Paraquat Tolerance of Bread Wheat (Triticum aestivum L.) Genotypes

The drought stress in one of the most significant environmental stress limiting the plant production over the agricultural lands of the world. Since, the stress caused by the pesticide paraquat (1, 1-dimenthy1-4, 4 bipyridilium dichloride) is similar to water stress which decreases the chlorophyll content of the leaves, paraquat tolerance is successfully used to determine the wheat genotypes resistant to drought. This study was carried to determine the Paraquat (PQ) tolerance of 64 bread wheat genotypes. The parameters of SPAD values before and after paraquat treatments, chlorophyll loss caused by paraquat and correspondingly calculated Paraquat Sensitivity Indexes (PSI) was investigated in this study. Significant differences were observed among the wheat genotypes with regard to all of the investigated parameters. SPAD values of genotypes before PQ treatment varied between 33.6-51.3 and varied between 28.8-47.0 after PQ treatment. Chlorophyll loss of genotypes due to PQ treatments was between 2.0-23.3%. PSI values of genotypes were found to be between 0.18-2.10. The varieties Cetinel, 2000, Alparslan, Sultan 95, Karahan and KirmiziYerli were found to be the most tolerant and Ankara 093/44, Ak 702, Haymana 79 and Conkesme varieties were found to be the most sensitive genotypes.