Glycoalkaloids and resistance to the Colorado potato beetle inSolanum chacoense Bitter

Resistance of 20 F₂ Solarium chacoense Bitter clones to the Colorado potato beetle,Leptinotarsa decemlineata (Say), was measured in a field test. Levels of total glycoalkaloids (TGA) and composición of the glycoalkaloid mixtures in foliage of the clones were also determined. Clones with either commersonine or dehydrocommersonine as the major foliar glycoalkaloid were significantly more resistant (lower damage ratings, fewer larvae and adult insects) than clones with solanine and chaconine. Damage ratings were negatively correlated (r = -0.67, p = 0.01) with foliar TGA levels. The results indicate that the types of glycoalkaloids present in the foliage ofS. chacoense may be as important as the level of TGA in limiting damage and numbers of insects.     

Effects of the application of ‘cash’ on the growth,fruit yield,and nutrient status of tomato (Solanum lycopersicum L.) grown in reclaimed saline soil

Summary

The effects of ‘cash’ [a novel 2:5:1 (w/w/w) mixture of calcium sulphate, ground sunflower heads, and humic acid] as a soil amendment on the growth, fruit yield, and leaf nutrient status of tomato (Solanum lycopersicum L.) grown on reclaimed saline soil (EC = 9.4 dS m^–1) were investigated. A glasshouse experiment was performed in a completely randomised design with six treatments (0, 10, 20, 30, 40, or 50 g ‘cash’ kg^–1 soil) each with four replicates. The results indicated that ‘cash’ increased both the shoot dry weight (DW) plant^–1 and the root DW plant^–1, the free proline contents of leaves, and leaf chlorophyll contents. The use of ‘cash’ also increased the number of fruit plant^–1, fruit yield pot^–1, and fruit vitamin C contents, although total soluble solids (TSS) contents were not affected. The contents of nitrogen (N), potassium (K), and calcium (Ca), and the Ca:Na ratios of leaf tissues increased with all application rates of ‘cash’. Leaf phosphorus (P) contents showed no response to any applied level of ‘cash’. Leaf sodium (Na) contents declined gradually with an increase in the level of ‘cash’ applied to the soil. We concluded that ‘cash’ has a pronounced positive effect on the growth and fruit yield of tomato plants grown in reclaimed saline soil. ‘Cash’ therefore has the potential to be used as a soil amendment for vegetable crops such as tomato to overcome the adverse effects of salinity in newly-reclaimed soils.     

Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban Sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of ...     

Risk factors of infestation by Psoroptes spp. mites in buffalo (Bubalus bubalis) at smallholder farms in the Nile Delta region, Egypt

The aim of the present study was to explore the prevalence and potential risk factors associated with infestation by Psoroptes spp. mites in buffalo at smallholder farms in the Nile Delta region, Egypt. A total of 318 out of 1234 buffalo in 77 small scale herds were examined. The age of buffalo varied from three months to seven years. In all, 53 (16.66%) buffalo were recorded to be infested; 51 (16.35%) with Psoroptes spp. mites and two cases (0.31%) with Chorioptes spp. mites. Multivariate logistic regression was performed for significant risk factors at univariate analysis on both animal and herd level. The results of multivariate analysis showed that, on the animal level, the prevalence was affected by animal age (P?<?0.01; OR: 0.71; CI 95%: 0.441–1.11), season (P?<?0.01; OR: 1.20; CI 95%:0.541–1.15), indoor management (P?<?0.001; OR: 6.625; CI 95%:2.489 –17.631) and rearing with other animals (P?<?0.01; OR: 2.22; CI 95%:1.340 –7.132). However, on the herd level, the prevalence was affected by indoor rearing (P?<?0.05; OR: 22.4; CI 95%:2.75–16.431), mixed rearing with other animal species (P?<?0.05; OR: 4.5; CI 95%:1.66–7.941), and season (P?<?0.01; OR: 2.3; CI 95%:0.575–2.426). Clinically, mild skin lesions with mild pruritis were significantly prevalent in buffalo with the infestation by Psoroptes spp. mites (P?<?0.001), where 33/51 cases showed mild lesions. Also, psoroptic mites had significant association with inappitence (P?<?0.001). The result of the present study indicates that Psoroptes spp. mites are the most prevalent in buffalo in the Nile Delta Region, Egypt. Moreover, recognition of risk factors associated with mange mites in buffalo may enable the practitioner to establish the most appropriate control measures.     

Beneficial effects of Oral Allspice,Pimenta dioica powder supplementation on the hemato‐immunological and serum biochemical responses of Oreochromis mossambicus

The present study investigated the effects of dietary allspice powder supplementation on welfare status of Tilapia, Oreochromis mossambicus assessed by hemato‐immunological and serum biochemical parameters. Five diets were formulated to contain 0 (control), 5, 10, 15 or 20 g of allspice kg^?1 of fish feed. Fish were fed experimental diets for 60 days. Supplementation of allspice powder at 10 g kg^?1 positively influenced the serum glucose, plasma lysozyme activity and myeloperoxidase activity. Dietary allspice powder at 15 g kg^?1 also positively influenced the serum biochemical parameters (total protein, albumin and globulin) and plasma lysozyme activity. However, 20 g kg^?1 allspice powder group had significantly lower values of respiratory burst activity and red blood cell count than other experimental groups (P < 0.05). In conclusion, the results of the present study demonstrated that supplementation of allspice powder at 10 or 15 g kg^?1 for 60 days, had beneficial effects on improvement of some immunological and serum biochemical status of O. mossambicus. These findings suggest that dietary supplementation of allspice powder might further improve the resistance to fish pathogens.     

