Positive effects of cold pretreatment, iron source, and silver nitrate on anther culture of strawberry (Fragaria x ananassa Duch.)

Androgenesis by anther culture or isolated microspore culture is the most efficient method for haploid production. In this study, the effects of cold pretreatment (4 A degrees C), silver nitrate, and iron source in the medium were investigated on anther culture of five strawberry cultivars (Camarosa, Selva, Pajaro, Paros, and Gaviota) in three independent experiments, and three traits including percentage of androgenic anthers, embryogenesis, and callogenesis were determined. In the first experiment, cold pretreatment of 4 A degrees C for 2 and 3 days produced the highest percentage of androgenic anthers in three cultivars (Camarosa, Selva, and Pajaro) and cold pretreatment of 4 A degrees C for 2 days produced the highest percentage of androgenic anthers in cultivar Paros. In the second experiment, the effect of Fe-EDDHA was more effective than Fe-EDTA, and increased the percentage of androgenic anthers and embryogenesis. The use of 57.5 mg l(-1) Fe-EDDHA produced the highest percentage of androgenic anthers in cultivar Camarosa and the best embryogenesis in cultivars Camarosa and Gaviota. In the third experiment, the use of 15 mg l(-1) silver nitrate in medium significantly increased the percentage of androgenic anthers and embryogenesis in cultivar Camarosa.