Plant species with physical seed dormancy are common in mediterranean fire-prone ecosystems. Because fire breaks seed dormancy and enhances the recruitment of many species, this trait might be considered adaptive in fire-prone environments. However, to what extent the temperature thresholds that break physical seed dormancy have been shaped by fire (i.e., for post-fire recruitment) or by summer...

BACKGROUND AND AIMS Seed dormancy enhances fitness by preventing seeds from germinating when the probability of seedling survival and recruitment is low. The onset of physical dormancy is sensitive to humidity during ripening; however, the implications of this mechanism for seed bank dynamics have not been quantified. This study proposes a model that describes how humidity-regulated dormancy on...

Dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. It has been clearly demonstrated that dormancy is induced by abscisic acid (ABA) during seed development on the mother plant. After seed dispersal, germination is preceded by a decline in ABA in imbibed seeds, which results from ABA catabolism through 8'-hydroxylation. The hormonal b...

       Seed dormancy has an important role in resistance and survival mechanisms of plants. Finding of some information about the range of primary dormancy and effective factors in dormancy breaking and optimal conditions of seed germination are necessary for weed control and other research purposes.  In this research, the seeds of 10 species of grass weeds in Tehran province fields (Echinocloa...

The decay of seed dormancy during after-ripening is not well understood, but elucidation of the mechanisms involved may be important for developing strategies for modifying dormancy in crop species and, for example, addressing the problem of preharvest sprouting in cereals. We have studied the germination characteristics of barley (Hordeum vulgare 'Betzes') embryos, including a description of a...

changes in seed dormancy were selected during the domestication of crop plants from wild-plant species, because some features of dormancy that provide ecological advantages presented agronomic disadvantages within a farmed system. seed dormancy varies widely among seed batches, even for seeds of the same genotype, indicating large environmental influences. for genetic studies, it is essential t...

Gibberellins act to overcome dormancy and increase the germination rate of seeds several species, including genus Annona. Considering that Annona have a high lipid content few sugars, degradation such reserves from application gibberellins has not been described so far. This study aimed evaluate how different gibberellic acid (GA3) concentrations acts on sugar pattern during atemoya (Annona x M...

The effect of various combinations of temperature and relative humidity on dormancy alleviation of sunflower seeds during dry after-ripening was investigated. The rate of dormancy alleviation depended on both temperature and embryo moisture content (MC). Below an embryo MC of 0.1 g H(2)O g(-1) dw, dormancy release was faster at 15 °C than at higher temperatures. This suggests that dormancy rele...