A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA (RAPD), amplified fragme...A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ‘Monagha’ and ‘Sefied’ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.展开更多
Evaluation of agronomic traits in Prunus breeding programs is a tedious process because of the long juvenile period of trees, the influence of juvenility and the existence of climatic factors affecting the expression ...Evaluation of agronomic traits in Prunus breeding programs is a tedious process because of the long juvenile period of trees, the influence of juvenility and the existence of climatic factors affecting the expression of the trait. For these reasons, marker-assisted selection (MAS) strategies are particularly useful in these cases. The objective of this work is the analysis of alternative low- cost strategies for development of molecular markers linked to agronomic traits in Prunus including the application of modified Bulked segregant analysis (BSA) using Simple sequence repeat (SSRs) markers and the application of Random amplified polymorphism microsatellite (RAMP) markers. First BSA results showed that two SSR loci were found to be tightly linked to flowering time in almond. On the other hand, RAMP analysis has been demonstrated to be a potentially valuable molecular marker for the study of genetic relationships in Prunus. Results showed the dominant nature of these markers with a great abundance and transferability although with a reduced polymorphism. In addition, RAMP application in F1 progenies showed its suitability for molecular characterization and mapping, and later Quantitative trait loci (QTL) or BSA analysis.展开更多
The objective of this work is to present an appropriate set of RAPD (random amplified polymorphic DNA) markers using single and multiplex PCR analysis suitable for the characterization of the endemic Cuban species Car...The objective of this work is to present an appropriate set of RAPD (random amplified polymorphic DNA) markers using single and multiplex PCR analysis suitable for the characterization of the endemic Cuban species Carica cubensis and the establishment of genetic relationships with the cultivated species Carica papaya. RAPD markers presented a high level of polymorphism. In addition, the incorporation of more than one RAPD primer in the PCR analysis increased the number of obtained bands and the polymorphism of these bands. A total of 73 RAPD bands were detected (45 of them polymorphic) with the nine RAPD markers assayed using single and multiplex PCR analysis. Results demonstrated a reduced genetic variability within the tested Carica cubensis accessions. The observed clustering in this species could be better explained according to geographic proximity and can indicate the similar precedence of the isolated studied populations. C. cubensis seem to be subspecies of C. papaya adapted to the environmental conditions of the mountains of Cuba or a endemic species close to C. papaya. The implications of these results in the creation of effective germplasm core collection in Carica species have been also discussed.展开更多
文摘A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ‘Monagha’ and ‘Sefied’ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.
文摘Evaluation of agronomic traits in Prunus breeding programs is a tedious process because of the long juvenile period of trees, the influence of juvenility and the existence of climatic factors affecting the expression of the trait. For these reasons, marker-assisted selection (MAS) strategies are particularly useful in these cases. The objective of this work is the analysis of alternative low- cost strategies for development of molecular markers linked to agronomic traits in Prunus including the application of modified Bulked segregant analysis (BSA) using Simple sequence repeat (SSRs) markers and the application of Random amplified polymorphism microsatellite (RAMP) markers. First BSA results showed that two SSR loci were found to be tightly linked to flowering time in almond. On the other hand, RAMP analysis has been demonstrated to be a potentially valuable molecular marker for the study of genetic relationships in Prunus. Results showed the dominant nature of these markers with a great abundance and transferability although with a reduced polymorphism. In addition, RAMP application in F1 progenies showed its suitability for molecular characterization and mapping, and later Quantitative trait loci (QTL) or BSA analysis.
文摘The objective of this work is to present an appropriate set of RAPD (random amplified polymorphic DNA) markers using single and multiplex PCR analysis suitable for the characterization of the endemic Cuban species Carica cubensis and the establishment of genetic relationships with the cultivated species Carica papaya. RAPD markers presented a high level of polymorphism. In addition, the incorporation of more than one RAPD primer in the PCR analysis increased the number of obtained bands and the polymorphism of these bands. A total of 73 RAPD bands were detected (45 of them polymorphic) with the nine RAPD markers assayed using single and multiplex PCR analysis. Results demonstrated a reduced genetic variability within the tested Carica cubensis accessions. The observed clustering in this species could be better explained according to geographic proximity and can indicate the similar precedence of the isolated studied populations. C. cubensis seem to be subspecies of C. papaya adapted to the environmental conditions of the mountains of Cuba or a endemic species close to C. papaya. The implications of these results in the creation of effective germplasm core collection in Carica species have been also discussed.
