Genome-wide association study for spot blotch resistance in Afghan wheat germplasm

Spot blotch (SB), caused by Bipolaris sorokiniana, is a devastating disease of wheat globally, especially in South Asia and South America. Understanding the genetics of resistance to SB is important for developing breeding strategies to improve resistance. A panel of 301 genotypes from Afghanistan was phenotyped over two crop seasons using a mixture of virulent B. sorokiniana isolates and genotyped using DArTSeq to obtain genome-wide markers. Fifty genotypes (16.6%) showed disease scores less than the resistant control. Principal component analysis using the genotypic data clustered the genotypes into five different groups. Among models used for genome-wide association mapping, the multilocus mixed model, and fixed and random model circulating probability unification algorithms were most effective in identifying significant marker-trait associations (MTA). Twenty-five MTAs at p ≤ .001 were identified on chromosomes 1A, 1B, 1D, 2B, 2D, 3A, 3B, 4A, 5A, 5B, 6A, 7A, and 7D, indicating the quantitative nature of resistance to SB. Phenotypic variation explained by these markers ranged from 2.0% to 17.7%, and genomic regions on the chromosomes 1D, 2D, 3A, 3B, 4A, 5A, and 5B coincided with loci identified in previous studies. Three single nucleotide polymorphism (SNP) markers on chromosomes 1B (SNP 1113207) and 5A (SNPs 5411867 and 998276) were significant in both crop seasons as well as in the combined analysis across seasons. Marker 5411867 is close to Vrn-A1, shown to be associated with SB in previous studies. Furthermore, among known SB resistance genes, Sb2 on chromosome 5B was predicted to be significant in this panel.     

饲料营养与鱼类的健康

营养状态是决定鱼类抵抗疾病能力的一个重要因子.优质饲料对改善养殖鱼类的健康与提高抗病能力至关重要,这一点已被大量实验所证实.饲料中蛋白质、脂肪、碳水化合物等主要营养成分含量不足,会影响鱼类的正常生长,甚至出现缺乏症;现越来越多的研究发现某些必需营养成分(必需氨基酸、必需脂肪酸、维生素和矿物质)含量不足的饲料会导致鱼类营养不良和抗病力弱,微量营养元素与鱼类抗病力的关系研究日益得到重视.     

Effect of set-size and storage temperature on bolting,bulbing and seed yield in two onion cultivars

The effects of three set-sizes (12.5, 17.5 and 22.5 mm in diameter) and seven storage temperatures (0, 5, 10, 15, 20, 25 and 30 °C) on bolting, bulbing and seed yield in two onion (Allium cepa L.) cultivars ‘Hygro’ and ‘Delta’ were investigated. The incidence of bolting increased linearly with set-size and curvi-linearly with decreasing storage temperature. Time to inflorescence emergence and floret opening showed a curvi-linear response to storage temperature with the earliest inflorescence emergence and floret opening occurring at 5 °C and the latest at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’. Seed yield per umbel also showed a curvi-linear response to storage temperature with the lowest seed yield occurring at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’ and the highest seed yield at 5 °C. For a seed crop, storage of large sets (22.5 mm) of these cultivars at 5 °C for 120 days appeared to be optimum with 5–12% higher seed yield per umbel than that of 90 days storage. Bulb yield showed a curvi-linear response to storage temperature with the highest bulb yield occurring at 25 °C and the lowest at 5 °C.     

Response of strawberry to organic versus inorganic fertilizers

The aim of this research was designed in order to optimize integrated plant nutrient supply (IPNS) through balanced fertilization of organic, inorganic and microbial inoculants in strawberry cv. Chandler. The potential efficiency of bio-organics used along with chemical fertilizers on cropping behaviour, physical-chemical and biological properties of rhizosphere soil, fruit yield, quality attributes and leaf nutrient content was investigated. The significant improvement in physico-chemical properties of the soil and nutrient uptake was recorded. The uninoculated control received farmyard manure (FYM) and inorganic nitrogen (N) recorded the highest cation exchange capacity (CEC) and soil organic carbon (OC) content. Highest available N and phosphorus (P) of soil were recorded in vermicompost and inorganic N applied in two and one split, respectively. The concentration of micronutrients cations viz., iron (Fe), zinc (Zn), manganese (Mn) in soil was higher in treatment received vermicompost and inorganic N in two splits. The integration of bio-organic nutrient supplements also significantly enriched the microbial status of the rhizosphere soil, leaf nutrient concentration and maintained soil health and productivity on long term basis for sustainable fruit production.     

