paclobutrazol was utilized to analyze its role in water stress amelioration and post drought recovery of container-grown pear ( pyrus communis cv. biroti ) saplings. following planting, paclobutrazol was applied as soil drench at concentration of 0, 0.15 and 0.3 mg per pot. three months following planting, saplings were subjected to three water stress treatments of: 0, -0.4 and -0.8 mpa. contro...

Rhamnus cathartica is an invasive shrub capable of high fecundity in North America. The physiology of R. cathartica has received little attention, but more is needed to understand traits that enhance its success in disturbed environments. Such data may help to predict invasiveness of closely related species such as Frangula caroliniana. We hypothesized that R. catharticawould have greater relat...

Essential in the Green Revolution was the development of high-yielding dwarf varieties of rice (Oryza sativa L.), but their selection was not based on responses to water limitation. We studied physiological responses to progressive drought of the dwarf rice mutant, d1, in which the RGA1 gene, which encodes the GTP-binding α-subunit of the heterotrimeric G protein, is non-functional. Wild-type (...

Photosynthetic capacity is one of the most sensitive parameters in vegetation models and its relationship to leaf nitrogen content links the carbon and nitrogen cycles. Process understanding for reliably predicting photosynthetic capacity is still missing. To advance this understanding we have tested across C(3) plant species the coordination hypothesis, which assumes nitrogen allocation to pho...

Accurately predicting photosynthesis in response to water and nitrogen stress is the first step toward predicting crop growth, yield and many quality traits under fluctuating environmental conditions. While mechanistic models are capable of predicting photosynthesis under fluctuating environmental conditions, simplifying the parameterization procedure is important toward a wide range of model a...

in order to study the interrelations of photosynthetic rate and surfaces and leaf proline content with yield and yield components of safflower under different irrigation regimes, a field experiment in a split plot arrangement under a ranomized complete block design with four replication was performed at lavark reasrch farm, isfahan university of technology, isfahan, iran in 2007. two irrigation...

Populus euphratica is a salt-tolerant tree species that develops leaf succulence after a prolonged period of salinity stress. In the present study, a putative xyloglucan endotransglucosylase/hydrolase gene (PeXTH) from P. euphratica was isolated and transferred to tobacco plants. PeXTH localized exclusively to the endoplasmic reticulum and cell wall. Plants overexpressing PeXTH were more salt t...

The effects of P deficiency on growth, N(2)-fixation and photosynthesis in white clover (Trifolium repens L.) plants were investigated using three contrasting relative addition rates of P, or following abrupt withdrawal of the P supply. Responses to a constant below-optimum P supply rate consisted of a decline in N(2)-fixation per unit root weight and a small reduction in the efficiency with wh...

1. Given the rapid and reversible impact of the environment on plant ecophysiological traits, it has been speculated that such traits may have low heritabilities, high phenotypic plasticity and experience selection which is highly variable. 2. We estimated heritabilities, phenotypic plasticity and natural selection on five ecophysiological traits (carbon : nitrogen (C : N) ratio, leaf water con...