Abstract
About 10 years ago, a new apple disease spread in North
Italy, starting from Alto Adige, then in Trentino, Veneto,
Piedmont and Emilia-Romagna. The disease affects
leaves and fruits. Leaves show small circular brown
spots, sometimes with concentric ring and purple-red
halo, while fruits show rounded brown-black spots, often
centered on lenticels, sometimes with a reddish halo. These symptoms loook like the "Alternaria blotch"
(caused by Alternaria mali) but preliminary studies
showed that the strains of Alternaria isolated in Italy don't
belong to A. mali. Within the research project
PRIN, 204 strains of Alternaria spp. were isolated from
either leaves (40%) or fruits (60%) sampled in the most
important apple-growing areas of northern Italy, and
tested for pathogenicity. Different inoculation protocols
were used, with either conidia or cultural filtrate (autoclaved
or not), different inoculation methods on
wounded or unwounded fruits or leaves, and incubation
periods. Inoculation of drops of cultural filtrates on
wounded leaves provided consistent results; 84 and 27%
of the strains isolated from fruits and leaves were pathogenic,
respectively. Highest frequency of pathogenic
strains was observed in Piedmont (81% of strains) and
the lowest in Emilia-Romagna (17%). Based on a morphological
characterization, 17 out of 37 pathogenic
stains belonged to the Tenuissima species-group, 12 to
Gaisen, 4 to Alternata, 3 to Arborescens, and 1 to Armoraciae.
This study made it possible to develop an
efficient bioassay for pathogenicity of Alternaria strains
and increased knowledge about etiology of this new
apple disease which is spreading in North Italy.
Lingua originale | Inglese |
---|---|
pagine (da-a) | 216-216 |
Numero di pagine | 1 |
Rivista | CHIH WU PING LI HSUEH PAO |
Volume | 2013 |
Stato di pubblicazione | Pubblicato - 2013 |
Evento | 10th International Congress of Plant Pathology - Pechino Durata: 25 ago 2013 → 30 ago 2013 |
Keywords
- Alternaria
- apple disease