Plant Cell, Tissue and Organ Culture 48: 147–152, 1997. 147 c 1997 Kluwer Academic Publishers. Printed in the Netherlands. Research note Regeneration of anther-derived plants of Avena sterilis Elina Kiviharju 1 , Matti Puolimatka 1 & Eija Pehu 2 1 Agricultural Research Centre of Finland, Institute of Crop and Soil Science, Plant Breeding Section, FIN-31600 Jokioinen, Finland; 2 Department of Plant Production, P.O.Box 27, FIN-00014 University of Helsinki, Finland; ( requests for offprints) Received 4 March 1996; accepted in revised form 17 March 1997 Key words: anther culture, antiauxin, haploid, oats Abstract Anther culture response of accessions of several hexaploid Avena species was studied with respect to requirement for auxin. The highest callus induction frequency was achieved with A. sativa L. cv. Stout (17.3%). The three most responsive genotypes, two of A. sativa and one of A. nuda L., had two-fold higher anther culture responses on growth regulator -free medium than on a medium containing 2,4-D. The A. sterilis L. accession CAV 2648 was the only genotype which consistently produced white, embryogenic structures (on solid MS+ 10% sucrose) and did so irrespective of the presence of 2,4-D. When transferred onto medium with lower sucrose concentration and an auxin transport inhibitor (TIBA), three green (two diploid [2n=6x=42] and one haploid [1n=3x=21]) and two albino plantlets were regenerated. The diploid regenerants set seed in the greenhouse. This first report of plants recovered from anther culture in the wild oat A. sterilis may provide an avenue to understand better and possibly overcome problems associated with androgenesis in cultivated oat. Abbreviations: acc. – accession; BA – 6-benzyladenine; 2,4-D – 2,4-dichlorophenoxyacetic acid; MS – Murashige and Skoog medium; NAA – -naphthaleneacetic acid; TIBA – 2,3,5-triiodobenzoic acid Oat (Avena sativa) is one of the most recalcitrant cereal species for anther culture. No reliable tissue culture method is available to produce doubled hap- loid plantlets in large numbers in order to assist breed- ing programmes. Few reports exist on regeneration of anther-derived Avena plants. The only successful regeneration of androgenic A. sativa plants was report- ed by Rines (1983). Sun et al. (1991) reported plant regeneration from anther cultures of A. nuda L. Haploid oat plants have also been produced in low frequency by applying maize, Zea mays L., pollen to emascu- lated oat (Rines and Dahleen, 1990). In this study we investigated the variation in anther culture response among different species and genotypes of Avena to determine if accessions of a wild oat species might be more responsive in anther culture than cultivated oat. An additional point of interest was to study if the presence of auxin in the induction medium was neces- sary for callus and proembryo initiation in oat anther culture. Seven genotypes from four different Avena species were included in this study. A. sativa cvs. Stout and Puhti were used based on success of anther culture for cv. Stout (Rines, 1983) and the commercial impor- tance of cv. Puhti in Finland. The other genotypes included were A. nuda cv. Foothill and acc. OT 194, A. byzantina L. cvs. Pazano and Fulghum, and A. ster- ilis acc. CAV 2648 (material was provided by Boreal Plant Breeding, University of Minnesota and Czech Research Institute for Crop Production). Seeds of the donor plants were sown in spring (7th April) into peat soil mix (11 cm pots) two seeds in one pot (15 pots/genotype) and fertilized with 1% solution of 5- Superex TM (Kekkil¨ a; 11%N, 4%P, 25%K). Plants were grown in the greenhouse under controlled conditions: 16 C/12 C day/night temperatures, 16-h photoperiod.