Articles
PEAR BREEDING AND SELECTION FOR FIRE BLIGHT RESISTANCE
The resistant parents were firstly choosen in oriental species : Pyrus pyrifolia, Pyrus ussuriensis or in hybrids between Pyrus communis and these species.
The poor quality of the fruits of the selected varieties prevented them from being cultivated in commercial orchards.
Before 1974 most of these varieties and some hybrids not yet named have been introduced in the collection of the INRA Research station of Angers.
In 1974 close contacts were established with North american and canadian researchers and the following conclusions were drawn out :
- The use of minor resistances in Pyrus communis could lead to less susceptible varieties with a good fruit quality if these low levels of resistance are accumulated through successives generations,
- The range of picking dates aimed at by these researchers is about the picking date of ‘Williams’ and the selected flavour is the one of ‘Williams’,
- Growers in these countries did not grow any of these new varieties.
These reasons made clear for us the need to begin in France our own breeding program in order to select new varieties with these two main characteristics :
- a low susceptibility to fire blight
- a late or medium late picking date.
The out-break of fire blight in 1978 in the pear growing area of the South West of France, where climatic conditions are usually favourable to the disease, Leconte et al. (/1/) allowed us :
- to test hybrids in an experimental orchard near Dax,
- to establish a collection of 60 european varieties in order to know their susceptibility in our conditions.
First results of these two actions are presented hereafter.