INVESTIGADORES
MARTINEZ eric Javier
artículos
Título:
Genetic relationship among Paspalum species of the subgenus Anachyris: taxonomic and evolutionary implications
Autor/es:
ZILLI, ALEX L.; HOJSGAARD, DIEGO H.; BRUGNOLI, ELSA A.; ACUÑA, CARLOS A.; HONFI, ANA I.; URBANI, MARIO H.; QUARIN, CAMILO L.; MARTÍNEZ, ERIC J.
Revista:
FLORA
Editorial:
ELSEVIER GMBH
Referencias:
Año: 2014 vol. 209 p. 604 - 612
ISSN:
0367-2530
Resumen:
Paspalum is one of the most important genus of the Poaceae family due to its large number of species and diversity. The subgenus Anachyris comprises six species mainly from South America grouped together by sharing rare spikelet characteristics. A genetic analysis using ISSR markers compared with the morphological and phenotypic variation observed in each one species was used to establish genetic relationships among 40 accessions with several ploidy levels belonging to 5 species of the subgenus Anachyris. Fourteen accessions of Paspalum malacophyllum (2x and 4x), 12 of P. simplex (2x, 3x, 4x and 6x), 4 of P. procurrens (2x and 4x), 4 of P. usterii (4x) and 6 of P. volcanensis (4x) were analysed. A total of 227 ISSR loci (98.7% polymorphic) were detected among all accessions with variable loci number and percentages of polymorphism according to species delimitations. Six main groups were identified by cluster analysis based on Jaccard?s genetic distance and UPGMA, four of which matched all the respective accessions of P. simplex, P. procurrens, P. usterii, and P. volcanensis, while the other two were consistent with two different groups of accessions of P. malacophyllum, one involving most tetraploid accessions, and the other one grouping together a tetraploid and two diploid accessions. The distinctive morphological characteristics and the separate clustering of these tetraploid and diploid cytotypes would merit consideration as a new multiploid species complex inside the subgenus Anachyris. Both cytotypes of P. procurrens, and the four co-specific cytotypes of P. simplex consistently clustered together forming two specific groups for the two multiploid taxons. This is in agreement with the existence of high phenotypic similarities between diploid and tetraploid cytotypes of P. procurrens, and among diploid, triploid, tetraploid, and hexaploid cytotypes of P. simplex. Since the polyploid cytotypes of these species reproduce by apomixis, the specific genetic clustering by ISSR markers and morphological and cytological results support the hypothesis that both multiploid species originated by autopolyploidy. Our results confirm previous studies suggesting a monophyletic origin for the subgenus Anachyris and are concordant with previous data regarding genomic homologies and phylogenetic analyses.