Molecular detection and characterization of Ehrlichia canis from dogs in Turkey

Seroprevalence of Ehrlichia canis antibodies among dogs in Turkey were previously reported, however, the ehrlichial organism has never been characterized in this region. The current study examined dogs from Ankara with febrile illness for E. canis infection with E. canis-specific PCR. Three of the 12 blood specimens from dogs showing clinical signs compatible with canine ehrlichiosis were found to be positive by PCR using E. canis-specific primers. E. canis detected in one of the blood specimens was designated as Kutahya strain. The representative E. canis strain was characterized by 16S rRNA gene sequencing and Western blot analysis of the plasma sample from the dog infected with E. canis. The 16S rRNA sequence (1,388 bp) of the E. canis Kutahya was identical to that of Ehrlichia ovina from a sheep in Turkey and Venezuelan Dog Ehrlichia (VDE) and was closely related (99.9%) to that of type strain of E. canis, Oklahoma. The plasma of the dog infected with E. canis Kutahya was analyzed by Western blotting using the purified E. canis Oklahoma strain as antigen. The reactive antibody profiles of the dog infected with E. canis Kutahya was found to be similar to those of dogs infected with E. canis Oklahoma and VDE, suggesting the antigenic similarities among these strains. The findings in this study would help for a better understanding of epidemiology of canine ehrlichiosis. This is the first report of molecular detection and characterization of an ehrlichial agent in Turkey.     

Evaluation of genetic diversity in Turkish melons (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.) based on phenotypic characters and RAPD markers

The genetic relationships among 56 melon (Cucumis melo L.) genotypes collected from various parts of Turkey were determined by comparing their phenotypic and molecular traits with those of 23 local and foreign melon genotypes to investigate the taxonomic relationships and genetic variation of Turkish melon germplasm. Sixty-one phenotypic characters and 109 polymorphic RAPD markers obtained from 33 primers were used to define the genetic similarity among the melon genotypes by dendrograms or two and three dimensional scaling. There were high correlations (r ≥ 0.97) among the four resulting matrices used in molecular characterization. The correlations between phenotypic (Euclidean) and molecular Euclidean, Jaccard, Simple matching, and Nei analyses were r = 0.41, r = −0.40, r = −0.43 and r = −0.40, respectively. Related genotypes or genotypes collected from similar regions were partitioned to similar clusters. Both analyses (phenotypic and molecular) indicated that non-sweet melon types were dissimilar from sweet types and diversity of Turkish melon genotypes was higher than that of sweet foreign cultivars examined, but similar to that of the reference accessions employed. It was also observed that sweet Turkish melon genotypes belonging to groups inodorus and group cantalupensis were highly variable and could have intermated or have crossed with other non-sweet types.     

Inheritance of tolerance to leaf iron deficiency chlorosis in tomato

By using two tomato genotypes, 227/1 (Fe chlorosis susceptible) and Roza (Fe chlorosis tolerant), and their reciprocal F₁, F₂ and BC₁ generations, the inheritance of tolerance to leaf Fe deficiency chlorosis of Roza was studied. Plants were grown in a nutrient solution and subjected to 2.0 × 10^–6 M Fe EDDHA and 10 mM NaHCO₃ to induce Fe deficiency stress by stabilization of pH to 7.8–8.2. A rating scale of 1–3 for chlorophyll was used and both monogenic and polygenic inheritance hypotheses were tested. Better responses to Fe deficiency, as measured by SPAD meter values, were obtained from the cross Roza × 227/1 than from the reciprocal cross. Data from F₂ and BC₁ suggest Fe chlorosis tolerance of Roza is to be controlled by polygenic loci with a relatively high additive effect.     

