GENETIC VARIATION AND MATING TYPES OF PODOSPHAERA XANTHII IN APULIA

Seventy-eight isolates of Podosphaera xanthii, one of the causal agents of cucurbit powdery mildew, were collected in Apulia (Southern Italy) from naturally infected leaves from 38 fields in different locations, hosting different cucurbit species. Isolates were crossed by pairing in dual cultures wi...

Full description

Saved in:
Bibliographic Details
Published in:Journal of plant pathology 2009-12, Vol.91 (4), p.S4.73-S4.73
Main Authors: Miazzi, M, Laguardia, C, Faretra, F
Format: Article
Language:English
Subjects:
Podosphaera xanthii
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Seventy-eight isolates of Podosphaera xanthii, one of the causal agents of cucurbit powdery mildew, were collected in Apulia (Southern Italy) from naturally infected leaves from 38 fields in different locations, hosting different cucurbit species. Isolates were crossed by pairing in dual cultures with each of two reference strains of known and opposite mating types and fertility was judged based on the appearance of cleistothecia and ascospores. Genetic variation was explored by random amplified polymorphic DNA (RAPD) analysis using 18 primers, which provided reproducible electrophoretic patterns. All the isolates belonged to a single mating type, which explains why cleistothecia of P. xanthii have never been found in Apulia. RAPD analysis yielded a total of 236 amplicons, 216 of which were polymorphic markers. A high degree of variation was observed since each isolate displayed a unique aplotype. Cluster analysis of RAPD data did not discriminate isolates on the ground of host plants, mating types, physiological races, and locations. This finding suggest the existence of an efficient source of variation in fungal populations, but the occurrence of sexual recombination is prevented by the apparent absence of one of the two mating types. Further investigations are needed to confirm these data. Furthermore, efficient measures should be taken to prevent the introduction of the P. xanthii mating type not yet present in the region.
ISSN:1125-4653