Gaps and perspectives of pathotype and race determination in Golovinomyces cichoracearum and Podosphaera xanthii

Abstract

Golovinomyces cichoracearum and Podosphaera xanthii (family Erysiphaceae) are the most important species causing cucurbit powdery mildew (CPM), a serious disease of field and greenhouse cucurbits. Both species are highly variable in their pathogenicity and virulence, as indicated by the existence of large number of different pathotypes and races. Various independent systems of CPM pathotype and race determinations and denominations are used worldwide. CPM pathotype identification is based on intergeneric and interspecific differences in host-CPM interactions. The most commonly used set of CPM pathotype differentials includes one genotype from four species representing three agriculturally important cucurbit genera plus two genotypes from a fifth species, melon Cucumis melo L. CPM races are characterized by specialization on different cultivars or lines of one host species and have, to date, been differentiated only on melon (C. melo L.). The most frequently used set of melon differentials includes 11 genotypes that can differentiate CPM races originating from melon and other cucurbits, e.g., cucumber, Cucurbita spp., and watermelon. In this paper, we critically review the current state, gaps, and perspectives in our understanding of pathogenicity variation in these two CPM pathogens at the pathotype and race levels.

Effect of extreme temperatures on powdery mildew development and Hsp70 induction in tomato and wild Solanum spp.

“…Lactuca spp.-Golovinomyces cichoracearum; Solanum spp.-O. neolycopersici; cucurbitaceous plants-Golovinomyces orontii, Podosphaera fusca; sweet cherry-Podosphaera clandestina; Cohen 1993;Mieslerová et al 2000;Olmstead et al 2000;Lebeda et al 2011Lebeda et al , 2013. In most of the studied pathosystems, results obtained from the leaf disc assay correlated well with results obtained with whole plants, indicating that the disc assay may accurately predict responses of whole plants.…”

Genetic structure and phylogeny of Italian and Czech populations of the cucurbit powdery mildew fungus Golovinomyces orontii inferred by multilocus sequence typing

“…These elements cause mutations and allow the rapid rise of favourable genotypes. This could be also due to the selection pressure caused by the current management practices used for the control of powdery mildews, such as resistant varieties and fungicide application (Lebeda et al ., ). These methods impose a strong selection on the pathogen populations, leading to permanent production of new genotypes (McDonald & Linde, ).…”

Detection of Golovinomyces orontii using species-specific primers and high-resolution melting analysis

“…The development of disease symptoms depends on humidity, light intensity, temperature, and inoculum concentration. Golovinomyces orontii has previously been reported as the causal agent of powdery mildew disease in different European countries, such as Italy (Branzanti and Brunelli 1987), Czech Republic (Lebeda et al 2011), Hungary (Nagy and Kiss 2006), Bulgaria (Velkov and Masheva 2002), and Ukraine (Tomason and Gibson 2006). Considering the economic losses caused on different cucurbit crops by G. orontii and the limited options available for pathogen suppression in the later stages of disease progress, accurate and rapid detection of the pathogen is vital for cucurbit crops production.…”