Morphometric and meristic variations in bream (Abramis brama orientalis, Berg, 1949) during larval development

This study was conducted to examine morphometric and meristic characteristics alongside pigmentation patterns of bream larvae, Abramis brama orientalis, in four stages of larval development. Morphological characters including total length (TL), standard length (SL), notochord length (NL), head length (HL), head depth (HD), eye diameter (ED) and mouth width (MW) were examined from hatching time through 30 days after hatching (DAH). The results showed morphometric variations in the different larval stages. Growth and development of fins occurred mainly at the Post Flexion stage with the completion of caudal fin at 9 mm TL and pelvic fin at 13.33 mm TL. At all larval stages, the highest concentration of pigments was seen on dorsal, ventral and somewhat on the lateral sides of body in descending order. The highest density of melanophores at larvae yolk sac stage was observed on the yolk sac and the back of head zone, while at preflexion and flexion stages melanophores were dominant on the back of head and on the skin folds which resulted from yolk absorption. At post flexion stage, high density of melanophores was found on the back of the head, bases of fins and caudal fin, while less concentrations of these cells were evident on the lateral sides of fish' body. In conclusion, a clear change in the growth and main morphological characters were observed in postflexion stage. This may be due to the main development of fins, which would suggest enhanced swimming capabilities and also prey capture efficiencies

Seroprevalence of hepatitis C and risk factors in haemodialysis patients in Guilan, Islamic Republic of Iran

ABSTRACT We assessed the prevalence of hepatitis C virus (HCV) infection and associated risk factors for all 298 haemodialysis patients in 7 dialysis units in Guilan province. Serum samples were screened for anti-HCV antibodies using a second generation enzyme-linked immunosorbent assay. Positive samples were confirmed by immunoblot assay. Overall prevalence was 24.8% (range: 9%-40%; 95% CI: 19.9-29.7): 80 patients tested positive and 74 were confirmed positive by immunoblot assay. Length of time on dialysis and history of rejected kidney transplant were statistically significantly associated with HCV infection. Age, sex and previous blood transfusion were not associated. Nosocomial transmission may play a role in the spread of HCV in haemodialysis units. A separate dialysis system should be used for seropositive HCV patients

Relationship between root and yield morphological characters in rainfed low land rice ( Oryza sativa L.)

Understanding the relationship between root system and yield related traits is an important objective in crop breeding programs. Canonical correlation analysis has been adopted to study the strength of association between the root morphological traits and grain yield components under low-moisture stress and well-watered conditions and to find the root morphological characters that have the largest influence on grain yield and its components under the two conditions. This study revealed that root to shoot length and weight ratios and root dry weight were had the largest effect on plant height, shoot dry weight and grain yield under well-watered condition. Under low moisture stress, maximum root length and root number were also important for improving grain yield and panicle length. The interrelationships clearly identified the importance of root to shoot length and weight ratios and root dry weight under well-watered condition. While, maximum root length and root number are a better combination under low moisture stress condition

Evaluation of the Combining Abilities and Gene Effects of Agronomic Traits in Sunflower Inbred Lines (Helianthus annuus L.)

Information about combining ability of inbred lines and genetic variance components of different agronomic traits is a prerequisite for improving the productivity of sunflower hybrids. For this purpose, 20 hybrids obtained from the crosses between five cytoplasmic male sterile lines with four fertility restorer lines were evaluated in a randomized complete blocks design with three replications in the Agricultural Research Station, University of Tabriz, Tabriz, Iran in 2009. Analysis of variance indicated significant differences between the hybrids for most traits and therefore it was possible to estimate genetic variance components through line × tester method. Results showed that plant height, head diameter, 1000-seeds weight and oil content were under the control of additive gene effects. Over dominance gene effects were observed for time of flower initiation, stem diameter and grain yield. This justifies the production of hybrid varieties. Male sterile line 52 and R50 restorer line had a better general combining ability for seed yield. Hybrids 52 × R26 and 222 × R50 had the highest specific combining ability. The results of this study indicated that due to existence of genetic variability for agronomic traits in genetic materials and presence of combinations with suitable combining ability, production of superior sunflower hybrids is feasible by selection and hybridization

Effect of Plant Density on Growth and Yield of Three Sunflower Hybrids (Helianthus annuus L.) as a Second Crop

