Seed dormancy is a mechanism underlying the inability of viable seeds to germinate under optimal environmental conditions. To achieve rapid and uniform germination, wheat and other cereal crops have been selected against dormancy. As a result, most of the modern commercial cultivars have low level of seed dormancy and are susceptible to preharvest sprouting when wet and moist conditions occur p...

JORDAN, M. S. & W. J. HAYDEN (1992). A Survey of Mucilaginous Testa in Chamaesyce. Collect. Bot. (Barcelona) 21 :79-89. Seeds of Chamaesyce were studied for presence of mucilaginous testa. Samples were selected to represent all major systematic sections within the genus. Observations were made with a dissecting microscope following brief hydration of seeds; additional SEM observations of both i...

The crop is characteristic of seed-eating birds today, yet little is known about its early history despite remarkable discoveries of many Mesozoic seed-eating birds in the past decade. Here we report the discovery of some early fossil evidence for the presence of a crop in birds. Two Early Cretaceous birds, the basal ornithurine Hongshanornis and a basal avian Sapeornis, demonstrate that an ess...

Changes in the nature of the seed coat caused by gut passage are considered to be the proximate causes of changes in germination patterns. Modifications of seed coat permeability may be decisive in saline environments (e.g. Mediterranean wetlands), in which the response of the seed to osmotic stress, or its resistance to toxicity caused by some ions may be affected. We analysed how passage thro...

Most commercial Glycine max (soybean) varieties have yellow seeds because of loss of pigmentation in the seed coat. It has been suggested that inhibition of seed coat pigmentation in yellow G. max may be controlled by homology-dependent silencing of chalcone synthase (CHS) genes. Our analysis of CHS mRNA and short-interfering RNAs provide clear evidence that the inhibition of seed coat pigmenta...

Abscisic acid (ABA) and gibberellin (GA) are two antagonistic phytohormones that regulate seed germination in response to biotic and abiotic environmental stresses. We demonstrate here that MOTHER OF FT AND TFL1 (MFT), which encodes a phosphatidylethanolamine-binding protein, regulates seed germination via the ABA and GA signaling pathways in Arabidopsis thaliana. MFT is specifically induced in...

The mechanism of inhibition of coffee (Coffea arabica cv. Rubi) seed germination by exogenous gibberellins (GAs) and the requirement of germination for endogenous GA were studied. Exogenous GA(4+7) inhibited coffee seed germination. The response to GA(4+7) showed two sensitivity thresholds: a lower one between 0 and 1 microM and a higher one between 10 and 100 microM. However, radicle protrusio...

Dispersal is thought to be a key process underlying the high spatial diversity of tropical forests. Just how important dispersal is in structuring plant communities is nevertheless an open question because it is very difficult to isolate dispersal from other processes, and thereby measure its effect. Using a unique situation, the loss of vertebrate seed dispersers on the island of Guam and thei...

The critical node (CN), which is the transition from the plateau phase to the rapid decreasing phase of seed ageing, is extremely important for seed conservation. Although numerous studies have investigated the oxidative stress during seed ageing, information on the changes in protein abundance at the CN is limited. In this study, we aimed to investigate the abundance and carbonylation patterns...