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The contrasting views of agricultural botanists Rowland Biffen and John Percival, on the relationship between science and technology based on plant breeding and Mendelian genetics, is influenced by the universities to which they are associated. Rowland Biffen of Cambridge University feels that improvement in crop cultivation requires the application of Mendelian genetics and techniques discovered during pure science research. John Percival of the University College at Reading believes that the existing traditional plant breeding methods are adequate to yield improvement in crop cultivation by the application of a systematic and rigorous approach to selection and varietal trials.

Widespread European consumer concern over the safety of genetically engineered food may sour trade relations between Europe and the US, the leading proponent of the biotechnology industry. Public pressure to reform biotechnology regulation has led the European Union to propose international biosafety standards. However, the biotechnology industry in the US expects free trade principles will outweigh environmental concerns.

Stress caused by the increased salinity of irrigated fields impairs plant growth and is one of the major constraints that limits crop productivity in many important agricultural areas. As a contribution to solving such agronomic problems, we have carried out a large-scale screening for Arabidopsis thaliana mutants induced on different genetic backgrounds by EMS treatment, fast neutron bombardment, or T-DNA insertions. From the 675,500 seeds we screened, 17 mutant lines were isolated, all but one of which yielded 25-70% germination levels on 250 mM NaCl medium, a condition in which their ancestor ecotypes are unable to germinate. Monogenic recessive inheritance of NaCl-tolerant germination was displayed with incomplete penetrance by all the selected mutants, which fell into five complementation groups. These were named SALOBRENO (SAN) and mapped relative to polymorphic microsatellites, the map positions of three of them suggesting that they are novel genes. Strains carrying mutations in the SAN1-SAN4 genes display similar responses to both ionic effects and osmotic pressure, their germination being NaCl and mannitol tolerant but KCl and [Na.sub.2] [SO.sub.4] sensitive. In addition, NaCl-, KCl-, and mannitol-tolerant as well as abscisic-acid-insensitive germination was displayed by san5, whose genetic and molecular characterization indicates that it carries an extremely hypomorphic or null allele of the ABI4 gene, its deduced protein product lacking the APETALA2 DNA binding domain.