Iron (Fe) deficiency tolerance in tomato recombinant inbred lines obtained from tolerant and sensitive genotypes

The first aim of this study was to determine the iron (Fe) deficiency tolerance levels of the reciprocal recombinant inbred lines (RILs) in tomato. The RILs (F6 generation) have been created using tolerant and sensitive inbred parents for long time studies since 1994. The second aim was to obtain data which can be used to map the quantitative trait loci (QTL) for iron (Fe) deficiency tolerance in tomato. In this study, a total of 224 genotypes have been used. 107 genotypes contained the cytoplasm of the tolerant parent - 'Roza' - and 117 genotypes contained the cytoplasm of the sensitive parent-227/1. The plants were grown in a growth chamber in hydroponic medium. 35-day-old plants were subjected to additional 10 mM NaHCO3 to induce Fe-deficiency stress by stabilization of pH to 7.8-8.2. At least 10 plants from each F6 family were evaluated in each of five replications. After 10 days under Fe stress condition, plants were monitored for chlorosis. In order to quantitatively measure chlorophyll status, a Minolta chlorophyll meter (SPAD-502) was used to measure differential tones of green colour of young leaves. The plants were classified on the basis of SPAD and total Fe concentrations. The measured parameters of the RILs indicated the normal distributions. There were significant differences among the RILs for active, total irons (P?0.05) and chlorophyll (P?0.001) concentrations. It was concluded that Fe deficiency tolerance in tomato is inherited quantitatively and controlled by multi genes. The findings of this study showed there was a lack of strong definitive data supporting the possible cytoplasmic interactions in the inheritance of this trait