Flanking SSR markers for alleles involved in the necrosis of hybrids between hexaploid bread wheat and synthetic hexaploid wheat

Hybrid necrosis in wheat (Triticum aestivum L.) is the premature death of leaves or plants caused by the interaction of two dominant complementary genes, Ne1 and Ne2, located on chromosomes 5B and 2B, respectively. We examined allelic interaction effects of necrosis alleles using simple sequence repeat (SSR) markers in F₂ populations derived from crossing the cultivar “Alsen” with a synthetic hexaploid “TA4152-37”. The SSR marker Xbarc7 was linked at a distance of 3 cM to the quantitative trait loci (QTL) located on chromosome 2B, and Xgwm639 was 11 cM from the 5B QTL. A significant additive by additive epistatic interaction was detected between Ne1 and Ne2 QTL, and the results suggest that Alsen possesses a moderate necrosis allele, Ne2^m; whereas, TA4152-37 possesses a moderate necrosis allele, Ne1^m. The Ne2^m allele had a stronger effect than the Ne1^m allele, and a total of 94.6% of phenotypic variance was explained by these genes and their interactions. This demonstrates the strong phenotypic effect due to even moderate necrosis alleles, and emphasizes the need for breeders to accurately predict and identify hybrids that will result in necrosis.     

The evaluation of the thermal and mechanical properties of aramid/semi-carbon fibers hybrid composites

In this research work, aramid and semi-carbon fibers (SCFs) were hybridized in the form of interlayer or layer by layer into epoxy matrix by hand lay-up method. Afterward, the effect of hybridization on the thermal and mechanical properties of epoxy composites was characterized by thermal analysis; horizontal burning; tensile and bending tests. Based on the results of the mechanical tests, increasing SCFs to aramid fibers ratio decreased tensile strength, elastic and flexural modulus. But with increasing this ratio to 53 % failure strain reduced, whereas in the ratios of more than 53 %, the failure strain enhanced. The results of thermal analysis curves indicated that there are three stage mass loss at the temperature ranges of 100-220, 270-470 and 500-620 °C. It was also found that with increasing the SCFs to aramid fibers ratio decreased the third-stage of the mass loss. The results of horizontal burning showed that increasing the SCFs to aramid fibers ratio decreased the rate of burning.     

Cluster Management to Improve Berry Quality in Young ‘Alborz’ Table Grape in the Intermountain West Region,USA

Cluster management in table grapes is an essential cultural practice for production of high quality table grapes. This issue has not been studied in the Intermountain West region in the United States. Thus, the objective of this project was to study the effects of cluster removal, cluster shortening, and vine girdling on yield and quality attributes of ‘Alborz’ table grape during 2012–14 growing seasons. Vines that did not receive cluster removal and cluster cutting (NoClRemNoClCut) tended to have a higher yield but smaller berry weight than those with other cluster managements every year. Vines receiving cluster removal, cluster shortening, and a trunk girdling (ClRemShort&Gird) regime tended to have larger berries and cluster weight than those with other treatments. However, girdled vines were more susceptible to cold damage. Vines receiving cluster removal and cluster shortening had slightly larger berries, better appearance, and marketability than those without cluster removal and without cluster shortening.     

The Potential of Caprifig Genotypes for Sheltering <Emphasis Type="Italic">Blastophaga psenes</Emphasis> L. for Caprification of Edible Figs

Caprifig (Ficus carica L.) as pollen sources, play a major role in edible fig caprification by Blastophaga psenes L. The present study was carried out to evaluate the potential of three caprifig genotypes (Poozdombali, Kouhi and Kouhaki) for the shelter of B. psenes wasp in Estahban region, Fars province, Iran. Summer (profichi) crop fruits per genotype were harvested in full maturity period and evaluated for five times for the shelter of B. psenes wasp. Significant differences among caprifig genotypes were found for B. psenes number for the three times carried out (0, 21 and 28 days), but they did not show significant differences for two times (7 and 14 days). At day of harvesting, Poozdombali showed the highest B. psenes wasp number (341.33) and Kouhaki had the lowest (200.00) and they showed significant differences for this character in this time. Also, seven days after harvesting, Poozdombali showed the highest wasp number (106.67) and Kouhi and Kouhaki had the lowest (104.33), but not significant difference. Number of B. psenes at the day of harvesting was the highest for all of the genotypes and at 28 days after harvesting was the lowest. Cluster analysis identified two major clusters with several sub-clusters. Caprifig trees with having high B. psenes number are essential for a suitable caprification. Thus, Poozdombali genotype with the highest B. psenes number, is suitable in this important trait to be used for edible figs caprification.     

