Oculimacula yallundae lifestyle revisited: relationships between the timing of eyespot symptom appearance, the development of the pathogen and the responses of infected partially resistant wheat plants

Abstract

Possible relationships between the timing of eyespot symptom appearance, the development of Oculimacula yallundae and the responses of infected wheat plants were investigated. By comparing, for 45 days after inoculation (d.a.i.), eyespotand mock-inoculated coleoptiles and leaf sheaths of a wheat line carrying the Pch1 partial resistance gene, this study showed that cell death, used as a criterion for symptom appearance, occurred on the first leaf sheath around 30 d.a.i. These results show that the wheat/ O. yallundae interaction is characterized by two distinct phases: the asymptomatic phase and the symptomatic phase. The possibility that O. yallundae should be considered hemibiotrophic rather than necrotrophic is discussed.

The 'Green Revolution' dwarfing genes play a role in disease resistance in Triticum aestivum and Hordeum vulgare

“…O. acuformis and O. yallundae infect the stem base of cereal hosts and present contrasting pathogenic lifestyles. The former is considered a necrotroph whilst there is evidence that the latter exhibits a short biotrophic phase of establishment before switching to necrotrophic nutrition ( Blein et al , 2009 ). Wheat GoF severe dwarfing mutant lines, Rht-B1c and Rht-D1c, showed significantly greater resistance to both O. acuformis and O. yallundae ( P <0.01 and P <0.05, respectively) compared with rht - tall lines ( Fig.…”

Differential effects of lesion mimic mutants in barley on disease development by facultative pathogens

“…collo - cygni , O . yallundae has a long period of asymptomatic colonization before the fungus enters the necrotrophic disease-causing phase ( Blein et al , 2009 ). Fusarium culmorum is also a hemibiotrophic fungus that causes disease in the ears, stems, leaves and roots of cereal plants ( Scherm et al , 2013 ).…”

Occurrence of Eyespot on Winter Wheat in the Central-Southern Region of Poland

“…A prevalence of O. acuformis and restricted occurrence O. yallundae may be related to the common use of carbendazim for controlling eyespot (Bateman 2002;Bierman et al 2002;Birchmore et al 1992;Blein et al 2009;Dayer et al 1995;Głazek et al 1993;Korbas et al 1999;Smith et al 1994).…”