BREEDING TOMATOES FOR SALT TOLERANCE - VARIATIONS IN ION CONCENTRATIONS ASSOCIATED WITH RESPONSE TO SALINITY

Accessions of four tomato species, Lycopersicon esculentum Mill. (Le), L. pennellii (Corr.) O'Arey (Lpen), L. cheesmanii Riley (Lc), and L. peruvianum (L.) Mill., (Lper), and interspecific populations were irri gated with saline water under field conditions and concentrations of N a, K, Cl, Ca, and Mg in leaves and stems were determined. Potassium: s odium ratios in leaves and stems of salt-tolerant genotypes were highe r under salinity and were moderately changed hy salinity compared to t he sensitive genotypes. In the tolerant wild accessions and F1 (Le x L pen), Cl concentrations in leaves and the ratio between Cl in leaves t o Cl in stems were lower than in the sensitive l,e cultivar. Regulatio n of the K: Na ratio was found in tolerant wild accessions and toleran t Le cultivars, while regulation of Cl concentration in leaves was fou nd only in the wild germplasm. The effects of ion concentrations on dr y matter of interspecific segregating populations, F2 (Le x Lpen) and BC1 (Le x (Le x Lpen)), were studied by regression analyses. Dry matte r was positively correlated with the K : Na ratio in stems and negativ ely correlated with the Cl concentrations in leaves and stems, thus co nfirming the results obtained by comparison between the tolerant and s ensitive accessions.