In Vitro Selection for Salt/Drought Tolerance in Colt Cherry (Prunus avium x pseudocerasus)

Abstract

Top-fruit trees are routinely exposed to several environmental abiotic stresses, amongst which salinity and drought probably stand as the most important factors, especially where irrigation water is scarce and/or contains high levels of salts. In this context, Prunus species were recently classified as being sensitive to both drought and salt stress (Maas 1985) and it would, therefore, be of special interest for fruit growers to have rootstocks of a wider environmental adaptation. Of the various possible Prunus genotypes, it was felt that a cherry rootstock would be the best genotype for the induction of tolerance to such stresses, since marginal soils are increasingly being used as sites for cherry orchards around the world, and also because there is no natural source of salt/drought tolerance among cultivated cherries (Fogle 1975). Over the last decades, selecting plants with resistance to salinity and drought has been one of the main objectives of many traditional breeding programs (Tal 1990). More recently, biotechnological approaches based on the exploitation of somaclonal variation have also been adopted for this purpose (Chandler and Thorpe 1986; Tal 1992).