Environmental and genotypic effects on bulb development in onion – a review

Environmental and genetic factors influence growth and bulb development of onions by affecting their physiology. Photoperiod plays critical a role in bulb development and determines the suitability of a cultivar for a particular region. Long days and high temperatures promote onion bulbing. Bulbing is regulated more by temperature than photoperiod, as determined by growing degree days. Far-red light promotes bulbing most effectively. High-temperature storage of sets (above 20–25°C) results in increased total bulb yields, while very high temperature (25.5–31°C) or temperature below 0°C depresses yield. Plant density has an impact on bulb size: the higher the plant density the smaller the bulb size. Onion is more sensitive to water stress during bulb formation and enlargement than during the vegetative stage. Nitrogen improves bulb development, but too much nitrogen promotes excessive vegetative growth and delays maturity. Growth hormones (gibberellins and ethrel) promote the growth and development of bulbs. Flowering and bulb formation in onion is regulated by different (Flowering Locus T) FT genes. Two antagonistic FT-like genes regulate bulb formation. AcFT1 promotes bulb formation, while AcFT4 prevents AcFT1 up-regulation and inhibits bulbing. There is a need to link our research with the genetics and physiology of onions, to enhance bulb yield.     

Evaluation of toxicosis of liposome-encapsulated cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum (II) in clinically normal cats

OBJECTIVE: To determine adverse effects of single and multiple doses of liposome-encapsulated cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum (II) (L-NDDP) administered IV to healthy adult cats. ANIMALS: 10 healthy adult cats. PROCEDURE: 8 cats were given a single dose of L-NDDP (at rates of 75, 100, 150, or 200 mg/m2), and 2 cats were given liposomal lipid (1,500 mg/m2). Six of the 10 cats were given doses of L-NDDP at the maximum tolerated dosage (100 mg/m2) or a lower dosage (75 mg of L-NDDP/m2) at 21-day intervals, for a total of 4 treatments. Hematologic and serum biochemical analyses, urinalyses, and physical examinations were used to monitor effects of L-NDDP. RESULTS: All cats had transient pyrexia, lethargy, vomiting (1 to 3 times/24 h), inappetence, and an acute species-specific infusion reaction that was prevented by administration of atropine-diphenhydramine. Dose-limiting toxicosis was evident as a 10-day course of lethargy, intermittent vomiting, and diarrhea. In cats given multiple doses, dose-related thrombocytopenia, cumulative myelosuppression, transient increased hepatic transaminase activity, and mild to moderate hepatic hydropic degeneration and proximal renal tubular lipidosis in excess of lipidosis expected for this species were detected. Bone marrow hypoplasia was detected in some cats that received higher doses (cumulative dosages of 300 or 400 mg of L-NDDP/m2). CONCLUSION: Cats can safely be given L-NDDP at potentially therapeutic dosages without inducing renal or pulmonary toxicoses. CLINICAL RELEVANCE: Because L-NDDP has better tumoricidal activity than cisplatin (in vivo and in vitro) and is not cross resistant, it may be similarly or more efficacious than cisplatin in humans and dogs.     

The effect of topical tripeptide-copper complex on healing of ischemic open wounds

OBJECTIVE: To evaluate the effects of topical glycyl-L-histidyl-L-lysine tripeptide-copper complex (TCC; Iamin 2% Gel; Procyte Corporation, Redmond, WA) on healing in ischemic open wounds. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Twenty-four adult male Sprague-Dawley rats. METHODS: Rats were divided into 3 groups: topical TCC, topical TCC vehicle (hydroxypropyl-methylcellulose), and no treatment (control). Six-mm-diameter, full-thickness wounds were created within an ischemic bipedicle skin flap on the dorsum of each rat. Each day, for 13 days, wound margins were traced, and the TCC and TCC vehicle groups were treated topically. Tracings were scanned, and wound perimeter and area were calculated. On days 6, 10, and 13, selected wounds were biopsied and analyzed for tumor necrosis factor alpha (TNF-alpha) and matrix metalloproteinases (MMP) 2 and 9. RESULTS: A significant decrease in wound area was seen in the TCC group, but not the vehicle group, when compared with the control group on days 3 to 5, 6 to 9, and 11 to 13 and when TCC was compared with TCC vehicle on days 3 and 9. On day 13, initial wound area had decreased by 64.5% in the TCC group, 45.6% in the vehicle group, and 28.2% in the control group. On days 6, 10, and 13, TCC-treated wounds contained significantly lower concentrations of TNF-alpha and MMP-2 and MMP-9 than control wounds. CONCLUSION: Topical TCC resulted in accelerated wound healing in ischemic open wounds. CLINICAL RELEVANCE: Topical TCC is an effective stimulant of healing of ischemic open wounds in rats and may have an application for the treatment of chronic wounds in other species. Clinical evaluation of topical TCC is warranted.     

