in order to evaluate the effects of organic, biological and chemical fertilizers on yield and yield components of milk thistle (silybum marianum l.), an experiment was conducted at the research station of ferdowsi university of mashhad based on complete randomized block design with three replications and six treatments during year 2007. treatments included inoculated seeds with azotobacter, com...

The performance of hybrids depends upon the inheritance and expression of resistance traits. Secondary chemicals are one such resistance trait. In this study, we measured the concentrations of phenolic glycosides and condensed tannins in parental and F1 hybrid willows to examine the sources of chemical variation among hybrids. S. sericea produces phenolic glycosides, salicortin and 2'-cinnamoyl...

Lignin impedes access to cellulose during biofuel production and pulping but trees can be genetically modified to improve processing efficiency. Modification of lignin may have nontarget effects on mechanical and chemical resistance and subsequent arthropod community responses with respect to pest susceptibility and arthropod biodiversity. We quantified foliar mechanical and chemical resistance...

Risk analysis for biological invasions is similar to other types of natural and human hazards. For example, risk analysis for chemical spills requires the evaluation of basic information on where a spill occurs; exposure level and toxicity of the chemical agent; knowledge of the physical processes involved in its rate and direction of spread; and potential impacts to the environment, economy, a...

Exploring the spatial distribution of variation in plant secondary metabolites is critical for understanding the evolutionary ecology of biochemical diversity in wild organisms. In the present study, concentrations of foliar sideroxylonal, an important and highly heritable defense chemical of Eucalyptus melliodora, displayed strong, fine-scale spatial autocorrelation. The spatial patterns obser...

The response of organisms to environmental stress is currently used in the assessment of ecosystem health. Morphological changes integrate the multiple effects of one or several stress factors upon the development of the exposed organisms. In a natural environment, many factors determine the patterns of morphological differentiation between individuals. However, few studies have sought to disti...

We investigated the effects of crossbreeding on slaughter traits and the chemical composition of chicken breast muscle. Trials were conducted using 120 broilers from four lines: Xiao-Shan chicken (XS), Xian-Ju chicken (XJ), Xiao-Shan chicken♂ × Xian-Ju chicken♀ (Zhenan 1, ZNY1) and Xiao-Shan chicken♂ × (Guang-Xi Yellow chicken♂×XianJu chicken♀)  ♀ (Zhenan 2, ZNY2). The birds were slaughte...

A tremendous diversity of plants exude sticky and toxic latex upon tissue damage, and its production has been widely studied as a defensive adaptation against insect herbivores. Here, we address variation in latex production and its constituent chemical properties (cardenolides and cysteine proteases) in 53 milkweeds [ Asclepias spp. (Apocynaceae)], employing a phylogenetic approach to test mac...

Environmental factors can directly influence phenotype such that a tight correlation between morphological and environmental variation is expected. However, morphological response to environmental variation may also reflect constraints imposed by interactions between adjacent structures such as the gills and the trophic apparatus in fishes. Such complex interactions help to explain why an organ...

BACKGROUND AND AIMS The lack of studies assessing the simultaneous expression of tolerance and resistance traits during seedling development and overall seedling defences as compared with adult plants, in general, constitutes a significant research need that can greatly improve our understanding of overall investment in defences during plant ontogeny. METHODS Using two seedling and two juveni...