3. Mutants for ear length:

Variation for ear length was also observed. Ear length in control ranged from 10-13 cms, while in treated population it ranged from 6-14 cms. Therefore, in general was a decrease in ear length in treated lines.

4. Mutants for awn length:

The M₃ population was also analysed for awn length. Both fully awned and awnless types were recovered. The control showed no variation and was fully awned. There were only six lines which were almost awnless. Another 70 lines showed segregation for variable awn length. Chimeric plants having variable awn length were also avaialable.

5. Mutants for ear morphology:

The ear morphology in treated lines was compared with control and a number of mutants were recorded:

(a) Compactoids: These were of three types: (i) squarehead, (ii) subcompactoid and (iii) compactoid. Several mutants showing variation in the density of ear were detected. The variation in ear density was often associated with a variation in plant height. For instance, a compactoid ear was associated with shorter plant height and subcompactoid with an intermediate plant height.

(b) Speltoids: Speltoid mutants were also isolated. In these mutants, the ears were lax and the glumes tightly enclose the kernels. The mutants were also late in maturity. These were hard in threshing and had sterile basal and terminal spikelets.

(c) Sphaerococcoids: Sphaerococcoid mutants were less frequent and were usually associated with mutations for erect leaves and short culm.

(d) Vavilovoids: These mutants were also infrequent and had short and lax ears with some sterile spikelets.

6. Mutants for heading time and maturity:

Mutants for heading time and maturity time were also isolated. In the control, the heading took 100-101 days for flowering. In the early flowering mutants, the heading time ranged from 95-99 days, while in the late flowering ones, it ranged from 102-110 days.

(Received June 6, 1974)