Juniperus navicularis - a study of Portuguese population structure and fitness

Juniperus navicularis Gand. is a dioecious endemic conifer that constitutes the understory of seaside pine forests in Portugal, areas currently threatened by increasing urban expansion. The aim of this study is to assess the conservation status of previously known populations of this species located on its core area of distribution. The study was performed in south-west coast of Portugal. Three populations varying in size and pine density were analyzed. Number of individuals, population density, spatial distribution and individual characteristics of junipers were estimated. Female cone, seed characteristics and seed viability were also evaluated. Results suggest that J. navicularis populations are vulnerable because seminal recruitment is scarce, what may lead to a reduction of genetic variability due solely to vegetative propagation. This vulnerability seems to be strongly determined by climatic constraints toward increasing aridity. Ratio between male and female shrubs did not differ from 1:1 in any population. Deviations from 1:1 between mature and non-mature plants were found in all populations, denoting population ageing. Very low seed viability was observed. A major part of described Juniperus navicularis populations have disappeared through direct habitat loss to urban development, loss of fitness in drier and warmer locations and low seed viability. This study is the first to address J. navicularis conservation, and represents a valuable first step toward this species preservation

Assessing the diversity of sea beet (Beta vulgaris L. ssp. maritima) populations

Beta vulgaris L. subsp. maritima (L.) Arcang., sea beet, is a morphologically and genetically variable species, belonging to beet primary gene -pool. This crop wild relative is a valuable genetic resource for resistance improvement in beets and could play an important role in crop yield sustainability. Eleven Madeiran sea beet populations were characterized using morphological descriptors and genetic markers. Our goal was to evaluate these populations as a potential source of valuable genetic material. Morphological characterization showed a high quantitative variation among populations. Plant height and inflorescence height parameters had the highest influence in the separation of populations. Molecular analysis was performed with polymorphic SSRs to determine genetic variability between populations. Both PCA and PCoA revealed three clusters that separated the populations according to morphological and genetic traits, respectively. This study contributes to the knowledge of sea beet diversity in Madeira’s archipelago and to the perception that the islands' specific environmental conditions influence its genetic variability, making these populations a possible gene source for sugar beet breeding programsinfo:eu-repo/semantics/publishedVersio

Molecular approach to characterize ectomycorrhizae fungi from Mediterranean pine stands in Portugal

Stone pine (Pinus pinea L.), like other conifers, forms ectomycorrhizas (ECM), which have benefi cial impact on plant growth in natural environments and forest ecosystems. An in vitro co-culture of stone pine microshoots with pure mycelia of isolated ECM sporocarps was used to overcome the root growth cessation not only in vitro but also to improve root development during acclimation phase. Pisolithus arhizus (Scop.) Rauschert and Lactarius deliciosus (L. ex Fr.) S.F. Gray fungi, were col lected, pure cultured and used in in vitro co-culture with stone pine microshoots. Samples of P. arhizus and L. deliciosus for the in vitro co-cultures were collected from the pine stands southwest Portugal. The in situ characterization was based on their morphotypes. To confirm the identity of the collected material, ITS amplification was applied using the pure cultures derived from the sporo carps. Additionally, a molecular profile using PCR based genomic fingerprinting comparison was executed with other genera of Basidiomycetes and Ascomycetes. Our results showed the effective ness of the techniques used to amplify DNA polymorphic sequences, which enhances the characte rization of the genetic profile of ECM fungi and also provides an option to verify the fungus identity at any stage of plant mycorrhization.info:eu-repo/semantics/publishedVersio

Assessing the Diversity of Sea Beet (Beta vulgaris L. ssp. maritima) Populations

Beta vulgaris L. subsp. maritima (L.) Arcang., sea beet, is a morphologically and genetically variable species, belonging to beet primary gene-pool. This crop wild relative is a valuable genetic resource for resistance improvement in beets and could play an important role in crop yield sustainability. Eleven Madeiran sea beet populations were characterized using morphological descriptors and genetic markers. Our goal was to evaluate these populations as a potential source of valuable genetic material. Morphological characterization showed a high quantitative variation among populations. Plant height and inflorescence height parameters had the highest influence in the separation of populations. Molecular analysis was performed with polymorphic SSRs to determine genetic variability between populations. Both PCA and PCoA revealed three clusters that separated the populations according to morphological and genetic traits, respectively. This study contributes to the knowledge of sea beet diversity in Madeira’s archipelago and to the perception that the islands' specific environmental conditions influence its genetic variability, making these populations a possible gene source for sugar beet breeding program