Konya İli Marul Ekim Alanlarında Sorun Olan Virüs Hastalıklarının Belirlenmesi

Lettuce (Lactuca sativa L.) is a member of the family Compositae (Asteraceae). This plant, which is grown for its leaves, is grown in open field and greenhouse conditions almost everywhere in the world and in Turkey. With the present study virus diseases of lettuce and their prevalence in Konya province was revealed for the first time. For this purpose, leaf samples were taken from lettuce plants showing virus diseases symptoms with surveys carried out in Konya province lettuce planting areas from May to August in 2020. Then the collected lettuce leaf samples were tested in laboratory conditions by Double Antibody Sandwich Enzyme-linked Immunosorbent Assay (DAS-ELISA) method to reveal infections of Cucumber mosaic virus (CMV), Miraflori lettuce big vein virus (MiLBVV), Lettuce mosaic virus (LMV), and Tomato spotted wilt virus (TSWV). According to the information obtained from the results of the study, it was determined that 40 out of 97 (41.23%) lettuce plant samples and all (6) weed samples were infected with at least one of the viruses. In lettuce leaf samples; TSWV (27.83%), LMV (12.37%), CMV (10.31%) and MiLBVV (5.15%) infections have been detected. In weed samples; infections of CMV (83.33%), LMV (66.66%), and TSWV (50%) have been revealed. The infections of TSWV, LMV, CMV, and MiLBVV on lettuce plants in Konya province were reported firstly with the study.

Antalya İli Kumluca İlçesindeki Biber Yetiştirilen Seralarda Domates Lekeli Solgunluk Virüsü (Tomato spotted wilt tospovirus-TSWV)’ nün Yaygınlığı ve Konukçu Yabancı Ot Türlerinin Belirlenmesi

There are many viruses that infect pepper and limit its production. Among these viruses, Tomato spotted wilt tospovirus (TSWV) infects crops in 35 plant families that are economically important, including pepper. In the present study; totaly 156 leaf samples were collected, including 57 from pepper plants showing virus-like symptoms and 99 from weeds and/or plants other than peppers in and around the greenhouse, through surveys carried out in pepper greenhouses in Kumluca district of Antalya province, from September to December 2020. Then, the plant leaf samples were tested to determine TSWV infections by the Double Antibody Sandwich Enzyme-linked Immunosorbent Assay (DAS-ELISA) method. According to result of the tests, it was determined that 55.76% of the tested leaf samples were infected with TSWV, while this rate was determined as 96.49% for pepper samples and 32.32% for other plant samples. During the survey studies, it was revealed that the leaf samples of 13 out of 31 weed and different plant species except pepper were infected with at least one of the viruses. In addition, pepper plants showing symptoms TSWV-like symptoms in pepper greenhouses were counted during the survey, and the prevalence of this virus disease was calculated on the basis of Kumluca district and neighborhoods. As a result of these calculations, the prevalences of TSWV; for Kumluca, Mavikent, Beykonak, Salur, Hacıveliler, Adrasan, Merkez, and Kavakköy were determined as 26.93%, 26.92%, 32.27%, 20.66%, 21.13%, 17.66%, 13%, and 25%, respectively.

Response of tomato (Solanum lycopersicum) varieties to Clavibacter michiganensis subsp. michiganensis infection

<p><em>Clavibacter michiganensis</em> subsp. <em>michiganensis</em> causes bacterial wilt and canker disease of tomato. The objectives of this research were i) to characterize and identify the most aggressive Cmm in Chignahuapan, Puebla, ii) to evaluate the tolerance in two phenological stages of 10 tomato varieties to infection by CP_Cmm1 in the greenhouse and the <em>in vitro</em> sensitivity of the bacteria to bactericides. 12 Cmm isolates were collected from tomato plants and a strain (CP_Cmm-1) with greater aggressiveness was selected according to the time of manifestation of symptoms in plants of var. Reserva. Afterward, the strain was inoculated by cutting with scissors embedded in a suspension with 3 x 108 UFC mL-1 in two phenological stages (at five and 10 true leaves). Symptoms were evaluated for 30 days after inoculation. Additionally, the sensitivity of CP_Cmm-1 to eight commercial bactericides <em>in vitro</em> was evaluated. The results showed that the CP_Cmm-1 strain was identified with 97% similarity with the API20 E system, positive with DAS-ELISA, and by PCR it showed 96.6% identity with <em>Clavibacter michiganensis</em> subsp. <em>michiganensis</em>. The Saher variety showed greater tolerance to infection (* = p?0.05) both in the stage of five and 10 leaves; the varieties Sv4401, Nápoles, and Súper óptimo showed greater susceptibility in the five-leaf stage. The Sv4401 variety was highly susceptible in both stages. Neither variety was resistant to infection by CP_Cmm-1. The use of the Sahel variety and kasugamycin could reduce the damage of this bacteria.</p>

