نتایج جستجو برای: ratios of genetic variation and environmental variation

تعداد نتایج: 24110272  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1388

foreign policy takes root from complicated matters. however, this issue may be more truth about armenia. although the new government of armenia is less than 20 years, people of this territory are the first ones who officially accepted christianity. in very past times, these people were a part of great emperors like iran, rome, and byzantium.armenia is regarded as a nation with a privileged hist...

Journal: :Addiction 2014
Leah S Richmond-Rakerd Wendy S Slutske Andrew C Heath Nicholas G Martin

AIMS To investigate the genetic and environmental contributions to age at first drink (AFD) and age first gambled (AFG), assess their overlap and examine sex differences. DESIGN Univariate twin models were fitted to decompose the variation in AFD and AFG into additive genetic, shared environmental and unique environmental factors. Bivariate genetic models were fitted to assess the genetic and...

2015
Michael K. Skinner

Environment has a critical role in the natural selection process for Darwinian evolution. The primary molecular component currently considered for neo-Darwinian evolution involves genetic alterations and random mutations that generate the phenotypic variation required for natural selection to act. The vast majority of environmental factors cannot directly alter DNA sequence. Epigenetic mechanis...

Objective: Estimation of genetic parameters for Kleiber ratio (KR) and genetic trends for pre-weaning weights of Arabi sheep has not been previously conducted.Methods: Data and pedigree information were collected at the Khuzestan Ramin Agricultural and Natural Resources University, Animal Science Research Station, located in southwest Iran, from 2001 to 2008. (Co)variance components and corresp...

Journal: :Ecology 2006
Courtney J Murren Larry Douglass Amanda Gibson Michele R Dudash

Low Ca/Mg ratios (a defining component of serpentine soils) and low water environmental conditions often co-occur in nature and are thought to exert strong selection pressures on natural populations. However, few studies test the individual and combined effects of these environmental factors. We investigated the effects of low Ca/Mg ratio and low water availability on plant leaf, stem, stolon, ...

ارزانـی, احمد, حبیبی, فرشاد , رخزادی , اسعد, سید طباطبایی, بدرالدین ابراهیم, عرب بیگـی, محبوبه , مجیـدی, محمد مهدی,

Aegilops cylindrica species (CCDD, 2n = 4x = 28) is one of the wild relatives of wheat and hence known as a valuable source of genes related to biotic and abiotic stress tolerance. In this study genetic variation of 66 Aegilops cylindrica genotypes collected from west and northwestern of Iran was evaluated using quantitative and qualitative morphological traits. The results indicated that glume...

Journal: :Nature 1972

نجفی‌پور, عظیمه, مجیدی, محمد مهدی ,

Little is known about genetic variation of seed related traits and their association with forage characters in sainfoin. In order to investigate the variation and relationship among seed yield and its components, 93 genotypes from 21 wild and cultivated species of genus Onobrychis were evaluated using a randomized complete block design with four replications at Isfahan University of Technology ...

Journal: :crop breeding journal 2013
e. ganji moghaddam h. ahmadi moghaddam s. piri

this study was conducted with the main purpose of investigating genetic variation among 13 selected sweetcherry (prunus avium cv. siah mashhad) genotypes, i.e., the most important iranian sweet cherry cultivars based on their pomological, morphological, and phonological characteristics. the experiment was laid out in a randomized complete block design with three replications at khorasan-e-razav...

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