Nature as a model for large-scale planting design – Least-difference method

An objective and systematic method for large-scale planting design was previously published. It involved multiple regression equations relating species abundance to topo-edaphic variables in a native (model) plant community, calculated from survey data collected by forestry departments. The method is appropriate for the number of sample plots currently surveyed in plant communities. With the imminent availability of a large volume of data through remote sensing technology, another method is presented in this article that emulates nature more closely and is not based on a mathematical model. It involves finding sample plots in the model community with topo-edaphic variables similar to those of the grid cells on the project site and assigning their species composition to the grid cells. Similarities of corresponding pairs of variables are decided using comparison tolerances for the variables, calculated based on their relative importance in species distribution in the model community.     

The effects of irrigation methods with effluent and irrigation scheduling on water use efficiency and corn yields in an arid region

A great challenge for the agricultural sector is to produce more food from less water, particularly in arid and semi-arid regions which suffer from water scarcity. A study was conducted to evaluate the effect of three irrigation methods, using effluent versus fresh water, on water savings, yields and irrigation water use efficiency (IWUE). The irrigation scheduling was based on soil moisture and rooting depth monitoring. The experimental design was a split plot with three main treatments, namely subsurface drip (SSD), surface drip (SD) and furrow irrigation (FI) and two sub-treatments effluent and fresh water, which were applied with three replications. The experiment was conducted at the Marvdasht city (Southern Iran) wastewater treatment plant during 2005 and 2006. The experimental results indicated that the average water applied in the irrigation treatments with monitoring was much less than that using the conventional irrigation method (using furrows but based on a constant irrigation interval, without moisture monitoring). The maximum water saving was obtained using SSD with 5907 m³ ha⁻¹ water applied, and the minimum water saving was obtained using FI with 6822 m³ ha⁻¹. The predicted irrigation water requirements using the Penman-Monteith equation (considering 85% irrigation efficiency for the FI method) was 10,743 m³ ha⁻¹. The pressure irrigation systems (SSD and SD) led to a greater yield compared to the surface method (FI). The highest yield (12.11 × 10³ kg ha⁻¹) was obtained with SSD and the lowest was obtained with the FI method (9.75 × 10³ kg ha⁻¹). The irrigation methods indicated a highly significant difference in irrigation water use efficiency. The maximum IWUE was obtained with the SSD (2.12 kg m⁻³) and the minimum was obtained with the FI method (1.43 kg m⁻³). Irrigation with effluent led to a greater IWUE compared to fresh water, but the difference was not statistically significant.     

An evaluation of common pan coefficient equations to estimate reference evapotranspiration in a subtropical climate (north of Iran)

Accurate reference evapotranspiration (ET₀) data are essential to water resources project planning and farm irrigation scheduling. Evaporation pans are widely used to estimate reference ET₀. Via the pan coefficient (K _p), ET₀ is estimated from evaporation pan data. Four common K _p equations (Orang in Potential accuracy of the popular non-linear regression equations for estimating pan coefficient values in the original and FAO-24 tables, unpublished report, 1998; Allen and Pruitt in J Irrig Drain Eng 117(5):758–773, 1991; Cuenca in Irrigation system design: an engineering approach, p 133, 1989; Snyder in J Irrig Drain Eng 118(6):977–980, 1992) to calculate daily K _p coefficients to estimate ET₀ were evaluated using a 10-year mean climate dataset for a subtropical climate (north of Iran). Overall results showed that ET₀ calculated using the daily K _p values from Orang (Potential accuracy of the popular non-linear regression equations for estimating pan coefficient values in the original and FAO-24 tables, unpublished report, 1998) provided more accurate daily, monthly, and annual total estimates compared to the others equations.     

Polyphosphate fertilizers increased maize (Zea mays L.) P,Fe, Zn,and Mn uptake by decreasing P fixation and mobilizing microelements in calcareous soil

Journal of Soils and Sediments - Polyphosphate (Poly-P) is an alternative source of phosphate (P) fertilizer. However, as a condensed P, the effects of different polymerization content of poly-P on...     

Characterization of phosphorus engineered biochar and its impact on immobilization of Cd and Pb from smelting contaminated soils

Journal of Soils and Sediments - Biochar has been used as an amendment to immobilize toxic metals (TMs) and increase nutrient content in the contaminated soil. In this study, Ca(H2PO4)2-engineered...     

Characterization of Major Soil Orders in Syria

Eurasian Soil Science - Soil is one of the most important natural resources that should be studied and characterized to provide decision-makers with sufficient information for reconstruction plans...