seed dormancy is a temporary failure of a viable seed to germinate. various methods are used for breaking seed dormancy, depending on plant species and type of dormancy. three seed populations originated from esfahan, semnan and fars provinces were exposed to different seed dormancy breaking treatments such as mechanical and chemical scarification, humid chilling, ga3 and polyethylenglycol 6000...

BACKGROUND AND AIMS α-Amylase in grass caryopses (seeds) is usually expressed upon commencement of germination and is rarely seen in dry, mature seeds. A heat-stable α-amylase activity was unexpectedly selected for expression in dry annual ryegrass (Lolium rigidum) seeds during targeted selection for low primary dormancy. The aim of this study was to characterize this constitutive activity bioc...

Dormant seeds in permanent soil seed banks change their germination probability with age, but little is known about the causes of this behavior. Since current adaptive models do not consider the age structure of the seed bank, the sole explanation is that changes in germination probability with age are due to passive accidental factors or to decay of seeds. Here we present a theory, which shows...

This study investigates the seasonal variation of germination ability of buried seeds of Monochoria vaginalis (Burm.f.) Presl var. plantaginea Solms. The ®eld-collected seeds were buried in a ̄ooded or an upland ®eld and then exhumed monthly. The exhumed seeds were germinated under four temperature regimes. The seeds exhumed from the ̄ooded soil were dormant at the beginning of burial and proceed...

Seed dormancy is a genetically inherited trait whose intensity is modified by the environment during seed development and maturation. In order to study the effect of harvest time on the seed quality and optimum time of sowing to obtain good quality seeds, freshly threshed seeds of ten diverse rice genotypes harvested from six environments were evaluated for seed dormancy and seedling vigour ind...

seed dormancy is a genetically inherited trait whose intensity is modified by the environment during seed development and maturation. in order to study the effect of harvest time on the seed quality and optimum time of sowing to obtain good quality seeds, freshly threshed seeds of ten diverse rice genotypes harvested from six environments were evaluated for seed dormancy and seedling vigour ind...

in order to investigate the environmental factors including temperature, moisture, and plant hormones on dormancy breaking of seeds of xanthium strumarium l. a number of experiments were conducted. x. strumarium seeds were dormant soon after being harvested. seed germination of cocklebur increased through a combination of cooling, temperature fluctuations following ripening. most seed germinati...

Seed dormancy is expected to provide ecological advantages by adjusting germination to the favorable growth period. However, many species produce nondormant seeds, particularly in wet tropical forests, a biogeographic pattern that is not well accounted for in current models. We hypothesized that the global distribution of dormant seeds derives from their adaptive value in predictably fluctuatin...

The mechanisms controlling seed dormancy in Arabidopsis (Arabidopsis thaliana) have been characterized by proteomics using the dormant (D) accession Cvi originating from the Cape Verde Islands. Comparative studies carried out with freshly harvested dormant and after-ripened non-dormant (ND) seeds revealed a specific differential accumulation of 32 proteins. The data suggested that proteins asso...