Filogenia Molecular das Jabuticabas: Elucidando relações evolutivas e identidade genérica de um fruto genuinamente brasileiro.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The jabuticabas (or jaboticabas) are much appreciated fruits in Brazil especially in the Southwestern and Central-western states where they are always present in gardens and orchards. They are essentially Brazilian fruits, infrequently cultivated in other countries. Although its production is essentially non-commercial, large amounts of these fruits are consumed during its short fruiting period. There are virtually no breeding programs, mainly because of the complex taxonomy and poor genetic characterization. Traditionally, the jabuticabas are defined as belonging to Myrciaria (mainly as M. jaboticaba, M. cauliflora and M. truncifilora), but a few authors consider them as belonging to the genus Plinia. Its circumscription becomes more complex when the genus Paramyrciaria is considered, forming a complex that is rather hard to define using morphological data. Recent studies using molecular data demonstrate that the genera Myrciaria and Plinia, together with Neomitranthes and Siphoneugena, form a monophyletic group denoted Plinia complex. Since previous studies were not able to establish a conclusive circumscription for the cultivated jaboticabas, we used a molecular approach using both a plastidial (matK) and a nuclear (ITS). Both Maximum Parsimony and Bayesian Analysis approaches were used, with essentially similar results. Sixty seven accessions from this group were obtained from field trips or living collections, including edible jabuticabas and allied groups (Siphoneugena, Neomitranthes e Plinia), together with outogroups. The trees obtained from each genomic compartment has proven to be slightly different, suggesting a possible distinct evolutionary story. In both analysis, the sampled jaboticaba species (M. jaboticaba, M. trunciflora and M. cauliflora) appeared in a single clade, although none of the sampled species appeared as monophyletic individually. Another interesting aspect is that the group containing the species usually accepted in Myrciaria sensu lato (including the type species of the genus, M. tenella) also appeared as distantly related to cultivated jaboticaba as any other sampled genera from the Plinia complex, whereas the type-species of Paramyrciaria (P. delicatula) also appears in an isolated clade. A third noteworthy aspect is that the species recognized as belonging to the genus Plinia appeared scattered among different clades of the Plinia complex (and even out ot if, as P. hatschbachiana) suggesting that Plinia could be a polyphyletic genus. These obtained results are clear enough to indicate that the Plinia complex may be well defined in subfamiliar and subtribal approaches, but lacks better studies on generic circumscription, specially concerning the genus Plinia. A broader sampling of Plinia, as well as the inclusion of P. pinnata, the type-species of this genus are both necessary prerequisites for the ultimate elucidation of the generic identity of the cultivated jabuticabas. Finally, we believe that this prospective analysis about the genetic relationships of the cultivated jabuticabas and their wild relatives can be successfully used as the first guideline for future breeding programs of this genuinely Brazilian fruit.

ASSUNTO(S)

myrciaria matk filogenia matk its plinia genetica jabuticaba jabuticaba myrciaria jabuticaba - melhoramento genético plinia its phylogenetic

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