Screening of Urfa pepper landraces for resistance to Meloidogyne incognita

Journal of Plant Diseases and Protection - The root-knot nematodes (Meloidogyne spp.) are significant pathogens that affect the yield and fruit quality in pepper cultivars (Capsicum spp.)....     

温带森林中风倒形成的坑和丘对土壤性质和温室气体排放的影响

Pit and mound micro-relief(resultant microsites from trees uprooted by windthrow) could have regimes of microclimate and soil features that differ from areas of undisturbed soil. In an attempt to provide a comprehensive evaluation of the significance of pits and mounds on soil features and also the dynamics of greenhouse gas(GHG) fluxes at local scale, this study was carried out in a reserved area of Darabkola forest in Mazandaran Province, northern Iran. The age of a pit and mound was considered equal to the degree of decay of the blown down tree. Three microsites were distinguished, consisting of pit bottom(PB), mound top(MT) and undisturbed area(UA). Soil samples were taken at 0–15 and 15–30 cm depths from all microsites and analysed for soil physical, chemical and biological features. Our findings suggested that in context of forest ecology, pits and mounds following windthrow events should be considered as an effective factor influencing soil features(i.e., density, texture, water content, p H, organic C, total N, available nutrients and earthworm density/biomass) and especially GHG fluxes. Results showed that MT acted as a sink for N2O(-0.010 mg N2 O m-2d-1) and CH4(-0.257 mg CH4m-2d-1) fluxes and also produced lower CO2 concentrations(0.095 mg CO2 m-2d-1) than PB(0.207 mg CO2 m-2d-1) and UA(0.098 mg CO2 m-2d-1). As a consequence, a separation into pits/mounds would be important for a precise budgeting of greenhouse gases.     

Soil Salinization in Some Irrigated Areas of the Kingdom of Bahrain

Monitoring and assessment of agricultural land degradation is of vital importance for better land and water management planning and reclamation. It requires setting baseline information and basic analysis at specific time and space. About 33 geo-referenced soil sampling spots were selected in two agricultural production locations in the Kingdom of Bahrain to assess the status and preliminary causes of land degradation. Soil samples were taken from 13 sites in Diraz location while 19 samples were taken from Budayyi location. The samples were taken to 90 cm depth at 30 cm intervals. Standard procedures were followed to determine soil physiochemical properties. In addition, field observations on farm condition, distance from the sea, method of irrigation and irrigation water source were taken. Some of the soil samples were deliberately taken from outside the irrigated basins among trees compared with samples taken from inside the actively growing area for comparison. The results indicated that the salinity level was significantly （P 〈 0.001） higher at the 0-30 cm soil depth compared with 30-60 cm or 60-90 cm depths in both locations. The distance from the sea did not show clear correlation with surface soil salinity in Budayyi area compared with Diraz. Both locations showed significantly higher salinity levels on samples taken outside the actively growing areas compared with those taken from within. The effect is more prominent at the 0-30 cm depth. The observed variability on salinity levels may be attributed to farm management practices and deteriorating quality of ground water. Thus, agricultural land degradation in Bahrain cannot be attributed to ground water deterioration alone. The use of tertiary treated sewage water （TSE） may ease the pressure on ground water, but the pH of the TSE should be carefully monitored and managed with proper studies on leaching requirements to avoid further salinity complications.     

Application of two way indicator species analysis in lowland plant types classification

A TWINSPAN classification of 60 sample plots from the Khanikan forest (North of Iran) is presented. Plant types were determined from field observations and sample plot data arranged and analyzed in association tables. The types were defined on the basis of species patterns of presence, absence and coverage values. Vegetation was sampled with randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively within each quadrate and using the two-way indicator species analysis. The objectives of the study were to plant type's classification for Khanikan lowland forest in North of Iran, Identification of indicator species in plant types and increase our understanding in regarding to one of Multivariate analysis methods (TWINSPAN). Five plant types were produced for the study area by TWINSPAN, i.e., Menta aquatica, Oplismenus undulatifolius, Carex grioletia, Viola odarata and Rubus caesius. Therefore, at each step of the process, the program identifies indicator species that show strongly differential distributions between groups and so can severe to distinguish the groups. The final result, incorporating elements of classification can provide a compact and powerful summary of pattern in the data set.     

The use of principal component analysis in studying physical, chemical and biological soil properties in southern caspian forests (North of Iran)

This research was conducted in Khanikan forests located in lowland of Mazandaran province (North of Iran). Eighteen profiles were dug and several chemical, physical and biological soil properties were investigated. The soil properties evaluated were soil pH, bulk density, saturation moisture content, electrical conductivity, organic carbon, total nitrogen, cation exchangeable capacity, available phosphorous, soil texture, calcium carbonate content, number and biomass of earthworms, litter carbon and litter nitrogen. Principal Component Analysis (PCA) was used to identify the variation of soil properties. PCA, a technique which reduces the dimensionality of multivariate data by removing Interco relations among variables, has a number of useful applications in forest researches. The results showed significant relationships between some soil factors with PC1 and PC2 axes, also, among different soil factors, the distribution of forest types was most strongly controlled with some soil characteristics such as acidity, bulk density, texture, phosphorous, organic carbon, total nitrogen and cation exchangeable capacity.     

