| On the eighth day (Table 1) first leaf appeared
in a few of the treatments viz. 10,000r treatments of Kharchia, R. S. 9-11
and Malvi Ekdania; 20,000r treatment of Jaipur Local and Malvi Ekdania and
in 30,000r treatment of Jaipur Local and R. S. 9-11. On this day all the
controls had the first leaf appeared. On the twelfth day some of the seedlings showed signs of degeneration. The various treatments were observed for vegetative growih in respect to the number of leaves in each treatment. In all the treatments Kharchia seemed to miaintain the vigour as before. In 30,000r treatment next best were Malvi Ekdania and Jaipur Local. If all treatments be taken together, C. 591 was the earliest to show cessation of growth .activity followed by R. S. 31-1. In these varieties appearance of a reduced stem and the radicle was followed by more or less substantial necrosis which soon killed the young plants. In conclusion, treatment of a diploid wheat, Malvi Ekdania was showing the best germination and survival in all the treatments as compared to the rest of the hexaploid wheat varieties during the plant germination stage. Among hexaploid Wheats Kharchia showed best resistance to the ill effects of irradiation at this stage. This indicates that the effects of irradiation depends greatly upon the physical and biological properties of the material in consideration. These results showed that different varieties are differently susceptible to irradiation and may also show these differences in different phases of plant development. Also as many of the induced mutations in bread wheats are chromosomal in origin, the increase in the amount of chromosomal damage induced by gamma-rays appears to be the cause for lower germination activity and survivals since the occurence of too many chromosomal structural changes might lead to disturbed conditions in the life cycle of plant material under consideration. |
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