García-Pereyra¹ J, CGS Valdés-Lozano², E Olivares-Saenz², O Alvarado-Gómez², G Alejandre-Iturbide³, E Salazar-Sosa⁴, H Medrano-Roldán⁵

Phyton-International Journal of Experimental Botany, Vol.78, pp. 53-60, 2009, DOI:10.32604/phyton.2009.78.053

Abstract We tested five Amaranthus genotypes (A. hypochondriacus 655, 653, 153-5-3, and Criollo Tlaxcala and A. cruentus genotype 33) at four population densities (31,250; 41,666; 62,500 and 125,000 plants/ha, during spring-summer (PV; July-December) 2000 and autumn-winter (OI) 2001 and 2002. Studies were conducted at the experimental station of the Agronomy Faculty of the Universidad Autónoma de Nuevo León, Mexico. A split plot experimental design on completely randomized blocks was used, with two replicates. The evaluated agronomic characteristics were grain yield (RG), dry matter yield (MS), plant height (AP), stem diameter (DT) and panicle length (LP). Crude protein (PC),… More >

Brevedan¹ RE, MI Aveldaño², MN Fioretti¹, MA Varillas², SS Baioni¹, HR Mirassón³, IR Palomo¹

Phyton-International Journal of Experimental Botany, Vol.78, pp. 49-52, 2009, DOI:10.32604/phyton.2009.78.049

Abstract Two experiments were conducted under greenhouse conditions to study the influence of P deficiency on nitrogen nutrition of non-nodulated soybean. There was a reduction of N and P content in P deficient (P-) plants of almost 50% after 50 days. During this period, dry matter of these plants was reduced by 33%. Nitrate reductase activity and shoot nitrate content were lower in Pthan in P+ plants. Seventy five percent of nitrates in P- plants were in the roots. Nitrate accumulation in roots would be due to the lower nitrate reductase activity in this organ and More >

Martínez-Corral¹ L, E Martínez-Rubín², F Flores-García¹, GC Castellanos², AR Juárez², MJD López³

Phyton-International Journal of Experimental Botany, Vol.78, pp. 43-47, 2009, DOI:10.32604/phyton.2009.78.043

Abstract The increasing demand of alfalfa crop production in the Lagunera Region has caused the search of new alternatives to the conventional methods of nutritional and hydric evaluation of alfalfa, where costs and time are optimized. The use of a machine vision system for computerized visual recognition of the crop hydric and/or nutritional stress implies the analysis and processing of certain characteristics, such as color, shape and object dimensions from a digital image. Due to the fact that identification parameters are closely related, it is necessary to compile information from specialists, foliar analysis, mathematical morphology and More >

Rivera-Reyes¹ JG, FA Peraza-Luna², JC Serratos-Arévalo², P Posos-Ponce³, SH Guzmán-Maldonado⁴, E Cortez-Baheza¹, G Castañón-Nájera⁵, M Mendoza-Elos^1*

Phyton-International Journal of Experimental Botany, Vol.78, pp. 37-42, 2009, DOI:10.32604/phyton.2009.78.037

Abstract Oats cereal is a worldwide significant crop. It is grown in restrictive climates and in rainy regions of temperate areas. Cultivation of oats produces high forage yields and grain quality, which gives it a wide variety of uses as animal feed and human food. However, the physiological quality of oat seeds in Mexico faces problems, which impact both their import and export. Phytic acid concentration in the oat seed plays a very important role since it affects seed viability, its germination capacity and potential seedling vigor. The objective of this study was to determine the… More >

Ochoa-Fuentes YM¹, E Cerna², J Landeros², O Vazquez¹, V Olalde³, A Flores²

Phyton-International Journal of Experimental Botany, Vol.78, pp. 25-30, 2009, DOI:10.32604/phyton.2009.78.025

