Transformation of genetical ratios in crosses involving X-ray irradiated pollen grains in rice (Oryza sativa L.)

Early reports on radiation dependant-genetical transformation indicated that sublethal levels of irradiated pollen grains allow development of normal hybrid progeny but in subsequent generations they occasionally express paternal characters due to differential inheritance of donor genes. However, detailed genetic analysis has not yet been followed up for confirmatory analysis of genetic transformation especially in rice (Oryza sativa L). Presently different crosses of (normal and treated) Cherumodan (green) x Japan Violet (purple) were effected by using X-ray irradiated pollen grains of the male parent in the treated crosses. The crosses were studied up to F₃ of the control and M₃F₃ of the treated generations for inheritance/differential inheritance for fourteen morphological characters. The results showed transformation of genetical ratios in respect of ten morphological characters in the M₂F₂ populations when compared to the control. Observations recorded In the FiM₂F₂ are duly confirmed by the results obtained from the FiM₃F₃ generations. It could be concluded that irradiation might have caused allelic differences as to transform genetical ratios concerned as discussed.