类番茄茄抗番茄黄花曲叶病毒 QTL 的定位

 采用田间自然接种番茄黄花曲叶病毒（TYLCV）的鉴定方法,对来自番茄野生种类番茄茄Solanum. lycopersicoides LA2951的渐渗系（Introgression Line,IL）群体进行了筛选,发现类番茄茄LA2951对TYLCV的抗性受多个位点控制。通过分析不同IL的抗性,共鉴定出7个QTL,分别位于染色体1、3、4、5、6、7和12上,其中位于染色体1上的QTL有待于进一步确定。     

Analysis of genetic diversity of soybean germplasm from five different origins using RAPD markers

The pattern of genetic diversity among 92 genotypes of soybean from 5 different origins/sources (Pakistan, the USA, Asian Vegetable Research Development Centre (AVRDC), Japan and North Korea) was analyzed using randomly amplified polymorphic DNA markers. Out of 20 random primers 6 tested, 10 were polymorphic among genotypes and they yielded 107 markers, with an average of 10.7 markers per primer. The proportion of polymorphic bands within genotypes ranged from 0.47 to 0.71 with an average of 0.59. Pakistani and US genotypes exhibited the highest number of polymorphic bands (95%), while North Korean genotypes revealed the lowest (60%). The mean band frequency of the primers among genotypes was 0.57 with a range of 0.08–0.99. The Shannon’s index and Nei’s genetic diversity index revealed that primer OPF-06 showed maximum genetic diversity among the genotypes. Dendrogram constructed using Unweighted Pair Group Mean Average (UPGMA) method divided the genotypes into 5 main groups consisting of 13 clusters. The results of cluster analysis indicated that the genetic diversity between Pakistani and US or AVRDC genotypes is much larger than that between Pakistani and North Korean or Japanese genotypes. The Pakistani genotypes had distinct bands from plant introductions. Therefore, the Pakistani genotypes may be useful to soybean breeders.     

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole C_max and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole.     

The effect of mineral fractions on physical and phosphorus-related chemical properties of peat-based substrates for pot plants

Physicochemical traits of peat-based pot substrates prepared from mixing of 20 or 40?vol.% of some different mineral fractions (sub. 1 to 7, subjected to decreasing amount of clay content of 66.1, 61.2, 49.7, 38.5, 26.0, 23.7 and 19.4%, respectively) with black peat were evaluated and then phosphorus uptake of poinsettia (Euphorbia pulcherima) simulated mechanistically as a case study pot plant. For preparation of substrate number 8, pure peat was mixed with 40?vol.% of the same mineral component as substrate number 6 (with 23.7% clay). Result revealed that adding different mineral fractions up to 40?vol.% to pure peat, water-holding capacity and total pore volume were reduced only by 11 and 15?vol.%, respectively. It was found that keeping the moisture content of peat-based substrates with 20?vol.% of mineral soils around 60%–70%, the optimum ventilation and enough free space of about 15%–25% will be provided around the root system. In addition, simulated P uptake did not change significantly with addition of 20?vol.% of different mineral components in peat-based substrates. As a result, P uptake mainly was dependent on the amount of plant available P level than different mineral fractions.     

Transform high seas management to build climate resilience in marine seafood supply

Climate change is projected to redistribute fisheries resources, resulting in tropical regions suffering decreases in seafood production. While sustainably managing marine ecosystems contributes to building climate resilience, these solutions require transformation of ocean governance. Recent studies and international initiatives suggest that conserving high seas biodiversity and fish stocks will have ecological and economic benefits; however, implications for seafood security under climate change have not been examined. Here, we apply global‐scale mechanistic species distribution models to 30 major straddling fish stocks to show that transforming high seas fisheries governance could increase resilience to climate change impacts. By closing the high seas to fishing or cooperatively managing its fisheries, we project that catches in exclusive economic zones (EEZs) would likely increase by around 10% by 2050 relative to 2000 under climate change (representative concentration pathway 4.5 and 8.5), compensating for the expected losses (around ?6%) from ‘business‐as‐usual’. Specifically, high seas closure increases the resilience of fish stocks, as indicated by a mean species abundance index, by 30% in EEZs. We suggest that improving high seas fisheries governance would increase the resilience of coastal countries to climate change.     

Does trade openness reduce a domestic fisheries catch?

