Carboanhydrase-Aktivität und extrahierbares Zink als Maßstab für die Zink-Versorgung von Pflanzen

Carboanhydrase activity and extractable zinc as indicator of the zinc supply of plants 1. Maize, millet, tobacco, sugar-beet and vine were grown under controlled environmental conditions with different zinc concentrations in the substrate. Plant growth, zinc and phosphorus content of the dry matter, extractable zinc and carbonic anhydrase activity in the leaves were measured. 2. Increasing supply of zinc to strongly zinc deficient plants resulted in a marked increase of growth, whereas total zinc content of the leaf dry matter was only slightly and carbonic anhydrase activity was strongly affected. In extremely zinc deficient plants carbonic anhydrase activity was close to zero even though the zinc content of the dry matter was higher than 10 μg/g. Therefore carbonic anhydrase activity appears to reflect the amount of physiologically active zinc in the leaf tissue. It seems to be useful to decide critical cases even at latent zinc deficiency. 3. The P/Zn ratio is also an indicator of zinc supply when plants are extremely zinc deficient, but not under latent deficiency. Moreover the P/Zn ratio can vary in a wide range when plants are well supplied with zinc. 4. The zinc concentration of aqueous leaf extracts increased with increasing level of zinc. 2-3 μg Zn/ml extract were found to be sufficient for all plant species used and all conditions of growth applied. Apparently, the Zn-concentration of the aqueous leaf extract is a better parameter of zinc supply than total zinc or carbonic anhydrase activity which, in addition, is much more difficult to determine.     

Effect of Supplementation With Omega-3 Fatty Acids,Magnesium, and Zinc on Canine Behavioral Disorders: Results of a Pilot Study

Recent discoveries have shown that the chances of a dog developing a behavioral disorder may depend upon a number of factors including nutrition. The current pilot study was designed to provide an assessment of the efficacy of a dietary supplement containing omega-3 fatty acids, magnesium, and zinc on some common behavioral disorders in a population of Iranian domestic dogs. In total, 48 dogs including 6 dogs without any behavior disorder (control group) and 42 dogs with at least 1 common behavioral disorder, namely excessive activity, inappropriate elimination, fearfulness, destructiveness, and aggression toward unfamiliar people and dogs (test group), were given daily oral dose of gelatin capsules of fish oil supplements containing 330 mg eicosapentaenoic acid and 480 mg docosahexaenoic acid. Moreover, all dogs received 12-15 mg/kg of magnesium citrate and 5 mg/kg of zinc sulfate. Data were obtained using a questionnaire that dog owners were invited to fill out 2 times before (Days 0 and 42) and 2 times after the supplement treatment period (Days 84 and 126). The questionnaire asked owners whether their dog had exhibited any of the 6 common behavioral disorders on a 5-point Likert-like scale ranging from 0 (never or very rarely) to 4 (very often). The results showed no significant changes for any of the evaluated behavior disorders scale in the control group. In dogs with behavior disorders, results showed a significant reduction in the median score for the severity of fearfulness (P?=?.0083), destructiveness (P?=?.002), and inappropriate elimination (P < .001). In addition, there were no significant differences in the median score for the severity of excessive activity (P = .162), aggression toward dogs (P = .281), and aggression toward unfamiliar people (P = .09) during the course of the study. Results of the study reported here support the hypothesis that a combination of omega-3 fatty acids, magnesium, and zinc may improve some of the behavioral disorders.     

Silicon-nanoparticle Mediated Changes in Seed Germination and Vigor Index of Marigold (Calendula Officinalis L.) Compared to Silicate Under PEG-induced Drought Stress

Gesunde Pflanzen - The current study explores the potential impact of seed priming with silicon nanoparticles (SiNPs, 0, 100, 200, 500?mg/L) and silicate (Si, 0, 1, 1.5, 2?mg/L) under...     

Novel droplet vitrification combined with fish antifreeze protein type III enhances cryoprotection of semen in wild endangered Persian sturgeon Acipenser persicus (Borodin, 1897)

In this study, the efficiency of a novel droplet vitrification technique along with different doses of fish antifreeze protein (AFP) type III on Persian sturgeon thawed spermatozoa quality (motility duration and motility percentage) was investigated. Semen of seven male individuals was pooled in equal volumes and diluted with 4°C Tris‐Hcl (100 mM), pH = 8 extenders containing 0, 5, 10, 15 μM of AFP type III in a ratio of 1:1 (semen/extenders). Treated semen was dropped into liquid nitrogen. Solidified droplets were stored for 2, 60 and 120 days and thawed by plunging them into a tube containing 5 mL Tris‐Hcl (100 mM), pH=8 with 1% BSA at 37°C. Motility duration in all treatments had no significant difference comparing to fresh sperm (P > 0.05), but their motility percentage was significantly lower. Treatment with 10 μM of AFP had significantly higher motility percentage (16.11 ± 0.5%) comparing to other treatments (P < 0.05). There was no significant difference between 0, 5, 15 μM of antifreeze protein treatments (P > 0.05), suggesting that antifreeze protein effectiveness are highly dose dependent, and dose of 10 μM is appropriate in Persian sturgeon spermatozoa droplet vitrification. Besides, the present technique obtained higher quality of spermatozoa comparing to its analogue techniques.     

