First report of Neoscytalidium novaehollandiae associated with branch dieback on Japanese persimmon in Turkey
- PDF / 140,113 Bytes
- 2 Pages / 595.276 x 790.866 pts Page_size
- 100 Downloads / 222 Views
DISEASE NOTE
First report of Neoscytalidium novaehollandiae associated with branch dieback on Japanese persimmon in Turkey Emel Ören 1 & Gülden Koca 1 & Harun Bayraktar 2 Received: 9 January 2020 / Accepted: 11 June 2020 # Società Italiana di Patologia Vegetale (S.I.Pa.V.) 2020
Keywords Neoscytalidium novaehollandiae . Japanese persimmon . Dieback
Japanese persimmon (Diospyros kaki L.) is an economically important tree fruit crop in Turkey. In the summer of 2019, an unknown disease was noticed on about 7% of persimmon trees in a commercial orchard located in Adıyaman, Gölbaşı province, Turkey. Disease symptoms involved branch dieback, stem canker, dark black lesions on the peduncle, causing early fruit drop, and then fruit rot. Pycnidia appeared on branch canker and fruit surface. Diseased tissues from branches and fruits were surface disinfected in 2% NaOCl for 2 min, rinsed with water and plated onto potato dextrose agar (PDA) with 0.1 g L− 1 streptomycin sulfate. The plates were incubated for 7 days at 23 °C in dark. Neoscytalidiumlike fungi were consistently isolated from the symptomatic tissues. The fungi isolated showed an abundant white mycelium that turned dark grey to black. Arthroconidia forming in singly or arthric chains in aerial mycelium that were dark brown, thick-walled, disarticulating, cylindrical to oblong, 0 to 1 septate, 5.9 to 7.3 × 3.6 to 4.3 µm. Pycnidia forming on sterilized pine needles placed on the surface of 2% water agar that were black, stromatic, semi-immersed, up to 160 µm diameter and long necked. Conidia were ellipsoidal to oval with rounded apices, initially hyaline, becoming sepia, 0-1-septate or 2-septate, 10.2 to 13.5 × 4.0 to 5.0 µm. The fungus was identified as Neoscytalidium novaehollandiae Pavlic, T.I. Burgess & M.J. Wingf. based on the description of Phillips et al. (2013). To confirm the identity of the representative isolates, the regions of the internal transcribed spacer (ITS) and translation elongation factor 1-α (EF1-α) were amplified
with primers ITS1/ITS4, EF1-728F/EF1-986R and deposited in GenBank (Accession Nos. ITS: MN905340, MN905341, EF1-α: MN911285, MN911286). Blast analysis was 100% (ITS, NR111260) and 99.3% (EF1-α, EF585574) identical to the reference Neoscytalidium novaehollandiae WAC12691. The isolates TP3 and TP4 were deposited in Ankara University Culture Collection with accession numbers AUZF-1068-69. Koch’s postulates were completed by inoculating branch segments at 30 cm in length from 5-year-old healthy plants. The outer bark at the inoculation point was surface disinfected with 70% ethanol and a wound of 5 mm was created in the center of each branch segment using a cork borer. A mycelial plug (5 mm in diameter) taken from the margin of an actively growing colony of the isolate TP4 was applied on the wounded surface. Inoculation wounds were wrapped with Parafilm and the branch segments were incubated at 23 °C in moist chambers. Control plants were inoculated with sterile PDA plugs. Four weeks after inoculation, dark brown necrotic lesions appea
Data Loading...
