RESUMO
Mutagenic effectiveness and efficiency are the utmost vital indices to determine the effective and efficient mutagenic concentrations for the generation of high frequency of desirable mutation in mutation breeding. Nevertheless, there are meager study are available for employing effective and efficient concentration of caffeine, EMS, Pb(NO3)2 and Cd(NO3)2 for the crop improvement. Thus, the current study was performed to assess the mutagenic effectiveness and efficiency of caffeine, EMS and heavy metals [Pb(NO3)2 Cd(NO3)2] and to determine the genetic variability of M2 and M3 lentil mutant lines. The frequency of different chlorophyll and chromophyll mutation was found highest at moderate and higher concentrations of chemical mutagens and heavy metals in M1 and M2 generation. The highest effectiveness was in 20 ppm Cd(NO3)2, followed by 20 ppm Pb(NO3)2, 0.10% EMS, and 0.10% caffeine. The present investigation also showed lower doses of caffeine, EMS, Pb(NO3)2, and Cd(NO3)2 were more efficient than higher concentrations, and caffeine was found more efficient followed by EMS, Pb(NO3)2, and Cd(NO3)2. Furthermore, a broad spectrum of viable mutations affecting different morphological characters of the plants viz., leaves, plant height, growth habits, flowers, pods, and seeds in M2 and M3 generation were recorded. Ten morphological mutants showing acceptable agronomic and horticultural features were identified, as genetic resources for further breeding.
RESUMO
Lens culinaris is a proteinaceous food crop that is consumed worldwide for protein requirements. Mutation breeding has been used to improve protein content, yield, and related traits, as well as to select highly desirable mutants that are economically significant. An investigation of genotypic variation in lentil germplasm was carried out using induced mutagenesis, with caffeine, ethyl methane sulfonate (EMS), lead nitrate, and cadmium nitrate as mutagens that resulted in 18 mutant lines in the M3 generation. For the present study, we analyzed the genetic diversity of lentil mutant lines using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and random amplified polymorphic DNA markers (RAPD). The heterozygosity of RAPD markers per primer ranged from 50.00-90.90% with an average of 71.04%. The genetic divergent analysis was performed using hierarchical clustering (UPGMA), exhibited that these mutant lines were classified mainly into five subpopulation or clusters. A close resemblance with highest genetic coefficient similarity (1.00) were observed between control and mutant H; between mutant M and E; between mutant Q and J2, while more divergent mutants were N2 with mutant B; and mutant R with mutant J1with least genetic coefficient similarity (0.22). Protein and mineral content (Fe, Zn and Cu) were increased significantly in some high yielding mutant lines concerning to the control plant, and showed polymorphic variations in polypeptide chains in terms of banding pattern. Stomatal morphology in high yielding mutants were perceived utilizing scanning electron microscopy (SEM), exhibiting variations in stomatal size, stomatal opening and number of stomata. The present study's promising mutant lines' biological, physiological, and molecular profiles provide a foundation for forthcoming preservation and consumption strategies to broaden the genetic diversity of the breeding population of lentil.
