Exploring the efficiency of Ethyl Methane Sulfonate (EMS) and Sodium Azide (SA) to induce mutation in chili (Capsicum annuum L.) germplasm

Exploring genetic diversity in traits of interest and utilizing it to breed high yielding, disease-resistant and high market value varieties is the prime objective of plant breeders. Unfortunately, genetic diversity in most of the crops has declined due to selection and reutilization of already adapted germplasm. Chemical mutagens are widely used to create novel changes in germplasm; however, these have been rarely tested for chili germplasm in Pakistan. We used ethyl methane sulfonate (EMS) and sodium azide (SA) to induce mutations for obtaining novel alterations in morphological and yield-related traits of four chili genotypes (i.e., 'Mexi', 'Dandi Cut', 'Nageena' and 'Talhari'). Firstly, concentrations of both mutagens were calibrated, i.e., 1.5 % EMS and 0.5 % SA. Afterwards, seeds of four chili cultivars were treated and grown in peat trays. As the nursery was established, seedlings were transferred to media (sand: silt: clay + 1 kg well-decomposed FYM) after 30 days of germination. Different mutants were isolated based on differential morphological and phenotypic expressions. It was found that efficiency of EMS was greater than SA and more variants were noticed in case of EMS-treated populations. Genetic analysis showed that almost all the traits were affected by mutagens in the M1 generations although the stability of isolated mutants was not checked in later generations. All the traits showed higher estimates of heritability but in some traits genetic advance was non-significant. It is recommended that isolated mutants could be used as rich genetic diversity source to breed new varieties. Furthermore, EMS proved a suitable mutagen for targeted mutations.