INCIDENCE OF TBRV AND ArMV VIRUSES IN NEW CHERRY PLANTATIONS FROM AREA OF ROMANIA

Viral diseases can influence negatively a good evolution of cherry plantations. Two of the viral diseases that attack this species are caused by the ArMV virus, which spreads by multiplying the infected propagating material, by seed and nematodes, and by the TBRV virus, which spreads by multiplying the infected material and nematodes. In order to study the incidence of the two viruses, 10 cherry plantations located in the south of the country were evaluated, in the district of Argeș, Dolj, Ialomița, Ilfov, Călărași, Dâmbovița, Buzău. The planting material used to set up the plantations was both from Romania and from an external source: the Netherlands, Greece, Italy. Viral evaluation performed visually and serologically by DAS-ELISA technique, identified viral infections in 2 of the 10 plantations. In one plantation, TBRV was identified in 20% of the tested samples and in the second, ArMV viruses were identified in 20% of the samples and TBRV in 5% of the samples.

Development of a Novel Double Antibody Sandwich ELISA for Quantitative Detection of Porcine Deltacoronavirus Antigen

Porcine deltacoronavirus (PDCoV) can cause diarrhea and dehydration in newborn piglets. Here, we developed a double antibody sandwich quantitative enzyme-linked immunosorbent assay (DAS-ELISA) for detection of PDCoV by using a specific monoclonal antibody against the PDCoV N protein and an anti-PDCoV rabbit polyclonal antibody. Using DAS-ELISA, the detection limit of recombinant PDCoV N protein and virus titer were approximately 0.5 ng/mL and 103.0 TCID50/mL, respectively. A total of 59 intestinal and 205 fecal samples were screened for the presence of PDCoV by using DAS-ELISA and reverse transcriptase real-time PCR (RT-qPCR). The coincidence rate of the DAS-ELISA and RT-qPCR was 89.8%. DAS-ELISA had a sensitivity of 80.8% and specificity of 95.6%. More importantly, the DAS-ELISA could detect the antigen of PDCoV inactivated virus, and the viral antigen concentrations remained unchanged in the inactivated virus. These results suggest that DAS-ELISA could be used for antigen detection of clinical samples and inactivated vaccines. It is a novel method for detecting PDCoV infections and evaluating the PDCoV vaccine.

Discrepancies in Serology-Based and Nucleic Acid-Based Detection and Quantitation of Tomato Spotted Wilt Orthotospovirus in Leaf and Root Tissues from Symptomatic and Asymptomatic Peanut Plants

Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) causes spotted wilt disease in peanuts. A serological test (DAS-ELISA) is often used to detect TSWV in peanut leaf samples. However, in a few studies, DAS-ELISA detected more TSWV infection in root than leaf samples. It was not clear if the increased detection was due to increased TSWV accumulation in root tissue or merely an overestimation. Additionally, it was unclear if TSWV detection in asymptomatic plants would be affected by the detection technique. TSWV infection in leaf and root tissue from symptomatic and asymptomatic plants was compared via DAS-ELISA, RT-PCR, and RT-qPCR. TSWV incidence did not vary by DAS-ELISA, RT-PCR, and RT-qPCR in leaf and root samples of symptomatic plants or in leaf samples of asymptomatic plants. In contrast, significantly more TSWV infection and virus load were detected in root samples of asymptomatic plants via DAS-ELISA than other techniques suggesting that DAS-ELISA overestimated TSWV incidence and load. TSWV loads from symptomatic plants via RT-qPCR were higher in leaf than root samples, while TSWV loads in leaf and root samples from asymptomatic plants were not different but were lower than those in symptomatic plants. These findings suggested that peanut tissue type and detection technique could affect accurate TSWV detection and/or quantitation.

Occurrence and Distribution of Viruses Associated with Okra and Their Alternative Hosts in Kaduna and Zamfara States, Nigeria.

One of the major constraints to production of okra (Abelmoschus esculentus L.) in Nigeria and in particular in Kaduna and Zamfara States, is the problem of okra mosaic virus and okra leaf curl virus. This study was carried out to provide information on the occurrence and distribution of okra mosaic and okra leaf curl viruses on okra, in Kaduna and Zamfara states, Nigeria. A survey of okra-producing farms was carried out during dry and wet seasons of 2017 cropping season in Kaduna (Zaria, Lere, and Igabi Local Government Areas) and Zamfara (Gusau, Bungudu, and Zurmi LGAs) states. Leaf samples (15) of symptomatic okra plants were collected from each farm in the study area. The total number of plants and the number of symptomatic plants within each subplot were recorded, and the disease incidence was determined. Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay (DAS- ELISA) kit was used in the detection of Okra Mosaic Virus while Polymerase Chain Reaction (PCR) was employed for the detection Okra Leaf Curl Virus. The results showed that all the okra leaf samples tested for OLCV were negative in this study while OkMV was tested positve in all the samples with a recorded incidence of 20 % and 14 % in Kaduna and Zamfara states respectively, however, only 8 out of total weed samples were also tested positive for OKV, but all were tested negative to OLCV.