Although trade liberalization may increase a country’s welfare, its specific effect on a country’s fishing industry has not been well studied. By decomposing the effect of international trade into four parts, i.e., scale-technique effects (ST), the indirect trade-induced composition effect (IC), the indirect effect of trade intensity through income (ITC), and the direct effect of trade intensity (DTC), this study empirically investigates the effect of trade openness on country-level fisheries production. To take into account the endogeneity of trade openness and income, we adopt the instrumental variable approach. We find that a rise in trade openness reduces fisheries catch on average. In particular, the long-run effect is large. This result implies that future production is affected by current overfishing through stock dynamics. Our decomposed elasticities indicate that the ST and ITC dominate in the trade elasticity of fisheries catch. While ST implies that overfishing would be affected by trade, ITC may either establish an “overfishing haven”, similar to a “pollution haven” in the environmental literature, or production shift of fisheries to countries with lax regulation to pass stringent regulation, which is more likely to occur in high-income countries.     

The anatomy of the auricular conchae of cattle, sheep and deer

The anatomy of the auricular conchae of ruminants has been studied by intravascular injection of radiopaque latex, by dissection and by histological sectioning. Drawings were made of the vascular network. The arrangement of nerves and blood vessels in association with the ridges on the rostral (concave) surface was observed. The spaces between the ridges are relatively free of larger blood vessels, nerves, hair and sebaceous glands. This distribution is discussed in relation to the insertion of ear tags.     

Caprine hepatic lipidosis induced through the intake of low levels of dietary cobalt

Forty-one, 10-week-old newly weaned goats were randomly allocated into two groups, namely control (n=22) and treated (n=19). Kids in both groups were fed Rhodegrass hay ad libitum that contained < 0.1 mg/kg DM cobalt and 150 g/day of a commercially prepared ruminant concentrate that contained approximately 0.12 mg/kg DM cobalt. This diet provided the minimum daily requirement of cobalt as specified for sheep. The treated goats were supplemented with bi-monthly subcutaneous injections of 2000 microg of hydroxycobalamin. All goats were weighed and blood samples collected monthly for haematological, clinical biochemical and serum vitamin B12 analysis. After a 10-month experimental period the goats were slaughtered. The control animals exhibited significantly (P<0.05) lower weight gains, and had dry scruffy hair coats. In addition, there was a decline in erythrocyte counts, mean haemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Controls also exhibited significantly (P<0.05) lower levels of total serum proteins and elevated levels of serum alkaline phosphatase compared to treated goats. Fourteen (63.6%) of the control goats developed pathology consistent with reported field cases of hepatic lipidosis associated with low liver levels of cobalt. Only one (5.3%) of the treated goats developed hepatic lipidosis. Contrary to previous reports that suggested that goats are less sensitive to low levels of dietary cobalt than sheep, it is apparent that this is not the case with Omani goats. This is the first report of the induction of hepatic lipidosis in goats due to feeding low levels of cobalt in their diet.     

In vitro and in vivo modulation of the equine immune response by parapoxvirus ovis

REASON FOR PERFORMING STUDY: While immune modulators are used routinely in equine medicine, their mechanism of action is not always known. OBJECTIVES: To determine the effect of a commercial preparation of inactivated parapoxvirus ovis (Orf virus; PPVO) on cytokine gene expression by equine peripheral blood mononuclear cells (PBMC) both in vitro and in vivo. METHODS: PBMC were prepared from 6 mixed-breed yearlings and cultured in vitro with PPVO with or without Concanavalin A (Con A) for 24 h. Effects on the expression of IFNalpha, IFNbeta IFNgamma, TNFalpha and IL-18 were analysed by real time quantitative PCR (RT-PCR). In addition, 12 yearling horses were treated with PPVO and whole blood RNA samples were prepared at regular intervals to assess effects on in vivo cytokine gene expression. Six of those yearlings were later treated with saline and served as treatment controls. Nine additional yearlings were injected intradermally with a single dose and their injection sites biopsied at 24 and 48 h for cytokine expression. RESULTS: In vitro culture of PBMC with PPVO led to a significant increase in IFNalpha and IFNbeta gene expression compared to mock-stimulated cultures. In addition, expression of IFNgamma and TNFalpha was significantly higher in PBMC stimulated with PPVO and Con A, than those stimulated with Con A alone. No changes were observed in IL-18 gene expression in vitro. Treatment of horses with a 3-dose regimen of PPVO resulted in elevation of IFNgamma gene expression, which was detected 24 h after the first dose and declined thereafter. Intradermal inoculation led to increased expression of IFNgamma along with IFNbeta, IL-15 and IL-18. CONCLUSIONS: Together these results indicate that PPVO stimulated IFNgamma production both in vitro and in vivo. Increased cytokine expression could account for its immunomodulatory activity. POTENTIAL RELEVANCE: The absence of adverse reactions and clear indications of increased expression of cytokine gene expression supports previous clinical uses for this immune modulator in those situations when increased expression of IFNgamma is warranted.