comparative study with commercial rootstocks to determine the tolerance to heavy metal (Pb) in the drought and salt stress tolerant eggplant breeding lines

Negative effects of heavy metals on plants are peroxidation of lipids in cell membranes, production of free oxygen radicals, disorders in photosynthesis, damages in DNAs and as a result death of the cell. Plant development, productivity and quality of the fruits are decreased in the plants that are exposed to Pb stress which is one of the most toxic heavy metals. Usage of rootstocks which is mainly used against biotic stress conditions also seems to be defined as a solution to abiotic stress conditions such as heavy metal stresses. In eggplant production, wild species and hybrids are used as rootstocks against soil based pathogens and nematode. Reactions of improvement lines derived from local gene resources for rootstock improvement to heavy metal stress which is one of the abiotic stresses were determined. While determining the resistance against Pb stress, commercially used eggplant rootstocks are compared. In this study 4 eggplant cultivars (S. melongena: Burdur Bucak, Mardin Kızıltepe, Artvin Hopa and Kemer) whose resistance potential against salt and drought stresses had been previously revealed and 6 rootstocks of wild eggplant species or hybrids (AGR-703, Doyran, Hawk, Hikyaku, Köksal-F1 and Vista-306) were tested against Pb stress. Eggplant seedlings were applied to 0, 150 and 300 ppm Pb solutions (Pb(NO3)2) during 4-5 true leaf stage. 20 days after the stress application wet and dry weight of green parts and roots, height of the body part and leaf areas were measured. Pb tolerance of Köksal F1 and AGR703 rootstocks were higher than other commercial rootstocks. Mardin Kızıltepe and Burdur Merkez genotypes which have high tolerances against abiotic stress gave lower values with respect to Artvin Hopa and Kemer which are sensitive genotypes and many other rootstocks while comparing the reduction ratios of stress signs such as shoot fresh weight and shoot length according to control under Pb stress