this research which aims to survey the relation between tobacco leaf yield and its components is done by using 118 varieties of tobacco in a research farm of guilan tobacco research institute. regarding to five random selections of plants, twenty three traits of each variety were evaluated. correlation between dry matter of leaf yield with plant height, stem diameter, leaf length, leaf width, l...

in order to investigate the effect of seed rate on seed yield and yield components of three rapeseed varieties, a split- plot experiment was conducted in randomized complete block design with four replicates during 2008-2009 at baykola agricultural research station, neka, mazandaran province. in this experiment four seed rates (5, 7, 9 and 11 kg.ha-1) as main plots, three rapeseed cultivars (hy...

this research was designed to identify garlic (allium sativum l.) bolting clones and determining the relationship between their morphological traits and bolting capacity by using statistical methods of analysis of variance, comparison of means, correlation coefficients, factor analysis, stepwise regression, path analysis and cluster analysis. traits including flowering ability, number, length a...

BACKGROUND AND AIMS Despite general agreement regarding the adaptive importance of plasticity, evidence for the role of environmental resource availability in plants is scarce. In arid and semi-arid environments, the persistence and dominance of perennial species depends on their capacity to tolerate drought: tolerance could be given on one extreme by fixed traits and, on the other, by plastic ...

A surprising number of recent Bayesian phylogenetic analyses contain branch-length estimates that are several orders of magnitude longer than corresponding maximum-likelihood estimates. The levels of divergence implied by such branch lengths are unreasonable for studies using biological data and are known to be false for studies using simulated data. We conducted additional Bayesian analyses an...

We modified the phylogenetic program MrBayes 3.1.2 to incorporate the compound Dirichlet priors for branch lengths proposed recently by Rannala, Zhu, and Yang (2012. Tail paradox, partial identifiability and influential priors in Bayesian branch length inference. Mol. Biol. Evol. 29:325-335.) as a solution to the problem of branch-length overestimation in Bayesian phylogenetic inference. The co...

A new method, PATHd8, for estimating ultrametric trees from trees with edge (branch) lengths proportional to the number of substitutions is proposed. The method allows for an arbitrary number of reference nodes for time calibration, each defined either as absolute age, minimum age, or maximum age, and the tree need not be fully resolved. The method is based on estimating node ages by mean path ...

The aim of our study was to test the robustness and efficiency of maximum likelihood with respect to different long branch effects on multiple-taxon trees. We simulated data of different alignment lengths under two different 11-taxon trees and a broad range of different branch length conditions. The data were analyzed with the true model parameters as well as with estimated and incorrect assump...

Developmental plasticity, the acclimation of plants to their local environment, is known to be crucial for the fitness of perennial organisms such as trees. However, deciphering the many possible developmental and environmental influences involved in such plasticity in natural conditions requires dedicated statistical models integrating developmental phases, environmental factors, and interindi...