In order to study the effects of plant density on growth, yield and oil percentage of three sunflower hybrids (Azargol, Alistar, Eroflor) an experiment was conducted at Agriculture Research Station of Myandoab in 2004. These hybrids were sown at four densities of 6, 8, 10 and 12 plants m-2 as factorial based on randomized complete block design with three replications. The results showed that dry matter accumulation (DM), crop growth rate (CGR) and relative growth rate (RGR) were increased with increasing plant density. By increment plant density, leaf area index (LAI) was slowly increased in early stages of growth but with beginning of plant rapid growth, increased dramatically. DM and CGR in Azargol and Eroflor were greater than Alistar. Analysis of variance showed that all traits were significantly affected by plant density. Yield per unit area, oil percentage and oil yield per unit area were increased, with increasing plant density. Although seed yield per plant at low densities was greater than that of high densities, but this increment was not enough for compensating the reduction of yield due to low density

Microsoft Word - 039-004-Iran-IJPAES-14-217.doc

ABSTRACT: To investigate the relations of agronomic traits in some hybrids of sunflower, 20 hybrids obtained from line × tester crosses of five cytoplasmic male sterile lines with four fertility restorer lines were evaluated in a randomized complete block design with three replications at Agricultural Research Station of the University of Tabriz. Data were collected for agronomic traits such as date of flowering initiation, date of flowering end, plant height, stem diameter, head diameter, date of maturity, head dry weight, number of seeds per head, empty seed number per head, grain weight per head, grain yield, 1000-seed weight and oil content. Positive and significant correlation were found between the grain yield and stem diameter, head diameter, number of seeds per head, plant height, grain weight per head, head dry weight; and between the oil content with the grain weight per head and number of seeds per head. Multiple regression analysis and path analyses of grain yield with yield components and some agronomic traits indicated that head diameter, number of seeds per head and stem diameter are important factors demonstrating grain yield. It seems that indirect selection for grain yield in segregating generations through these traits will be effective for extracting desirable genotypes

Identification of Fusarium Head Blight Resistance QTLs in a Wheat Population Using SSR Markers

Fusarium head blight (FHB) caused by Fusarium graminearum is a destructive disease of wheat. Breeding for FHB resistance by conventional breeding methods is feasible but laborious and expensive. Detection of DNA markers associated with FHB resistance quantitative tract loci (QTL) will accelerate breeding programs. This study was conducted to identify simple sequence repeat (SSR) markers linked FHB resistance QTLs in wheat. A population of 167 F ₂:₃ from the cross Wangshuibai (resistant)/Falat (suspectible) was used. The Type II resistance (spread by pathogen within a spike) was evaluated on F₃ families derived from F₂ plants in the greenhouse. Two QTLs were detected that together explained 25.1% of the phenotypic variation. A QTL region on chromosome 3B explained 16% of the variation. Additional QTL was located on chromosomes 2A accounting for 9.1% of the phenotypic variation

Effect of Water Deficit on Morphological Traits and Water Use Efficiency of Two Soybean (Glycine max L.) Cultivars

In order to investigate the effect of water limitation on morphological traits and water use efficiency in two soybean cultivars, a split-plot experiment was conducted in 2004 at the Research Farm of the Faculty of Agriculture, University of Tabriz, Iran. Irrigation treatments ( I1, I2, I3 and I4: irrigation after 60±3, 80±3, 100±3 and 120±3 mm evaporation from class A pan, respectively) were assigned to main plots, and two soybean cultivars (Zane and Huck) were allocated to the subplots. The results indicated that the Huck required less GDD (growing-degree days) to complete the growth and developmental stages, compared with Zane. Flowering and maturity for Huck occurred about 3 days earlier than those for Zane. The mean number of branches, plant height, biological and grain yields under well watering (I1) were higher than those under limited irrigations (I2, I3 and I4). All these traits were decreased with increasing water deficit. The highest harvest index was obtained from I1 treatment, however, this superiority was not significant statistically, when compared with other irrigation treatments. Therefore, it was concluded that water use efficiency (WUE) could be improved, with decreasing irrigation. However, the volume of water at each irrigation increased and grain yield decreased, as water deficit severed. Consequently, it seems that irrigation with low volume and short intervals might be more suitable for soybean production