ISSN:
1573-5036
Keywords:
Botrytis cinerea
;
Lycopersicon esculentum
;
nitrogen availability
;
pathogen resistance
;
relative growth rate
;
α-tomatine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The aim of this study was to investigate the effect of nitrogen availability on susceptibility of tomato leaves to the fungal pathogen Botrytis cinerea. Plants with varying nitrogen availability were grown by adding N daily in exponentially increasing amounts to a nutrient solution at different rates. Leaves of plants grown at low nitrogen availability had a high leaf C/N ratio (21 g g-1) and were about 2.5 times more susceptible to primary lesion formation by B. cinerea compared to plant grown at high nitrogen availability, which had a low leaf C/N ratio (11 g g-1). Leaf C/N ratio accounted for 95% of variation in susceptibility. This relationship between C/N ratio and susceptibility persisted when plants were grown with exponential P addition and optimal N supply, and was thus independent of plant growth rate or related factors. We could not explain the effect of nitrogen availability by variation in the most obvious N-based resistance compound α-tomatine because more susceptible leaves with a high C/N ratio contained more α-tomatine. These leaves also contained more soluble carbohydrates. The level of soluble carbohydrates correlated positively with susceptibility, independent of the growth method. We therefore suggest that the effect of N availability on susceptibility must be explained by variation in levels of soluble carbohydrates and speculate about the role of these carbohydrates in the infection process.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004661913224
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