Detection of Pear Vein Yellows Disease caused by Apple stem pitting virus (ASPV) in Hatay province of Turkey

Pear vein yellows disease (PVYD) caused by Apple stem pitting virus (ASPV) was studied in 9 pear orchards and 3 nurseries in Hatay province of Turkey. A survey was carried out to inspect the symptoms of PVYD on pear (Pyrus communis). Leaf symptoms consist of yellow vein banding, reddening and flecking along the veins that were observed during the late spring to winter (dropping leaves). ApMv, ACLSV which are important viruses of pome fruits were also investigated on pear orchards and several quince (Pyrus cydonia) trees in pear orchards. The shoot and leaf samples were taken randomly from inspected trees in orchards and seedlings in nurseries for ApMv, ACLSV and for ASPV in April of 2008 and 2009. A total of 20 pear samples from 15 symptomatic and 5 asymptomatic young trees of local pear cultivars (‘Mustafa Bey’ and ‘Ankara’ cvs.) and 6 from quince (unknown cultivar) were collected. All samples were detected for the presence of the viruses by ELISA. Fifteen samples (ten samples selected from symptomatic plants and 5 samples from asymptomatic trees) were also tested for the viruses by Bioassay-sap inoculation. Sap extracts were mechanically inoculated on some indicator plants (Chenopodium amaranthicolor, C. quinoa, Cucumis sativus, Gompherena globulosa, Nicotiana benthamiana, N. glutinosa, N. occidentalis). Although, mild symptoms including vein clearing and leaf necrosis were observed on N. glutinosa, and N. occidentalis test plants, in general, no symptoms associated with the investigated viruses appeared on test plants. Some samples from local pear cultivars in Hatay were found to be infected with PVYD by serological tests. ASPV was found to be present in 60% of the ELISA-tested samples in 2008. This preliminary study demonstrated that a high rate of ASPV infection was present for local pear cvs. in the province. ApMV, ACLSV infections were not tested in detected samples. Keywords: ELISA, Ilarvirus, pear, pome fruit, test plan

An investigation on Rose Mosaic Disease of Rose in Hatay-Turkey

Field inspections were carried out to investigate Apple mosaic virus (ApMV), Arabis mosaic virus (ArMV) and Prunus necrotic ringspot virus (PNRSV) which are associated with rose mosaic disease (RMD) during the years of 2008 and 2009. Characteristic symptoms, including chlorotic line patterns (zigzag pattern), vein-banding and mottles in leaves were observed during spring. Symptoms were also evident during summer on leaves produced until early summer. Flower abnormalities as phyllody were also exhibited during autumn. Distortion and reduction in flower size and early leaf drop have been observed on symptomatic plants in winter. Leaf samples taken from 15 rose plants from ‘Rosa hybrida L.’ neighboring stone fruit orchards were tested by mechanical inoculation to herbaceous plants and enzymelinked immunosorbent assay (DAS-ELISA) for the presence of ApMV, ArMV and PNRSV, which are the viruses related to RMD. Catharanthus roseus L. G. Don, Chenopodium amaranthicolor Coste and Reyn., C. quinoa Wild, Cucumis sativus L., Gomphrena globosa L., Lagenaria siceraria (Mol.) Standl, Nicotiana benthamiana L., N. clevelandii L., Nicotiana glutinosa L., Phaseolus vulgaris L., Vigna unguiculata L. test plants were incubated after mechanical inoculation for symptom appearance at 25°C±2 and 16:8 h photoperiod (day:night) conditions in an insectproof room. Symptoms including chlorotic local lesions, systemic necrosis, stunting and yellow mottling began to appear on C. quinoa and C. sativus in 2-3 weeks after sap inoculation. Serological tests of test plants are in progress. The rose plants showing symptoms in home gardens were re-tested for the viruses in spring by ELISA. According to the results of the Bioassay by sap inoculation and ELISA on symptomatic rose plants, the causal agent of RMD is PNRSV. The viruses affecting rose plants spread through cuttings from a diseased plant because new plants are generally produced by the rooting of cuttings in home gardens in Hatay. Further detailed investigations are necessary to find out the causal agent/s of RMD in rose in the region, because infected rose plants can be an important factor in the epidemiology of virus diseases caused by these agents in rose plantations. Keywords: ApMV, Bioassay, ELISA, Oil Rose, PNRSV, viru