Effect of Garlic,Echinacea, Organic Green and Vet-Yeast on Survival,Weight Gain,and Bacterial Challenge of Overwintered Nile Tilapia Fry (Orechromis niloticus)

The purpose of this study was to examine the effect of some immunostimulants and probiotics on the survival rate, final weight, and disease resistance of overwintered tilapia fry. There were five treatments: T1 (control) fed a balanced diet (35% protein) without additives. Treatments 2 to 5 were fed diets supplemented with 4% garlic, 4 g/kg Echinacea, 4 g/kg Organic Green or 4 g/kg Vet-Yeast, respectively. Growth and resistance to disease challenge with Aeromonas hydrophila and Pseudomonas flourescens were not different among treatments, but survival of overwintered fry increased in treatments fed probiotics or immunostimulents. The use of garlic in overwintering feeds could allow hatchery operators to increase their prices for fry and fish farmers to stock production ponds earlier, increasing hatchery revenues by 74% and improving land use efficiency and productivity for the Egyptian aquaculture industry.     

樱桃砧木吉赛拉组培快繁生产中玻璃化及污染分析

[目的]解决樱桃砧木吉赛拉组培快繁生产中玻璃化苗发生及污染问题.[方法]通过对培养基中激素、蔗糖、琼脂浓度的调节及培养温度的控制,防止玻璃化苗发生;通过培养基中加入杀菌剂,寻求解决组培苗污染.[结果]培养基中细胞分裂素6 - BA的浓度控制在1 mg/L以下、蔗糖浓度40 g/L、琼脂浓度6 g/L左右、培养温度24℃左右,可有效地预防玻璃化苗的发生;在培养基中加入500～1 000 mg/L多菌灵50;可湿性粉剂,可有效防止污染的发生.[结论]在樱桃砧木吉赛拉5号组培快繁中,细胞分裂素6 - BA浓度、蔗糖浓度、琼脂浓度、培养温度对试管苗产生玻璃苗都有一定的影响,其中,细胞分裂素6 - BA浓度、培养温度的影响更为明显.为了防止污染的发生,培养基中添加多菌灵50;可湿性粉剂效果较好.     

Biodegradation kinetics of dicofol by selected microorganisms

The capacity of some plant growth promoters (seven species of bacteria namely, Azospirillium barasilense, Azotobacter chroococcum, Klebsilense pneumoneae, Pseudomonas cepacia, Bacillus subtilis, Pseudomonas fluorescens and Bacillus polymyxa) and some control agents for plant pathogens (two species of fungi namely, Trichoderma viride and Trichoderma harzianum) to degrade dicofol pesticide (DCF) in liquid culture media was investigated. The recovered amount of DCF was extracted based on the solid phase extraction (SPE) with methylene chloride and then analyzed by HPLC. Contrary to published reports, no intermediate or final degradation metabolites of DCF could be observed. About 26-33% of DCF degradation was observed after 3 days of incubation with the tested bacteria which increased to 61-80%, 74-85%, 77-87% and 75-94% after 7, 14, 21 and 28 days of incubation, respectively. On the other hand, the tested fungi removed roughly 35% of available DCF within the first three days of incubation which increased to 84-87%, 89-95%, 91-95% and 92-96% after 7, 14, 21 and 28 days of incubation, respectively. A biphasic model was assumed to explore the disappearance of DCF from media enriched with either bacteria or fungi, where the rate of disappearance in the first phase was faster than the second. This is clearly reflected in the half-life (t_1/2) for the first and second phases, where the t_1/2 values of DCF ranged from 2.82-4.42 to 19.32-29.73 days, respectively. The results have implications for the development of a bioremediation strategy.     

Species composition and seasonal-occurrence of spider mites and their predators in sprayed and unsprayed apple orchards in Tokat, Turkey

The species composition and seasonal cycle ofTetranychus urticae Koch (two-spotted spider mite) andEotetranychus uncatus Garman (garman spider mite; the two species were evaluated together),Amphitetranychus viennensis (Zacher) (hawthom red spider nite),Panonychus ulni (Koch) (European red mite),Bryobia rubrioculus (Scheuten) (brown mite) (Acari Tetranychidae),Cenopalpus pulcher Can and Fanz. (flat scarlet mite) (Tenuipalpidae) and their natural enemies (Phytoseiidae and Stigmaeidae family members) were compared in two apple orchards during the years 2000 to 2002 in Tokat, Turkey. One orchard was pesticide-free, and the other was sprayed. Surveys were carried out once a week from April to November and the differences in the dominant species of spider mites and phytoseiid mites between the two orchards were recorded. In the sprayed orchard, the dominant phytophagous mites wereA. vienensis andP. ulmi whereas in the unsprayed orchardE uncatus andC pulcher were abundant. It was found that the predatory mites were able to control spider mites in the unsprayed orchard, but the population level was not adequate to control them in the sprayed orchard, presumably due to the excessive use of pesticides.