AFLP-Based Analysis to Study Genetic Variability and Relationships in the Spanish Species of the Genus Aegilops

Abstract

Amplified fragment length polymorphism (AFLP) DNA markers were used to characterize the genetic diversity and relationships in wild species of the genus Aegilops. Fifty populations, which included the species Aegilops biuncialis (UUMM), Ae. neglecta (UUMMNN), Ae. ovata (UUMM), Ae. ventricosa (DDNN) and Ae. triuncialis (UUCC) were selected. These populations are distributed in the Iberian peninsula and Balearic islands. Five AFLP selective primer combinations generated a total of 527 amplification products of which 517 (98.10%) detected polymorphisms. Aegilops neglecta showed the least variation in contrast with Ae. biuncialis that presented the highest degree of polymorphism. Genetic relationships within the populations were evaluated by generating a similarity matrix based on the Jaccard index. In the resulting phenogram Ae. ventricosa appears segregated from the other species, probably owing to the influence of the D genome. The species sharing the U genome are located in the main cluster. The branching pattern of the U genome group reflects the proximity of the species sharing the M genome. Ae. biuncialis and Ae. ovata are clearly separated suggesting that the super index system should be used to differentiate the M genomes of both species. The variation among populations within species in relation to their geographical origin and results previously obtained by the authors using biochemical and molecular markers are discussed.

Intra-population genetic diversity of two wheatgrass species along altitude gradients on the Qinghai-Tibetan Plateau: its implication for conservation and utilization

“…For each primer, the number of amplified fragments in the hexaploid E. nutans was greater than those in the tetraploid E. burchan-buddae, probably due to the additional H genome in the hexaploid E. nutans. Five selective primer combinations generated a large number of fragments across all samples, similar to the previous reports in hop cultivars (Hartl and Seefelder 1998) and Spanish species of the genus Aegilops (Monte et al 2001), in terms of fragment polymorphisms. This suggests that the automated and fluorescence-labeled AFLP technique is a powerful tool for the detection of genetic diversity in Elymus species.…”

“…Small population size may also lead to a decrease in intra-population diversity at the range edges of two Elymus species. Similar situations were also commonly found in other species (e.g., Monte et al 2001), therefore, we believe that E. nutans and E. burchan-buddae have an enhanced intra-population genetic diversity at their favored altitudes, where E. nutans is a predominant species to the grassland of the Qinghai-Tibetan Plateau. These phenomena can be proven by a greater plant density in the medium altitude zone, where vascular flora and other gramineous species are also predominant .…”

Markers associated with altitude and ecological factors in hexaploid Campeiostachys nutans (Griseb.) J. L. Yang, B. R. Baum et C. Yen and tetraploid Roegeneria nutans (Keng) Keng

“…The hexaploid C. nutans species is highly evolved and is indigenous to the high, cold rangeland of the Qinghai-Tibetan Plateau (Wang et al 2006). Similar situations are also commonly found in other polyploid plants (e.g., Monte et al 2001;Ohsawa et al 2007;García-Verdugo et al 2009). The findings regarding two wheatgrasses indicate that a high degree of polyploidy can provide a strong resistance to adverse conditions, which supports the hypothesis that polyploidy, is a driving force in the evolution of plant species (Stebbins 1950).…”

Selection of U and M genome-specific wheat SSR markers using wheat–Aegilops biuncialis and wheat–Ae. geniculata addition lines

“…Many types of molecular markers (RFLP, SSR, S-SAP) have been employed to determine relationships between the Aegilops species (Lelley et al 2000;Monte et al 2001;Pestsova et al 2000b;Sasanuma et al 2004;Hang et al 2006;Nagy et al 2006;Leonova et al 2009). Very few chromosome-specific molecular markers have been described in Aegilops species, and most of those are RFLP markers (Gill et al 1991;Lagudah et al 1991;Castilho et al 1997).…”