II.32 Improvement in yield attributes and grain protein through gamma irradiation in barley (Hordeum vulgare).
Jagdamba Singh and Rishi Muni Singh. Department of Genetics & Plant Breeding Faculty of Agriculture, Banaras Hindu Unviersity Varanasi 221005, India.
Seed of barley cultivar "Amber" adjusted to different seed moisture levels i.e. 7.5, 6.0, 5.5, 4.5, 3.5 and 3.0 per cent, were irradiated with gamma rays (15 kr) to improve its yielding ability and grain quality. Out of a large number of mutants, affecting several morphological characters, isolated in M2 and further tested in M3, five mutants appeared quite promising. These mutants were grown in randomized block design with three replications along with control line 'Amber' in M4 generation. Observations were recorded on yield components and total protein (Table 1).
It is evident from the data that all the mutants were shorter than the control and differed significantly at 5% level. The height of mutants ranged from 63.3 cm to 98.1 cm as against 112.4 cm for control. The mutants showed height reduction from 12.72 to 43.68 percent over the control value. The maximum reduction in height occurred in mutant HUB-5 followed by HUB-3. The mean number of effective tillers of mutants did not differ significantly from control. The spike length of mutants HUB-2, 3 & 5 differed significantly and those of HUB-1 and HUB-4 did not differ significantly from control. Number of spikelets/spike and number of grains/spike increased in mutants HUB-1 and HUB-4 and decreased in the remaining mutants as compared to control. Yield/ plant was also higher in these mutants. Test weight and yield/plot of mutant HUB-1 was higher and of remaining mutants lower than the control.
Total protein of different mutants ranged from 9.56 to 12.19 per cent as against 8.83 percent for control. All mutant showed significant improvement in total protein. The magnitude of increase in total protein over the control value was 8.26 to 38.05 per cent.
It is quite clear from the data that out of five mutants studied for different characters, mutants HUB-1 and HUB-4 combined a number of desirable traits such as reduced plant height, erect growth habit, bright grain colour, increased no. of grains/spike, test weight, yield/plant, and total grain protein than the mother variety. The two other mutants HUB-5 and HUB-3 having very reduced plant height and higher protein content can be used in crossing programme. It may be added that all these mutants occurred in low moisture levels i.e. between 3.5 to 7.5 per cent.
Findings of present investigation clearly indicates the role of low moisture in modifying the effectiveness of gamma rays in inducing desirable mutations for both yield and quality characters in barley.
