Potato Virus Y-resistant Mutation Induced by the Combination Treatment of Ion beam Exposure and Anther Culture in Nicotiana tabacum L.

Abstract

To develop an efficient procedure for obtaining a desired mutation, we performed ion beam exposure on tobacco anthers and selected Potato Virus Y (PVY)-resistant mutants in the haploid generation.Anthers were exposed to C ion beams of 5 to 200Gy or He ion beams of 5 to 400Gy, and cultured on modified Nakata's medium. Anther culture response, the percentage of anthers producing plantlets, was markedly reduced by the exposure and, at higher doses, all plantlets were vitrified. RD50 based on the anther culture response was about 5Gy for C ion beams and about 10Gy for He ion beams. The frequency of mitotic cells with chromosome aberrations in root tips of plantlets derived from exposed anthers, ranged from 11.9% to 16.4%, compared to 3.1% in the control.All plants in the non-exposed regimen died within 21 days after inoculation of PVY. On the other hand, 15 of 472 plants in the exposed regimen were viable and continued to grow, with minor disease symptoms observed in some plants after 50 days. Accordingly, these plants were considered to be PVY-resistant. In particular, one plant showed no disease symptoms and grew vigorously.