in order to study effect of seed weight on germination and growth of wheat seedling, an experiment in seed technology laboratory of aboureihan paradise university of tehran in 2005 has been done. in this experiment, at first stage, the seeds separated by longitude step, latitude step and set frequency parameters of gravity separator set. in second stage, 10 treatments of 1000 seed weight entere...

The somatotrophic axis (GH-IGF) is a key regulator of animal growth and development, affecting performance traits that include milk production, growth rate, body composition, and fertility. The aim of this study was to quantify the association of previously identified SNPs in bovine growth hormone (GH1) and insulin-like growth factor 1 (IGF-1) genes with direct performance trait measuremen...

A central goal of comparative plant ecology is to understand how functional traits vary among species and to what extent this variation has adaptive value. Here we evaluate relationships between four functional traits (seed volume, specific leaf area, wood density, and adult stature) and two demographic attributes (diameter growth and tree mortality) for large trees of 240 tree species from fiv...

Seed plants vary tremendously in size and morphology; however, variation and covariation in plant traits may be governed, at least in part, by universal biophysical laws and biological constants. Metabolic scaling theory (MST) posits that whole-organismal metabolism and growth rate are under stabilizing selection that minimizes the scaling of hydrodynamic resistance and maximizes the scaling of...

The rate of herbicide resistance evolution in plants depends on fitness traits endowed by alleles in both the presence and absence (resistance cost) of herbicide selection. The effect of two Lolium rigidum spontaneous homozygous target-site resistance-endowing mutations (Ile-1781-Leu, Asp-2078-Gly) on both ACCase activity and various plant growth traits have been investigated here. Relative gro...

an analysis of the stages of crop growth presents an important step in the improvement of production management. through growth analysis, planning for planting systems, fertilization, pruning operations, harvest time as well as obtaining economical yield can be more accessible. therefore, a development of mathematical models simulating plant growth would be helpful in improving crop management,...

OBJECTIVE This study estimated the genetic parameters for body weight gain and growth curve parameter traits in Korean native chicken (KNC). METHODS A total of 585 F1 chickens were used along with 88 of their F0 birds. Body weights were measured every 2 weeks from hatching to 20 weeks of age to measure weight gain at 2-week intervals. For each individual, a logistic growth curve model was fit...

water deficit is one of the most important problems facing crop production in arid and semiarid regions in iran. application of super absorbent polymers may somehow control yield reduction in some crop plants under drought stress conditions. in this investigation, the effect of different levels of super absorbent polymer, superab a200 (0, 100, 200, 300 kg/h), and three irrigation intervals (7, ...

in order to evaluate the effects of drought stress at different phenological stages on growth indices of chickpea (cicer arietinum l.) cultivar jam, an experiment was carried out at the research greenhouse of faculty of agriculture, ferdowsi university of mashhad, using a completely randomized design with four replications. drought stress was applied by preventing irrigation until the soil mois...