Articles
EFFECT OF SALINITY ON THE YIELD AND QUALITY OF NORMAL AND NON-RIPENING MUTANT TOMATOES *)
Article number
190_17
Pages
175 – 182
Language
Abstract
A mutation of tomatoes that prevents the fruit from ripening at the expected time is known as ‘non-ripening’ (nor). This character has been introduced by a backcross programme into two contrasting tomato cvs., Ailsa Craig and Moneymaker.
Homozygous lines isogenic with each cv. were grown under glasshouse conditions together with parental material in a replicated trial.
The treatments consisted of adding 500ml per day of ½% NaCl, 1% NaCl, 15% sea water, 30% sea water, or a water control to plants growing in separate volumes of a peat-loam mix, starting with the anthesis of the first flower.
Normal liquid feeding with major and minor nutrients was continued throughout the trial.
When fruit from the normal lines were ripe, they were picked and analysed for a wide range of physical and chemical attributes of fruit maturity and quality.
At the same time, fruit from the isogenic mutant lines were also picked and tested in the same manner.
Salt-treatment speeded up the ripening up the normal cvs., reduced fruit weight for all four lines and increased the dry matter, electrical conductivity of the sap, also the titratable acidity, reducing sugar, sodium and chloride levels.
Activity of the softening enzyme, poly-galacturonase, was not affected.
The mutant lines containing the nor alleles, which ripen only very slowly unless subjected to stress conditions, gave indications of beginning to ripen at the time of sampling.
All lines grown under saline conditions possessed excellent flavour when ripe.
While it is possible to grow tomatoes under fairly severe salinity conditions, this results in the fruit weight being reduced to about half the normal figure, but the compositional quality of the resulting crop is exceptional.
High salinity partially over-comes the inhibition of ripening that the nor alleles induce.
Homozygous lines isogenic with each cv. were grown under glasshouse conditions together with parental material in a replicated trial.
The treatments consisted of adding 500ml per day of ½% NaCl, 1% NaCl, 15% sea water, 30% sea water, or a water control to plants growing in separate volumes of a peat-loam mix, starting with the anthesis of the first flower.
Normal liquid feeding with major and minor nutrients was continued throughout the trial.
When fruit from the normal lines were ripe, they were picked and analysed for a wide range of physical and chemical attributes of fruit maturity and quality.
At the same time, fruit from the isogenic mutant lines were also picked and tested in the same manner.
Salt-treatment speeded up the ripening up the normal cvs., reduced fruit weight for all four lines and increased the dry matter, electrical conductivity of the sap, also the titratable acidity, reducing sugar, sodium and chloride levels.
Activity of the softening enzyme, poly-galacturonase, was not affected.
The mutant lines containing the nor alleles, which ripen only very slowly unless subjected to stress conditions, gave indications of beginning to ripen at the time of sampling.
All lines grown under saline conditions possessed excellent flavour when ripe.
While it is possible to grow tomatoes under fairly severe salinity conditions, this results in the fruit weight being reduced to about half the normal figure, but the compositional quality of the resulting crop is exceptional.
High salinity partially over-comes the inhibition of ripening that the nor alleles induce.
Publication
Authors
A.R. Sharaf, G.E. Hobson
Keywords
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