Identification of Nematode Fauna in Vineyards of South of Western Azerbaijan and Determination of the Dominant Parasitic Species

Introduction: Grapevine belongs to the Vitaceae family that consists of 14 genera and about 700 species. Only in the genus Vitis fruits are edible. Italy is the largest producer of grapes and Iran has the seventh position in the world from this point of view. Western Azarbaijan province comprises a high diversity of crops including wild grapes. Although, some nematodes are free living and antagonists of another soil microfauna, the other are plant parasitic agents. Most of which live in the agricultural soils where they are widely dispersed. Effectiveness of the disease management strategies are affected by the accurate identification of the plant disease causal agents and the nematodal diseases are not the exception from this rule. Therefore, for control of the diseases caused by the nematodes, it is necessary to separate the parasitic nematodes from the suspected contaminated soils and identify them. Although separation and identification of the nematodes are partly time-consuming, it is not very complicated. Some nematodes likeXiphinema, Longidorus and Ditylenchus are cosmopolitan and catastrophic nematodes in vineyards worldwide. So far no study has been performed regarding the plant parasitic nematode in vineyards of the south of Western Azerbaijan. Therefore, in this study as an introduction to the management ofthe vineyard parasitic nematodes, the dominant nematodes of the plant were identified. In the next step, investigation of nematodes bioecology, the interaction of nematodes with the other plant pathogens, their host range and their damages to the host plants would be studied. Materials and Methods: In order to identify the fauna of plant parasitic nematodes in vineyards of the south of Western Azarbaijan, during 2013-2014, 50 soil samples were collected from the rhizosphere of grapevine. The sampling was carried out from the vineyards of five grapevine growing cities including Mahabad, Bookan, Sardasht, Piranshahr and Miyandoab. The samples were collected from the rhizosphere of grapevines from the depth between 10 and 80 cm from the soil surface after digging and separating the surface dry soil. About 2 kg soil from each vineyard from several places were collected and by means of a plastic bag was transferred to the laboratory where they were kept in the refrigerator at 4-degree centigrade until used. Nematodes were extracted from the soil by combined sieving and centrifugal-flotation method and processed to be transferred to glycerin. After preparing microscopic slides, the morphological and morphometrical features of the nematodes were studied using the light microscope equipped with a drawing tube. Identification of the genera and species was performed using reliable sources and valid nematode identification keys and the morphological features. The measurements of the extracted nematodes were compared with those ones given in literature and their similarities and differences with original descriptions and closest species were discussed. Results and Discussion: As a result, 23 species belonging to 15 genera including Amplimerliniusglobigerus, Basiriatumida, Boleodorusthylactus, Discotylenchusdiscretus, Ditylenchusacutus, Ditylenchusmyceliophagus, Filenchus vulgaris, Geocenamusbrevidens, Geocenamusrugosus, Helicotylenchuspseudorobustus, Helicotylenchus vulgaris, Mesocriconemaantipolitanum, Mesocriconemaxenoplax, Paratylenchuslabiosus, Pratylenchoidesvariabilis, Pratylenchuscoffeae, Pratylenchusneglectus, Pratylenchuspenetrans, Pratylenchussefaensis, Praylenchusscribneri, Scutylenchuspaniculoides, Xiphinema index andZygotylenchusguevaraiwere identified. Five isolated species namely, Helicotylenchus vulgaris,Mesocriconemaantipolitanum, Mesocriconemaxenoplax, Helicotylenchuspseudorobustusand Pratylenchusneglectus respectively based on the frequency and distribution in the soil samples are determined as dominant parasite species. Here, the two more dominant species, Helicotylenchus vulgaris and Mesocriconemaantipolitanum are a little bit described. Helicotylenchus vulgaris, initially worldwide was reported by Yuen in 1964 and for the first time from Iran in 1995 was reported by KargarBideh, and his collaborators from Hamdan province. The species from morphological and morphometrical characteristic point of view is very close to Helicotylenchusminzi.Mesocriconemaantipolitanum firstly in 1991 was reported from Iran by Loof and Barooti from apple, wheat and lucerne roots from Karaj, potato from Lorestan, lucerne from Zanjanand apricot from Northern Azarbaijan. In the research, the species was isolated from Piranshahr, Miyandoab, Bookan and Mahabad vineyard cities of Western Azarbaijan. The species is very similar to M. surinamense. Conclusion: Nine species including Discotylenchusdiscretus, Ditylenchusacutus, Ditylenchusacutus, Paratylenchuslabiosus, Pratylenchoidesvariabilis, Pratylenchuscoffeae, Pratylenchuspenetrans, Pratylenchusscribneri, Pratylenchussefaensisand Scutylenchuspaniculoides were recorded for the first time from the rhizosphere of grapevine from Iran. Considering thatall the nematodes are already recorded from Iran, herein only the dominant species are described

Investigation of Genetic Diversity of Wilsonomyces carpophilus in Khorasan Razavi Using rep-PCR Marker

