Determination of genotipic variations for salinity tolerance at early plant growth stages in green beans

ABSTRACTMSc THESISDETERMINATION OF GENOTIPIC VARIATIONS FORSALINITY TOLERANCE AT EARLY PLANT GROWTHSTAGES IN GREEN BEANSSibel KOÇDEPARTMENT OF HORTICULTUREINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF CUKUROVASupervisor : Assoc. Prof. Dr. H.Yıldız DAŞGANYear : 2005, Pages : 87Jury : Assoc. Prof. Dr. H.Yıldız DAŞGANProf. Dr. Nebahat SARIAssist. Prof. Dr.Selim EKERIn this study, 67 various bean genotypes were screened in the early plantgrowth stages for the salinity tolerance by the deep flowed water culture technique.These genotypes were exposed to 125 mM of NaCl salinity stress and wereinvestigated for the ion regulation. Moreover, new practical techniques with highvalidity were tried in order to employ them in mass screening studies. Genotypesdeveloped different mechanisms for ion regulation under salinity stress condition.While some absorbed plenty Na ion in their bodies and showed high tissue tolerancewith a mechanism called Na-inclusion, some absorbed few Na ion and protect themself from its danger with a mechanism called Na-exclusion. The total 67 beangenotypes expressed a very high variation for salinity tolerance and the 13, 17, and37 of them were classified as highly tolerant, medium tolerant, and susceptible,respectively.At the end of the present study examing the green bean cultivars for salinitytolerance with mass screening, the different parameters were determined for eitherthe Na-inclusion group or Na-exclusion group. The low Na/K and Na/Ca ratios, thelow Na concentration, and the high K and Ca concentrations were found to besuitable salt tolerance screening criteria for the Na-exluder bean genotypes. The highNa/K and Na/Ca ratios and high Na and the low K and Ca concentrations were foundto be suitable salt tolerance screening parameters for the Na-includer bean genotypes.Key words :Phaseolus vulgaris L., NaCl, salt tolerans, screening, ion regulationsII