Tomato ringspot nepovirus (ToRSV) in wild blackberry (Rubus fruticosus L.) in Hatay province of Turkey

During observations of virus-like symptoms in wild blackberry (Rubus fruticosus L., Rosaceae) some stunted plants growing in the border of stone-fruit orchards in Hatay were found showing severe yellow blotching and deformity of the leaves. Samples (shoots and leaves) were collected in September 2008 and May 2009 from wild blackberry plants growing at the border of apricot orchards and neighboring stone fruit nurseries in Hatay province in Eastern Mediterranean Region of Turkey. Each of 12 wild blackberry samples taken from 7 symptomatic and 5 symptomless plants were tested for virus by mechanical inoculation of sap to herbaceous plants. Sap was inoculated on Chenopodium amaranthicolor, C. quinoa, Cucumis sativus, Gombhrena globosa L., Nicotiana benthamiana, N. clevelandii, N. glutinosa, Phaseolus vulgaris L. and Vigna unguiculata L. Sap from six symptomatic plants induced symptoms of necrotic or chlorotic lesions, and ringspot on test plants. No symptoms were induced in the test plants inoculated by sap from symptomless blackberry plants. A sap-transmissible virus was obtained from all symptomatic plants and later identified as Tomato ringspot nepovirus (ToRSV) by enzyme-linked immunosorbent assay-ELISA. Thus, results of biological indexing were also confirmed by serological assays (ELISA). Cuttings of symptomatic plants were rooted in pots and kept in an insect-proof growing room for symptom observations and testing. Investigations on the other viruses in wild and cultivated Rubus spp. and its vector/s are still in progress. Further studies are necessary to investigate the distribution and natural transmission of the main virus diseases in cultivated Rubus spp. in particular because of the economic importance of Rubus cultivation and the recent increase in new commercial plantings in Hatay. This work represents the first report of ToRSV in wild blackberry (R. fruticosus) in Turkey. Keywords: Bioassay, Blackberry, ELISA, Rubus, ToRSV, viru

PCR/RFLP-based method for molecular characterization of ‘Candidatus Phytoplasma prunorum’ strains using the aceF gene.

New molecular typing tools for phytoplasmas belonging to the 16SrX phytoplasma group have recently been developed based on the non-ribosomal genes aceF, pnp, imp, and SecY. In the present work we chose to perform a PCR-RFLP method based on the aceF gene. This genetic marker had previously shown high variability among strains of the 16SrX group, moreover, it had allowed for the differentiation of French hypovirulent ‘Candidatus Phytoplasma prunorum’ strains from virulent ones.Most of the stone fruit samples were collected in north-east Italy, although a few samples from Bosnia and Herzegovina, and Turkey were also included in the work to explore variability. French hypovirulent and virulent strains, one Azerbaijan strain and ‘Ca. P. prunorum’ strains maintained in periwinkles were used as reference strains. Some of the Italian samples were not collected in the field and they became infected by Cacopsylla pruni under controlled conditions.Sequencing of the aceF gene was performed on some of the samples tested and based on the alignment, a few restriction enzymes were selected for ‘Ca. P. prunorum’ strain differentiation. Nested PCR was performed using previously developed primers on all samples and RFLP analyses were carried out with BpiI, HaeIII and Tsp509I enzymes. BpiI and HaeIII enzymes generated two different profiles, one profile was undigested and the second one constituted by two different fragments. The Tsp509I enzyme enabled three different pattern types to be distinguished. Combining the results obtained with the three restriction enzymes, it was possible to distinguish between the ‘Ca. P. prunorum’ strains investigated in this study: 6 different RFLP subgroups AceF-A, -B, -C, -D, -E and –F. We confirmed that strains belonging to 4 subgroups, AceF-A, -B, -C and -E were present in north-east Italy, where a large number of the samples were processed. The strains of AceF-A and -E subgroups were the predominant ones (21.6% and 17.0%, respectively) and mixed infections of AceF-A+E subgroups (17.0%), and AceF-B+E (14.8%) subgroups were quite common. Keywords: phytoplasma, European stone fruit yellows, molecular differentiation, sequencin

