Effect of drought stress on root yield and some morpho-physiological traits in different genotypes of sugar beet (<Emphasis Type="Italic">Beta vulgaris</Emphasis> L.)

To study the effects of different levels of drought stress on root yield and some morpho-physiological traits of sugar beet genotypes, a study was conducted in the research farm of Islamic Azad University of Birjand, Iran in 2013 as strip-split plot experiments based on randomized complete block design. Different levels of drought stress were considered as vertical factor in three levels including normal irrigation, moderate stress, and severe stress. Horizontal factor was assigned to five varieties of sugar beet. Drought stress had a significant effect on root dry weight, total dry weight, root yield, and leaf temperature at 1% probability level and on leaf dry weight, crown dry weight, and harvest index at 5% probability level. Drought stress had an adverse effect on root yield of investigated genotypes of sugar beet. Under normal conditions, the mean of root yield was higher than middle and severe drought stress. Different investigated genotypes of sugar beet responded to drought stress based on their yield potential. The highest positive correlation of root yield was observed with root dry weight (r=0.977**). Stepwise regression analysis and path coefficient analysis showed that root dry weight and petiole dry weight are the most important traits that can affect root yield of sugar beet under drought stress and can used as selection criteria in investigated cultivars of sugar beet. Finally, 7221 genotypes can be considered as tolerant genotypes in the next studies. In comparison, Jolgeh cultivar (as susceptible control) yielded well in areas with normal irrigation, but under moderate and severely stresses its root yield was reduced.     

Erratum to: Wild pistachio tree (Pistacia mutica) in the Qalajeh forest region of western Iran

<正>Erratum to:Journal of Forestry Reasearch,(2013)24(3):611-614DOI10.1007/s11676-013-0393-2The original version of this article unfortunately contained one mistake in author name in the footnote.The second author's name,"Mousa Rasouli",actually should be Hamid Soofi Mariv.The corrected version of the footnote should be as the following:     

Measuring crop status using multivariate analysis of hyperspectral field reflectance with application to disease severity and plant density

Using spectral reflectance to estimate crop status is a method suitable for developing sensors for site-specific agricultural applications. When developing spectral analysis methods, it is important to know the influence of different crop parameters on the spectral reflectance profile. The objective of this report was to present and evaluate a multivariate method for objective hyperspectral analysis in the examination of how different parts of the reflectance spectrum are affected by disease severity and above ground plant density. Data from two field experiments were used; fungal disease severity assessments in wheat 1998 and above ground plant density measurements 2003. The analysis method consisted of two steps: a pre-processing step where the data was normalized and a classification step for estimating the crop variable. Using only 12% of the data as training data, the method resulted in coefficients of determination (R ²) of 94.3% for the disease severity data and 96.9% for the plant density data. The hyperspectral analysis method presented could also be used to extract spectral signatures of disease severity and plant density using the experimental data. In general, two types of spectral signatures for both data sets, with respect to increasing disease severity and decreasing plant density, were observed (1) a flattening of the green reflectance peak together with a general decrease in reflectance in the near infrared region and, (2) a decrease of the shoulder of the near infrared reflectance plateau together with a general increase in the visible region between 550 and 750 nm.     

A genomic regulatory network for development

Development of the body plan is controlled by large networks of regulatory genes. A gene regulatory network that controls the specification of endoderm and mesoderm in the sea urchin embryo is summarized here. The network was derived from large-scale perturbation analyses, in combination with computational methodologies, genomic data, cis-regulatory analysis, and molecular embryology. The network contains over 40 genes at present, and each node can be directly verified at the DNA sequence level by cis-regulatory analysis. Its architecture reveals specific and general aspects of development, such as how given cells generate their ordained fates in the embryo and why the process moves inexorably forward in developmental time.     

