In vitro assessment of wheat tolerance to drought

Abstract

Analyzed in this paper were the in vitro effects of drought stress in 13 genotypes of winter wheat, one genotype of spring wheat, and three Triticale genotypes of different geographic origin. Callus tissue was induced from immature zygotic embryos (10-15 days after pollination) on a modified MS nutrient medium. After two weeks, callus tissue was transplanted onto the same medium enriched with 5% high-molecular polyethylene glycol (PEG 6000), which was used as the stress agent to produce the effect of drought chemically. A control group of calluses was grown on an identical medium but without PEG. After four weeks of growing calluses on these mediums, we assessed callus mass survival ability of the genotypes before the transplantation as well as percentage reduction of callus fresh weight after the transplantation onto the nutrient medium with 5% PEG. Statistically significant differences were found among the genotypes in their response to the induced stress. The best survival ability before the transplantation was found in the genotype Mexicol20 (83%), while the lowest was recorded in Slavija (11.3%). Culture growing under stress conditions significantly reduced callus fresh weight in all of the genotypes. The lowest decrease of the callus mass relative to control was recorded in Rozofskaja (14.4%) and the highest in Miranovska (58.4%), indicating the genotypes' tolerance levels towards drought stress.