Routinely collected data for randomized trials: promises, barriers, and implications

This work was supported by Stiftung Institut für klinische Epidemiologie. The Meta-Research Innovation Center at Stanford University is funded by a grant from the Laura and John Arnold Foundation. The funders had no role in design and conduct of the study; the collection, management, analysis, or interpretation of the data; or the preparation, review, or approval of the manuscript or its submission for publication.Peer reviewedPublisher PD

Detection of a new medium for budwood culture in vitro of citrus [Turunçgillerde in vitro aşigözü kültürü i·çin yeni bir ortam i·çeriginin araştinlmasi]

The transfer of new and quality citrus species and cultivars from one country or growing area to another may lead to the introduction of new pests and diseases. Therefore the import and direct production of citrus budwood without adequate control measures has a high risk. The citrus virus and virus-like disease agents can be successfully eliminated using the shoot-tip grafting (STG) technique which is routinely used to obtain virus-free plants in citrus improvement programs in major citrus-growing countries. Many methods are used to obtain flushes as a source of scion material for STG in vitro. The budwood culture in vitro is one. used to obtain flushes from bud sticks for STG. The budwood culture medium is composed of Murashige and Skoog (MS) salt solution and is used to culture the plant in vitro after shoot-tip grafting. This research was conducted with the objective of simplifying the usual procedure of budwood culture. Instead of culturing in tubes containing nutrient medium and fine sand as a substrate, a new medium with distilled water without salt solution or sand was tried, to obtain flushes from Washington Navel orange (Citrus sinensis (L.) Osb.), Minneola tangelo (Citrus reticulata x Citrus paradis!) and Interdonato limon (Citrus limon (L.) Burm.) cultivars. Distilated water medium is more practical and more economical than usual the medium composition. This new medium has been used successfully with several cultivars (especially imported) of sweet orange, mandarin, lemon, grapefruit and ornamental citrus to obtain a source of shoots for STG at the Subtropical Fruits Research and Experimental Centre of the University of Cukurova since 1993

DETECTION AND CHARACTERISATION OF PHYTOPLASMAS IN DISEASED STONE FRUITS AND PEAR BY PCR-RFLP ANALYSIS IN TURKEY

During the late summer-early autumn of 2002, surveys were carried out in Turkey to determine the presence of phytoplasma diseases in fruit trees. Phytoplasmas were detected and characterized by PCR-RFLP analysis and TEM technique in stone fruit and pear trees in the eastern Mediterranean region of the country. Six out of 24 samples, including almond, apricot, peach, pear and plum, gave positive results in PCR assays. RFLP analysis usingSspI andBsaAI enzymes of PCR products obtained with primer pair f01/r01 enabled identification of the phytoplasmas involved in the diseases. Stone fruit trees, including a local apricot variety (\u2018Sak\u131t\u2019) and a pear sample, were found to be infected with European stone fruit yellows (ESFY, 16SrX-B) and pear decline (PD, 16SrX-C) phytoplasmas, respectively. This is the first report in Turkey of PD phytoplasma infecting pear and of ESFY phytoplasma infecting almond, apricot, myrobalan plum and peach; ESFY phytoplasma infecting Japanese plum was previously reported