The absorption, translocation, and assimilation of urea, nitrate, and ammonium in tomato plants within 24 h after N labeled compounds were applied at four different growth stages: seedling, ̄owering, fruiting, and harvesting. The absorption of urea-N was only 25% of NO3-N at seedling stage, but it was up to about 80% of NO3-N at the subsequent growth stages. The translocation of urea-N was limit...

The mobilization and utilization of the major storage proteins in loblolly pine (Pinus taeda L.) seeds following imbibition were investigated. Most of the seed protein reserves were contained within the megagametophyte. Breakdown of these proteins occurred primarily following radicle emergence and correlated with a substantial increase in the free amino acid pool in the seedling; the majority o...

Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a 5-year period (2003-2007) after a mast flowering event (2003). We examined flowering culm a...

Activity-guided fractionation of twigs of Pistacia chinensis resulted in the isolation and characterization of two novel ingredients as potent estrogen agonists. On the basis of spectral analysis and comparison with a related compound their structures were elucidated as 3,3''-dimers of 4-aryldihydrocoumarins (3,4-dihydro-4-(4'-hydroxyphenyl)-7-hydroxycoumarin) differing only in the stereochemic...

seedling characteristics of different sunflower (helianthus annus l.) cultivars under drought stress and inoculation with the azospirillum lipoferum in a spilt-factorial layout based on randomized complete block design with three replications were evaluated. treatments included dehydration stress (seed produced on maternal plants which irrigated after 60 (desirable irrigation), 120 (medium stre...

An in vitro zygotic embryo germination protocol was developed for apricot (Prunus armeniaca L. “Hacıhaliloğlu”). A hundred percent of germination was obtained when isolated embryos were cultured in vitro, a result alike those reported in the literature with traditional dormancy breaking treatments. In vitro seedling development was optimal in a modified full-strength Murashige and Skoog (1962) ...

Cotton seedlings were subjected to a 96 hour chilling treatment (5 degrees or 10 degrees ) after periods of germination at 31 degrees ranging from 0 to 48 hours. Inhibition of subsequent growth at a favorable temperature by chilling was dependent on level of low temperature and stage of seedling development when chilled. Two periods of chilling hypersensitivity were observed during germination:...

BACKGROUND AND AIMS A meta-analysis of global change experiments in arctic tundra sites suggests that plant productivity and the cover of shrubs, grasses and dead plant material (i.e. litter) will increase and the cover of bryophytes will decrease in response to higher air temperatures. However, little is known about which effects these changes in vegetation structure will have on seedling recr...

Three hypotheses have been proposed to explain the functional relationship between seed mass and seedling performance: the reserve effect (larger seeds retain a larger proportion of reserves after germinating), the metabolic effect (seedlings from larger seeds have slower relative growth rates), and the seedling-size effect (larger seeds produce larger seedlings). We tested these hypotheses by ...