Articles
INTERACTION BETWEEN FUSARIUM WILT RESISTANCE GENES IN TOMATO AND FUSARIUM OXYSPORUM F. SP. LYCOPERSICI RACES 1 AND 2
Article number
1069_10
Pages
77 – 80
Language
English
Abstract
Fusarium wilt of tomato, caused by the soil-borne pathogen Fusarium oxysporum f. sp. lycopersici (Fol), is an important disease responsible for significant economic losses.
Resistant cultivars introgressed with the I, I-2 and/or I-3 resistance genes have become the most effective method for controlling this disease.
It has been reported that the Avr1 gene of certain isolates of Fol race 1 are able to inhibit the effectiveness of the I-2 and I-3 genes to provide resistance to race 1. In this study, the reaction of seven tomato genotypes containing various combinations of I and/or I-2 was evaluated on plants inoculated with Fol races 1 and 2 individually or jointly.
All genotypes containing I were resistant to race 1, and all genotypes lacking I-2 were susceptible to race 2. Inbred lines containing only I were susceptible in both the race 2 inoculation and the combined races 1 and 2 inoculation; although the percentage of susceptible plants in the combined inoculation were significantly less than with race 2 alone.
This reduction may have been due to a number of factors including the competition between the races or possibly from the I gene by Avr1 interaction.
Inbred lines containing I and I-2 were resistant in the race 2 inoculation and also in the combined races 1 and 2 inoculation.
Thus the reported suppression of I-2 by the race 1 Avr1 gene when both races 1 and 2 were present was not observed in this study.
Resistant cultivars introgressed with the I, I-2 and/or I-3 resistance genes have become the most effective method for controlling this disease.
It has been reported that the Avr1 gene of certain isolates of Fol race 1 are able to inhibit the effectiveness of the I-2 and I-3 genes to provide resistance to race 1. In this study, the reaction of seven tomato genotypes containing various combinations of I and/or I-2 was evaluated on plants inoculated with Fol races 1 and 2 individually or jointly.
All genotypes containing I were resistant to race 1, and all genotypes lacking I-2 were susceptible to race 2. Inbred lines containing only I were susceptible in both the race 2 inoculation and the combined races 1 and 2 inoculation; although the percentage of susceptible plants in the combined inoculation were significantly less than with race 2 alone.
This reduction may have been due to a number of factors including the competition between the races or possibly from the I gene by Avr1 interaction.
Inbred lines containing I and I-2 were resistant in the race 2 inoculation and also in the combined races 1 and 2 inoculation.
Thus the reported suppression of I-2 by the race 1 Avr1 gene when both races 1 and 2 were present was not observed in this study.
Publication
Authors
M. Niederheitmann, J. Gonçalves, A. Mat, T. Bentley , J. Green
Keywords
Solanum lycopersicum L., fungus-plant relation, fungus suppression, strains coexistence, gene-for-gene theory
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