*Part of the dissertation necessary for the M.Sc. degree in Plant Pathology of the first author, Universidade de Brasília (2002). CAPES fellowship Determination of virus diversity in the field is vital to support a sustainable breeding program for virus resistance of horticultural crops. The present study aimed to characterize four field potyvirus isolates found naturally infecting sweet pepper...

Naturally occurring variation in wild species can be used to increase the genetic diversity of cultivated crops and improve agronomic value. Populations of introgression lines carrying wild species alleles afford an opportunity to identify traits associated with the introgressed regions, and facilitate characterization of the biochemistry and genetics underlying these phenotypes. Understanding ...

HsfA2 is a heat stress (hs)-induced Hsf in peruvian tomato (Lycopersicon peruvianum) and the cultivated form Lycopersicon esculentum. Due to the high activator potential and the continued accumulation during repeated cycles of heat stress and recovery, HsfA2 becomes a dominant Hsf in thermotolerant cells. The formation of heterooligomeric complexes with HsfA1 leads to nuclear retention and enha...

Heterostyly is thought to have evolved because it confers efficiency of cross-pollination. While it can be an alternative to an incompatibility mechanism in tube-shaped flowers, its effectiveness in dish-shaped flowers, such as those of Fagopyrum esculentum, has not been demonstrated. Stigmatic pollen loads were examined over the daily course of pollination in a planted field of this crop speci...

HE red color of the cultivated tomato, Lycopersicon esculentum Mill. is due to T the carotenoid lycopene. LEROSEN et al. (1941) and ZECHMEISTER et al. (1941) first analyzed the carotenoids of yellow (rr) and tangerine (tt) strains, each of which differs from the red by a single recessive gene. MACKINNEY and JENKINS (1952), JENKINS and MACKINNEY (1953), and TOMES et al. (1953) have examined the ...

The fungal pathogen Alternaria alternata f. sp. lycopersici produces AAL-toxins that function as chemical determinants of the Alternar ia stem canker disease in the tomato (Lycopersicon esculentum). In resistant cultivars, the disease is controlled by the Asc locus on chromosome 3. Our aim was to characterize novel sources of resistance to the fungus and of insensit ivity to the host-selective ...

A tomato gene that is induced early after infection of tomato (Lycopersicon esculentum Mill.) with root-knot nematodes (Meloidogyne javanica) encodes a protein with 54% amino acid identity to miraculin, a flavorless protein that causes sour substances to be perceived as sweet. This gene was therefore named LeMir (L. esculentum miraculin). Sequence similarity places the encoded protein in the so...

Buckwheat (Fagopyrum esculentum Moench) is a pseudocereal grown on limited extensions in Italy and Western Europe in general, but is currently the subject of considerable interest from the scientific community and consumers for its unique nutritional properties: it is rich in vitamins and mineral salts, dietary fiber and antioxidant substances, and it is free of gluten. This species also has ag...

rbc (EC 4.1.1.39) is a bifunctional enzyme involved in carbon fixation. It consists of eight chloroplast-encoded large subunits containing the active site and eight nuclear-encoded small subunits required for enzyme assembly and function (Akazawa et al., 1984). We report the isolation and analysis of a cDNA clone for the rbcS from Malus (Table I). A Malus leaf cDNA library (from an unclassified...

Aluminium (Al) toxicity is a major factor reducing crop productivity worldwide. There is a broad variation in intraand inter-specific Al resistance. Whereas the Al resistance mechanisms have generally been well explored in Al-excluding plant species, Al resistance through Al accumulation and Al tolerance is not yet well understood. Therefore, a set of 94 genotypes from three Fagopyrum species w...