Screening of sugar beet tissue culture clones for resistance to rhizomania disease

In this study, sugar beet tissue culture clones were used to screen rhizomania resistant genotypes. At first, explants derived from shoot tips of sugar beet seedlings were transferred to shoot tip elongation media after surface sterilization. Then, the grown shoots were transferred to media containing various hormonal combinations NAA, BA, IBA and GA3 for multiplication, growth and rooting. Later, the clones were transferred to soil-peatmoss mixture were adapted to greenhouse conditions. For screening clones against rhizomania, the genotypes of adapted clones were selected and inoculated to rhizomania-infested soil. This experiment was in a randomized complete block design with three replicates (three inoculation times) in greenhouse. Adapted plants were transferred to the soil containing rhizomania virus. All infested soils were diluted 3 to 7 with sand. After two months, infested plants were examined by DAS-ELISA test also optical densities of the samples were analyzed by SAS program. Significant differences among genotypes and blocks were observed. Genotypes were classified to few groups (ranked from completely susceptible to completely resistant). The difference between blocks was because of difference of inoculation time temperature. Use of clones of each genotype caused an increase in selection accuracy of resistant genotypes. By use of this method, chance of escaping from inoculation factor decrease and researchers can determine to be resistance of plants with high level of confidence and apply in breeding programs.     

Effects of herbivory on the reproductive effort of 4 prairie perennials

Background  

There is an urgent need to explore and utilize naturally occurring products for combating harmful agricultural and public health pests. Secondary metabolites in the leaves of the Tree of Heaven, Ailanthus altissima L. have been reported to be herbicidal and insecticidal. The mode of action, however, of the active compounds in A. altissima are not understood. In this paper, we report the chemical characteristics of the herbicidal and insecticidal components in this tree, and will discuss the effect of light on the bioactivity of the active components.     

Prophylactic and Therapeutic Effects of Oleuropein on Reperfusion-Induced Arrhythmia in Anesthetized Rat

Background:

This study was conducted to reveal that whether i.v. injection of oleuropein, the most potent polyphenolic antioxidant in olive leaf, has any effect on the magnitude of reperfusion arrhythmia in anesthetized rats or not.

Methods:

Eighty male Wistar rats were divided into 8 groups of 10 each: groups 1 and 5 were assigned as the prophylactic and treatment control groups, groups 2 and 6 as the prophylactic and treatment groups with lidocaine (10 mg/kg), groups 3 and 4 as the prophylactic groups with 10 and 50 mg/kg oleuropein (i.v.), and groups 7 and 8 as the treatment groups with 10 and 50 mg/kg oleuropein (i.v.), respectively. Reperfusion injury was induced by 5-min regional ischemia and 15-min reperfusion of left anterior descending coronary artery. Heart rate, blood pressure, and electrocardiogram were monitored throughout the procedure.

Results:

blood pressure was significantly decreased by infusion of 50 mg/kg oleuropein in groups 4 and 8, but unlike the lidocaine as a standard anti-arrhythmic drug in groups 2 and 5 had not significant effect on heart rate. The onset of arrhythmia in groups received oleuropein (groups 3, 4, 7, and 8) was significantly delayed. The mortality rate due to irreversible ventricular fibrillation was also significantly reduced in groups 3, 4, 7, and 8. The effect of lidocaine in groups 2 and 5 was more potent than that in oleuropein group.

Conclusion:

These findings indicate that i.v. injection of oleuropein possibly through its antioxidant activity reduces the magnitude of reperfusion-induced arrhythmia.Key Words: Oleuropein, Arrhythmia, Reperfusion, Rats     

Exploring the potential uses of <Emphasis Type="Italic">Vitis vinifera</Emphasis> L. leaves as raw material for textile dyeing without metal mordants

This paper explores the potential uses of the aqueous extract of Vitis vinifera L. leaves in dyeing linen and silk fabrics without a metal mordant. The focus will be on investigating the tinctorial potential of Vitis vinifera L. leaves and its dyeing properties. The anthocyanins amounts of leaves from different Vitis vinifera L. varieties were determined by the spectrophotometry method. The effect of the main dyeing parameters (pH of the dye bath, temperature, and dyeing duration) on the dyeing quality results has been studied. Tannic acid and pomegranate peel extract have been used as a natural mordant. Experimental results have shown that fastness properties of dyed fabrics ranged from average to very good.     

