Low-Dose Gamma-Irradiation Promotes Wheat Anther Culture Response

Abstract

This study examined the anther culture response of wheat to different doses of gamma radiation, and the interaction of radiation dose with a cold pretreatment of ears stored prior to culturing. The cultivars Grebe and Kite were chosen on the basis of their anther culture response, Grebe being highly responsive and Kite being non-responsive. Spikes of the two cultivars were exposed to various levels of gamma radiation (⁶⁰Co source) ranging from 0 to 10 Gy (0.53 Gy min^-1) before anthers were plated on an agarose-solidified medium. For Grebe, doses of 1, 3 and 5 Gy resulted in more embryoids, higher green plant regeneration, and a greater number of spontaneously doubled haploids (DH), than in the non-irradiated control. The response in Kite was similar but less pronounced. The higher doses of radiation (7 and 10 Gy), however, were detrimental in both cultivars and at 10 Gy no embryoids or regenerants were produced. Anthers subjected to a cold pretreatment prior to irradiation responded significantly less than those cultured fresh. This study indicated that low-dose gamma irradiation of fresh explants can significantly improve regeneration from anther cultures in wheat and may stimulate a low frequency of regeneration in an otherwise non-responsive cultivar.