Use of ISSR,SRAP, and RAPD markers to assess genetic diversity in Turkish melons

The genetic relationships among 63 melon (Cucumis melo L.) genotypes collected from various regions of Turkey were determined by comparing their molecular ISSR, SRAP, and RAPD markers with those of 19 foreign melon genotypes to investigate the taxonomic relationships and genetic variation of Turkish melon germplasm. Total 162 polymorphic markers (69, 18, and 75 obtained from ISSR, SRAP, and RAPD primers, respectively) were used to define the genetic similarity among the melon genotypes by dendrogram or two and three dimensional scalings. The average similarity (SM coefficient) between any two pairs of accessions examined as estimated by molecular variation was 0.73 ± 0.48. Within-group genetic similarities ranged between 0.46 and 0.96. Related genotypes or genotypes collected from similar regions were partitioned to similar clusters. Southeastern Anatolian genotypes were distinctly apart from group inodorus and group cantalupensis (sweet) genotypes. This reinforced the position of Turkey in the secondary genetic diversity center of melon. The genetic diversity among Turkish genotypes (H = 0.28 and I = 0.42) was only a little less than that of the world accessions (H = 0.30 and I = 0.45). On the other hand, the percentage of polymorphic loci among Turkish melon genotypes (90.7%) was even higher than that of the world accessions (87.6%).     

Genotype by environment interactions and combining ability for strawberry families grown in diverse environments

Ten seedlings from 36 crosses representing eastern and western North American short day and remontant genotypes were evaluated in 2011 and 2012 in California, Michigan, New Hampshire and Oregon, for phenology, flower related traits, plant characteristics, fruit characteristics and fruit chemistry traits. There was significant variability among genotypes, locations and evaluation year for most of the characteristics; however, few genotype × location and genotype × year interactions were detected. General combining ability variance components were significant for all traits and greater than SCA variance components for peduncle length, total flowering weeks, flowering cycles, truss size, growing degree days for harvest data, remontancy, achene position, ease of capping, fruit weight, percent soluble solids, titratable acidity and soluble solids/titratable acidity. ‘Sarian’ was identified as the best contributing parent for remontancy. Narrow-sense heritability estimates were moderate to high (0.33–0.78) for total flowering weeks, flowering cycle, truss size, remontancy, number of runners, fruit weight, pH, and titratable acidity. Having a better understanding of these attributes will provide breeders guidance on the most effective breeding strategies for incorporating superior traits from this germplasm into their programs.     

大麦籽粒总花色苷含量的遗传变异及其与粒色的相关分析

有色大麦较普通大麦含有较多花色苷等活性成分,具有较好的保健和辅助治疗功能。为了解大麦籽粒花色苷的遗传特点,选育高花色苷含量的大麦新品系,本研究以紫光芒裸二棱×Schooner构建的193个重组自交系为材料,测定3个试点[玉溪(2013年)、白邑(2014年)及嵩明(2015年)]的大麦籽粒总花色苷含量和粒色,分析大麦籽粒总花色苷含量的遗传变异及其与粒色的相关性。结果表明,大麦RIL群体籽粒总花色苷含量遗传变异大,3个试验点大麦总花色苷含量变异范围分别为0.36~1.38、0.50~1.50、0.50~1.58 mg·g^-1,变异系数为25.00%~33.85%。大麦总花色苷含量呈右偏态、尖顶峰分布,由主效基因控制遗传。高海拔冷凉气候在一定程度上有利于大麦籽粒总花色苷含量累积。3个试点大麦总花色苷含量与粒色均呈极显著正相关,表明大麦籽粒颜色越深,其总花色苷含量越高。与紫光芒裸二棱相比,3个试点有8个共同株系(27、34、35、37、38、60、138、167)的总花色苷含量显著或极显著提高。本研究结果为高花色苷含量大麦种质创新及育种提供了一定的理论依据。     

Characterisation and toxicity of Bacillus thuringiensis strains from hazelnut pests and fields