Quantifying Transport Between the Tropical and Mid-Latitude Lower Stratosphere

Airborne in situ observations of molecules with a wide range of lifetimes (methane, nitrous oxide, reactive nitrogen, ozone, chlorinated halocarbons, and halon-1211), used in a tropical tracer model, show that mid-latitude air is entrained into the tropical lower stratosphere within about 13.5 months; transport is faster in the reverse direction. Because exchange with the tropics is slower than global photochemical models generally assume, ozone at mid-latitudes appears to be more sensitive to elevated levels of industrial chlorine than is currently predicted. Nevertheless, about 45 percent of air in the tropical ascent region at 21 kilometers is of mid-latitude origin, implying that emissions from supersonic aircraft could reach the middle stratosphere.     

Effects of deoxynivalenol exposure time and contamination levels on rainbow trout

The trend toward using plant‐based ingredients in aquafeeds is set to intensify; however, mycotoxin contamination might be a challenge. Two diets, with deoxynivalenol (DON) levels of 1,166 μg/kg (1.1 DON) and 2,745 μg/kg (2.7 DON), were prepared for short‐term DON exposure (50 days). A third diet with a low DON level of 367 μg/kg (0.3 DON) was prepared for long‐term DON exposure (168 days). Ingestion of DON by trout during both short‐term/high‐dosage exposure (50 days; 1,166 μg/kg and 2,700 μg/kg DON) and long‐term/low‐dosage exposure (168 days; 367 μg/kg DON) impacted growth performance and, to a lesser extent, liver enzyme parameters (2.7 DON). Histopathology showed mild to moderate changes in the liver but not in the other sampled tissues (intestine and kidney). Despite these effects, short‐term exposure of rainbow trout to high doses of DON did not result in increased susceptibility to Yersinia ruckeri. In both the short‐ and long‐term studies, the effects of DON showed a high interindividual variability. The present study confirms that subclinical levels of mycotoxins affect rainbow trout. The effects of such low mycotoxin levels could be masked by other production challenges while still negatively affecting productivity.     

Integrated mite management in apples in Israel: Augmentation of a beneficial mite and sensitivity of tetranychid and phytoseiid mites to pesticides

Augmentative releases of the phytoseiid miteTyphlodromus athiasae were evaluated during summer 1987 in an apple orchard designated to be maintained under an IPM (integrated pest management) regime. Evaluation for establishment and recovery 2 weeks after each release showed complete absence of the mite and high population density of the injurious tetranychid mites. It was suspected that pesticides that had been used to control key pests may have been the cause. Laboratory tests with the pesticides used showed that the insect growth regulators triflumuron and fenoxycarb and the fungicide triadimenol caused only slight mortality of the predacious mitesT. athiasae (0-12%) andPhytoseiulus persimilis (6–10%), but a highly significant reduction in fecundity. Four days after treatment a reduction of 94%, 74% and 100% in fecundity ofT. athiasae, and 2 days after treatment a reduction of 78%, 53% and 80% in fecundity ofP. persimilis was brought about by triflumuron, fenoxycarb and triadimenol, respectively. On the other hand, 4 days after treatment there was a 27%, 16% and 9% increase in fecundity of the phytophagous miteTetranychus cinnabarinus caused by triflumuron, fenoxycarb and triadimenol, respectively. Laboratory and field tests were carried out to evaluate 13 other pesticides as to their selectivity toT. athiasae. The compounds azinphos-methyl, penconazole, vamidothion and diflubenzuron were found to be relatively harmless to this beneficial mite and they replaced the materials mentioned above in the coming seasons in several orchards. This caused recovery in high density of the predacious mite, which allowed reduced application of acaricides and the achievement of integrated mite management.     

