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- Molecular characterization of Phaseolus vulgaris L. genotypes included in Bulgarian collection by ISSR and AFLP (TM) analysesPublication . Svetleva, D.; Pereira, G.; Carlier, Jorge; Cabrita, L.; Leitão, J. M.; Genchev, D.Seventy-eight (33 Bulgarian and 45 foreign) common bean (Phaseolus vulgaris L.) genotypes included in Bulgarian collection were screened for ISSR (Inter Simple Sequence Repeats) and AFLP (TM) (Amplified Fragment Length Polymorphism) markers. ISSR analysis was performed with 13 primers, and 55 (36.7%) out of the 150 bands observed were polymorphic. One hundred and sixty-four AFLP (TM) fragments were obtained with three primer combinations, of which 54 (32.9%) were polymorphic. UPGMA (Unweighted Pair Group Method Arithmetic Averages) analysis was performed using DICE coefficient and dendrograms were constructed using either the data from each method (ISSR and AFLP (TM)) separately or combined in a single joint matrix. Despite some genetic heterogeneity observed in both pools (Middle American origin: M and Andean origin: A) the genotypes were separated in to main groups: one gathering genotypes mainly from pool M and the other more genotypes from pool A. Moreover, Bulgarian genotypes were spread over the two groups suggesting that they are not subject to genetic erosion and that the Phaseolus genetic diversity is conserved. (c) 2006 Elsevier B.V. All rights reserved.
- Population genetic structure of Cistus ladanifer L. (Cistaceae) and genetic differentiation from co-occurring Cistus speciesPublication . Carlier, Jorge; Leitão, J. M.; Fonseca, FilomenaAmplified fragment length polymorphism and inter simple sequence repeat markers were used to assess the genetic structure of Cistus ladanifer and its genetic differentiation from co-occurring Cistus species. Clear genetic differentiation was found between two populations corresponding to the morphological description of Cistus palhinhae and the 23 Cistus ladanifer populations analyzed. However, the magnitude of differentiation (DICE coefficients > 0.98) appears to be more in agreement with the taxonomic designation of Cistus ladanifer ssp. sulcatus, which has been proposed by some authors, and not C. palhinhae. Dendrogram analysis of the genetic relationships among Cistus ladanifer, Cistus populifolius, Cistus monspeliensis, Cistus crispus, Cistus libanotis, Cistus salvifolius and Cistus albidus, with Halimium halimifolium as an outgroup, showed two main clusters. Taxa composition of these clusters concurs with the taxonomic classification proposed for Iberian species on the basis of flower color. One cluster comprised species with pink flowers (C. crispus and C. albidus, P = 81.3%) classified into the subgenus Cistus, and the other cluster contained the remaining five species (P = 77.9%) that have white flowers and are classified into two subgenera, Leucocistus (C. ladanifer, C. populifolius, C. salvifolius and C. monspeliensis) and Halimioides (C. libanotis). Within the subgenera Leucocistus, C. ladanifer was found to be distinct and can be separated into the section Ladanium, while the remaining species that are grouped together in a branch (P = 74.8%) can be separated into the section Ledonia.
- Mapping of a locus for adult plant resistance to downy mildew in broccoli (Brassica oleracea convar. italica)Publication . Farinho, M.; Coelho, P.; Carlier, Jorge; Svetleva, D.; Monteiro, A.; Leitão, J. M.The identification of the gene Pp523, conferring downy mildew resistance to adult plants of broccoli (Brassica oleracea convar. italica), led to the construction of a genetic map that included this resistance locus, 301 amplified fragment length polymorphisms, 55 random amplified polymorphic DNAs, 46 inter-simple sequence repeats, three simple sequence repeats, four other PCR markers and a flower colour locus, all gathered into nine major linkage groups. Nineteen additional molecular markers were clustered into one group of four markers, one group of three markers and six pairs of markers. The map spans over 731.9 cM, corresponding to 89.5% of the 818 cM estimated to be the total genome length. A significant number of the mapped markers, 19.3%, showed distorted segregation. The average distance between mapped adjacent markers is 1.64 cM, which places this map among the densest published to date for this species. Using bulked segregant analysis, we identified a group of molecular markers flanking and closely linked in coupling to the resistance gene and included these in the map. Two markers linked in coupling, OPK17_980 and AT.CTA_133/134, are located at 3.1 cM and 3.6 cM, respectively, at each side from the resistance gene. These markers can be used for marker-assisted selection in breeding programs aiming at the introgression of this gene in susceptible B. oleracea genotypes. The fine mapping of the genomic region surrounding the Pp523 resistance gene is currently being carried out, a basic condition for its isolation via positional cloning.
- Genetic maps of RAPD, AFLP and ISSR markers in Ananas bracteatus and A-comosus using the pseudo-testcross strategyPublication . Carlier, Jorge; Reis, A.; Duval, M. F.; d'Eeckenbrugge, G. C.; Leitão, J. M.Genetic maps of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphisms (AFLP) and inter simple sequence repeats (ISSR) markers in pineapple (2n = 2x = 50) are reported for the first time. On the basis of a segregating population of 46 F1 individuals from a cross Ananas comosus x A. bracteatus, genetic maps of these two species were constructed using the two-way pseudo-testcross approach. The A. bracteatus map consists of 335 markers (60 RAPDs, 264 AFLPs and 11 ISSRs) assembled into 50 linkage groups, 26 of them with at least four markers. The A. comosus map consists of 157 markers (33 RAPDs, 115 AFLPs, eight ISSRs and the 'piping' trait locus) organized into 30 linkage groups, 18 of them with at least four markers. These maps cover, respectively, 57.2% of the A. bracteatus genome estimated as 3693 cM long, and 31.6% of the A. comosus genome calculated as 4146 cM. A rough estimate of 120 and 127 kbp/cM on average was found for the relationship between physical and genetic distance for A. bracteatus and A. comosus, respectively.