Liu DaJun

Asymmetric somatic hybridization between haploid common wheat and UV-irradiated Haynaldia villosa

UV irradiated protoplasts from young embryo derived calli of Haynaldia villosa were fused with protoplasts originated from anther derived calli of Triticum aestivum cv. 24-2 by the PEG method. Regenerated calli from fusion cells were obtained but none of them differentiated into plants. The cell clones that formed early were examined for their hybrid nature, chromosome counting and isozyme analysis suggested that they were nuclear hybrid. Further unequivocal confirmation was accomplished using the technique of in situ hybridization (ISH) and RAPD analysis, which facilitated the identification of the hybrid nature in fusion products. The results revealed that UV might have played an important role in breaking donor chromosomes and ensuring the introduction of alien chromatin into the recipient via asymmetric hybridization. The failure of plant regeneration of the somatic hybrids was discussed and further investigations are being conducted.