Articles
INTROGRESSION OF RESISTANCE TO VERTICILLIUM DAHLIAE RACE 2 INTO PROCESSING TOMATO CULTIVARS IN CALIFORNIA
Article number
724_3
Pages
39 – 43
Language
English
Abstract
As early as in 1957 a new race of Verticillium dahliae was identified.
This race, designated race 2 is already well established in many countries.
Research over the last two decades has not revealed a source with a high level of resistance to race 2. The main goal of this work was to introgress the resistance to race 2 from the authors line Veda into open pollinated tomato cultivars, developed by the CTRI. Along with the introgression, several other field and greenhouse trials were carried out, aiming to challenge the Veda line with different race 2 pathotypes, and to confirm the mode of inheritance of the resistance when the line was inoculated with Californian isolates of the pathogen.
A standard root-dip technique was used to inoculate the seedlings.
The evaluation of all plant materials was based on foliar symptoms and vascular discoloration.
A classical backcross method was applied to introgress the resistance into CTRI cultivars.
The Veda line showed a high level of resistance in field and greenhouse trials when challenged with nine isolates from California.
The data confirmed previous results about the dominant inheritance of race 2 resistance in the Veda line.
Two CTRI cultivars ‘4863’ (VFFN) and ‘1056’ (VFFNPto) were chosen as a desirable background in which to introgress resistance to race 2. In 2004, the third backcross to CTRI lines was performed.
On completion of the backcross program, the resulting BC5S1 lines can be used as OP cultivars or can be easily developed into race 2 resistant processing tomato hybrids by commercial seed companies.
This race, designated race 2 is already well established in many countries.
Research over the last two decades has not revealed a source with a high level of resistance to race 2. The main goal of this work was to introgress the resistance to race 2 from the authors line Veda into open pollinated tomato cultivars, developed by the CTRI. Along with the introgression, several other field and greenhouse trials were carried out, aiming to challenge the Veda line with different race 2 pathotypes, and to confirm the mode of inheritance of the resistance when the line was inoculated with Californian isolates of the pathogen.
A standard root-dip technique was used to inoculate the seedlings.
The evaluation of all plant materials was based on foliar symptoms and vascular discoloration.
A classical backcross method was applied to introgress the resistance into CTRI cultivars.
The Veda line showed a high level of resistance in field and greenhouse trials when challenged with nine isolates from California.
The data confirmed previous results about the dominant inheritance of race 2 resistance in the Veda line.
Two CTRI cultivars ‘4863’ (VFFN) and ‘1056’ (VFFNPto) were chosen as a desirable background in which to introgress resistance to race 2. In 2004, the third backcross to CTRI lines was performed.
On completion of the backcross program, the resulting BC5S1 lines can be used as OP cultivars or can be easily developed into race 2 resistant processing tomato hybrids by commercial seed companies.
Authors
J. Stamova
Keywords
Lycopersicon esculentum, disease resistance, breeding
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