Premium
Induction of Verticillium wilt disease symptoms in detached shoots of resistant and of susceptible tomato plants
Author(s) -
BLACKHURST FRANCES M.
Publication year - 1963
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1963.tb03729.x
Subject(s) - shoot , wilting , biology , verticillium wilt , pectinase , inoculation , verticillium , horticulture , xylem , botany , enzyme , biochemistry
SUMMARY Induction of disease symptoms and water loss from detached shoots placed in cell‐free filtrates from cultures of Verticillium albo‐atrum and dilute solutions of substances of high molecular weight have been studied. There was no difference between the effect of these solutions on resistant and on susceptible plants. Freezing and heating decreased the effect of culture filtrates in reducing water loss and causing wilt. Solutions of pectic substances as dilute as 30 p.p.m. induced wilting and were 30 times as effective as solutions of certain polysaccharides in reducing water loss. Filtrates from pectate cultures had a very high polygalacturonase activity and when diluted up to 250 times induced typical disease symptoms in leaves of cut shoots in 70 hr.; this property was lost on autoclaving. No difference was found in the composition of xylem exudates from resistant and susceptible plants. Filtrates from cultures on a synthetic plant‐sap medium to which insoluble plant material from resistant and from susceptible plants had been added were found to have different effects on cut shoots; this may depend on the different polygalacturonase activities of these filtrates. Studies on water loss from shoot‐inoculated resistant and susceptible plants showed that the water loss/fresh weight was reduced to almost the same extent in resistant and susceptible shoots, despite the fact that resistant plants developed only mild symptoms of disease. Resistant plants were found to be more drought‐resistant than susceptible plants.