Differential sensitivity of Verticillium dahliae, V. albo-atrum, and V. nigrescens to benomyl

Abstract

HALL, R. 1975. Differential sensitivity of Vi.rticillirrm dnkline, V. nlbo-ntrrrtn, and V . nigrescetls to benornyl. Can. J. Bot. 53: 452455.Small but significant (P = 0.05) differences in sensitivity to benornyl in vitro were observed among collections of Verticillirrtrr rlrrlrlirrp (21 isolates), V . nlbo-ntrrrtn (9 isolates), and V. trigre.scet~s (8 isolates). Mean species effective dose (milligrams per liter) (ED,,) values were, respectively, 0.36, p.26, and 0.19 (significantly different from one another). The corresponding mean species values for the slope of the probit inhibition -log dose curve were 10.55, 12.55'(not .significantly different), and 6.87 (significantly different). However, positive identification of an isolate by its ED,, value or the slope of the dose-response curve was not possible because of overlap in the range of values within species. HALL, R. 1975. Differential sensitivity of Verficilliritn rlolrlirre, V . o l h o -n r~~r~t ?~, and V . t~igrescetl~ to benornyl. Can. J. Bot. 53: 452455. Des differences faibles rnais significatives ( P -0.05) dans la sensibilite au bknornyl in vitro ont ete obse~.vees entre des collections de Verficillirrt,~ rlrilrlirre (21 souches), V . rrlho-atrrlnl (9 souches) et V . tlig~~e.sc~etls (8 souches). Les valeurs rnoyennes (rnilligrarnrnes par litre) pour la DEso des troi's especes etaient respectivernent 0.36, 0.26 et 0.19: ces trois valeurs sont significativernent differentes I'une de I'autre. Les valeurs rnoyennes correspondantes pour la pente de la courbe de I'inhibition en valeurs probit en fonction du log de la dose ktaient respectivernent de 10.55, 12.55 (non significativernent difikrentes) et 6.87 (significativernent ditrkrente) pour les trois espkces. Cependant, il s'est avere impossible d'identifier les souches individuelles par leur valeur DE5, ou par la courbe de la reponse en fonction de la dose, i cause du recoupernent entre les diverses valeurs chez les espkces. [Traduit par le journal]

Behaviour in vitro and in vivo of a Benomyl Insensitive Strain of Verticillium dahliae

“…Insensitive strains are readily produced in the laboratory (HASTIE and GEORGOPOULOS 1971, VAN TUYL 1975), have also been found in the field (BOLLEN and SCHOLTEN 1971, DEKKER 1975), and there is good evidence that they occur in populations of pathogens not known to have been exposed to the fungicides (SCHREIBER and TOWNSEND 1976, WuEST et al, 1975). Insensitive strains of V. dahliae have also been isolated in the laboratory from sensitive strains (HALL 1975).This paper describes the characteristics and behaviour of a strain of V. dahliae highly insensitive to benomyl and related substances.…”