The effects of osmotic pre‐sowing treatment on laboratory germination in a range of wild flower species

Abstract

Sown seed of many wild flower species have slow or delayed germination which can allow unsown and undesirable species to colonise a prepared site. Ideally all seed sown should germinate immediately. Priming seed in an inert osmoticum can improve synchronisation and speed of germination. The objective of this study was to assess the efficacy of priming on a selection of 60 wild flower species from a total of 21 different families. The majority of the species selected were common constituents of commercial seed mixtures. Seeds were primed in the light at 15°C for 14 days in a polyethylene glycol '6000' solution giving an osmotic potential of either -10 or -15 bars. Priming had a highly significant effect on speed of germination reducing the median germination time by 2.8 t 0.27 days in the -10 bar treatment and 1.6 5 0.27 days in the -15 bar treatment. At the species level, 28 species had significantly reduced median germination times following priming. Priming significantly enhanced the final germination percentage in 15 species and significantly reduced it in eight species, with the adverse effect being more pronounced at -15 bars than at -10 bars. Nonhierarchical cluster analysis showed no clear patterns in response to priming either in relation to the comparative ecology or the plant family of the species tested, with the possible exception of the Leguminosae species. Only one out of six members of this family showed any enhancement in germination rate or percentage.The study demonstrates that a priming treatment could improve speed of germination, in a wide range of commonly sown semi-natural grassland species,

Seed Priming: New Comprehensive Approaches for an Old Empirical Technique

“…Such variability is a major limitation of the priming method since numerous trials are required to identify the most appropriate strategy for each situation. There is no "general rule" concerning modalities of seed priming and there is no clear trend of priming response according to the taxonomic position of the species [188]. This, undoubtedly, limits the commercial implementation of priming treatments.…”

The germination niches of grassland species targeted for restoration: effects of seed pre-treatments

“…Priming was carried out in darkness for 14 d at 168C, using the incubator (MIR-253; Sanyo Electric Co., Ltd., Osaka, Japan) subsequently also used in the germination study. The selected water potential and duration are known to work well across a wide range of grassland species (Adegbuyi et al, 1981;Tallowin et al, 1994). At the end of the 5-week cold-stratification or 14-d priming periods, seeds were thoroughly rinsed in distilled water and blotted dry, and then sown into 55-mm Petri dishes containing two layers of filter paper (VWR,No.…”

Condicionamento fisiológico de sementes de milheto

“…O condicionamento fisiológico de sementes têm sido estudado e utilizado ao longo dos anos (Heydecker e Coolbear, 1977), especialmente para sementes pequenas e de alto valor agregado, como algumas espécies de hortaliças e de gramíneas que também têm sementes pequenas (Jett et al, 1996;Tallowin et al, 1994).…”