Gamma rays role in the improvement of yield and early maturity in soybean

Seeds from soybean variety glycine max (L) Merr., were irradiated with three doses of gamma rays: 100, 150 and 200 Gray in order to obtain high yielding and early maturity mutants to grown after wheat in a two crop rotation. All the three doses induced morphological and physiological variation and malformation that increased with increasing the dose. Coefficient of variation values were higher in M2 than in their respective values of M3. The results showed no selection efficiency under the non optimal environmental growing conditions with this lack of efficiency being more evident for yield than for early maturity. Using FTAB statistical programme 20 M2 and M3 plant were selected for each character and when evaluated in the following generation, it was clear that selection efficiency was higher for early maturity than for yield; the latter being high yielding and 4 early maturing m 4 mutants were obtained. 3 tabs