Identification and characterization of Capsicum mutants using, biochemical, physiological, and single sequence repeat (SSR) markers

Abstract

Identification and characterization of crop mutants through molecular marker analysis are imperious to develop desirable traits in mutation breeding programs. In the present study, macromolecular variations with altered morphological, quantitative, and biochemical traits were generated through chemically induced mutagenesis via alkylating agents and heavy metals. Statistical analysis based on quantitative traits indicating enhanced mean value in mutant lines selected from the M₄ generation as compared to previous generations. Identification and characterization of morphology in selected mutant lines are based on altered phenotypes (e.g. tall and dwarf mutant with high yield, fruits with thick texture and bold seeds, etc.) in comparison to control populations. The useful mutations were recorded in phytochemicals (e.g. capsaicin and dihydrocapsaicin) and macro and micro nutrients profile (e.g. protein, iron, copper, cadmium and zinc) in selected mutant lines of Capsicum annuum L. Single Sequence Repeats (SSRs) markers analysis in selected mutant lines revealed genetic diversity in Capsicum. annuum L. The total of 44 alleles were observed with average number of allele 4.00. The Unweighted Pair Group Arithmetic Mean Method (UPGMA) showed maximum dissimilarity was recorded between mutant A-III and F-III followed by mutant G-III and C-III, while mutant B-III and G-III showed the lowest dissimilarity to each other followed by mutant L-III and mutant J-III. Correlation and Principal Component Analysis (PCA) revealed genetic diversity among mutant lines indicating their prioritization over other traits in indirect selection and also revealed that mutants treated with lower and medium concentrations were divergent. These mutant lines could be suitable in crop improvement programs for the broadening the genetic base of C. annuum L. Hierarchical Cluster Analysis (HCA) grouped the mutants into two clusters with variable euclidean distance indicated heterogeneous mutant lines developed from induced mutagenic treatments. Thus beneficial mutations could be induced in chilli genotypes via mutation breeding to enhance genetic variability in limited resources, period, and efforts.