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

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

GENETIC TRANSFORMATION OF FRAGARIA SPP. BY USING DIRECT AND AGROBACTERIUM-MEDIATED TECHNIQUES

DONNOLI R., SABINA M.R., MARTELLI G., SUNSERI F., GRECO I.

Dip. Biologia, Difesa, Biotecnologie AgroForestali, Università della Basilicata, C.da Macchia Romana, 85100 Potenza

sunseri@unibas.it

strawberry, Fragaria vesca L., particle bombardment, somatic embryogenesis

Several studies on organogenesis and genetic transformation have been reported (Jones et al. 1988, Plant Cell Tis. Organ Cult. 12: 235-241; Nehra et al. 1990, Plant Sci. 66: 119-126; Orlando et al. 1997, Plant Cell Rep. 16: 272-276) in the cultivated strawberry (Fragaria x ananassa Duch.) despite its octoploid genome structure. On the other hand, the genetic transformation in the diploid Fragaria vesca L. is not frequently reported (El Mansouri et al. 1996, Plant Cell Rep. 15: 642-646; Haymes and Davis 1998, Plant Cell Rep. 17: 279–283).

Since different transformation strategies have been developed during the past 10 years, the techniques are highly genotype-dependent and the transformation frequencies obtained are frequently below 10%.

Three strawberry cultivars (Clea, Irvine, Pajaro) useful for South Italy conditions and four accessions of Fragaria vesca, coming from Southern Italy areas, were utilized and tested for plant regeneration and genetic transformation by using particle bombardment and Agrobacterium-mediated techniques. Four different MS-based media were tested in order to obtain callus proliferation and shoot regeneration. Leaf disks were also co-cultivated with a LBA 4404 Agrobacterium tumefaciens containing a plasmid with the selectable marker gene NPTII. The infection was performed in a vacuum chamber for 20 minutes.

High percentage of organogenesis and plant regeneration were obtained in strawberry (cv “Clea”) and Fragaria vesca by using a MS medium supplemented with 5 µM IBA and 5 µM BAP. Somatic embryogenesis events were observed when the explants were mantained in darkness during callus induction step (the first 4 weeks). A sufficient number of genetic transformation events were obtained either in strawberry or in Fragaria vesca. Genetic transformation results by direct and undirect methodologies were compared and an interesting results by particle bombardment were observed.

The genetic transformation protocols for the genotypes utilized were optimized, several experiments will carry out in order to introduce several agronomic interesting genes in Fragaria spp. As recently reported by Cordero de Mesa et al. (Aust. J. Plant Physiol. 2000, 27: 1093-1100) in Fragaria, combined techniques (wounding tissue before Agrobacterium infection, by means of particle gun) that could improve the transformation efficiency will be test.

In the present study, a highly efficient and reliable protocol for plant regeneration and interesting results of transformation in strawberry and in Fragaria vesca L. by particle gun has been reported. In the protocol, either organogenesis or somatic embryogenesis has been observed.