Isoelectrofocusing of superoxide dismutase (SOD) isoforms was carried out on the extracts of 117 nematode populations belonging to the so-called Xiphinema americanum-group. These populations came from USA (77), Chile (5), Argentina (1), Venezuela (5), Portugal (15), Italy (2), Crete (1), Montenegro (1), Slovakia (4), Hungary (3), Egypt (1), and India (2). A total of 17 bands of enzyme activity were observed in the screening, while single enzyme phenotypes showed from 2 to 8 bands. The high degree of SOD polymorphism of this nematode collection allowed arranging, by a cluster analysis, the populations into 7 different homogeneous groups, characterized by specific combinations of SOD markers. Sub-groups could be discriminated for larger groups. The small groups 3 and 5 were constituted mostly by populations from USA east coast states (i.e., NY and PA, respectively). The larger Group 1 resulted from the association of populations coming from various and distant North American States. In other large groups North American populations are present together with South American and European populations. Generally, data presented here suggest that geographic separation and different hosts do not seem to be the source of genetic diversity for the X. americanum-group. When an adequate number of populations were collected from the same country, the variability expressed by such sub-sample was comparable with that of the whole nematode collection. For the first time homogeneous populations of a large collection of X. americanum were associated by molecular means in order to explore further approaches to establish the taxonomy and phylogeny of this debated group.
SOD polymorphism in the Xiphinema americanum-group (Nematoda: Longidoridae).
Molinari S;
2004
Abstract
Isoelectrofocusing of superoxide dismutase (SOD) isoforms was carried out on the extracts of 117 nematode populations belonging to the so-called Xiphinema americanum-group. These populations came from USA (77), Chile (5), Argentina (1), Venezuela (5), Portugal (15), Italy (2), Crete (1), Montenegro (1), Slovakia (4), Hungary (3), Egypt (1), and India (2). A total of 17 bands of enzyme activity were observed in the screening, while single enzyme phenotypes showed from 2 to 8 bands. The high degree of SOD polymorphism of this nematode collection allowed arranging, by a cluster analysis, the populations into 7 different homogeneous groups, characterized by specific combinations of SOD markers. Sub-groups could be discriminated for larger groups. The small groups 3 and 5 were constituted mostly by populations from USA east coast states (i.e., NY and PA, respectively). The larger Group 1 resulted from the association of populations coming from various and distant North American States. In other large groups North American populations are present together with South American and European populations. Generally, data presented here suggest that geographic separation and different hosts do not seem to be the source of genetic diversity for the X. americanum-group. When an adequate number of populations were collected from the same country, the variability expressed by such sub-sample was comparable with that of the whole nematode collection. For the first time homogeneous populations of a large collection of X. americanum were associated by molecular means in order to explore further approaches to establish the taxonomy and phylogeny of this debated group.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
