Acclimatization and early growth of tissue culture-derived Stevia rebaudiana at low altitude area in Bogor, Indonesia (Aklimatisasi dan pertumbuhan awal Stevia rebaudiana asal kultur jaringan pada dataran rendah di Bogor, Indonesia)

Abstract

Aklimatisasi merupakan masa transisi sebelum kultur in vitro dapat ditanam di lingkungan ex vitro. Di daerah tropis, stevia seyogianya ditanam di dataran tinggi. Pengembangan klon stevia yang sesuai untuk dataran rendah di kawasan tropis sangat penting untuk memungkinkan penggunaan mekanisasi pada pertanaman stevia yang luas. Tujuan penelitian ini adalah menentukan pengaruh kondisi eksplan dan periode hardening terhadap daya hidup dan pertumbuhan pada tahap aklimatisasi dan pertumbuhan awal stevia klon BS 22 pada area terbuka di dataran rendah di wilayah tropis. Penelitian pertama dilangsungkan menggunakan umur tunas yang berbeda: 0, 1, 2, dan 3 minggu yang dikultur pada media padat sebagai sumber bahan eksplan. Penelitian kedua menggunakan satu buku stevia pada periode hardening dalam media cair selama 1, 4, 7 dan 10 hari. Aklimatisasi dilaksanakan dengan menanam eksplan dalam medium tumbuh campuran pada multi-tray dan diletakkan di dalam sungkup plastik tertutup selama 1 bulan. Tanaman yang berhasil hidup kemudian dipindah ke polibeg pada area terbuka dengan sinar matahari penuh. Pengamatan daya hidup dan pertumbuhan dilakukan pada akhir tahap aklimatisasi dan setelah 2 bulan di area terbuka. Hasil penelitian menunjukkan bahwa eksplan umur 1 minggu yang dikultur pada media padat mempunyai daya hidup tertinggi yakni 83%. Buku tunggal stevia yang dikultur pada medium cair pada tahap hardening selama 4 hari meningkatkan daya hidup menjadi 97% selama aklimatisasi 1 bulan. Setelah aklimatisasi, tinggi tanaman secara rata-rata adalah 2,6 cm dengan 10,6 helai daun. Tanaman yang dipindah ke area terbuka tumbuh pesat dengan tinggi tanaman mencapai 12 cm dengan 30 helai daun dan daya hidup 63% setelah 2 bulan. Hal ini menunjukkan bahwa stevia klon BS 22 mungkin sesuai untuk dataran rendah di daerah tropis. [Kata kunci: tanaman pemanis, eksplan tunas, tahap hardening, daya hidup, tropika] AbstractAcclimatization is a transition period before in vitro culture can be planted in ex vitro environment. In the tropical region, stevia is should be planted at high altitude areas. The development of stevia clones suitable for low land area in the tropics is important to make it possible to apply mechanization in a large scale stevia plantation. The purpose of this research was to determine the effect of explant conditions and hardening period on survival rate and growth during acclimatization stage and early growth of stevia clone B 22 in an open area at low altitude area in the tropics. The first experiment was conducted using different shoot ages: 0, 1, 2 and 3 weeks cultured on solid media as an explant material source. The second experiment was using single node of stevia in different hardening periods in liquid media for 1, 4, 7 and 10 days. Acclimatization was carried out by planting the explants on a mixture growing medium in multi-trays and placed inside a closed plastic tunnel for 1 month. The survival rate and growth parameters were observed at the end of acclimatization stage and after 2 months in the open area. The results show that 1-week explant age on solid media had the highest survival rate at 83%. Hardening single node of shoot in a liquid medium for 4 days increased the survival rate to 97% in 1 month acclimatization stage. After acclimatization, the plant height on average was 2.6 cm with 10.6 leaves. The survived plants planted in an open area grew rapidly to 12 cm in height with 30 leaves and survival rate 63% within 2 months. It indicates that stevia clone BS 22 may suitable for a low altitude area in the tropics. [Key words: sweetener plant, shoot explant, hardening period, survival rate, tropics]

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

“…In the case of Cocos nuficera var Kopyor, specific plantlet criteria are needed to increase survival rates, such as plantlet height and root and leaf vigor (Sumaryono & Riyadi, 2016). This is in contrast to stevia, where the highest survival rate is achieved when using only one node of plantlet, and the height must not be over-excessive to prevent tipping during acclimatization (Sinta & Amanah, 2019). For oil palm, vigorous criteria is required.…”

“…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.…”