Using RAPD markers to analyse genetic diversity in Portuguese potato cyst nematode populations

The two species of potato cyst nematodes (PCN) have different spectra of virulence towards host resistance genes and a proper identification is important in the control of these nematodes by means of resistant potato cultivars. Genetic variability of 32 populations of Globodera rostochiensis and three of G. pallida from different regions of Portugal were analysed and compared using random amplified polymorphic DNA and sixteen primers. In addition, a population of G. pallida (Luffness) from Scotland, UK, was included for comparison. The patterns obtained were evaluated using the Nei coefficient and the UPGMA cluster method. The resulting clusters were expressed as dendrograms in the Phylogeny Inference Package (PHYLIP) program. Separation of the two species of PCN was achieved with an average similarity of 43%. Two populations of G. rostochiensis (PT1 and PT82) appear to be distinct from the main group of this species. One population of G.pallida (PT104) was distinct from the others of this species and the Luffness population was linked most closely with PT5701. Distinct clusters were observed within both species but the clusters could not be related to the geographic proximity of the populations.

Diversidad genética y relaciones filogenéticas del ganado criollo colombiano

<p>La caracterización genética del ganado criollo colombiano (gcc) ha demostrado el valor de estas razas en los sistemas productivos tropicales, lo que ha despertado el interés para desarrollar programas de conservación y multiplicación. Se adelantó un estudio de análisis genético con las siete razas de ganado criollo colombiano, (rgcc): Blanco Orejinegro (BON), Romosinuano (R), Costeño Con Cuernos (CCC), Sanmartinero (SM), Chino Santandereano (Ch), Hartón del Valle (H) y Casanareño (Ca), utilizando el Cebú (C) como control, con el objeto de evaluar su diversidad genética y relaciones filogenéticas. Se usaron 7 microsatélites (STR) para establecer las distancias genéticas amplificadas mediante PCR. El tamaño de los loci se definió mediante marcaje con ɣ³² P seguido de un pase en geles de poliacrilamida (PAGE) o marcados con fluorescencia y electroforesis capilar. Los datos se analizaron usando los programas Genepop, GDA y Phylip. El número promedio de alelos por locus fue de 8,9 y Ia heterocigosidad promedia observada fue de o,52. El árbol filogenético construido con el programa Phylip, empleando la distancia de Nei y el algoritmo de Neighbour-joining, agrupó en dos las gcc. En el grupo uno las razas: BON, SM, R, CCC y H; y en el grupo dos las razas: Ch, Ca y C. Los resultados de evaluación filogenética de las gcc indicaron que existe diversidad genética adecuada en estas razas para programas de mejoramiento genético; sin embargo, se recomienda continuar el estudio con un mayor número de marcadores genéticos.</p><p><strong><br /></strong></p><p><strong>Diversity and Phylogenetic Relations of Colombian Criollo Cattle.</strong></p><p>Studies of genetic characterisation of Colombian criollo cattle (gcc) has shown the value of these breeds in tropical production systems; consequently attention is noticeably growing to develop conservation and multiplication programs. A genetic analysis study was conducted including the seven criollo cattle breeds: Blanco Orejinegro (BON), Romosinuano (R), Costeño Con Cuernos (CCC), Sanmartinero (SM), Chino Santandereano (Ch), Hartón del Valle (H) and Casanareño (C), using Cebu as external control breed, with the purpose to evaluate genetic diversity and philogenetic relations. Seven microsatellite (STR) were used to detect length variations amplified by the PCR and sized by means of ɣ³² P, runned in PAGE or tagged with a fluorescent dye and electrophoresis. Data were analysed using Genepop, GDA and Phylip programs. Mean number of alleles by loci were 8.9 and mean heterozygocity was o.52. The phylogenetic tree developed using Phylip program, the Nei's distance and the neighbour-joining aglorithm grouped in two the gcc. Group one included: Bon, SM, R,CCC and H, and the second group included Ch, Ca, C. Results of the phylogenetic relations of gcc showed that these breeds have adequate genetic diversity for breeding Programs; however we suggest to carry out studies including higher number of genetic markers.</p>