José Manuel Leitão

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Twenty-five Pyrus communis L. cultivars including eight traditional Portuguese pears, and four commercial Pyrus pyrifolia (Burm.) Nak. (Japanese pear or `nashi') cultivars were analysed by RAPD and AFLP techniques focusing on their molecular discrimination and the assessment of their genetic relatedness. Twenty-five primers generated 324 RAPD markers, among(More)
We have recently induced two powdery mildew (Erysiphe pisi Syd) resistant mutants in Pisum sativum L. via ethylnitrosourea (ENU) mutagenesis. Both mutations (er1mut1 and er1mut2) affected the same locus er1 that determines most of the identified natural sources of powdery mildew resistance (PMR) in this crop. The mutated gene er1mut2 was mapped to a linkage(More)
Forty-one apple (Malus × domestica Borkh.) cultivars were screened for RAPD (Random Amplified Polymorphic DNA) and AFLP(Amplified Fragment Length Polymorphism) markers. RAPD analysis was performed with 35 arbitrary 10-mer primers, selected from 60 primers tested (kits A, C and E, Operon Technologies, Inc.). Of a total of 362bands observed, 208 (57.5%) were(More)
Despite the paramount importance of pineapple (Ananas comosus L.) in world production and trade of tropical fruits, the genomics of this crop is still lagging behind that of other tropical fruit crops such as banana or papaya. A genetic map of pineapple was constructed using an F2 segregating population obtained from a single selfed F1 plant of a cross A.(More)
Two pea (Pisum sativum L.) powdery mildew-resistant mutant lines, S(er1mut1) and F(er1mut2), were previously obtained by experimental chemical mutagenesis with ethylnitrosourea. Identification and subsequent analysis of the genomic sequence of the PsMLO1 gene revealed one single nucleotide mutation in each mutant line that leads to either a transversion or(More)
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(More)
Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for(More)
The alkylating compounds and strong mutagens methylnitrosourea (MNU) and ethylnitrosourea (ENU) were used to widen the genetic variability of pea (Pisum sativum L.) via experimental mutagenesis. Amongst multiple mutations of agronomical interest, for the first time two mutations conferring broad-range resistance to powdery mildew (Erysiphe pisi Syd.) were(More)
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(More)