Plant Cell Reports (2000) 19 : 674–679 Q Springer-Verlag 2000 E. Kiviharju 7 M. Puolimatka 7 M. Saastamoinen E. Pehu Extension of anther culture to several genotypes of cultivated oats Received: 12 April 1999 / Revision received: 19 August 1999 / Accepted: 8 September 1999 Communicated by H. Lörz E. Kiviharju (Y) 7 M. Puolimatka Agricultural Research Centre of Finland, Plant Production Research, Crops and Soil, FIN-31600 Jokioinen, Finland e-mail: elina.kiviharju6mtt.fi Fax: c358-3-41882496 M. Saastamoinen Boreal Plant Breeding, FIN-31600 Jokioinen, Finland E. Pehu Department of Plant Production, P.O. Box 27, FIN-00014 University of Helsinki, Finland Abstract To improve plant regeneration from oat anther culture, the basic medium, hormonal supple- ments and genotype effect were studied. Six of the 14 genotypes tested regenerated plants. Cultivars Kolbu, Katri, Stout and naked oat Lisbeth produced green plants, cultivars Virma and line OT 257 only albinos. The total number of green plantlets regenerated was 22, of which 13 (11 haploid, 2 doubled haploid) survived into the greenhouse, and 37 albinos. Regener- able-type embryos were induced from heat-pretreated anthers on media containing 2, 3 or 5 mg l –1 2,4-di- chlorophenoxyacetic acid and 0.2 or 0.5 mg l –1 kine- tin as hormonal supplements. 6-Benzylaminopurine promoted albino plant regeneration especially in W 14 medium. Colchicine treatment was applied successfully to haploid regenerants. Key words Androgenesis 7 Avena sativa 7 Chromosome doubling 7 Haploids 7 Naked oat Abbreviations BAP: 6-Benzylaminopurine 7 2,4-D: 2,4-Dichlorophenoxyacetic acid 7 DH: Doubled haploid 7 H: Haploid 7 2-iP: N 6 -(2-Isopentyl)adenine 7 MS: Murashige and Skoog (1962) 7 NAA a-Naphthaleneacetic acid 7 W 14 : Ouyang et al. (1989) Introduction Doubled haploids can be used to assist variety breeding programs and as material for research purposes. Repro- ducible production of oat (Avena sativa L.) haploids has been reported via intergeneric crosses (Rines and Dahleen 1990; Matzk 1996; Riera-Lizarazu et al. 1996; Rines et al. 1997). In anther culture, plant regeneration was reported in oat (Rines 1983; Kiviharju and Tauriainen 1999), hexaploid naked oat (Sun et al. 1991) and wild red oat (Kiviharju et al. 1997; Kiviharju et al. 1998). However, regeneration frequencies of cultivated oats have been very low and strongly affected by geno- type. Induction of embryo structures was generally increased by heat pretreatment and by use of maltose instead of sucrose (Kiviharju and Pehu 1998). In a recent study (Kiviharju and Tauriainen 1999), combina- tion of a high concentration of 2,4-dichlorophenoxya- cetic acid (2,4-D) with a low level of kinetin in the induction medium was essential in order to obtain plant regeneration from induced embryo structures. In this study, regeneration of microspore-derived plants from anther culture of several oat genotypes is reported. The effect of growth regulators and basic medium on embryo induction and plant regeneration of oat anther culture is discussed. Materials and methods Anther-donor plants were grown, cut tillers pretreated at c4 7C for 7 days and anthers isolated as described in Kiviharju et al. (1998). Anthers were placed onto 3.5-cm-diameter Petri dishes (Falcon), 30 anthers per dish, containing MS or W 14 salts and vita- mins (Murashige and Skoog 1962; Ouyang et al. 1989), 10% maltose, pH adjusted to 5.8 (MS) or to 6.0 (W 14 ) and growth regulators. Double layer induction media containing 0.3% Phytagel (Sigma) in the solid part and 10% Ficoll 400 (Pharmacia Biotech) in the liquid part were prepared as described in Kivi- harju and Tauriainen (1999). Isolated anthers were pretreated at c32 7C for 5 days in the dark before culturing at c25 7C in the dark (Kiviharju and Pehu 1998). Anther response was assessed