Regresar

Detection of candidate genes for resistance and plant development in guava (Psidium guajava L.)

Abstract:

Guava (Psidium guajava L.) is native to the tropical regions of the Americas. Its economic importance is related to the use of its fresh fruit that contains high amounts of vitamins A and C, dietary fiber and calcium and to processed food products (juice, cream, marmalade, desserts etc.). Thus, in addition to the demand for local consumption, guava presents a valuable opportunity for export. The molecular analysis of the guava genome is part of an international project ("GUAVAMAP") funded by the European Commission under INCO-DEV-2. The objective of the present work was to identify gene families representing putative genes for resistance (resistance gene-like (RGL) sequences) and homeotic genes involved in plant development. For this, a guava genomic cosmid (COS) library was established for the economically important Cuban cultivar "Enana roja cubana". COS clones (6-7 equivalents of the guava genome) were individualized and spotted in duplicates onto membrane filters (macroarrays). Molecular hybridization was done with heterologous probes for resistance (RGL sequences) and homeotic genes (MADX-box and HOMEO-box genes). The macroarray hybridization data were verified by Southern blot analysis on isolated COS clone DNAs. A total of 117 positive clones for RGL sequences, 37 for MADS-box and 22 for HOMEO-box were identified. Guava mutants with respect to growth habit and flower morphology are present in the Cuban germplasm collection and may provide the material for a possible association of the mutant phenotype to the isolated genes.