Division of Genetics, Indian Agricultural Research Institute, New Delhi
*A part of the M. Sc. thesis submitted by B. L. Dhonukshe, to the Facutty of the Post-Graduate School, I. A. R. I., New Delhi. hhe abstract of the present paper was presented to the ‘Symposium on use of Radiation and Radioisotopes in studies of Plant Productivity’ held in April, 1974 at Pantnagar.
Radiation induced mutation studies were carried with three dwarf wheat varieties vz., Sonalika, Chhoti Lerma and Hira which are considered to be single, double and triple dwaffs respectively. It was envisaged to induce more variability in polygenic characters like culm length, tiller number and yield, for enlarging the scope of selection in these varieties.
Induced variation in culm length, tiller number and yield was noted in all the three varieties in the M2 generation. Mean culm length was significantly decreased with increased variance in the M2 population of all the three varieties. In case of Sonalika and Chhoti Lerma, the variance and mean for tiller number and yield were increased considerably. In Hira, mean yield per plant was shifted in the negative direction, though mean and variance for tiller number were increased.
Enlargement of the means and variances in the dwarf varieties has provided a scope of selection and hence a further improvement of these varieties. A few promising selections have been made in all the three varieties.
