Anther Culture of Papaya (Carica Papaya L.)
Papaya (Carica papaya L.) anthers containing microspores in tetrads to early-binucleate stages were successfully cultured in one-half strength Murashige and Skoog (MS) medium (full-strength of NaFeEDTA) supplemented with 2 mg/1 naphthaleneacetic acid (NAA), 1 mg/1 N6-benzyladenine (BA), and 6% sucrose for callus formation. Highest frequencies of callus induction were obtained from anthers with uninucleate-mitosis stage microspores. Callus could be induced under either light or dark conditions although better results were obtained when anthers at uninucleate stage were cultured in darkness. Haploid plantlets and pollen-derived embryoids were obtained from anthers cultured at the uninucleate stage on 3% sucrose-containing MS medium without any growth regulator and low light intensity. Mass propagation was achieved when these embryoids were transferred to MS medium with 3% sucrose and no growth regulators. Some haploid plants were further developed from these embryoids. Examination of root tips of embryoid-derived plants showed the chromosome number of 9 (18 chromosomes for diploid papaya). It was thus concluded that the embryoids originated from pollen.