Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 5.13

HCRVF2 GENE, CLONED FROM THE VF REGION, IS ABLE TO CONFER RESISTANCE TO SCAB (VENTURIA INAEQUALIS) IN GALA APPLE TRANSFORMED PLANTS

E. BELFANTI*, E. SILFVERBERG-DILWORTH**, M. BARBIERI*, S. TARTARINI*, A. PATOCCHI**, J. ZHU*^, ***, B.A. VINATZER*^,****, L. GIANFRANCESCHI**^,*****, C. GESSLER**, S. SANSAVINI*

*) Dipartimento di Colture Arboree (DCA), University of Bologna, Italy

**) Plant Pathology, Institute of Plant Science, Swiss Federal Institute of Technology, ETH Zurich, Switzerland

***) Current address: Dept. of Horticulture, Laiyang Agricultural University, Laiyang, Shadong, P. R. China

****) Current address: Dept. of Molecular Genetics and Cell Biology, University of Chicago, USA

*****) Current address: Dept. of Biomolecular Sciences and Biotechnology, University of Milan, Italy

Venturia inaequalis, Malus x domestica, Vf-resistance gene cloning, genetic transformation, GM-apples

Malus floribunda 821 carring the Vf gene has been used in breeding programs for over fifty years as resistance source to apple scab. Cultivars derived from this wild species showed to be resistant to the infection of Venturia inaequalis but at a lower level than M. floribunda 821 and this is probably due to the loss of some minor genes during the gene introgression. The characterization of the Vf gene started at Bologna’s DCA and Zurich’s ETH and led to identify its position inside a region of 350kb on chromosome 1. Three similar expressed sequences, named HcrVf1, HrVf2 and HcrVf4, were then isolated from this region and they were homologous to the Cf resistance gene family of tomato. HcrVf2 gene was introgressed into Gala leaf and internode explants by Agrobacterium tumefaciens mediated transformation. Several transformed lines expressing the transgene were obtained and preliminary in vitro results indicated an increase of resistance (Barbieri et al., 2003). These plants were than evalutated in greenhouse by infection with a conidia suspension of Venturia inaequalis. The results show that the introgression of HcrVf2 gene is sufficient to transform the susceptible cultivar Gala into a resistant one. However it’s not yet possible to affirm that HcrVf2 is the only gene at Vf region that confer resistance toward scab infection as the effect of the other expressed sequences remains to be investigated.