Genetic Analysis of Tomato Fruit Ripening at Polypeptide Profiles Level through Quantitative and Multivariate Approaches

Multivariate analysis became essential in functional and structural Genomics because of the large quantity of biological data provided by these new research areas. Diallel mating design was widely applied to analyze the heritability of quantitative traits but it was recently used for approaching to the inheritance patterns of other levels of gene expression such as transcript profiles. Investigating the inheritance pattern of total polypeptide profiles with a diallel design remains as a vacancy subject. The objective of the present research was to infer the inheritance of total polypeptides profiles from tomato pericarp tissue at four different ripening stages in a diallel mating design including five recombinant inbred lines (RILs) and their ten second cycle hybrids (SCH). To achieve this objective, a multivariate analysis was applied to identify eventual inheritance patterns through a data mining approach and then univariate analyses were used to verify these patterns. Mainly dominance and also overdominance, though in a minor percentage, contributed to the gene actions involved in their genetic basis. Multivariate analysis was efficient in identifying inheritance patterns of total polypeptide profiles through a data mining approach, and univariate analyses largely verified the identified gene actionsFil: Marchionni Basté, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Biologia. Cat.de Genetica; ArgentinaFil: Pereira Da Costa, Javier Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Biologia. Cat.de Genetica; ArgentinaFil: Rodríguez, Gustavo Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Biologia. Cat.de Genetica; ArgentinaFil: Zorzoli, Roxana. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Biologia. Cat.de Genetica; Argentina. Universidad Nacional de Rosario. Consejo de Investigaciones; ArgentinaFil: Pratta, Guillermo Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Biologia. Cat.de Genetica; Argentin

Molecular genetics of quantitative traits in tomato diallel crosses

The purpose of this research was to evaluate molecular markers and some quantitative fruit traits,  in a complete diallel cross without reciprocals, among five tomato recombinant inbred lines and their hybrids. Amplified fragment length polymorphism  (AFLP) and pericarp polypeptide profiles were obtained in four stages of fruit maturity of 15  genotypes. Among other traits, fruit weight, titratable acidity, pH, shelf life, and firmness were evaluated. The percentages of polymorphism for molecular markers and for the genetic variability for quantitative characters were calculated in the recombinant lines, hybrids and total genotypes. Cluster analyses were done for each level of genetic variation. The percentage of polymorphism varied between 34 and 54% for AFLP, and between 40 and 78% for polypeptide profiles. Higher polymorphism was observed in the group of hybrids. The genetic variability was 100% for titratable acidity and 34% for firmness, and the highest values were found in the parents. The genetic similarity varied among genotypes according to the level of genetic variation; however, the clustering consistency of some recombinant lines and their hybrids was conserved, which evidenced associations among molecular and phenotypic data.El objetivo de este trabajo fue evaluar marcadores moleculares y caracteres cuantitativos en un cruzamiento dialélico completo sin recíprocos, entre cinco líneas recombinantes de tomate y sus híbridos. Se obtuvieron perfiles de AFLP ("amplified fragment length polymorphism") y de polipéptidos del pericarpio en cuatro estados de madurez del fruto de 15 genotipos. Se evaluaron, entre otros: peso, acidez titulable, pH, vida poscosecha y firmeza. Se calculó el porcentaje de polimorfismo para los marcadores moleculares y el porcentaje de variabilidad genética para los caracteres cuantitativos en el grupo de líneas recombinantes, el de híbridos y el conjunto de genotipos. Se realizaron análisis de agrupamiento con cada nivel de variación genética. Para AFLP, el porcentaje de polimorfismo varió entre 34 y 54% y, para los perfiles polipeptídicos, entre 40 y 78%. Mayor polimorfismo fue observado en el grupo de híbridos. La variabilidad genética fue de 100% para acidez y 34% para firmeza, con los mayores valores en los parentales. La similitud genética varió entre los genotipos según el nivel de variación genética; pero la consistencia en el agrupamiento de algunas líneas recombinantes y sus híbridos fue conservada, lo que evidenció asociaciones entre los datos moleculares y fenotípicos.The purpose of this research was to evaluate molecular markers and some quantitative fruit traits,  in a complete diallel cross without reciprocals, among five tomato recombinant inbred lines and their hybrids. Amplified fragment length polymorphism  (AFLP) and pericarp polypeptide profiles were obtained in four stages of fruit maturity of 15  genotypes. Among other traits, fruit weight, titratable acidity, pH, shelf life, and firmness were evaluated. The percentages of polymorphism for molecular markers and for the genetic variability for quantitative characters were calculated in the recombinant lines, hybrids and total genotypes. Cluster analyses were done for each level of genetic variation. The percentage of polymorphism varied between 34 and 54% for AFLP, and between 40 and 78% for polypeptide profiles. Higher polymorphism was observed in the group of hybrids. The genetic variability was 100% for titratable acidity and 34% for firmness, and the highest values were found in the parents. The genetic similarity varied among genotypes according to the level of genetic variation; however, the clustering consistency of some recombinant lines and their hybrids was conserved, which evidenced associations among molecular and phenotypic data

Tomato second cycle hybrids as a source of genetic variability for fruit quality traits

The objective of this study was to investigate the phenotypic and molecular variability in a F2 generation derived from a SCH (Second Cycle Hybrid) in order to detect QTLs for some fruit traits of tomato. Genome coverage at different levels was achieved by three types of molecular markers (polypeptides, sequence-related amplified polymorphism-SRAP and amplified restriction fragment polymorphism - AFLP). Different degrees of polymorphism were detected by SRAP and AFLP at the DNA structure level and also by polypeptides at the DNA expression level. The first two markers, associated with phenotypic variation, detected QTLs involved in important agronomic traits such as fruit shelf life, soluble solids content, pH, and titratable acidity. New gene blocks originated by recombination during the first cycle of crossing were detected. This study confirmed that the observed phenotypic differences represent a new gene rearrangement and that these new gene blocks are responsible for the presence of the genetic variability detected for these traits.IICAR-CONICET-UNR (Instituto de Investigaciones en Ciencias Agrarias de Rosario - Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Rosario). Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario

Genética molecular de caracteres cuantitativos en cruzamientos dialélicos de tomate

El objetivo de este trabajo fue evaluar marcadores moleculares y caracteres cuantitativos en un cruzamiento dialélico completo sin recíprocos, entre cinco líneas recombinantes de tomate y sus híbridos. Se obtuvieron perfiles de AFLP ("amplified fragment length polymorphism") y de polipéptidos del pericarpio en cuatro estados de madurez del fruto de 15 genotipos. Se evaluaron, entre otros: peso, acidez titulable, pH, vida poscosecha y firmeza. Se calculó el porcentaje de polimorfismo para los marcadores moleculares y el porcentaje de variabilidad genética para los caracteres cuantitativos en el grupo de líneas recombinantes, el de híbridos y el conjunto de genotipos. Se realizaron análisis de agrupamiento con cada nivel de variación genética. Para AFLP, el porcentaje de polimorfismo varió entre 34 y 54% y, para los perfiles polipeptídicos, entre 40 y 78%. Mayor polimorfismo fue observado en el grupo de híbridos. La variabilidad genética fue de 100% para acidez y 34% para firmeza, con los mayores valores en los parentales. La similitud genética varió entre los genotipos según el nivel de variación genética; pero la consistencia en el agrupamiento de algunas líneas recombinantes y sus híbridos fue conservada, lo que evidenció asociaciones entre los datos moleculares y fenotípicos