Genetic Diversity in Rosa as Revealed by RAPDs

We aim to study the variability within genus Rosa. To accomplish this we have analyzed a plant material collection (109 accessions) including all sections but one, as well as many intermediate forms and hybrids. We also aim to study the consistency of the groups considered within section Caninae (‘caninae’, ‘rubiginosa’ and ‘tomentosa’) as well as of the subgenus Hulthemia. A dendrogram was constructed based on RAPDs data. The variability found in the dendrogram was discussed according to sectional status and geographic origin. Our results indicate that there is no clear distinction between Caninae groups when many intermediate forms are considered. Besides, the subgenus Hulthemia seems to merit just a sectional status as proposed by other authors for other subgenus. The heterogeneity found in the dendrogram with respect to sectional status suggests the lack of clear reproductive barriers as is common with long lived woody perennial plants. Sect. Cassiorhodon may be considered as the Type of the genus since it shows the widest geographical distribution, the widest crossing ability within the Genus and it appears in most groups of the dendrogram suggesting to be the most representative Section

Potential of local varieties for the improvement of durum wheat

El trigo duro en Andaluc&iacute;a se cultiva fundamentalmente en ambiente mediterr&aacute;neo caracterizado por&nbsp; precitaciones&nbsp; estacionales,&nbsp; alta&nbsp; probabilidad&nbsp; de&nbsp; sequ&iacute;a&nbsp; al&nbsp; final&nbsp; del&nbsp; ciclo&nbsp; y&nbsp; ambientes&nbsp; secos durante el desarrollo del grano. Estas condiciones suponen un riesgo importante ya que tanto la sequ&iacute;a como el calor pueden producir reducciones importantes del rendimiento.Los modelos de predicci&oacute;n de cambio clim&aacute;tico sugieren un incremento de la frecuencia de altas temperaturas durante la floraci&oacute;n en Europa que podr&iacute;an provocar una disminuci&oacute;n en la fertilidad de&nbsp; las&nbsp; espigas&nbsp; y&nbsp; una&nbsp; senescencia&nbsp; acelerada&nbsp; de&nbsp; las&nbsp; hojas,&nbsp; con&nbsp; el&nbsp; consiguiente&nbsp; efecto&nbsp; sobre&nbsp; el rendimiento. En este contexto, las variedades locales pueden jugar un papel importante ya que al haber sido seleccionadas en condiciones locales durante generaciones pueden presentar caracter&iacute;sticas de adaptaci&oacute;n a estos ambientes.</p