Inhibition of peroxynitrite-mediated reactions by vanillin

Several neurodegenerative diseases such as Alzeimer's and Parkinson's as well as septic shock and inflammation involve formation of reactive oxygen and nitrogen species that include peroxynitrite (PON). PON can also react with endogenous antioxidants. Therefore, dietary supplementation with antioxidants may help in these diseases. An exogenous antioxidant, vanillin (4-hydroxy-3-methoxybenzaldehyde), used widely as a food flavoring agent, was evaluated for its ability to scavenge PON and inhibit PON-mediated reactions. Nitration of tyrosine by PON was assessed by high-performance liquid chromatography (HPLC). This reaction was inhibited by vanillin. The oxidation of dihydrorhodamine 123 to fluorescent rhodamine 123 was also inhibited by vanillin. The kinetics of reaction between PON and vanillin was studied by stopped-flow technique. The products of this reaction were analyzed by HPLC, and hydroxyvanillin was identified as one of the five products with absorption at 350 nm. These data demonstrate that vanillin effectively scavenges PON in cell-free systems.     

Free radical studies of ellagic acid, a natural phenolic antioxidant

Ellagic acid, a plant-derived polyphenol, inhibits gamma-radiation (hydroxyl radical) induced lipid peroxidation in rat liver microsomes in a dose- and concentration-dependent manner. Its antioxidant capacity has been estimated using the 1,1-diphenyl-2-picrylhydrazyl radical assay. To understand the actual mechanisms involved in antioxidant activity and the free radical scavenging ability,a nanosecond pulse radiolysis technique has been employed. The rate constants for the reactions of several reactive oxygen species and reactive nitrogen species such as hydroxyl, peroxyl, and nitrogen dioxide radicals have been found to be in the range of 10(6)-10(9) M(-1) s(-1). The ellagic acid radicals have been characterized by the absorption spectra and decay kinetics. Studies on the reactions of ellagic acid with the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical and the radicals of ellagic acid with ascorbate have been used to estimate its one-electron reduction potential. Ellagic acid has also been found to be a good scavenger of peroxynitrite. Using stopped-flow reaction analyzer with absorption detection, the rate constant for this reaction has been determined to be 3.7 x 10(3) M(-1) s (-1). The electron spin resonance spectra of the oxidized ellagic acid radicals have been recorded by horseradish peroxidase and hydrogen peroxide method.     

Inhibitory effect of a bioactivity-guided fraction from Rheum undulatum on the acid production of Streptococcus mutans biofilms at sub-MIC levels

Rheum undulatum root has been used traditionally in Korea for the treatment of dental diseases. The purpose of this study was to separate a fraction from R. undulatum showing anti-acid production activity against Streptococcus mutans biofilms and identify the main components in that fraction. Methanol extract of R. undulatum root and its fractions were prepared. To select a fraction exhibiting anti-acid production activity, suspension glycolytic pH-drop assay was performed. Among the fractions tested, dichloromethane fraction exhibited the strongest activity in a dose-dependent manner. To examine the effect of the selected fraction on the anti-acid production of S. mutans biofilms, 74 h old S. mutans biofilms were used. The selected fraction reduced the initial rate of acid production of S. mutans biofilms at sub-minimum inhibitory concentration (MIC) levels. HPLC qualitative analysis of the selected fraction indicated that the presence of anthraquinone derivatives, such as aloe-emodin, emodin, chrysophanol and physcion, as main components.