Towards genetic transformation of local onion varieties

PABLO MARINANGELI; BERNARDO DELUCHI; RAÚL RÍOS; PASCUAL FRANZONE; CLAUDIO GALMARINI; FERNANDO ROSSELLO; NÉSTOR CURVETTO

ELECTRONIC JOURNAL OF BIOTECHNOLOGY

Pontificia Universidad Católica de Valparaíso

Año: 2006 vol. 9 p. 331 - 334

0717-3458

The aim of this work was to explore the possibility of obtaining transgenic plants of onion varieties cultivated in Argentina, starting from calli induced from mature zygotic embryos, using two strains of Agrobacterium tumefaciens as transfection vectors. Mature embryos from  three varieties of ‘Valenciana’ onion, Torrentina, Cobriza INTA and Grano de oro were in vitro cultivated for callus induction. After three to four months an average of 57.4% success for the three varieties was reached. Transformation was carried out with Agl1 or LBA 4404 A. tumefaciens strains, both carrying a binary vector containing the marker gene gus a and the selection gene nptII. At the end of the selection period, 342 portions of calli were recovered and transferred to regeneration medium. Of the selected calli evaluated by the expresión of the b-glucuronidase enzyme, 42% presented extensive blue areas or were completely blue. At the end of the first subculture in the regeneration medium, 54 calli were considered potentially organogenic because of the  green areas observed. At the end of the wole regeneration period, just one normal plant was obtained, that was negative to PCR analysis using specific primers for gus a and nptII. The highest quantity of selected calli came from the Torrentina variety transformed with the strain LBA 4404.