Mutation breeding of strawberry for tolerance to water stress using ethyl methane sulfonate
Chemical and physical mutagens have been used to increase genetic variability in many plants. Among chemical mutagens, ethyl methane sulphonate (EMS) is quite commonly used in plants since it causes a high frequency of nucleotide substitutions detected in different genomes. Although in vitro propagation of strawberry is simple and easy, in vitro mutagenesis studies are very limited, especially under abiotic stress conditions. Water stress is a serious environmental restriction to strawberry productivity. Hence, the objective of this study was to evaluate their effectiveness in inducing mutations and also with the aim of producing mutants tolerant to water stress. In the experiment, the effects of different EMS concentrations (0, 0.2, 0.4, 0.6 and 0.8%) and durations (60, 90 and 120 min) under in vitro polyethylene glycol 6000 (PEG 6000) induced water stress conditions have been investigated using tissue-cultured meristems on Osmanli, Camarosa and Festival strawberry cultivars. The results showed that water stress tolerant lines could be obtained from induced variations. Explant survival rates, number of shoots, number of roots, root length, number of leaves, plant health index and plant survival rates decreased when EMS concentrations and durations were increased on tested strawberry cultivars. In Osmanli and Camarosa strawberry cultivars, 30% survival rate was determined in control treatment (3% PEG without EMS), whereas 40% survival rate was indicated in No 1 treatment (60 min/0.2% EMS) with 3% PEG6000 medium. In the experiment, the highest shoot number, root and leaf number explant‑1, plant health index and plant survival rates were determined in No 1 treatment (60 min/0.2% EMS). Depending on increase in concentrations and durations, abnormalities such as dwarfism, colour changes on leaves, and aberrant morphologies were observed in plants. The highest morphological variant ratio was 2.22% for Osmanli and No 7 treatment (60 min/0.6% EMS) while the lowest ratio was 1.11% in No 1 treatment (60 min/0.2% EMS) which has been identified under the PEG-induced in vitro condition. This study demonstrates the application of in vitro mutagenesis in selection of water stress tolerant lines of strawberry as a convenient, cheap, and rapid technique.
Adak, N. and Kaynak, L. (2020). Mutation breeding of strawberry for tolerance to water stress using ethyl methane sulfonate. Acta Hortic. 1285, 235-246
in vitro mutagenesis, chemical mutagen, PEG 6000, abiotic stress