Variation induced by plant regeneration from cultures treated with NAA and seed irradiation for soybean improvement

The selection of high 100-seed weight with 10% intensity in progeny regenerated from callus cultures treated with 0, 1, 2 mg/L NAA caused an improvement of this trait in R2-generation for A 3127 and Williams 82 varieties. The improvement ranged from 13.9% (l mg/L) to 18.7%(2 mg/L) and from 23.1% (2 mg/L) to 31.1% (1 mg/L) for Williams 82 and A 3127, respectively. The improvement in weight of 100-seeds was associated with an increase in No. of pods per plant and seed yield per plant for 1 mg/L NAA. On the other hand, post irradiation of seeds with 40 Gy and selection in M2 for high 100-seed weight caused an advancement for this trait in M3 by about 8% (Williams 82) and 19.4% (A 3127) with no significance differences in the other studied characters Moreover, high heritability values were noted in M3-population for moderate dose (40 Gy) as well as in R2-population with 1 mg/L NAA (A 3127) and 2 mg/L (Williams 82) for the most characters. Therefore, furthermore effective selection of this trait and/or other characters could be achieved in subsequent generations. 3 tab