ISHS Acta Horticulturae 465: IV International Peach Symposium
GENETIC RESISTANCE TO PLUM POX POTYVIRUS IN PEACHES |
| Authors: | V. Escalettes, F. Dosba, M. Lansac, J.P. Eyquard |
| Keywords: | Prunus persica, Plum pox potyvirus, resistance, embryos, organogenesis, thidiazuron, tissue culture |
| Abstract:
Sharka disease due to the Plum pox potyvirus (PPV) has become one of the most damaging diseases of Prunus species. Breeding of resistant cultivars requires to find genitors of resistance or to develop transgenosis. More than 250 cultivars or hybrids of peaches or wild species have been evaluated towards PPV between 1991 and 1997. Only two clones belonging to ornamental peaches and eight seedlings of P. davidiana showed some resistance to the virus indicating that sources of PPV resistance among peach group are very limited, particularly when the pathogen variability is taken into account. Genetic engineering offers great possibilities in such woody species to integrate resistance genes in commercially interesting cultivars. It first requires the control of regeneration steps. A direct regeneration protocol was developed on GF305 immature cotyledons. It gave till 22% regeneration on cotyledons removed from the most immature embryos (8% of maturity index). Regeneration could also be obtained on 39 and 65% maturity index cotyledons on media containing thidiazuron (3.0 or 7.5μM) associated with NAA or IBA. Until now, good sources of resistance to PPV within the peach group are not available. These first results on GF305 regeneration encourage us to envisage the obtention of transgenic individuals for this commercially important clone in the near future and to develop new strategies against PPV. | |
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