INVESTIGADORES
SEIJO jose guillermo
congresos y reuniones científicas
Título:
16. Species, genomes and diversification in section Arachis. .
Autor/es:
J.G. SEIJO
Reunión:
Congreso; 8th International Conference of the Peanut Research Community on Advances in Arachis through Genomics and Biotechnology (AAGB). Savannah, Georgia,USA. 14 -19 Noviembre 2014; 2014
Resumen:
SPECIES, GENOMES AND DIVERSIFICATION IN SECTION
ARACHIS
Guillermo Seijo, Sebastián Samoluk, Laura Chalup,
Marina Grabiele and Germán Robledo.
Botanical
Institute of the Northeast (IBONE, UNNE-CONICET), and Faculty of Exact and
Natural Sciences and Agrimensure, National University of the Northeast (UNNE).
Corrientes, Argentina.
In the last ten
years, botanical collections of Arachis
species have been intensified in Bolivia. Several new species have been
discovered with some very interesting characters, and the range of geographic
distribution was expanded for many of known taxa. In the same period the
species of section Arachis were re-arranged in six different genomes and in three
karyotypic subgroups. In this study we analyzed the distribution of the Arachis
section species and the variability of chloroplast sequences (trnT?S and
trnT?Y) in order to understand the dispersal pathways and to shed light
on the evolutionary history of the section. The range distribution of the
species showed a biogeographic segregation of most of the genome and karyotype groups.
Most of them were associated to different biogeographic regions and river
basins but the chloroplast haplotypes recovered from the species did not. The
major diversity of haplotypes was concentrated in the Chiquitanía region, in the
San Ignacio Planalto. Two central haplotypes were recognized, one of them for
the A genome species and the other for the B, D, K, F and G genomes. Both
central haplotypes were widely distributed, covering most of the species range.
The remaining haplotypes (19) were more restricted or specific to particular
populations. The patterns of species and haplotype distributions, together with
the analyses of main paleochannels in central South America, suggests that hydrochory
may have played a key role in long distance dispersal and establishment of
founders in allopatry. Genome differentiation may have occurred in different
river basins during Pliocene, while speciation within each genome may have occurred
also in isolation with incomplete linage sorting for the markers analyzed.