Congruence between morphological and molecular markers for genetic diversity analysis applied to forage palm genotypes propagated via bioreactors

摘要

The in vitro multiplication of forage palm by temporary immersion bioreactors (TIBs) is a technique that allows the young plants production in a large scale with genetic and health quality. Phenotypic variables expressed at this stage may be useful in estimating genetic dissimilarity among forage palm species. One way to confirm to this hypothesis is to compare it with dissimilarity obtained via molecular analysis. The objective was to estimate the genetic divergence among eleven forage palm genotypes through morphological characterization in in vitro propagation and to relate it to molecular characterization. Genotypes were multiplied in temporary immersion bioreactors. At this phase, morphological descriptors such as length, diameter, dry and fresh mass of cladodes was evaluated. Molecular genotyping was performed by DNA extraction from young cladodes using (RAPD) primers. Dissimilarity based on molecular markers was estimated using the Jaccard Index. The morphological characteristics were compared individually by the Scott-Knott cluster test (p < 0.05) and were compared together for dissimilarity by Euclidean distance. Individual dendrograms were obtained for each analysis using the IJPGMA method. A tanglegram was generated to illustrate the similarities between the associations of the two dendrograms. There were significant differences in all characteristics related to length, cladode width, fresh and dry mass of plants. The morphological descriptors obtained via temporary immersion bioreactors maintained all intrinsic morphological characteristics of the genotypes, grouping them according to genus. Based on the morphological characterization, it was possible to obtain two distinct groups. Morphological similarity was observed between pairs of genotypes of different genera and species. Molecular investigation allowed us to differentiate genotypes at species and genera levels, discriminating those considered morphologically similar. Molecular research made it possible to differentiate genotypes at species and genus level, discriminating those considered morphologically similar. The comparison between morphological and molecular data revealed divergences and similarities. The obtained information is useful in understanding the diversity within groups and how it is structured. Molecular markers outline these groups indicating the existence of genetic divergence. Morphological descriptors, obtained through bioreactors, are useful in studies of genetic diversity in forage palm.