NAA-Induced Direct Organogenesis from Female Immature Inflorescence Explants of Date Palm.

Abstract

Micropropagation has great potential for the multiplication of female and male date palms of commercially grown cultivars by using inflorescences. This approach is simple, convenient, and much faster than the conventional method of using shoot-tip explants. We describe here a stepwise micropropagation procedure using inflorescence explants of Iraqi date palm cultivar Maktoom. Cultured explants were derived from 0.5-cm-long spike segments excised from 8 to 10-cm-long spathes. About 70% formed adventitious buds on Murashige and Skoog (MS) medium supplemented with 2mg/L naphthalene acetic acid (NAA), 4mg/L benzylaminopurine (BAP), and 40g/L sucrose and maintained in the dark for 16weeks before transferring to normal light conditions. The best multiplication rate was achieved with 3mg/L 2ip and 2mg/L; for shoot elongation, the best medium is MS containing 0.5mg/L BAP, 0.5mg/L 2ip, and 1mg/L GA3. Well-developed shoots were cultured for rooting in half MS medium amended with 1mg/L NAA and 45g/L sucrose. Plantlets with well-developed roots were successfully hardened in the greenhouse. Inflorescence explants proved to be a promising alternative explant source for micropropagation of date palm cultivars.