Page 23 - Volume 2,Issue 2, July 2009

Laboratory of Mycology, Department of Phytopathol-

ogy, Benaki Phytopathological Institute, 8 St. Delta str.,

GR-145 61 Kifissia (Athens), Greece.

e-mail:

kalomoiraelena@yahoo.gr

Hellenic Plant Protection Journal

2:

67-69, 2009

SHORT COMMUNICATION

Occurrence of

Phomopsis

sp. on kiwi plantations in Northern

Greece

K. Elena

Summary

Symptoms of severe

shoot cankers with internal wood discoloration were observed in

commercial kiwi plantations, cv. Hayward, in the region of Skydra, Northern Greece. Additional symp-

toms included browning of the abaxial surface of leaves, necrotic, slightly depressed lesions with in-

ternal rot on fruit and peduncle necrosis resulting in formation of smaller fruit. The fungus

Phomopsis

sp. was consistently isolated from the diseased tissues. In artificial inoculations of shoots and detached

fruit, symptoms of the disease similar to those occurring in nature (internal wood discoloration and

fruit rot) were reproduced.

on PDA dishes at 22°C. One droplet (20 μl) of

the conidial suspension was placed on top

of each shoot or fruit wound (8 mm-diam-

eter). In addition, an 8 mm in diameter disc

of bark was removed from each shoot with

a cork borer and a mycelial disk (8 mm in di-

ameter) was inserted with the mycelium fac-

ing the shoot. Fruit were inoculated by in-

serting the mycelial disk 3-4 mm under the

skin. Wounded shoots were wrapped with

Parafilm one hour after inoculation, where-

as fruit were placed in polyethylene bags

immediately after inoculation. In anoth-

er experiment, unwounded fruit were sim-

ilarly inoculated with a conidial suspension

or a mycelial disk.

Control shoots and fruit

were treated with sterile distilled water or

sterile PDA disks. For each treatment, seven

shoots and/or fruit with two wounds each

were used as replicates. Inoculated and con-

trol shoots and fruit were incubated at 20-

25°C. Ten and 15 days after inoculation, dis-

ease symptoms were observed on wounded

shoots and fruit by means of wood discol-

oration and fruit rot, respectively and

Pho-

mopsis

sp. was re-isolated from the artificial-

ly inoculated shoots and fruit

.

No symptoms

were observed on unwounded fruit or con-

trol shoots and fruit.

The fungus has been reported to cause

In September 2008, severe shoot necroses

of kiwi plants (

Actinidia deliciosa

C.F. Liang.

& A.R. Ferguson), cv. Hayward, with inter-

nal wood discoloration (Figure 1) were ob-

served in commercial plantations in the re-

gion of Skydra, Northern Greece. Fruit rots

commencing from necrotic, slightly de-

pressed lesions (Figure 2), peduncle necro-

sis bearing fruit of reduced size and brown

discoloration of the abaxial surface of the

leaves, were also observed. Isolations were

made from diseased tissues on PDA medium

in order to identify the causal agent. Black

pycnidia were produced in culture with two

types of hyaline conidia: α-conidia, ellipsoid,

one-celled, 5-8.5 × 2-3.5 μm and β-conidia,

filiform, curved or bent, one-celled, 17.5-27.5

x 1.3 μm (Figure 3). The cultural and mor-

phological characteristics of the isolates fit-

ted the description of

Phomopsis

sp.

Pathogenicity was determined by wound-

inoculating shoots of 2-year-old potted kiwi

(cv. Hayward) plants and detached fruit with

either a conidial suspension (10

6

conidia/ml)

or a mycelial disk (8 mm in diameter), both

deriving from 3-week-old cultures grown