Observation sur la pénétration de Cercosporella herpotrichoides Fron, agent du piétin-verse, dans l'épiderme de quelques espèces de Triticum sensibles et résistantes

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

“…These variations were probably caused by various factors, such as host and pathogen genotypes and experimental conditions. For instance, it is known that eyespot development is influenced by temperature (Scott, 1971; Higgins & Fitt, 1985; Wan et al ., 2005), which was lower here (9°C) than in the studies of Khan et al . (1986) and Murray & Ye (1986) (10°C and 13°C, respectively).…”

“…This lengthy time could have resulted from the partial resistance conferred by the Pch1 gene. In their study, Khan et al . (1986) observed that penetration occurred at 15 d.a.i.…”

“…The timing of O. yallundae development observed during this phase differed from that described in previous studies, since penetration in the coleoptile of a host carrying the Pch1 gene, observed here at 21 d.a.i., was reported to occur at 30 d.a.i. by Khan et al . (1986) and at 4 d.a.i.…”

“…Following conidial germination on the coleoptile, O. yallundae forms appressoria and hyphae that ramify and proliferate on the plant surface, leading to the development of a mycelial network (Defosse, 1966; Daniels et al ., 1991). Multicellular stromas were reported to form from the surface mycelium (Khan et al ., 1986). Direct penetration into the coleoptile occurs from appressoria, allowing the pathogen to grow intramurally (Daniels et al ., 1991) and intracellularly (Soulié et al ., 1985) into the coleoptile, and to reach the first leaf sheath.…”

Eyespot (Pseudocercosporella herpotrichoides) epidemiology in relation to prediction of disease severity and yield loss in winter wheat—a review

“…Whilst the process of infection by P. herpotrichoides on wheat has been studied in detail (Defosse & Dekegel, 1974;Fehrmann & Mendgen, 1975;Khan et al, 1986), there has been little work to establish the optimum and range of conditions under which infection occurs. In experiments in controlled-environment rooms and glasshouses, inoculated plants have developed lesions at temperatures from 6 to 18 C (Lange-de la Camp, 1966bCamp, , 1967Scott, 1971;Bateman & Taylor, 1976a, 1976bHiggins & Fitt, 1985a, 1985b, which implies that infection can take place over this range.…”