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The value of combining hybridization and mutagenesis in sesame was examined to determine if treating hybrid sesame plant material with mutagens generated greater genetic variability in four key productivity traits than either the separate hybridization or mutation of plant material. In a randomized block design with three replications, six F2M2 varieties, three F2varieties, and three parental varieties were assessed at Odisha University of Agriculture and Technology, Bhubaneswar, Odisha, India. The plant characteristics height, number of seed capsules per plant, and seed yield per plant had greater variability in the F2M2 generation than their respective controls (F2), however, the number of primary branches per plant varied less than in the control population. The chances for trait selection to be operative were high for all the characteristics examined except the number of primary branches per plant, as indicated by heritability estimates. Increases in the mean and variability of the characteristics examined indicted a greater incidence of beneficial mutations and the breakdown of undesirable linkages with increased recombination. At both phenotypic and genotypic levels strong positive correlations between both primary branch number and capsule number with seed yield suggest that these traits are important for indirect improvement in sesame seed yield. As a result of the association analysis, sesame seed yield and its component traits improved significantly, which may be attributed to the independent polygenic mutations and enlarged recombination of the polygenes controlling the examined characteristics. Compared to the corresponding control treatment or to one cycle of mutagenic treatment, two cycles of mutagenic treatment resulted in increased variability, higher transgressive segregates, PTS mean and average transgression for sesame seed yield. These findings highlight the value of implementing two EMS treatment cycles to generate improved sesame lines. Furthermore, the extra variability created through hybridization may have potential in subsequent breeding research and improved seed yield segregants may be further advanced to develop ever-superior sesame varieties.

The investigation was made to estimate the combined effects of hybridization and ethyl methane sulphonate (EMS) induced mutagenesis on the variability of seed yield and its attributes in F3M3 generation. A total of 15 populations were grown in randomized block design (RBD) with three replications. F3M3 results indicated an increase in variability for plant height, number of capsules per plant and seed yield per plant, whereas non significant variability was observed for number of primary branches per plant in mutant populations than respective controls. Increased mean value and increase in variability in the present investigation denoted the occurrence of more favorable mutations and breaking up of undesirable linkages with enhancing recombination. Correlation study in F3M3 generation indicated remarkable changes among seed yield per plant and its component traits and these changes might have come through independent polygenic mutations and enhanced recombination of polygenes affecting different traits. The outcome of this study will facilitate in understanding the effectiveness of combined effects of hybridization and EMS induced mutagenesis for sesame improvement.

The present investigation was undertaken to estimate the combined effects of hybridization and Ethyl Methane sulfonate (EMS) on variability of polygenic traits associated with productivity in F1M1 generation of sesame crop. Three popular and well adapted sesame varieties were crossed and three nonreciprocal crosses were made. These F1s seeds were divided into two lots and one lot from each cross were used for EMS treatment. F1s seeds of each cross were presoaked separately in distilled water overnight followed by treating with 0.5 percent freshly preparer EMS solutions for 3 hours. Seed s of total nine populations (three EMS treated populations "F1 1 M1", three respective crosses as controls "F1s" and three parents) were shown in a randomized block design (RBD) with 3 replications during the summer season, 2017. Observations were recorded on four polygenic traits and statistical analysis like ANOVA of mean, standard deviation and CV was carried out and the significant differences among various treatments were tested by ' F' and t -tests. Reduced mean and increased standard deviation was observed for plant height whereas increased mean and standard deviation was observed for number of capsules per plant and seed yield per plant in EMS treated F1 1 M1s. Increased in variability in mutant populations for above characters might be due to breakage of linkage between favorable and unfavorable genes. Three F1M1 populations used in this study showed differential sensitivity with respect to different quantitative characters. The changes in different polygenic traits of mutant populations than respective controls must have arisen through induced micro-mutations. The relative magnitudes of genetic change in the hybrids as a result of chemical mutagen would be better known from analyses in later generations.