EX VITRO ROOTING OF OIL PALM (Elaeis guineensis Jacq.) PLANTLETS DERIVED FROM TISSUE CULTURE

Abstract

Plantlets of oil palm (Elaeis guineensis Jacq.) derived from somatic embryos sometimes do not form well developed-roots. Root formation of unrooted-plantlets can be induced with auxin during ex vitro acclimatization period to simplify the procedure and to reduce seedling production cost. Experiments were conducted using a completely randomized design to determine the effect of different types of auxin, i.e. indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and 1-naphthalene-acetic acid (NAA) at different concentrations, i.e. 0, 2, 4, 8, and 16 mM on root development of oil palm plantlets. The plantlets used were derived from somatic embryos of MK 649 oil palm clone. The basal end of the shoots was dipped in auxin solution for 10 minutes before the shoot was cultured in a small plastic pot containing a mixed growing medium. The cultures were then placed inside a closed transparent plastic tunnel (240 cm x 100 cm x 95 cm) for 12 weeks. The results showed that without auxin treatment only 15% of the shoots formed roots. Dipping in auxin solution increased significantly root frequency to more than 50%. The best root formation was found on the shoots treated with 2 mM NAA by which rooting frequency was 80%. Auxin treatments also increased root quality as indicated by more number of primary and secondary roots. IAA, IBA, and NAA treatments at all concentrations tested increased significantly shoot height on average by 42% and shoot diameter by 30% compared to control treatment, but did not influence root length. The best treatment for inducing roots of oil palm plantlets ex vitro was by dipping the basal end of the plantlets in 2 mM NAA solution. The result showed that rooting of oil palm plantlets could be successfully conducted ex vitro that would eliminate sterile rooting stage thus simplify the protocol and reduce seedling production time and cost.

Sterilization method of contaminated oil palm plantlets affects the survival rate during acclimatization

“…The material used was fungi-contaminated oil palm plantlets. The plantlets have an average height of 17 cm, four leaves, and two primary roots, or categorized as class 4 plantlets according to Sumaryono & Riyadi (2011). Fungal contamination is characterized by the appearance of hyphae on the medium's entire surface and the plantlets' lower part.…”

“…The plantlets were planted in a non-sterilized mixture of soil and organic matter (1:3) (v/v) in a small transparent plastic pot (350 mL) ), with 5 holes for the water circulation in the bottom part (Sumaryono & Riyadi, 2011). The sterilized plantlets were planted in the medium and covered with a transparent plastic lid of the same size; these lids were sealed to maintain humidity during acclimatization.…”

“…As known, plantlets were previously obtained nutrients heterotrophically, including sugars and minerals, but during the acclimatization plantlets must now be self-sourced through the absorption of fertilizer and water from the soil and photosynthesis (Hazarika, 2003). The growth of these plantlets can be measured based on the increase in plantlet height, the addition of new leaves, stem diameter, and so forth (Idris et al, 2015;Manjusha et al, 2010;Sinta et al, 2013;Sumaryono et al, 2012;Sumaryono & Riyadi, 2011).…”

“…The success of this stage is paramount, as any failure during acclimatization can lead to the demise of all produced plantlets. The outcome of the acclimatization process is influenced by several factors, including the readiness of the plantlets for acclimatization, the composition of the medium used, and the acclimatization techniques employed (Idris et al, 2015;Sinta et al, 2013;Sinta & Amanah, 2019;Sumaryono & Riyadi, 2011. Plantlets ready for acclimatization should meet specific criteria, such as possessing vigorous leaves, appropriate height, and a well-developed root system (Sumaryono & Riyadi, 2016), and free from contaminants.…”

Optimasi sistem kultur dan media untuk peningkatan tinggi tunas in vitro kelapa sawit

“…Tinggi tunas merupakan salah satu parameter kesiapan planlet untuk masuk ke tahap aklimatisasi. Sumaryono & Riyadi (2011) mengemukakan bahwa kondisi terbaik planlet siap aklimatisasi adalah memiliki tinggi 9,5 cm dengan 2-3 daun. Namun penelitian mengenai optimasi percepatan penambahan tinggi tunas in vitro kelapa sawit secara terpadu mencakup aspek media dan lingkungan mikro masih jarang dilakukan.…”