Zinc Uptake by Spinach (Spinacia oleracea L.) as Affected by Zn Application Rate,Zeolite, and Vermicompost

Zinc deficiency in calcareous soils is a serious problem, which may be ameliorated by the application of some soil amendments. A completely randomized factorial experiment was done to investigate the effect of zeolite, vermicompost, zeolite + vermicompost, and Zn application to a calcareous soil on Zn availability, dry weight of spinach (Spinacia oleracea L.), and Zn concen-tration in spinach. Results indicated that zeolite had no effect on soil Zn availability, dry weight, and Zn concentration in spinach. Vermicompost significantly increased dry weight (1.33 g pot^?1) and decreased Zn concentration in spinach (16 mg kg^?1). Application of zeolite + vermicompost significantly increased dry weight (by 2.8 times) and Zn uptake in spinach and it also decreased Zn concentration in spinach less than vermicompost. Zinc application increased Zn concentration in spinach (up to 496 mg kg^?1), but did not affect dry weight except in soils treated with zeolite + vermicompost. Generally, application of zeolite + vermicompost is recommended instead of separate zeolite or vermicompost application for improvement of soil Zn fertility and Zn uptake by spinach.     

Artificial neural network estimation of reference evapotranspiration from pan evaporation in a semi-arid environment

The objective of this study was to test an artificial neural network (ANN) for converting pan evaporation data (E _p) to estimate reference evapotranspiration (ET₀) as a function of the maximum and minimum air temperature. The conventional method that uses Pan coefficient (K _p) as a factor to convert E _p to ET₀, is also considered for the comparison. The ANN has been evaluated under semi-arid conditions in Safiabad Agricultural Research Center (SARC) in the southwest of Iran, comparing daily estimates against those from the FAO-56 Penman–Monteith equation (PM), which was used as standard. The comparison shows that, the conventional method underestimated ET₀ obtained by the PM method. The ANN method gave better estimates than the conventional method that requires wind speed and humidity data.     

Optimizing dosage of sethoxydim and fenoxaprop-p-ethyl with adjuvants to control wild oat

Using adjuvants to optimize and increase the efficacy of herbicides is an acceptable manner to reduce herbicides undesirable impact on the environment. Therefore, to detect suitable adjuvants for sethoxydim or fenoxaprop-p-ethyl, two dose-response experiments were conducted separately. The treatments consisted of six doses of sethoxydim or fenoxaprop-p-ethyl with and without adjuvants of Frigate, Citogate and Adigor against wild oat (Avena fatua L.). Moreover, the surface tension of a range of concentrations of adjuvants and adjuvants + sethoxydim or fenoxaprop-p-ethyl aqueous solutions was determined. Lower and higher surface tension values were obtained with aqueous solution of Citogate and Frigate alone and with herbicides. When adjuvants were combined with herbicides, wild oat control was significantly increased and was more than when were used alone. Between evaluated herbicides, adjuvant receptivity for sethoxydim was higher than for fenoxaprop-p-ethyl. Among evaluated adjuvants, the addition of Frigate and Adigor had the lowest and the highest effect, respectively, on the performance of sethoxydim or fenoxaprop-p-ethyl in controlling wild oat, which supports the solubilizing nature of cuticular waxes by Adigor as a theory.     

A comparison of root distribution of three hardwood species grown on a hillside in the Caspian forest,Iran

Slope is a complex environmental factor that can subject plants to a number of mechanical stresses. The anchorage of roots and improvement of slope stability mainly depend on specific properties of root systems, such as root distribution. In the present study, 24 trees (from three species) growing on gentle slopes (10–20°) were randomly chosen for root distribution analysis. The profile trenching method was used to obtain root characteristics. The findings indicated that root area ratio (RAR) decreased with depth and that maximum RAR values were observed in the upper layers; RAR values were between 0.0004% and 6.6444%. Average RAR values were not statistically different in upslope and downslope layers except in one case. The dot grid method (100 × 150 mm) usually overestimated the RAR values. The amount of roots decreased with depth following a power law. About 50% and 90% of roots were located in the first 30 and 60 cm depths, respectively. Results of analysis of covariance (ANCOVA) showed a significant effect of diameter at breast height (DBH) on total RAR but not on the total number of roots. About 70% of roots had diameter of less than 10 mm. Spearman’s correlation showed significant negative correlation between the total number of roots and the amount of N, P, and K elements, and a positive correlation between DBH and RAR. The results serve to develop understanding of the biotechnical characteristics of root systems of Caspian species.     

Assessing the effect of administering probiotics in water or as a feed supplement on broiler performance and immune response

1.?Two routes of probiotic administration in broiler farms, in water and in feed, were compared using 360 one-day-old male broiler chickens. Controls received no probiotics or antimicrobials. The water group received a probiotic preparation at a rate of 0·5 g/l, and the feed group received it at an inclusion rate of 1 g/kg.

2.?Performance of broilers in terms body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) improved when probiotic was provided via drinking water, compared to the control and feed groups. Probiotic administration reduced plasma cholesterol and triglyceride concentrations.

3.?Spleen (28 and 42 d) and bursa (42 d) relative weights were influenced by method of probiotic administration, which also improved T-cell dependent skin thickness response to phytohaemagglutinin (PHA) injection. The effect of challenge by dinitrochlorobenzene (DNCB) depended on the method of probiotic administration.

4.?The method of probiotic administration can influence the performance and immune competence of birds, and administration via drinking water appears to be superior to the more conventional in-feed supplementation method.