RESUMEN
Tomato (Lycopersicon esculentum Mill.) is an economically important and widely cultivated vegetable crop that is consumed both fresh and processed. The nutritional value of tomato fruits is related to the content of carotenoids, polyphenols, sugars, organic acids, minerals and vitamins. Currently, there is a growing interest in the qualitative and quantitative increase in the content of health-promoting compounds in tomato fruits. VIR Lycopersicon (Tourn.) Mill. genetic resources collection includes 7678 accessions of one cultivated and nine wild species, which in turn provides ample opportunities for searching for information on the variability of the content of biologically active substances and searching for sources with a high content of them in the gene pool. Our work presents the results of the study of 70 accessions of cultivated and wild tomato on the main biochemical characteristics: the content of dry matter, ascorbic acid, sugars, carotenoids, chlorophylls and anthocyanins. As the basis for the selection of accessions for the study, accessions with various colors of fruits, including new accessions with varying content of anthocyanin, were taken. As a result of this study, the amplitude of variability in the content of dry matter (3.72-8.88 and 9.62-11.33 %), sugars (1.50-5.65 and 2.20-2.70 %), ascorbic acid (12.40-35.56 and 23.62- 28.14 mg/100 g), titratable acidity (0.14-0.46 and 0.33-0.48 %), chlorophylls (0.14-5.11 and 2.95-4.57 mg/100 g), carotenoids (0.97-99.86 and 1.03-10.06 mg/100 g) and anthocyanins (3.00-588.86 and 84.31-152.71 mg/100 g) in the fruits of cultivated and wild tomatoes, respectively, was determined. We have determined correlations between the content of dry matter and monosaccharides (r = 0.40, p ≤ 0.05), total sugars (r = 0.37, p ≤ 0.05) and ascorbic acid (r = 0.32, p ≤ 0.05); the content of ascorbic acid and carotenoids (r = 0.25, p ≤ 0.05). A high dependence of the content of chlorophyll a and b among themselves (r = 0.89, p ≤ 0.05), as well as between the content of chlorophyll b and anthocyanins (r = 0.47, p ≤ 0.05), the content of ß-carotene (r = 0.26, p ≤ 0.05) and the content of monosaccharides (r = -0.29, p ≤ 0.05) has been noted. We have identif ied tomato accessions with a high content of individual chemical substances, as well as with a complex of traits that can be used as sources in breeding for a high content of dry matter, sugars, ascorbic acid, pigments and anthocyanins.
RESUMEN
RAPD genome analysis of 53 species and cultivars of the genus Lycopersicon (Tourn.) Mill. revealed their high genetic polymorphism (Tourn.) Mill., based on which their phylogenetic relationships were inferred. In total, 248 polymorphic DNA fragments were amplified. Intraspecific polymorphism was maximum (79%) in L. peruvianum and minimum (9%) in L. parviflorum. In general, genome divergence among cross-pollinating tomato species was substantially higher than in self-pollinating species. An UPGMA dendrogram constructed from the RAPD patterns was consisted with the Lycopersicon phylogeny inferred from the molecular data of RFLP, ISSR, and microsatellite analyses and with a classification based on morphological characters. The relationships of taxa within the genus Lycopersicon are discussed.
Asunto(s)
Filogenia , Polimorfismo Genético , Técnica del ADN Polimorfo Amplificado Aleatorio , Solanaceae/genética , Solanaceae/clasificaciónRESUMEN
Inter-simple sequence repeat (ISSR) analysis was for the first time used to study the genetic diversity and phylogenetic relationships in 54 wild accessions and cultivars of the genus Lycopersicon. Analysis involved 14 ISSR primers homologous to microsatellite repeats and containing additional selective anchor nucleotides. In total, 318 ISSR fragments were amplified for the wild and cultivated tomato genomes. The interspecific polymorphism revealed with the ISSR primers was 95.6%. Species-specific ISSR fragments were detected for each tomato species. The highest number (more than 20) of species-specific fragments were obtained for L. esculentum sensu lato, although the intraspecific variation of ISSR patterns was low. UPGMA cluster analysis was used to construct a dendrogram and to estimate the genetic distances between the species of the genus Lycopersicon; between populations of L. peruvianum, L. pimpinellifolium, and L. esculentum; and between tomato cultivars. The ISSR-based phylogeny was generally consistent with Lycopersicon taxonomy based on morphological and molecular evidence, suggesting the applicability of ISSR analysis for genotyping and phylogenetic studies in tomato.