Impact of cycocel on seed germination and growth in some commercial crops under osmotic stress conditions

Most of plant growth regulators are known to alleviate negative effects of osmotic stress on crop growth. To evaluate the effects of cycocel (CCC), as a growth regulator, on crop seed germination, early growth, and vegetative growth under osmotic stress conditions, a study was conducted under controlled conditions. Six crops, wheat, barley, maize, sunflower, safflower, and rapeseed were grown under five osmotic potentials (0, as non-stress, ?0.5, ?1.0, ?1.5, and ?2.0 MPa), which were raised from seeds treated with three CCC concentrations (0, 2.5, and 3.5 g l^?1). Reduced germination, seedling and vegetative growth as well as enhanced leaf free proline and chlorophyll content index were observed under osmotic stress. The extent of these changes depended on the type of the used crops. Priming with optimum CCC concentration mitigated to great extent stress-induced adverse effects on these crops. The positive effect of CCC priming on wheat, maize, and rapeseed was observed only at moderate osmotic levels, whereas on barley and safflower the priming effects were found in all levels of osmotic stress. However, sunflower did not respond to CCC priming treatments which might have been due to its thick achene coat. CCC priming was found to be effective in diverting a major proportion of assimilates to root, because root to shoot dry weight ratio increased due to CCC application under all osmotic stress regimes. Since barley and safflower were found to be most responsive to CCC priming, further research for better understanding of mechanisms of CCC priming on their germination and vegetative growth is recommended.     

Iron Fortification of Whole Potato Using Vacuum Impregnation Technique with a Pulsed Electric Field Pretreatment

In this study, the effect of a vacuum impregnation (VI) process with pulsed electric field (PEF) pretreatment on fortification of whole potato with ferric pyrophosphate was investigated. The VI process and PEF pretreatment were optimized with respect to physicochemical attributes of PEF-VI-processed samples using response surface methodology (RSM). The results indicated that the iron content of VI-processed and PEF-VI-processed potatoes was increased about 126 and 457%, respectively, compared to unprocessed potatoes. A more intensive PEF pretreatment led to a higher cell disintegration, decrease in colour and textural parameters and also increase in components leakage from treated potato. Our study suggests that whole 180-g potatoes should be pretreated at 394 V/cm with 36 pulses and then treated at 3.5 kPa for 37 min in vacuum stage and 39 min restoration time in atmospheric stage to achieve the highest iron fortification and the lowest physicochemical changes during PEF-VI processing.     

Genotypic analysis of virulence genes and antimicrobial profile of diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> isolated from diseased lambs in Iran

The aim of the present study was to determine the analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs. Two hundred ninety E. coli isolates were recovered from 300 rectal swabs of diarrheic lambs and were confirmed by biochemical tests. The pathotype determination was done according to the presence of genes including f5, f41, LTI, STI, bfp, ipaH, stx ₁ , stx ₂ , eae, ehlyA, cnf ₁ , cnf ₂ , cdIII, cdIV, and f17 by PCR method. Sixty-six isolates (23.72%) possessed the STI gene and categorized into entrotoxigenic E. coli (ETEC). Nine isolates (3.1%) and five isolates (1.72%) were positive for the cnf1 and cnf2 genes which categorized into necrotoxic E. coli (NTEC). Hundred and seventeen isolates (40.34%) harbored stx ₁ and/or stx ₂ and classified as Shiga toxin-producing E. coli (STEC). Thirteen isolates (4.48%) were assigned to atypical entropathogenic E. coli (aEPEC) and possessed eae gene. Two isolates (0.68%) were positive for ipaH gene and were assigned to entroinvasive E. coli (EIEC). Statistical analysis showed a specific association between eae gene and STEC pathotype (P?<?0.0001). The most prevalent resistance was observed against lincomycin (96.5%) and the lowest resistance was against kanamycine (56.02%), respectively. The high prevalence of STEC and ETEC indicates that diarrheic lambs represent an important reservoir for humans. ETEC may play an important role for frequent occurrence of diarrhea in lambs observed in this region. Due to high antibiotic resistance, appropriate control should be implemented in veterinary medicine to curb the development of novel resistant isolates.     

Sowing date effects on dry matter remobilization and yield of triticale (Triticosecale wittmack) under late season drought stress

A 2-year field experiment using a randomized complete block design with the treatments arranged as split-split-plot with three replicates was conducted to investigate the effects of different sowing dates. Different irrigation regimes and different triticale cultivars were tested during 2014 and 2015 growing seasons. Under cutting off irrigation at the milk development stage, Sanabad with 46.2% had higher relative water content on December 3 sowing date. Assimilate remobilization in cutting off irrigation at dough development was more than that at milk development and Sanabad had the highest assimilate remobilization on 3 December sowing date in both years. In both years, Sanabad had the highest remobilization efficiency. The highest contribution of pre-anthesis assimilates to grain was obtained on 3 December sowing date in both years in Sanabad. Lower grain yield in Juanillo cultivar under cutting off irrigation, appeared to be due to reduction in remobilization efficiency, especially by cutting off irrigation at milk development stage in late sowing date. Overall, Sanabad was more tolerant to cutting off irrigation than Juanillo.