Browsing by Author "Duval, M. F."
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- 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.
- Main results from the EU-funded project "evaluation and utilization of pineapple genetic resources from the amazon to breed resistant varieties"Publication . D'Eeckenbrugge, G. Coppens; Cabral, J. R. S.; Matos, A. P. de; Carlier, Jorge; Leitão, José; Duval, M. F.; Noyer, J. L.; Ferreira, F. R.; Leal, F.; Maggioni, L.; Suarez, Z.This project was aimed at obtaining knowledge and tools for the development of cultivars resistant to the main diseases in South America, by (i) characterizing and evaluating available genetic resources, (ii) studying the genetic structure of the genera Ananas and Pseudanas (iii) developing and applying resistance screening techniques for important pests and disease in the region, (iv) studying the heredity of agronomic traits, and (v) testing the potential of partial inbreeds in breeding. In addition, a standard database is being established in collaboration with IPGRI, to promote information on germplasm exchange. The project, which started in 1997 and ended in 2001, has produced an inventory of the germplasm held in its collections, allowing exchange and repatriation of lost germplasm. The list of descriptors has been revised. Multivariate analyses of the morphological data have produced consistent results. Molecular characterization, based on RFLP of genomic DNA and PCR-RFLP of cpDNA has confirmed the proximity of Ananas and Pseudananas, the absence of interspecific barriers in Ananas, the importance of a geographic component of variation, and the existence of a higher genetic diversity in the North of South America. Pineapple taxonomy has been revised. Genetic mapping was based on isozyme, RAPD, AFLP and ISSR markers and was carried out on a hybrid progeny between A. bracteatus and A. comosus, following the pseudotestcross approach. It resulted in a first map of 390 and 174 DNA markers distributed in 46 and 31 linkage groups for these two species. New sources of resistance to fusariosis have been identified, some of which show other interesting traits for the Brazilian producers. According to the first inheritance studies, this resistance seems monogenic and dominant, a result still to be confirmed. Selfprogenies obtained from the cultivars Perolera, Primavera, and Roxo de Tefé, showed inbreeding depression, but normal segregation for major leaf traits (spininess, colour). Subsequent hybridization of the inbreeds restored vigour.