Response of orange trees to deficit irrigation strategies in the north of Iran

This work examines the effects of two deficit irrigation strategies, conventional deficit irrigation (DI) and partial root-zone drying (PRD), on mature navel orange trees. The study carried out during two consecutive years (2008 and 2009) in a semi-arid climate on a silty–clay–loam soil in the north of Iran. Both DI and PRD trees were irrigated at two levels, 75 and 50% (DI75, PRD75, DI50 and PRD50) of the full irrigation (FI). In DI, irrigation water was applied to both sides of the tree rows, similar to FI. In PRD, irrigation water was applied alternately to only one side, at each irrigation event. Results showed that DI treatments reduced fruit yield by ～30% compared with FI, but PRD treatments caused no reduction in fruit yield. No negative impact was detected in fruit quality after applying DI and PRD treatments. Shoot growth decreased in all DI and PRD treatments in both years. In DI, stomatal resistance was higher (50%) than in FI, but it was not significantly affected in PRD. The irrigation water use efficiency of PRD trees increased to nearly twice that of FI. According to these two years' results, we recommend PRD as an acceptable deficit irrigation strategy in the region.     

First feeding of burbot, Lota lota (Gadidae, Teleostei) larvae under different temperature and light conditions

The burbot (Lota lota) is the only fresh water member of the cod family, Gadidae, and is adapted to cold waters. The effects of temperature and light on the growth and survival of burbot larvae were investigated under hatchery conditions. Three temperature regimes (12, 16 and 20°C) were applied under continuous light and darkness during the experiment. Rotifer, Brachionus calyciflorus (L.) were fed to the larvae in the first 10 days and the diet was then replaced with Artemia nauplii. At the end of the feeding stage with rotifer, growth in terms of the total length and wet weight were larger at higher temperatures under continuous light. At day 10, survival rates of the fish held at 12°C under continuous light and darkness regime were higher than those held at 16°C and 20°C kept under the same conditions. From day 10 onwards, larval growth improved remarkably after changing the live food from rotifer to Artemia in all treatments. At the end of the study, the highest survival rate was recorded among the larvae held at 12°C exposed to continuous light. Under light condition, the temperature of 20°C did not result in an improved larval growth compared with 16°C. This may indicate that high temperature and continuous light are not beneficial for larval growth and survival when they reach older stage of development. The results indicate a significant interaction for the combination of temperature, light and time with respect to survival and wet weight, making unambiguous interpretation of the main effects difficult.     

Determination of soybean yield gap and potential production in Iran using modeling approach and GIS

Increasing crop production is necessary to maintain food security for the growing global population.Reducing the gap between actual and potential yield is one of the important ways to increase yield per unit area.Potential yield and the yield gap of soybean were determined for Golestan Province,Iran,using Soybean Simulation Model (SSM-i Crop2) and Geographical Information System (GIS).Information from 24 weather stations and soil data of the region were used.Yield gap and production gap were calculated at county and province levels.The average actual yield of soybean in this province was2.28 t ha~(–1) while the province’s potential yield was 4.73 t ha~(–1),so the yield gap was estimated 2.44 t ha~(–1).Thus,there is a great potential for increasing soybean yield in Golestan,which is possible through improving crop management of soybean in farmers’fields.The average water productivity of soybean was estimated to be 0.81 kg m~(–3).Spatial distribution of water productivity in soybean farms showed that the highest and the lowest water productivities (0.99 and 0.44 kg m~(–3)) were in western and eastern regions of the province,respectively,in accordance to vapour pressure deficit.It was concluded that soybean production in the province could increase by 66%(from 109 970 to 182 170 tons) if 80% of the current yield gap could be removed.     

Some Morpho-Physiological Characteristics of Mung Bean Mycorrhizal Plants under Different Irrigation Regimes in Field Condition

In this study we determined some morpho-physiological characteristics of mung bean plants under various irrigation regimes (irrigation after 50, 100, 150 and 200 mm evaporation from pan class A) and mycorrhizal fungi inoculation (Glomus mosseae, Glomus intraradices). The highest and lowest seed yield was obtained from plants irrigated after 50 and 200 mm evaporation from pan, respectively. Root dry weight, root volume, leaf phosphorus and relative water content were decreased in plants under water deficit stress. Whereas, under various level of severe water deficit the proline content, total soluble carbohydrates and leaf nitrogen were increased. Mycorrhizal colonization was observed to be higher in well-watered plants rather than in stressed plants. Furthermore, the mycorrhizal plants produced a higher seed yield (161 g/m²), leaf phosphorus, leaf nitrogen, chlorophyll index, proline, total soluble carbohydrates content, relative water content, root length, root volume, root dry weight and root/shoot weight ratio as compared with non-mycorrhizal plants.     

Effect of chitosan addition on the surface properties of kenaf (Hibiscus cannabinus) paper

The present paper studies the effect of chitosan, cationic starch and polyvinyl alcohol (PVA) as sizing agents to enhance surface properties of kenaf paper. The polymers were incorporated into the sheets by spray application. The results clearly showed that the addition of chitosan to a sheet formed from beaten fibers had excellent improvement in surface properties, compared to the effect of other additives. Sizing quality of cationic starch fairly matched with the sizing quality of chitosan, however, it was able to reduce the water absorption potential of paper more than chitosan at a same concentration. In most other properties, particularly the most important property for printing papers, surface smoothness, chitosan-sized papers are superior to the paper sized with cationic starch or PVA.     