BACKGROUND: In order to find and identify more toxic insecticidal Bacillus thuringiensis Berliner (Bt) strains, a survey was carried out of B. thuringiensis isolate pests belonging to Coleoptera, Lepidoptera and Diptera and from soils in hazelnut fields. Of 16 isolates having Bacillus cereus‐B. thuringiensis morphology, eight were classified as B. thuringiensis because of the production of parasporal δ‐endotoxin crystals. RESULTS: In this study, eight isolates of B. thuringiensis from hazelnut pests (isolates Bn1, Mm2, Mnd and Xd3) and from hazelnut soils (isolates 6, 27, 40 and 46) have been characterised in detail. These isolates were compared with reference strains by electron microscopy, SDS‐PAGE analysis, cry gene content, serological test and insecticidal activity. CONCLUSION: Results indicate that Bn1 and MnD are B. thuringiensis subsp. kurstaki, and Mm2 and Xd3 are B. thuringiensis subsp. tenebrionis. In addition, isolate 6 is B. thuringiensis subsp. israelensis, isolates 27 and 46 are B. thuringiensis subsp. kumamotoensis and isolate 40 is B. thuringiensis subsp. indiana. The four B. thuringiensis isolates from hazelnut pests may be valuable as biological control agents against coleopteran and lepidopteran insects. Copyright © 2009 Society of Chemical Industry     

Modulation of human lymphocyte proliferation by salivary gland extracts of ixodid ticks (Acari: Ixodidae): effect of feeding stage and sex

Ixodid ticks remain attached to their hosts for several days to weeks. During this extended feeding process new proteins involved in the modulation of host immune responses are expressed in tick salivary glands. In our study a stimulatory or inhibitory effect of salivary gland extracts (SGE) of unfed and partially fed female Ixodes ricinus (Linnaeus, 1758), female and male Amblyomma variegatum (Fabricius, 1794) and Rhipicephalus appendiculatus Neumann, 1901 ticks on human lymphocyte proliferation induced by Concanavalin A (ConA) and phytohaemagglutinin (PHA), respectively, was investigated. SGE of all female ticks examined suppressed proliferation of ConA-induced lymphocytes; highly significant suppression was observed in the presence of unfed I. ricinus and 9-day fed A. variegatum SGE. SGE of partially fed A. variegatum and I. ricinus females suppressed PHA responses of lymphocytes. Lymphocytes showed reduced PHA and ConA responses in the presence of SGE of unfed and 2-day fed R. appendiculatus females, while SGE of 6-day fed females enhanced PHA responses, but reduced their ConA responses; generally SGE of 2-day fed females displayed the strongest inhibition. Amblyomma variegatum male SGE slightly enhanced PHA, but significantly reduced ConA responses of lymphocytes and their inhibitory effect increased during feeding. SGE of unfed and 2-day fed R. appendiculatus males enhanced PHA and ConA responses and those of 6-day fed males suppressed lymphocyte proliferation. The results suggest that (i) species- and sex-specific differences exist in the effects of tick salivary gland antigens on human lymphocyte proliferation and (ii) effect of SGE on human lymphocyte responses to mitogens varies depending on the tick feeding status.     

Genotypic variation in the response of pepper to salinity

Using 102 pepper (Capsicum annuum) genotypes, a greenhouse experiment has been conducted to study genotypic variation in tolerance to 100 mM sodium chloride (NaCl) in nutrient solution. Based on the severity of leaf symptoms caused by the NaCl treatment there was a substantial genotypic variation in salt tolerance. From this screening experiment, six sensitive and six tolerant genotypes were chosen to study dry matter production and root and shoot concentrations of sodium (Na), potassium (K) and calcium (Ca) in a growth chamber experiment in a nutrient solution with and without 150 mM NaCl. The genotypes selected as sensitive were highly damaged and developed severe chlorosis and necrosis under NaCl treatment, while the genotypes selected as tolerant were slightly affected. On average, decreases in shoot dry matter production caused by NaCl were greater in the sensitive than the tolerant genotypes. Application of salt increased shoot Na concentration at greater amount in the sensitive than the tolerant genotypes. Of the tolerant genotypes, the genotype Cac (Capsicum annuum var. cerasiforme) and 1245 F1 had around 2.45% Na in shoot while the sensitive genotypes Kandil and Pazarcik contained, on average, 5.4% Na. All sensitive and tolerant genotypes exhibited more or less similar shoot concentrations of K and Ca. There was very significant and positive correlation between severity of leaf symptoms and shoot Na concentration, but no correlation could be found in the case of K or Ca concentrations with the severity of leaf symptoms. The results indicate existence of substantial genotypic variation in tolerance to NaCl stress in pepper. It seems very likely that exclusion of Na from roots into growth medium plays a critical role in expression of high Na tolerance in pepper.