First report of Phytophthora cinnamomi causing root and crown rot of Ficus carica in Turkey

[No abstract available

First Report of Phytophthora chlamydospora Causing Root and Crown Rot on Almond (Prunus dulcis) Trees in Turkey

WOS: 000380299200089In June 2015, ∼10% of 10,000 8-year-old almond [Prunus dulcis (Miller) D.A. Webb. cv. Ferragnes] trees grafted on the GF677 rootstock in a commercial almond orchard in Besni of Adıyaman Province, showed wilting and lack of vigor, with severely infected trees dying from root and crown rot. The incidence of infected trees on soils with poor water drainage was greater than that on well-drained soils. Crowns of symptomatic plants had a reddish brown discoloration in the inner bark with a sharp contrast between infected and healthy tissue. Most fine roots were completely rotted and the inner bark of infected larger roots showed similar discoloration. Tissue samples taken from the margins of crown and root lesions were placed on carrot agar (CA) amended with 5 mg of pimaricin, 250 mg of ampicillin, 10 mg of rifampicin, 100 mg of pentachloronitrobenzene, and 50 mg of hymexazol (P5ARPH) per liter. Plates were incubated for 5 days at 28°C in the dark and Phytophthora chlamydospora was consistently isolated from the tissues. Isolates produced petaloid colonies and abundant spherical, thin-walled, intercalary but lateral and terminal chlamydospores (30 to 46 μm diameter, 38.5 μm average). Colonized agar discs were submerged in sterilized deionized water at 25°C. After incubation on submerged discs for 24 h, all isolates produced hyaline, nonpapillate, noncaducous sporangia of ovoid to obpyriform shape, with internal and external proliferation, 34.0 to 56.5 μm long, 26.5 to 39.5 μm wide, with a length/breadth ratio of 1.4 to 1.7, formed on simple, unbranched, occasionally sympodial sporangiophores. Globose to subglobose hyphal swellings in branched chains also formed in water. The optimum and maximum temperatures for mycelium growth on CA were 27 and 37°C, respectively. All these characteristics were similar to those described for P. chlamydospora Brasier and Hansen sp. nov. (Hansen et al. 2015), previously known as P. taxon Pgchlamydo. Genomic DNA was extracted from two representative isolates. The ITS region of rDNA was amplified using the ITS6/ITS4 primer pair and sequenced (GenBank KU647271 and KU647272). BLAST searches showed 99 to 100% identity to P. chlamydospora isolates, including the type isolate P236 (99% identity) (AF541900) (Hansen et al. 2015), deposited in GenBank and Phytophthora-ID databases, which confirmed morphological identification. Primary roots of ten 1-year-old P. dulcis cv. Ferragnes seedlings were wounded with a scalpel, and mycelial disks (3 per plant) of P. chlamydospora grown on CA were placed under the cortical tissue, after removing 10 to 15 cm of soil around the root base. The inoculated and exposed roots were then covered with soil. P. chlamydospora caused severe wilt and browning of leaves within 1 and 2 months and extensive root necrosis and rot after 2 months of incubation in a greenhouse. During this period, soil was kept wet by watering plants daily as required. Koch’s postulates were satisfied after reisolating P. chlamydospora from symptomatic roots of inoculated plants. No disease occurred in 10 controls, similarly inoculated with sterile CA disks, and the pathogen was not recovered from these plants. P. chlamydospora has only rarely been recovered from several ornamental and woody species (Blomquist et al. 2012; Brasier et al. 2003; Ginetti et al. 2014), but not from fruit trees so far. To our knowledge, this is the first report of P. chlamydospora infection of almond, which represents a new host for this pathogen. This is also the first record of P. chlamydospora in Turkey. Within a month, all naturally infected almond trees in this orchard were collapsed and destroyed and the number of infected trees increased dramatically, indicating that it might be a significant threat to almond plantations and orchards, particularly on sites where excess soil water occurs periodically

First Report of Canker and Dieback Caused by Botryosphaeria dothidea on Apple in Turkey.

WOS: 000375634200040Apple is one of the most commercially profitable fruit crops in Turkey, and is grown on 150,847 ha with 2,889,000 tons of fruit produced annually. In June 2015, we observed trees with sunken and reddish-brown limb cankers. Blighted shoots had circular spots or blisters around lenticels with lesions extending along the entire branch, often leading to bark cracking. More than 20% of the 8-year-old apple trees (Malus domestica Borkh) in a 15-ha orchard (37°59ʹ29ʺ N; 38°02ʹ11ʺ E) near Malatya planted with ‘Golden Delicious’ were affected. Samples from the inner cambium from cankered branches were collected from declining trees, surface sterilized in 70% ethanol, plated on potato dextrose agar (PDA), and incubated at 22°C..

New disease caused by Neoscytalidium dimidiatum devastates tomatoes (Solanum lycopersicum) in Turkey

A novel disease of tomato (Solanum lycopersicum L.) was observed in the Southeast Anatolia Region of Turkey. Symptoms were blight of all aerial parts of the plant, including stems, branches, leaves, petioles, flowers and fruits, defoliation, root rot, inner stem necrosis, and plant death. The disease was found in 13.9% of surveyed fields, with an incidence varying from 3% to nearly 75% (average 21.2%) of the plants in symptomatic fields. The average severity of blight on stem in fields with the symptomatic plant surveyed was 1.4%. A Botryosphaeriaceae species, identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers using morphological and cultural features, was consistently isolated from symptomatic roots, inner stems, and blighted leaves, shoots, stems, fruits and flowers. The partial nucleotide sequence data for three gene loci, including nuclear rDNA internal transcribed spacer (ITS), large subunit (LSU) genes and the translation elongation factor 1-alpha (TEF-1?), confirmed the morphological identification. Furthermore, sequence data of actin genes from N. dimidiatum was, for the first time, deposited to the GenBank. Koch's postulates were fulfilled by testing the susceptibility of different tomato tissues (leaves, stems, inner stems and roots of tomato seedlings, and detached tomato fruits and flowers) to N. dimidiatum inoculation. To our knowledge, this is the first report of N. dimidiatum on tomato. © 2018 Elsevier Lt