Development of Pseudocercosporella herpotrichoides (Fron) Deighton var. herpotrichoides and var. acuformis on Wheat Plants Measured by ELISA

Abstract

Using the ELISA method, the development of Pseudocercosporella herpotrtchoides var. herpotrichoides and var. acuformis in a susceptible cultivar of winter wheat was compared under controlled and held conditions. In the greenhouse, var. acufornis grew less vigorously, was slower in penetrating the coleoptile and the successive leaf sheaths and in colonizing the stem tissue than var. herpotrichoides. In the field, these differences were confirmed on the last leaf sheaths and the stem. At ripening stage, however, identical ELISA values were measured for both varieties. Moreover, a significant variation was observed between the individual isolates of each variety. Comparison of the effect of both varieties of P. herpotrichoides on 20 wheat cultivars characterized by different resistance levels showed significant interactions. The cultivars carrying the Pch‐1 gene always remained the less diseased genotypes. In general, var. acuformis developed less antigen in the cultivars than var. herpotrichoides. It is concluded, that in tests for resistance to P. herpotrichoides mixtures of many highly pathogenic isolates of both fungus varieties should be used. Less complex mixtures or single isolates may result in wrong estimates of resistance.

Differentiation and quantification of the cereal eyespot fungi Tapesia yallundae and Tapesia acuformis using a PCR assay

“…herpotrichoides (presumed to be T. yallundae) isolates colonized hosts faster than var. acuformis (presumed to be T. acuformis) isolates (Poupard et al, 1994). The results of the glasshouse test indicate that the relationship between fungal DNA content and visual disease is also worthy of further investigation, as the results presented here suggest that the DNA content of wheat seedlings with similar disease scores might differ greatly depending on the species of Tapesia involved.…”

Development ofOculimacula yallundaeandO. acuformis(eyespot) on leaf sheaths of winter wheat in the UK in relation to thermal time

“…In contrast, use of chronological time (e.g. days after sowing) to describe eyespot development (Fitt et al ., 1988; Goulds & Fitt, 1990a, 1991; Poupard et al ., 1994) is less accurate, because there may be prolonged periods during winter in the UK when temperatures are too low for organisms to grow. A base temperature of 0°C for pathogen growth was assumed throughout these studies, because no detailed studies have been done in planta to examine whether OY and OA grow at ambient temperatures below 0°C, as has been done with Mycosphaerella graminicola infecting wheat leaves (Lovell et al ., 2004a).…”

“…Thermal time (accumulated °C days) provides a more appropriate scale than a scale based on days from sowing, and has previously proved helpful in describing the progress of foliar disease of cereals (Beresford & Royle, 1988; Lovell et al ., 2004a). However, only days after sowing has previously been used as a measure to compare progress in stem‐base tissues of eyespot caused by OY and OA (Goulds & Fitt, 1990a; Poupard et al ., 1994).…”

Advances and Prospects in Wheat Eyespot Research: Contributions from Genetics and Molecular Tools

“…The method was applied to study the stability of eyespot response measured by ELISA in 20 wheat cultivars studied in six environments (Lind et al. 1994), relative rates of O. yallundae and O. acuformis development in wheat (Poupard et al. 1994), variation in eyespot response in Pch1 ‐carrying genotypes (Lind 1999) and quantitative inheritance of eyespot resistance in diallel crosses (Lind 2000).…”

“…Differential response to the two Oculimacula species is a related subject more often discussed in recent publications. Poupard et al. (1994) showed that cultivars with Pch1 (‘Roazon’ and ‘Rendezvous’) carried much less O. acuformis material as measured by ELISA than O. yallundae material, in the same experimental field and the same environmental conditions where plants had been inoculated separately with isolates of the two species.…”