In Guyana, we investigated seed output, and resulting seedling establishment and survival, during a 'mast' year, by the ectomycorrhizal, monodominant rainforest canopy tree Dicymbe corymbosa (Caesalpiniaceae), a species with high, synchronous seed production at intermittent years. By utilizing seed traps, the mast seed output, predation, carbon and mineral investment, and masting synchrony were...

The effect of essential oils (EO) of medical plant seeds and spices on rumen microbial fermentation of alfalfa hay, sugar beet pulp and barley grain (as substrate) were evaluated under in vitro conditions. In vitro incubations were carried out using the gas production method with glass syringes. Treatments were as follows; a control (no additive), monensin, EO of cinnamon, black pepper seed, cu...

Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this...

Nitrogen (N) remobilization from reserves to sinks is essential for seedling establishment and seed production. Cytosolic glutamine synthetase (GS1) is up-regulated during both seed germination and seed filling in plants. However, the specific roles of the individual GS1 isogenes with respect to N remobilization, early seedling vigour, and final seed productivity are not known. In this study, i...

Although seed vigor is a complex physiological trait controlled by quantitative trait loci, technological advances in the laboratory are being translated into applications for enhancing seed vigor in crop plants. In this article, we summarize and discuss pioneering work in the genetic modification of seed vigor, especially through the over-expression of protein L-isoaspartyl methyltransferase (...

Cheatgrass (Bromus tectorum L.) is a winter annual weed that presents a serious obstacle to rangeland restoration in the Intermountain West. The objective of this study was to evaluate factors regulating the size and persistence of cheatgrass carryover seed banks on semiarid sites in western Utah. We prevented current-year seed production in each of four habitats, then tallied emerging seedling...

Background The purpose of a seed train is the generation of an adequate number of cells for the inoculation of a production bioreactor. This is timeand cost-intensive. From volumes used for cell thawing or cell line maintenance the cell number has to be increased. The cells are usually run through many cultivation systems which become larger with each passage. The seed train steps have a signif...

INTRODUCTION Sunflower (Helianthus annuus L., Asteraceae), currently cultivated for its seeds, is the world’s fourth largest oil-seed crop. World seed production was 25.2 million tonnes (t) during 1995/1996 from approximately 50 million ha of cultivated land. In the US, during 1999, sunflower seed production was 1,971,205 t from 1,438,000 ha, according to the National Agricultural Statistics Se...

BACKGROUND AND AIMS The Janzen-Connell model predicts that common species suffer high seed predation from specialized natural enemies as a function of distance from parent trees, and consequently as a function of conspecific density, whereas the predator satiation hypothesis predicts that seed attack is reduced due to predator satiation at high seed densities. Pre-dispersal predation by insects...

INTRODUCTION: Head scab caused by Fusarium graminaerum (Schwabe) has caused significant losses in the soft red winter wheat crop in Kentucky and in small grain crops in many regions of North America. Damage from head scab results in reductions in seed quality, emergence, and yield of wheat. In addition, losses in food-grain quality are caused by production of fungal mycotoxins, specifically vom...