The need to produce salt-tolerant crops was evident in ancienttimes (Jacobsen and Adams, 1958) and the possible ways to increasetolerance have been extensively rehearsed. Epstein et al. (1980)described technical and biological ‘fixes’ to theproblem of salinity. The ‘biological fix’ was foundedon salt tolerance having a genetic basis, for which the evidence(Epstein et al., 1980) was the existence of a salt-tolerantflora (halophytes) and differences in salt tolerance betweengenotypes within species. Varietal differences in salt tolerancehave been known since the 1930s (Epstein, 1977) and intraspecificselection for salt tolerance was, by the 1980s, shown to bepossible with rice (Akbar and Yabuno, 1977) and barley (Epsteinet al., 1980).
In spite of early promise, the ‘biological fix’has been slow in arriving. In 1993, Flowers and Yeo (1995) reviewedthe evidence for the paucity of new salt-tolerant cultivarsand concluded that the number was likely to be fewer than 30.Since 1993, there have been just three registrations of salt-resistantcultivars in Crop Science (Owen et al., 1994; Al-Doss and Smith, 1998;Dierig et al., 2001) and one patent registered in theUS (Dobrenz, 1999); one other patent claims a method to increasetolerance in cereals by the incorporation of a late embryogenesisabundant (LEA) protein (Wu and Ho, 1996). Flowers and Yeo (1995)concluded that, although salinity might be of profound localimportance, it had not yet had sufficient impact on regionalagricultural production to warrant the effort necessary to producenew salt-tolerant cultivars.
Answers to all your Biology Questions
