ISHS Acta Horticulturae 277: III International Symposium on Processing Tomatoes
STATE AND PROSPECTS OF BREEDING AND GENETIC METHODS FOR TOMATO VARIETIES DESIGNED FOR INDUSTRIAL PROCESSING |
| Authors: | V.K. Andryushchenko, M.V. Shilina |
| Abstract:
The breeding and development of up-to-date technologies for raising tomatoes designed for canning - have their origin in the pre-industrial stage of the establishment of the quality of the produce. It is important already at this stage, i.e. at the level of creating a new variety - to maximally guarantee the output of high-qualtity tomato canned products. The implementation of this programme is facilitated by clearly defined demands to new varieties for processing - currently being developed. The development of a model variety with a preset genetic potential for expressing commercially valuable traits - is a major stage of the breeding process. The breeding of a tomato designed for processing - suitable for mechanized cultivation and once-over harvesting requires the development of varieties with a compact determinate type of bush; uniform establishment of yield (yielding not less than 50 tons/ha), preserving a high marketability of fruit in the process of their overmaturation (20–30 days); jointless association with the truss (j-2in, j-2); a minimum contact between fruit and soil surface (the establishment of not less than 95% of fruit above the soil surface); an optimum ratio of fruit mass to vegetative mass (1.0–1.5:1.0); having fruit of high hirmness (the specific effort of crushing - not less than 80g/g of fruit mass; fruit cracking under uniform irrigation - absent; with optimal effort of detaching the fruit from the pedicel (1.0 – 2.5 kg) or specific effort of detaching the fruit from the fruit stem (25 – 35 g/g of fruit mass); the effort required to tear away the fruit-stem from the plant (in the case of the commom joint) should surpass the effort for detaching the fruit from the fruit-stem by 0.5–0.6 kg; with round to oval, oval or plum-shaped type of fruit (fruit with index 1.2–1.8 would be more desirable); having a fruit mass of 45–80 gr. (depending on the purpose); with fruit without hollows or with small ones; with thickness of pericarp and cavity walls - over two cm; having small seeds and quantities of not more than 0.1% of fruit mass; with smooth or slightly faceted fruit surface; with the force of perforating the skin being not less than 130–150g)mm2; with a small space of attachment of the fruit to fruit-stem; with a specific mass of mature fruit - over 1gr/cm3; with a bright red uniform fruit colour - without green hues (lycopene content in fruit flesh not less than 5–7mg.%, and carotene content - in the range of 1.0–1.2mg.%); with a minimum portion of a fibro-vascular bundle in fruit; with the portion of raw waste under processing being not more than 6%; having an optimal viscosity of' juice and content of alcohol-insoluble substances; with a content of extractive dry matter - not less than 5.5%, sugars - not less than 30%, titratable acids 0.5–0.7%, ascorbic acid - 25–30mg.%, pectins - not more than 250mg.%, cellulose - not exceeding 0.3%, mineral salts in the range 0.5%, pH - not above 4.2, sugar-acid coefficient not less than 7.0, ratio of soluble to non-soluble dry matter - not less than | |
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