Tissue Culture of Four Varieties of Date Palm Grown in Indonesia

Abstract

Abstract In vitro propagation of date palms adaptive to Indonesian agroclimate is one of the solutions for providing superior date palm planting material. This study aimed to induce embryogenic calli and regenerate the calli into plantlets of four varieties of date palm grown in Indonesia: three female varieties (Barhee, Ajwa, and Khalas) and one male variety (Jarvis). The materials used were offshoots of the date palm trees that had been flowered at the Jonggol Farm, Bogor, Indonesia. Four layers (layer 1 is the innermost layer and 4 is the outermost layer) of the offshoot were cultured on MMS media added with 100 mg/L 2,4-D combined with 1 and 3 mg/L 2-iP. The results showed that primary callus for var Bahee and Ajwa emerged at 12 weeks after culture. Barhee and Ajwa, and at 18 weeks for Jarvis and Khalas. In var. Jarvis and Khalas, calli were induced only in layer 1 cultured on the media with 1 and 3 mg/L 2-iP. In comparison, callus induction of var. Barhee date palm was successfully performed in layer 1 and 2 on the media with 1 mg/L 2-iP. On the contrary, callus induction in var. Ajwa was successful in layer 1 and layer 2, on the media supplemented both with 1 or 3 mg/L 2-iP. Germination of the date palm somatic embryos into shoots, using non-hormone media occurred successfully in var. Ajwa, Jarvis, and Khalas, but not in Barhee. Regeneration of the shoots into plantlets was carried out successfully only in var. Ajwa and Jarvis. In conclusion, in vitro propagation of date palm was successfully conducted in Jarvis and Ajwa varieties, while var Barhee was the most difficult among the four varieties.