ISHS Acta Horticulturae 789: XV Meeting of the EUCARPIA Tomato Working Group
GENETIC STUDY ON PROLONGED FRUIT LONGEVITY IN TOMATO (LYCOPERSICON ESCULENTUM MILL.) LINES |
| Authors: | B. Atanassova, E. Balacheva, E. Molle, HR. Georgiev |
| Keywords: | long shelf life, genetic variability, additive gene effects |
| Abstract:
The prolonged longevity or long shelf life is an important characteristic of the tomato fruit. However, once it was considered as a trait of primary importance, now it is not appreciated if not combined with good flavor and/or texture. One way to develop hybrids that meet market requirements for quality and fruit firmness under field conditions and subsequent postharvest operations and marketing is the search for parental lines on the basis of interspecific hybridization. The present study was designed to evaluate the genetic control of the prolonged fruit longevity in three tomato lines including in their pedigrees Lycopersicon chilense and L. pimpinellifolium. Despite the tender fruit pericarp, they all possessed fruit firmness and prolonged shelf life. The three genotypes differed, however, in the way that fruit longevity character was expressed. Fruits of Ch 21 (including in its pedigree L. chilense) and B317 (including in its pedigree L. chilense and L. pimpinellifolium) were very firm and showed longer shelf life than that of St 9, but tended to decay when softening. Fruits of St 9 (including in its pedigree L. pimpinellifolium) were more fleshy, softened more rapidly, but then softening tended to dry and began to decay 8–12 days later than those of Ch 21 and B 317. Preliminary studies on F1, F2 and BC generations including the three genotypes showed that the control of the prolonged fruit longevity was polygenic. Hence, the study was performed on a diallel cross, (reciprocal crosses not included) between the four genotypes characterized by relatively prolonged longevity of the fruits and another two not possessing this character. The analysis of the results obtained showed that additive gene effects predominated in the genetic control of the character “number of days to 50% discarded fruits”. Heterotic performance concerning this character was evaluated in 20% of the F1 crosses studied. All this provided evidence that the three lines may be employed in breeding programs aiming at the development of tomato hybrids characterized by good flavor and market quality. | |
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