Browsing by Author "Monteiro, A. A."
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- Composted organic residues as a substrate component for tomato transplant productionPublication . Reis, Mário; Martinez, F. X.; Soliva, M.; Monteiro, A. A.Pine bark and grape marc composts were tested in the production of tomato seedlings as substrate components after composting in 1.2 m3 boxes. The composting process of pine bark took 20 weeks with a low temperature increase. Grape marc composting process took 16 weeks, reaching a higher temperature. Composts were used as single substrate components and in mixtures with a sphagnum peat, in the proportions of 25, 50 and 75% (v/v) of compost. Tomato seeds were seeded in modular trays of 35 cm3 and irrigated by “ebb and flood” irrigation system. The growth of tomato plants in the mixtures was similar or better than in a standard peat substrate, mainly in the first year of trials. Pine bark performed generally better than grape marc. Plant growth was significantly correlated with the physical properties of the substrates mainly in grape marc mixtures and in the trials under higher levels of radiation. A higher incorporation of compost determines a lower water retention capacity and a poor performance of the mix. Good tomato seedlings growth was possible using mixtures with an incorporation of composts reaching 100% of pine bark and 50% of grape marc.
- Physical mapping in a triplicated genome: mapping the downy mildew resistance locus Pp523 in Brassica oleracea L.Publication . Carlier, Jorge; Alabaça, Cláudia S.; Sousa, N. H.; Coelho, P. S.; Monteiro, A. A.; Paterson, A. H.; Leitão, J. M.We describe the construction of a BAC contig and identification of a minimal tiling path that encompass the dominant and monogenically inherited downy mildew resistance locus Pp523 of Brassica oleracea L. The selection of BAC clones for construction of the physical map was carried out by screening gridded BAC libraries with DNA overgo probes derived from both genetically mapped DNA markers flanking the locus of interest and BAC-end sequences that align to Arabidopsis thaliana sequences within the previously identified syntenic region. The selected BAC clones consistently mapped to three different genomic regions of B. oleracea. Although 83 BAC clones were accurately mapped within a similar to 4.6 cM region surrounding the downy mildew resistance locus Pp523, a subset of 33 BAC clones mapped to another region on chromosome C8 that was similar to 60 cM away from the resistance gene, and a subset of 63 BAC clones mapped to chromosome C5. These results reflect the triplication of the Brassica genomes since their divergence from a common ancestor shared with A. thaliana, and they are consonant with recent analyses of the C genome of Brassica napus. The assembly of a minimal tiling path constituted by 13 (BoT01) BAC clones that span the Pp523 locus sets the stage for map-based cloning of this resistance gene.
- SCAR and CAPS markers flanking the Brassica oleracea L. Pp523 downy mildew resistance locus demarcate a genomic region syntenic to the top arm end of Arabidopsis thaliana L. chromosome 1Publication . Farinhó, M.; Coelho, P.; Monteiro, A. A.; Leitão, J. M.We recently mapped the Pp523 locus that includes a single, dominant gene conferring resistance to downy mildew expressed in adult plants to a 75.1 cm long linkage group on a genetic linkage map of Brassica oleracea L. More recently, we identified a new AFLP marker 2.8 cm downstream from the resistance gene. The five DNA markers within an 8.5 cm region encompassing the Pp523 gene were cloned and sequenced. Three of these markers were transformed into SCARs (sequence characterised amplified regions), however, two among them were monomorphic and were analysed as CAPS (cleaved amplified polymorphic sequence) markers among the mapping population. Searched against genomic databases, the five B. oleracea DNA-marker sequences matched Arabidopsis thaliana L. gene sequences that delimit a conserved syntenic region in the top arm end of chromosome 1 of this last species. Considering the close genetic relatedness between both species, the information on this specific genomic region in A. thaliana is particularly useful for the construction of a fine-scale map of the corresponding genomic region in B. oleracea. The identified SCAR and CAPS markers can be used for marker assisted selection (MAS) in breeding programs aimed at the introgression of the Pp523 resistance locus, allowing the reliable indirect identification of plants harbouring the resistance gene with a margin of error of approximately six in ten-thousand selected plants.
- The downy mildew resistance locus Pp523 is located on chromosome C8 of Brassica oleracea L.Publication . Carlier, Jorge; Alabaça, Cláudia S.; Coelho, P. S.; Monteiro, A. A.; Leitão, J. M.We have previously constructed a genetic map of Brassica oleracea L. containing the Pp523 locus that confers downy mildew resistance to adult plants. In this work, 44 SSR markers of reference for the Brassica C genome chromosomes were added to the map, allowing the nine major linkage groups to be assigned to the nine chromosomes of B. oleracea. Locus Pp523 was located on chromosome C8, and a locus determining flower colour was mapped to chromosome C3. In comparison with the first version of the map, the new map is denser and more compact. The available genomic information on B. oleracea was enriched with the chromosome location of two phenotypic traits and 421 DNA markers (RAPD, ISSR, AFLP, SCAR, BAC-end derived STS, SSR and other PCR markers). Conversely, the genomic information on B. oleracea chromosome C8 is being used as an additional tool for the map-based cloning of Pp523, the first gene for adult plant resistance to downy mildew precisely located to a specific chromosome of this crop species.