†Background and Aims Mimetic seeds simulate the appearance of fleshy fruits and arilled seeds without producing nutritive tissues as a reward for seed dispersers. In this strategy of seed dispersal, seeds may remain attached to the mother plant for long periods after maturity, increasing their availability to naı̈ve seed dispersers. The hypothesis that seed coat impermeability in many tropical F...

At harvest, sunflower (Helianthus annuus L.) seeds are dormant and unable to germinate at temperatures below 15 degrees C. Seed storage in the dry state, known as after-ripening, is associated with an alleviation of embryonic dormancy allowing subsequent germination at suboptimal temperatures. To identify the process by which dormancy is broken during after-ripening, we focused on the role of r...

BACKGROUND Hypoxis hemerocallidea, arguably the most well-known medicinal species in South Africa, has been the subject of intensive harvesting from the wild leading to recent conservation concerns. The seeds of this species do not propagate easily and can lie dormant for up to twelve months. MATERIALS AND METHODS In the in vitro germination experiments water, acid and chemical pre-sowing tre...

BACKGROUND AND AIMS Mimetic seeds simulate the appearance of fleshy fruits and arilled seeds without producing nutritive tissues as a reward for seed dispersers. In this strategy of seed dispersal, seeds may remain attached to the mother plant for long periods after maturity, increasing their availability to naïve seed dispersers. The hypothesis that seed coat impermeability in many tropical Fa...

An understanding of the biology of seeds has been greatly advanced in recent years. The progresses, particularly in the field of seed dormancy and germination research, have been made at a remarkable speed. Some of the possible epigenetic mechanisms, including an involvement of non-coding RNA, which were predicted for DELAY OF GERMINATION1 just a few years ago, have now been demonstrated with s...

As seed dormancy is released within a seed population, both the rate and percentage of germination increase progressively with increasing dose of a dormancy-breaking treatment or condition. Population-based models can account for this behaviour on the basis of shifting response thresholds as dormancy is alleviated. In particular, hydrothermal time analysis of germination sensitivity to water po...

guaiacol peroxidases (gp) are haem-containing enzymes participating in many physiological processes in plants. the expression pattern of these enzymes is organ-specific and developmentally regulated. methods: the presence of gp activity in extract samples, prepared from crocus sativus l. corms that were either dormant or rooting for 3, 6 and 10 days, was investigated. results: kinetic studies r...

Seed biology is a relevant aspect of tropical forests because it is central to the understanding of processes of plant establishment, succession and natural regeneration. Anadenanthera colubrina var. cebil is a timber tree from South America that produces large seeds with thin weak teguments, which is uncommon among legumes. This study describes the morphology and anatomy of the seed coat, the ...

BACKGROUND Problem weeds in agriculture, such as Lolium rigidum Gaud., owe some of their success to their large and dormant seed banks, which permit germination throughout a crop-growing season. Dormant weed seed banks could be greatly depleted by application of a chemical that stimulates early-season germination and then kills the young seedlings. Fluridone, a phytoene desaturase-inhibiting he...

Dormant seeds from Fraxinus species require cold-temperature after-ripening prior to germination. Earlier, we found that abscisic acid (ABA) will inhibit germination of excised nondormant embryos and that this can be reversed with a combination of gibberellic acid and kinetin. Using Milborrow's quantitative "racemate dilution" method the ABA concentration in 3 types of Fraxinus seed and pericar...