Chlorophyllian durum wheat plants obtained by isolated microspores culture: importance of the pre-treatments

In Triticum turgidum subsp. durunt (Desf.) Husn., the utilization of in vitro anther culture is hampered by the very high frequency of albinism of the regenerated plants reaching in most cases 100%. Only in vitro ovary culture or intergeneric crosses with maize produce gynogenetic green haploid and doubled haploid plants. This paper is concerned with another very interesting method of androgenetic doubled haploid plant production, the in vitro isolated microspore culture. It is shown that this method, associated with cold alone or cold plus mannitol pre-treatments, of the spikes kept within their sheath leaves, during different times, have significant positive effects, not only on embryo production, but also on chlorophyllian plant regeneration. All pretreatments and control taken together, a total of 16490 embryos was obtained from 17.4 x 10(6) microspores of two T durum varieties, among which 9320 embryos were transferred to regeneration medium and developed 150 chlorophyllian plants. Thus a long-term (five weeks) 4 degrees C cold pre-treatment of the microspores could be promising for green regeneration in durum wheat.