Stress treatments and ficoll for improving green plant regeneration in triticale anther culture

Anther culture of 10 winter triticale cultivars of diverse origin was studied. Two-week cold pretreatment was applied to all cultivars. In addition, cold pretreatment in combination with heat shock or mannitol starvation and prolonged cold stress of three weeks were tested on some of the genotypes. Field and greenhouse conditions were compared for growing the mother plants. Anthers for stress treatment testing were cultured on solid W14. Ficoll-supplemented induction medium was tested with three cultivars. A total of 378 green regenerants were analysed for DNA-ploidy with flow-cytometry. Morphological observations and seed-set were recorded for 317 plants grown to maturity. Large genotypic differences were noted between the cultivars. Seven out of 10 cultivars exhibited a differential response to the treatments and it was possible to improve green plant production considerably by applying increased stress or by culture on a medium containing ficoll. Cold pretreatment complemented with heat shock improved androgenetic response of the three cultivars tested. Prolonged cold pretreatment increased generally both the proportion of green plants and the proportion of spontaneous doubling. Morphological abnormalities, possibly caused by aneuploidy and associated with loss of fertility, were observed in 23% of the plants. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.