Effect of chemical mutagens on Sesbania sesban

摘要

The mutagenic effects of two chemical mutagens, EMS and NMU on seed germination, seedling survival and growth and performance of plants with reference to the fodder yield related traits in Sesbania sesban were studied. Treatments of varying doses ofmutagens exhibited marked effects on all the parameters. Chemical mutagenesis had considerable deleterious effects on all the traits studied when compared to control. The most affected parameters were seed germination, seedling survival and dry matter weight, indicating that mutagens affect establishment of the propagules in the short, term and also the physiology and growth rate, etc. in the long run. NMU showed comparatively more lethality in the higher doses of the treatments than EMS. There was a gradual decrease in the height, above ground biomass produced as well as pod length in the plants developed from the mutagen-treated seeds in correspondence with the increase in the doses of mutagens and the decrease was significant in case of seeds per pod, seed yield and pollen fertility. Pod length and, seed yield per plant were drastically affected at higher concentrations of NMU than those of EMS. LD 50 value was found to be 0.076 per cent NMU for the mutation studies involving NMU as the mutagen. Pollen fertility was reduced by more than 50 per cent with the increased doses of mutagens. On cytological examination, it was revealed that the frequency of irregularities caused by mutagens was more in meiosis than in mitosis and more meiotic irregularities were generated in anaphase I than in metaphase I.