ABSTRACT
The development of varieties with a high content of antioxidant compounds, such as carotenoids, has become a major focus in the marketing of tomato. Several mutants have been used in the development of high pigment varieties, but the significant influence of the environment on carotenoid content and the presence of negative side effects in vegetative growth and yield have limited the success of these variants. Consequently, the identification of alternative sources of variation in the quest for high carotenoid content is ongoing. In this study, 12 accessions of Solanum lycopersicum (including the former var cerasiforme) and S. pimpinelifolium have been evaluated in three different environments: open field and glasshouse cultivation at two sites. Three accessions (BGV6195 of S. pimpinellifolium, LA1423 of the former var cerasiforme and LA3633 a possible hybrid between S. pimpinellifolium and S. lycopersicum) showed outstanding and stable lycopene content, that doubled in all three environments the content of the positive control LA3538, with the high pigment-1 mutation (hp1). In addition, accession CATIE14812 would also be interesting as regards improvement of -carotene content. These materials offer new opportunities in the development of tomato varieties with enriched and reliable carotenoid content and the close taxonomic relationship of these accessions with cultivated tomato will facilitate their use in breeding programs.
Subject(s)
Antioxidants , Carotenoids , Solanum lycopersicum , Selection, Genetic , Agriculture , Pigments, Biological , Crops, AgriculturalABSTRACT
The development of varieties with a high content of antioxidant compounds, such as carotenoids, has become a major focus in the marketing of tomato. Several mutants have been used in the development of high pigment varieties, but the significant influence of the environment on carotenoid content and the presence of negative side effects in vegetative growth and yield have limited the success of these variants. Consequently, the identification of alternative sources of variation in the quest for high carotenoid content is ongoing. In this study, 12 accessions of Solanum lycopersicum (including the former var cerasiforme) and S. pimpinelifolium have been evaluated in three different environments: open field and glasshouse cultivation at two sites. Three accessions (BGV6195 of S. pimpinellifolium, LA1423 of the former var cerasiforme and LA3633 a possible hybrid between S. pimpinellifolium and S. lycopersicum) showed outstanding and stable lycopene content, that doubled in all three environments the content of the positive control LA3538, with the high pigment-1 mutation (hp1). In addition, accession CATIE14812 would also be interesting as regards improvement of -carotene content. These materials offer new opportunities in the development of tomato varieties with enriched and reliable carotenoid content and the close taxonomic relationship of these accessions with cultivated tomato will facilitate their use in breeding programs.(AU)
Subject(s)
Solanum lycopersicum , Antioxidants , Carotenoids , Selection, Genetic , Crops, Agricultural , Agriculture , Pigments, BiologicalABSTRACT
Growing evidence suggests that the phytohormone abscisic acid (ABA) plays a role in fruit development. ABA signaling components of developmental programs and responses to stress conditions include the group of basic leucine zipper transcriptional activators known as ABA-response element binding factors (AREBs/ABFs). AREB transcription factors mediate ABA-regulated gene expression involved in desiccation tolerance and are expressed mainly in seeds and in vegetative tissues under stress; however, they are also expressed in some fruits such as tomato. In order to get an insight into the role of ABA signaling in fruit development, the expression of two AREB-like factors were investigated during different developmental stages. In addition, tomato transgenic lines that overexpress and downregulate one AREB-like transcription factor, SlAREB1, were used to determine its effect on the levels of some metabolites determining fruit quality. Higher levels of citric acid, malic acid, glutamic acid, glucose and fructose were observed in SlAREB1-overexpressing lines compared with those in antisense suppression lines in red mature fruit pericarp. The higher hexose concentration correlated with increased expression of genes encoding a vacuolar invertase (EC 3.2.1.26) and a sucrose synthase (EC 2.4.1.13). No significant changes were found in ethylene content which agrees with the normal ripening phenotype observed in transgenic fruits. These results suggest that an AREB-mediated ABA signal affects the metabolism of these compounds during the fruit developmental program.