Journal Article

Development and characterization of an EMS-mutagenized wheat population and identification of salt-tolerant wheat lines

Sirijovski, Nick, Shakil, Shahriar S. M., Olsson, Olof, Lethin, Johanna, Aronsson, Henrik, Töpel, Mats, Hassan, Sameer

2020

Overview

Background Triticum aestivum (wheat) is one of the world’s oldest crops and has been used for >8000 years as a food crop in North Africa, West Asia and Europe. Today, wheat is one of the most important sources of grain for humans, and is cultivated on greater areas of land than any other crop. As the human population increases and soil salinity becomes more prevalent, there is increased pressure on wheat breeders to develop salt-tolerant varieties in order to meet growing demands for yield and grain quality. Here we developed a mutant wheat population using the moderately salt-tolerant Bangladeshi variety BARI Gom-25, with the primary goal of further increasing salt tolerance. Results After titrating the optimal ethyl methanesulfonate (EMS) concentration, ca 30,000 seeds were treated with 1% EMS, and 1676 lines, all originating from single seeds, survived through the first four generations. Most mutagenized lines showed a similar phenotype to BARI Gom-25, although visual differences such as dwarfing, giant plants, early and late flowering and altered leaf morphology were seen in some lines. By developing an assay for salt tolerance, and by screening the mutagenized population, we identified 70 lines exhibiting increased salt tolerance. The selected lines typically showed a 70% germination rate on filter paper soaked in 200 mM NaCl, compared to 0–30% for BARI Gom-25. From two of the salt-tolerant OlsAro lines (OA42 and OA70), genomic DNA was sequenced to 15x times coverage. A comparative analysis against the BARI Gom-25 genomic sequence identified a total of 683,201 (OA42), and 768,954 (OA70) SNPs distributed throughout the three sub-genomes (A, B and D). The mutation frequency was determined to be approximately one per 20,000 bp. All the 70 selected salt-tolerant lines were tested for root growth in the laboratory, and under saline field conditions in Bangladesh. The results showed that all the lines selected for tolerance showed a better salt tolerance phenotype than both BARI Gom-25 and other local wheat varieties tested. Conclusion The mutant wheat population developed here will be a valuable resource in the development of novel salt-tolerant varieties for the benefit of saline farming.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abiotic stress / Agricultural and Veterinary sciences / Agricultural Biotechnology / Agricultural production / Agriculture / Bangladesh / Biomedical and Life Sciences / Bioteknologi med applikationer på växter och djur / Botanical research / Chemical mutagenesis / Chemical properties / Comparative analysis / Coverage / Crops / Crops, Agricultural - genetics / Cultivars / Deoxyribonucleic acid / DNA / drought / EMS / Ethyl Methanesulfonate / Europe / Filter paper / Flowering / Flowers & plants / food crops / format / Gene expression / Gene mutation / Genetic aspects / genetics / Genetics and Breeding in Agricultural Sciences / Genetics and crop biotechnology / Genetik och förädling inom lantbruksvetenskap / Genomes / Germination / Grain / grain quality / Halophytes / human population / Human populations / Identification and classification / Lantbruksvetenskap och veterinärmedicin / leaf morphology / Life Sciences / Morphology / Mutagenesis / Mutagenesis - genetics / Mutagenized population / Mutagens / Mutant frequency / Mutants / Mutation / Mutation Rate / Northern Africa / Nucleotide sequence / nucleotide sequences / Phenotype / Phenotypes / plant / Plant breeding / Plant growth / Plant Sciences / Population / Research Article / responses / root growth / Salinity / Salinity tolerance / Salt / Salt tolerance / Salt Tolerance - genetics / Screening / Seeds / Single-nucleotide polymorphism / Sodium chloride / Soil salinity / Tolerance / Tree Biology / Triticum - genetics / Triticum aestivum / Varieties / West Asia / Wheat