DIRECT EMBYOGENESIS FROM ANTHER CULTURE OF LOQUAT

Loquat (Eriobotrya japonica Lindl.) anthers containing the microspores at the tetrad, uninucleate and binucleate stages were successfully cultured on full strength MS medium supplemented with full strength Na-Fe-EDTA, 0.23 µM zeatin (ZT) and 0.45 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 7% sucrose. Highest frequencies of somatic embryo induction were obtained from anthers with microspores at the uninucleate stage cultured in the dark. The best respond for direct embryogenesis was achieved in anthers with uninucleate microspores cultured at 15°C. Embryoids were induced in cultures at 15°C and 20°C. Increase in temperature resulted in the induction of callus from the anthers. On the medium containing lower concentrations of ZT and 2,4-D, embroids could be induced, and with the increase in 2,4-D and ZTconcentrations, the callus induction rate increased and embryoid induction rates declined. More embryoids formed on the surface when anther-derived embryoids were transferred to hormone-free MS medium added with 3% sucrose.