Comparison of different soilless media for growing gerbera under alkalinity stress condition

A factorial experiment was developed with two factors of the growing medium (v/v): 100% coconut fiber (CF), 75% vermicompost+25% perlite (VP), 25% zeolite+75% perlite (ZP), 75% peat+25% perlite (PP), 75% coco chip+25% perlite (CCP), 75% coconut fiber+25% perlite (CFP) and 100% perlite (P); and sodium bicarbonate (NaHCO₃) (0, 20 and 40 mM) involving the growth of gerbera cv. Dafne. Compared with CF substrate, NaHCO₃ in the nutrient solution caused significant decrease in vegetative and reproductive traits and nutrient concentration [especially iron, phosphorus, and magnesium (Fe, P and Mg)] in the rest of the media. The improved crop performance of plants grown onto CF substrate was attributed to their strong capacity to accumulate Fe in the aerial part under alkaline conditions and to maintain a better plant nutritional status (higher P and Mg). It is concluded that the use of CF substrate could provide a useful tool to improve alkalinity tolerance of gerbera plants under NaHCO₃ stress.     

Rhizosphere effects on Cu availability and fractionation in sewage sludge‐amended calcareous soils

Rhizosphere processes have a major impact on copper (Cu) availability and its fractions in soils. A greenhouse experiment with wheat was performed to investigate availability (using seven chemical procedures) and fractionation of Cu in the rhizosphere of ten agricultural soils (Typic Calcixerepts) amended with sewage sludge (1% w/w) using rhizoboxes. The results show that available Cu concentrations in rhizosphere soils were significantly (P < 1%) lower than in bulk soils. In comparison with the bulk soils, in the rhizosphere soils the concentration of Cu associated with organic matter and residual Cu increased by 24 and 4%, respectively, whereas exchangeable Cu, Cu associated with iron‐manganese oxides, and Cu associated with carbonate decreased by 20, 14, and 12%, respectively. Dissolved organic carbon (DOC) and Cu associated with iron‐manganese oxides and Cu associated with organic matter in the rhizosphere and bulk soils were significantly correlated (P < 5%). The results show that the differences between rhizosphere and bulk soils in chemical conditions such as DOC concentrations can change the proportion of soil Cu fractions and, therefore, Cu availability for wheat in calcareous soils amended with sewage sludge. The results show that the wheat root‐induced modifications of chemical and biological soil conditions do not only lead to Cu depletion in mobile soil Cu fractions, but also to modification in soil Cu fractions which are commonly considered as more stable.     

伊犁河谷土壤含盐量空间变异和格局分析

基于区域变量理论,在GPS和GIS技术支持下,通过地统计学的半变异函数和Kriging空间插值,以察布查尔县为例,定量分析伊犁河谷不同层次土壤盐分的空间异质性.结果表明:0～20 cm、20～40 cm、60～80 cm层土壤盐分的半变异函数符合球状模型,40～60 cm层符合高斯模型.不同层次土壤盐分之间的空间自相关...     

伊犁河谷地下水盐运动规律研究

根据研究区地质地貌,将整个研究区划分为三层阶地,通过对三层阶地的地下水盐动态进行实时监测,运用双因子方差分析方法,详细论述了地下水电导率随地下水位在不同时期及不同分布条件下的变化情况.结果表明,地下水电导率变化与水位变化有很大关系,且表现出很强的区域特征:各阶地电导率(EC)值均随水位的上升而增加,高EC值出现在高水位...     

Effect of Nano Fe-Chelate,Fe-Eddha and FeSO4 on Vegetative Growth,Physiological Parameters and Some Nutrient Elements Concentrations of Four Varieties of Lettuce (Lactuca sativa L.) In NFT System

In order to investigate the effects of different iron (Fe) sources (nano iron (Fe)-chelate, Fe- ethylenediamine-di(o-hydroxy phenyl acetic acid (EDDHA) and iron (II) sulfate (FeSO₄)) on lettuce (Lactuca sativa) growth in alkaline solutions, an experiment was arranged in hydroponic system. This study showed that leaf Fe content and overall plant growth was significantly increased by Fe-chelate application, and the highest values of leaf Fe, plant pigments and vegetative growth were recorded in plants treated with nano Fe-chelate. The lowest Fe, chlorophyll, carotenoids and soluble sugars in leaves were observed in FeSO₄ treatment. There were no difference in soluble sugars contents of plants between nano Fe-chelate and Fe-EDDHA treatments. Fertilization of lettuce plants with different Fe-chelate sources had a beneficial effect on the manganese (Mn) and zinc (Zn) uptake in plants. It is concluded that application of chelated form of Fe (especially nano Fe-chelate) must be performed in hydroponic system with alkaline water, to overcome Fe deficiencies and to make better nutritional status.