Emergence of new virulence in Plasmopara halstedii (sunflower downy mildew)

Sakr, N. (2015) Emergence of new virulence in Plasmopara halstedii (sunflower downy mildew). Acta Phytopathologica et Entomologica Hungarica, 50 (1). pp. 17-28. ISSN 0238-1249


Download (208kB) | Preview


The fast evolution of Plasmopara halstedii (downy mildew) remains a major risk for sunflower crop, as new races of the pathogen are bypassing the resistance of sunflower hybrids. In order to understand the processes which led a new virulence to appear in a local P. halstedii population, the genetic relationships were studied using 12 EST (Expressed Sequence Tag)-derived markers between five progeny isolates of races 300, 304, 314, 704 and 714 and two parental ones of races 100 and 710. All genetic analyses were carried out using five single zoosporangium isolates per P. halstedii isolate. There was no intra-isolate genetic variation among the seven pathogen isolates and five multilocus genotypes (MLG) were identified among the 35 P. halstedii single zoosporangium isolates. The single zoosporangium isolates of races 314, 704 and 714 had an intermediary genetic position between the single zoosporangium isolates of two parental isolates. The single zoosporangium isolates of three isolates of races 100, 300 and 304 were localized in the same genetic clade. Two genetic mechanisms could explain the emergence of new virulence in P. halstedii as a recombination between races and mutations in a clonal lineage.

Item Type: Article
Subjects: Q Science / természettudomány > QH Natural history / természetrajz > QH540 Ecology / ökológia
Q Science / természettudomány > QK Botany / növénytan > QK10 Plant physiology / növényélettan
Q Science / természettudomány > QL Zoology / állattan > QL01 Systematic zoology / állatrendszertan
Depositing User: Ágnes Sallai
Date Deposited: 04 Jul 2016 06:36
Last Modified: 04 Apr 2023 11:28

Actions (login required)

Edit Item Edit Item