Gamma Irradiation as Tool for Mutation Breeding in Wheat

Abstract

Mutation breeding is used to modify a specific character of a plant, while all other characteristics remain the same. Adaptation obtained through mutation breeding to biotic (disease and insect pest resistance) and abiotic (aluminum toxicity, drought, high temperature, salt tolerance) stresses leads to better harvest growth, yield and quality. The main aim is to promote the efficiency of energy conversion into growth as a tool for the prediction of the optimal gamma irradiation dosage for mutation breeding in wheat. Cytogenetic analysis done on Triticum turgidum ssp. durum cv. Orania will be presented in the form of nucleolar activity to determine incomplete mitosis as well as in the form of bridges, fragments, micronuclei and ring chromosomes that will be compared with the efficiency of energy conversion into growth. Studies done on two Triticum aestivum cultivars, namely Ratel and Kwartel, included observation of double spikes, reduction in fertility and determination of the window for the optimal dosage for mutation breeding. Cultivars/breeding lines that are more resistant to gamma irradiation have a wider window for the optimal dosage range for mutation breeding. The ideal gamma irradiation dosage range for the three cultivars, namely, Orania, Ratel and Kwartel were determined.