Prevention of Nonalcoholic Steatohepatitis in Rats by Two Manganese-Salen Complexes

Background: Nonalcoholic steatohepatitis (NASH), a progressive stage of nonalcoholic fatty liver disease (NAFLD), is characterized by steatosis with inflammation. Investigations have suggested that oxidative stress may play an important role in the progress of NAFLD to NASH. To provide further insights into beneficial effects of antioxidants in NASH prevention, we employed two manganese-superoxide dismutase/catalase mimetics, manganese N,N`-bis(salicyldene) ethylene diamine chloride (EUK-8) and manganese-3-methoxy N,N`-bis(salicyldene)ethylenediamine chloride (EUK-134), as two salen representatives and vitamin C as the standard antioxidant. Methods: Experimental NASH was induced in Male N-Mary rats by feeding a methionine/choline-deficient (MCD) diet to rats for 10 weeks. The rats (n = 5, 30 mg/kg/day) were randomly assigned to receive vitamin C, EUK-8, EUK-134 or vehicle orally. Results: Administration of salens together with the MCD diet reduced the serum aminotransferases, glutathione transferase and alkaline phosphatase, cholesterol, and LDL contents. In addition, the EUK-8 and EUK-134 improved NASH pathological features in liver of MCD-fed rats. Conclusion: EUK-8 and EUK-134 supplementation reduces NASH-induced abnormalities, pointing out that antioxidant strategy could be beneficial for prevention of NASH.Key Words: Fatty liver, Oxidative stress, Antioxidants     

Effect of sugar/osmotica levels on in vitro microtuberization of potato (Solanum tuberosum L.)

In order to evaluate of using microtubers for conservation of potato germplasm, the main effects of sucrose, mannitol and PEG on percentage of microtuber initiation and formation, size and fresh weight of microtuber were studied. PEG decreased production and weight of microtubers, whereas higher concentrations of sucrose promoted microtuber production, microtuber size as well as microtuber fresh weight. Increasing of sucrose concentrations were improved efficiently in vitro microtuber production without negative side effects. Addition of mannitol to all media was increased microtuberization than media containing PEG. So, alcoholic sugars such as mannitol increased microtuberization, but after 5 weeks, microtuberization in media supplied with sucrose was more than the mannitol. Such studies might help to reduce the cost of production of virus free potato seed from different cultivars.     

The Effect of Ascorbic Acid and Garlic Administration on Lead-Induced Apoptosis in Rat Offspring's Eye Retina

Introduction: Lead toxicity induces retinal cell apoptosis. Vitamin C and garlic may decrease lead-induced apoptosis. This study was undertaken to investigate vitamin C and garlic protective effects on lead-induced apoptosis in eye retina. Methods: Pregnant Wistar rats (n = 72) were divided randomly into 9 groups: (L) treated rats with lead acetate in drinking water and (L+AA) with leaded water and vitamin C intraperitoneally;(L+G), the rats received leaded-water and garlic juice via gavage; (L+AA+G) treated rats with leaded water, ascorbic acid, and garlic juice, (AA) with ascorbic acid, and (G) with garlic juice; (AA+G) treated rats with vitamin C and garlic juice and (Sh) with tap water plus normal hydrogen chloride (HCl) and glucose; normal (N). After 21-day lactation, blood lead level (BLL) in rats was measured, and then their offspring and the rat offspring''s eyes were removed and processed for using TUNEL method. TUNEL positive cells in the eye retina were counted and all groups were compared. Results: BLL increased in L group compared to the control groups and decreased significantly in L + G, L + AA, and L+ AA + G groups compared to L group (P<0.05). TUNELL positive cell number in eye retina significantly increased in L group compared to control groups (P<0.05) and decreased in L+ G, L+ AA, and L+AA + G groups compared to L group (P<0.05). Conclusion: Garlic juice and ascorbic acid administration during pregnancy and lactation may protect lead-induced apoptosis in rat offspring''s eye retina. Key Words: Lead, Garlic, Ascorbic acid, Apoptosis, Retina     

Microglial Activation in Rat Experimental Spinal Cord Injury Model

Background: The present study was designed to evaluate the secondary microglial activation processes after spinal cord injury (SCI). Methods: A quantitative histological study was performed to determine ED-1 positive cells, glial cell density, and cavitation size in untreated SCI rats at days 1, 2, and 4, and weeks 1, 2, 3, and 4. Results: The results of glial cell quantification along the 4900-µm long injured spinal cord showed a significant increase in glial cell density percentage at day 2 as compared to other days. Whereas the highest increase in ED-1 immunoreactive cells (monocyte/phagocyte marker in rats) was observed at day 2 (23.15%) post-injury. Evaluation of cavity percentage showed a significant difference between weeks 3 and 4 post-injury groups. Conclusions: This study provides a new insight into the multiphase immune response to SCI, including cellular inflammation, macrophages/microglia activation, glial cell density, and cavitation. Better understanding of the inflammatory processes associated with acute SCI would permit the development of better therapeutic strategies. Key Words: Spinal cord injuries, Inflammation, Microglia, Macrophages