Haploid Plantlet Production through Somatic Embryogenesis in Anther-Derived Callus of Bupleurum falcatum

Abstract

This study was carried out to verify the production of haploid plantlets through somatic embryogenesis of Bupleurum falcatum in anther culture (2n=16). Flowers with anthers at the uninucleate stage, less than 200μm in anther length, were exposed to 10°C for 5 days (cold pretreatment) and the anthers were cultured on MS medium supplemented with 2,4-D and/or picloram at various concentrations at 30°C. The optimal supplement for callus formation was a mixture of 0.075 mg ^-1 2,4-D + 0.075 mg L^-1 picloram or 0.75 mg ^-1 2,4-D without picloram. Only a few calli were induced from the anthers without cold pretreatment. The calli were transplanted to MS medium without phytohormones and cultured at 25°C for plant regeneration. Among one hundred twenty root tips of the regenerated plantlets examined, 14.2% were haploid (n=8). However, in the plantlets regenerated from anthers without cold pre-treatment only 2.5% was haploid. In both haploid and diploid regenerated plantlets, the chromosome number was fixed without variation. Among the regenerated plantlets, one was albino. Haploid plantlets were transplanted to the field after acclimation in pots filled with vermiculite under 90% humidity for a month, and haploid plant were produced. The potential of haploid plants derived from anther culture for production of high-yield and good-quality cultivars is discussed.