Effect of GnRH Dose on Occurrence of Short Oestrous Cycles and LH Response in Cyclic Dairy Heifers

Prostaglandin F_2α (PGF_2α) and GnRH treatments given 24 h apart have been shown to result in short oestrous cycles (8–12 days) in some cows and heifers. The differences in responses may depend on the dose of GnRH. Therefore, the effect of the dose of GnRH on occurrence of short cycles and LH response was studied here. Oestrus was induced with dexcloprostenol (0.15 mg) in two groups of Ayrshire heifers. A second luteolysis was induced similarly on day 7 after ovulation; 24 h after PGF_2α treatment, the heifers were administered either a high (0.5 mg, n = 15, group T500) or low (0.1 mg, n = 10, group T100) dose of gonadorelin. Blood samples for progesterone analyses were collected daily from the second PGF_2α administration to the second ovulation after the PGF_2α injection. Beginning 24 h after the GnRH treatment, ovaries were examined by transrectal ultrasonography every 6 h until ovulation, and daily between day 4 and the next ovulation. Five heifers from both groups were sampled for LH analyses via a jugular catheter every 30 min from 1 h before to 6 h after the GnRH administration. Short oestrous cycles were detected in 7 of 10 cases in group T100 and in 12 of 15 cases in group T500. No significant differences in LH responses were detected between the groups. In group T500, the rise in LH concentration tended to be somewhat slower than in group T100. The dose of GnRH (0.1 vs 0.5 mg) did not affect the occurrence of short oestrous cycles and LH response.     

Extensive release of an antigen associated with the sporogonic stages of myxobolus cerebralis (Myxozoa: Myxosporea) is detected by a heterologous antibody raised to Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea)

Monoclonal antibody B4 (mAb B4) was previously developed to the myxozoan parasite Tetracapsuloides bryosalmonae Canning, Curry, Feist, Longshaw et Okamura, 1999, the causative agent of proliferative kidney disease of salmonids, Here we describe the reaction of mAb B4 against Myxobolus cerebralis Hofer, 1903, the parasite that causes 'whirling disease' in salmonids. Tissues examined were collected from experimentally infected rainbow trout Oncorhynchus mykiss (Walbaum) and the aquatic oligochaete Tubifex tubifex (O.F. Müller), the two hosts involved in the life cycle of M. cerebralis. Paraffin sections of infected rainbow trout taken at 4 h and 3, 10, 17 and 54 days post-exposure to infective M. cerebralis actinospores were immunohistochemically stained with mAb B4. Longitudinal sections through infected T. tubifex sampled 120 days post-exposure to M. cerebralis myxospores were also examined using this method. The only phase of the M. cerebralis life cycle that expressed the mAb B4 antigen was during sporogenesis in the salmonid host. The immunohistochemical staining demonstrated that the antigen was released into the tissues surrounding the spore and sporogonic stages of the parasite. The localisation of the antigen was diffuse in the fish, suggesting that the possible effect of M. cerebralis infection is extensive through the head tissues and not limited to areas of cartilage destruction as previously thought.     

Effects of pesticide residues on ground-dwelling lycosid and micryphantid spiders in laboratory tests

The effects of residues of three commercial pesticides in common use in Europe against cereal pests, on two dominant spider species, a lycosid and a micryphantid, were evaluated in the laboratory. Insecticide assay methods for juvenile and adult hunting and adult web-building, ground-dwelling spiders are described. Results varied with different sprayed substrates and species. Fenvalerate was more toxic than other pesticides and had a longer residual effect on all spiders when tested on moistened sand than on filter paper. Endosulfan was of high initial toxicity on sand, but was more toxic on filter paper to both adults and juveniles ofPardosa spp. Pyrazophos was non-toxic to the spiders tested, regardless of substrate. In general, the lycosids were more affected by pesticides than web-building spiders because of their different life strategies. A sprayed sand substrate matched field conditions better as a method to test the effects of pesticides on ground-dwelling spiders.