Introduction: Shot hole disease of stone fruit trees resulted from Wilsonomyces carpophilus can weaken the trees and reduce the quantity and quality of the crops worldwide particularly in semi-arid regions. Coryneum blight or shot hole disease infects all the stone fruit trees including peach, nectarine, apricot, sour cherry, plum, cherry, and almond. One of the most important strategies to manage any plant disease is to use resistant cultivars. In this way, it is very important to have knowledge about the status of genetic diversity and to determine the relationship between isolates of the causal agent fungus. The main objective of the present research was to study the genetic diversity of W. carpophilus in Khorasan Razavi province using the rep-PCR molecular fingerprinting method. Materials and Methods: Sampling was performed from peach, nectarine, plum, apricot and cherry orchards of Quchan, Torqabeh, Shandiz, Chenaran, Neishabur, Kalat, Torbat Heidarieh and Mashhad during spring and summer of 2012 and 2013. Mono-conidial isolates were recovered from infected leaves, fruits, and twigs of different parts of orchards. Infected collected leaves, twigs, and fruits were transferred to the laboratory. By using techniques of Klimesova and Prasil (1989) and Mehta (1998) from the cut parts between infected and healthy tissues of each isolate, cuts of 2-3 mm from leaf, fruit and twig were prepared by the scalpel. These pieces were surface sterilized with 1% sodium hypochlorite liquid about 1 to 3 minutes based on the thickness of tissue. Then, the samples were cultured on PDA, MEA, and WA media and incubated at 18, 20, and 25 °C. The isolated fungi were purified and identified. The research was performed on 20 fungal isolates collected from different stone fruit trees. Genomic DNA was amplified using BOX A1R, ERIC2, ERIC1R, REP2-I, and REP1R-I primers. Thirty-eight of 39 fragments amplified were polymorphic for 100 to 5000 base pairs. Similarity matrix between isolates was calculated based on Jacquard Coefficient and cluster analysis and construction of dendrogram were done based on UPGM using NTYSIS.PC 2.0 software. Results and discussion: From 39 amplified bands, 38 bands (97.5%) showed polymorphism. The molecular weight of amplified DNA fragments was between 100 to 5000 bp. Based on analysis of banding pattern of REP primer set, isolates of W. carpophilus were categorized into 12 groups at the 69% similarity level. The most genetic similarity of isolates (94%) was between AK (apricot of Kalat) and PK (peach of Kalat) and the least genetic similarity of W. carpophilus isolates was between AQ (apricot of Quchan), AN (apricot of Neishabur), AC (apricot of Chenaran), PlM (plum of Mashhad), PM2 (peach of Mashhad number 2), and CC (cherry of Chenaran) with the other isolates. Based on the results of this study rep-PCR could separate isolates of W. carpophilus very well and also could separate similar isolates and hosts which have the close genetic relationship. Similar results were obtained by Edel et al. (1995) and Jedryczka et al. (1999). Edel et al. (1995) compared three different molecular methods for characterization of Fusarium oxysporum strains. The marker also separated isolates of Kalat and Chenaran geographically and to some extent isolates of plum in terms of hosting from the other isolates. Toda et al. (1999) in their study, about the investigation of genetic correlation among and within different isolates of Rhizoctonia solani by rep-PCR divided the 41 isolates into 7 groups which indicate considerable genetic diversity among isolates. Also, Karimi et al. (2010) in their study about the investigation of genetic diversity of Sclerotinia sclerotiorum at 64% similarity level, divided the isolates into 7 groups and separated most of the isolates geographically. Conclusion: The results obtained in this study indicated that rep-PCR is a practical, rapid, and accurate technique for separation of W. carpophilus isolates. Considering the high genetic diversity observed in the population of this fungus, making attempts to plant cultivars with high resistance and resistant genes can largely prevent the outbreaks and intensity of the pathogen. Therefore, further researches in this area can be placed in breeding, production and reproduction of cultivars with particular resistance programs against shot hole disease. The present research study is a prelude to solving problems related to this important disease

Brown alga Ascophyllum nodosum extract-based product, Dalgin Active®, triggers defense mechanisms and confers protection in both bread and durum wheat against Zymoseptoria tritici

International audienceAlternative control strategies are increasingly encouraged to develop sustainable crop protection. In this aim, we assessed the ability of Dalgin Active ® , an Ascophyllum nodosum extract-based product, to induce resistance in bread wheat and durum wheat against Zymoseptoria tritici, a major fungal pathogen on these crops. Foliar application of the product provided a strong and significant reduction of disease intensity on both wheat species without any direct effect against the pathogen. Infection process monitoring revealed that Dalgin Active ® did not prevent fungal epiphytic growth and leaf colonization, but its application results in an inhibition of sporulation as well as fungal cell wall-degrading enzyme and protease activities. During the early stages of infection, Dalgin Active ® activated several plant defense markers on both wheat species, including PR protein, antioxidant metabolism, phenylpropanoid, and octadecanoid-based pathways. Although few differences were recorded, the induced defense reaction patterns were overall similar in both wheat species, suggesting that Dalgin Active ® could be used to biocontrol Z. tritici on both crops