Abstract Forty two Mexican isolates of Phytophthora cinnamomi Rands were examined for genetic diversity by the random amplified polymorphic DNA assay. The amount of genetic variation was evaluated by polymerase chain reaction amplification with a set of twenty one random 10-mer primers. All amplifications revealed scorable polymorphisms among the isolates, and a total of 23 band positions were scored for the 21 primers tested. Genetic distances among the isolates were calculated, and cluster analysis was used to generate a dendogram which showed relationships between them. These results suggest that the geographic groups were strong. More >

Sánchez E¹, G Ávila-Quezada¹, AA Gardea¹, E Muñoz¹, JM Ruiz², L Romero²

Phyton-International Journal of Experimental Botany, Vol.78, pp. 11-16, 2009, DOI:10.32604/phyton.2009.78.011

Abstract The objective of this work was to determine the effect of different P doses on nitrogen assimilation in roots and leaves of green beans plants (Phaseolus vulgaris L. cv. Strike). Phosphorus was applied in the nutrient solution as H₃PO₄, at the nutrient doses of: P1 = 0.40 mM; P2 = 0.80 mM; P3 = 1.60 mM; P4 = 3.20 mM; P5 = 4.80 mM, and P6 = 6.40 mM P. Our results indicate that both P toxicity and deficiency gave similar responses to N assimilation. Phosphorus and NO3 - interacted on the absorption and translocation processes affecting More >

Chan RL

Phyton-International Journal of Experimental Botany, Vol.78, pp. 5-10, 2009, DOI:10.32604/phyton.2009.78.005

Abstract Transcription factors (TFs) are proteins able to specifically recognize DNA sequences in the regulatory regions of their target genes. They bind these specific sequences, an event that leads to the activation or repression of whole signal transduction pathways. In plants about 1500 TFs were informatically identified; identification was mainly based in the presence of DNA-binding domains in the translated sequences. They were classified in families and subfamilies according to several features, including the conservation of the DNA binding domain, the genes structures and the functions they exert. Among transcription factors, several seem to be potential… More >

Ugo Galvanetto, Paul Robinson, Agostino Cerioni, Carlos Lopez Armas

Structural Durability & Health Monitoring, Vol.5, No.2, pp. 161-190, 2009, DOI:10.3970/sdhm.2009.005.161

Abstract This paper presents a simple mathematical model to investigate various formulations of interface elements which are used to simulate fatigue driven delamination in composite materials. To illustrate the effectiveness of the model it is used to evaluate the performance of several different static constitutive laws and damage definitions coupled with a particular fatigue degradation strategy. It is shown that the model can be used to readily assess the robustness and reliability of the different formulations by examining hundreds of thousands of sets of parameter values in a rational and efficient manner. More >

M. Lavella¹, T. Berruti¹

Structural Durability & Health Monitoring, Vol.5, No.4, pp. 337-350, 2009, DOI:10.3970/sdhm.2009.005.337

Abstract Results of residual stress measurements on Inconel 718 turbine components after machining are here presented. The work is focused on the experimental detection of the residual stress state produced after turning (orthogonal cutting and standard) and milling. The aim of the experimental activity was to supply an experimental data base of proved reliability for milling and turning model validation. This activity was performed inside the EU STREP project VERDI. The residual stresses were detected by means of X-ray diffraction technique. The experimental plan of measurements was performed on components worked with different working parameters (cutting More >

Smitha Gopinath¹, J. Rajasankar^1,2, Nagesh R. Iyer¹, T. S. Krishnamoorthy¹, B.H.Bharatkumar¹, N. Lakshmanan¹

Structural Durability & Health Monitoring, Vol.5, No.4, pp. 311-336, 2009, DOI:10.3970/sdhm.2009.005.311

Abstract In this paper, a two-phase strain-based constitutive model is proposed for concrete under tension. First phase deals with modelling uncracked concrete while the behaviour of concrete in cracked condition is modelled in second phase with appropriate theoretical support. A bilinear tension softening curve of concrete defined in crack width-stress space is taken as the basis to propose the model. Smeared representation of reinforcement and cracks along with multi-layered geometry definition of reinforced concrete (RC) structures is used to implement the model. Through this, it is shown that change in the orientation of tensile cracks with… More >