Abstract

ESPINOSA-HUERTA, Elsa; QUINTERO-JIMENEZ, Anareli; CABRERA-BECERRA, K. Virginia  and  MORA-AVILES, M. Alejandra. Stable and efficient Agrobacterium tumefaciens mediated transformation of Phaseolus vulgaris. Agrociencia [online]. 2013, vol.47, n.4, pp.319-333. ISSN 2521-9766.

Common bean breeding requires novel techniques to incorporate genes that may not be available in bean genetic diversity. The objective of the present study was to analyze the main variables involved in Agrobacterium tumefaciens-mediated transformation of common bean towards providing an efficient system to introduce new agronomic traits. Bean cultivars Flor de Mayo Anita and Pinto Saltillo were inoculated with different A. tumefaciens strains, constructs and selection was done using two selection agents (kanamycin ot glufosinateammonium herbicide). Five-day old hypocotyls regenerated organogenic buds (cell clusters) 5 d after inoculation. A randomized complete blocks experimental design was used and the experimental unit was a petri dish with at least 10 hypocotyls. Analysis of variance and Tukey test (p≤0.05) were perfotmed on data. Transformation efficiency was 10-28 % with small variations due to the genetic backgtound of each cultivar, the Agrobacterium strain and selection agent used. Transfotmation efficiency was higher using kanamycin (28.6 %) in relation to glufosinate-ammonium (10.2 %). Similarly, Pinto Saltillo cultivar showed better regeneration response (21-28 %) than that of Flor de Mayo Anita cultivar (10-17 %) and this was consistent when selection agents were compared within each cultivar. Molecular analysis for detection and gene expression quantification by using end point PCR and q-PCR showed evidence of presence and activity at different expression levels through several generations (T0 to T3). transformed lines of common bean with potential for fungal resistance and drought tolerance were successfully obtained via Agrobacterium tumefaciens with evidence of generic stability.

Keywords : bud clusters; drought stress tolerance; fungal resistance; Gamborg medium; hypocotyls; organogenesis.

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