski et al, 1997). However, the conditions used to dry back seeds after priming has a remarkable importance to avoid physiological deterioration (Butler et al, 2009), as demonstrated in primed and dried seeds which can retain priming benefits (Barbedo et al, 1997;Kikuti and Marcos-Filho, 2008).…”

The Effect of Seed Priming and Accelerated Aging on Germination and Physiochemical Changes in Milk Thistle (Silybum marianum)

“…Priming could not improve the germination at high levels of aging because irreversible damage repair may not be (Butler et al, 2009). During the programmed cell death (PCD), Catalase rate and sensitivity reduce and indicate that the aging causes PCD and subsequent the reduction of seed's viability.…”

Prediction of Canola Seed Longevity in the Drying Process

“…Butler et al [18] applied probit analysis for Digitalis purpurea and Soltani [19] tested with Haloxylon persicum. Pozitano and Usberti [20] obtained good relationship for controlled deterioration in grass seeds, using the theory of probit analysis and Surki et al [21] applied for soybean viability.…”