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

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 4.36

LARGE- DNA TRASFORMATION AS TOOL TO TRASFER MULTIPLE GENE TRAITS IN TETRAPLOID POTATO

ERCOLANO M.R.*^,**, BALLVORA A.**, STEINBISS H.**, HENSELEWSKI H.**, SALAMINI F.**, GEBHARDT C.**

*) Department of Soil, Plant and Enviromental Science, Via Università 100, 80055 Portici, Italy

**) Max-Planck Institut für Züchtungsforschung, Carl von Linné Weg 10, 50829 Köln, Germany

BAC, biolistic transformation, potato, Phytophthora infestans

The cultivated potato (Solanum tuberosum) is a a polysomic polyploid with tetrasomic inheritance that make conventional breeding efforts rather difficult. Alternative strategies have been developed to obtain valuable genotypes. Relevant progress has been made by genetic engineering to understand and manipulate plant genomes. Several genes have been integrated in potato to increase resistance to abiotic and biotic stress and to modify agronomic and quality traits. However there are still some difficulties to transfer DNA molecules larger than 25-30 kb. Trasformation with large genomic fragments could be useful to facilitate simultaneous introduction of several genes and for molecular analysis of complex traits. In this work we tested the introduction of large pieces of DNA and phenotyped the transgenic plants for functional complementation. Transformation of potato with DNA from BAC plasmid BA87d17 with a total size of 108 kb is described. The large DNA fragments were transferred into plant by biolistic transformation to clone R1 gene for race specific resistance to Phytophthora infestans. In total, thirty-six plants were regenerated from three independent shooting experiments with DNA from BA87d17, with an average of about 8.5 plants per bombardment. Out of 34 kanamycin resistant regenerated plants 12 were resistant to P. infestans race 4 containing the Avr1 gene. To our knowledge, this is the first example of functional complementation by using large constructs in a cultivated plant. This metodology open the door to new and effective solutions to agronomic problems to the genetic improvement of the cultivated as well as other crop plants.