SELEKSI GENETIK Falcataria moluccana PUTATIF TOLERAN Uromycladium falcatarium

ASRI INSIANA PUTRI, Prof. Dr. Ir. Mohammad Naiem, M.Agr.Sc; Dr Sapto Indrioko, S.Hut., MP.; Dr. Ir. Sri Rahayu, MP.

2017 | Disertasi | S3 Ilmu Kehutanan

Dalam beberapa dekade terakhir epidemi penyakit karat tumor (gall rust) pada sengon menyerang secara luas pada berbagai wilayah secara luas di Indonesia. U. tepperianum (Sacc.) McAlp. telah diidentifikasi sebagai penyebab penyakit karat tumor pada tanaman sengon. Penggunaan bioteknologi dinilai lebih meningkatkan efektivitas, akurasi dan percepatan seleksi genetik toleran penyakit untuk memperoleh tanaman unggul termasuk dalam ketahanan terhadap penyakit dibandingkan secara konvensional. Tujuan penelitian ini adalah melakukan seleksi genetik F. moluccana putatif toleran penyakit karat tumor yang disebabkan oleh U. tepperianum. Seleksi genetik dilakukan secara langsung in vivo dan secara tidak langsung in vitro, yaitu: 1) uji efektivitas inokulasi secara langsung spora patogen pada semai untuk seleksi sengon toleran karat tumor, 2) uji efektivitas filtrat gall karat tumor untuk seleksi sel kalus sengon in vitro, 3) analisis anatomi jaringan semai sengon hasil seleksi genetik, 4) analisis aktivitas enzim kitinase, β-1,3-glukanase dan total fenol endogen semai sengon, 5) identifikasi alel dan alel prifat sengon toleran maupun tidak toleran karat tumor, dan 6) uji efektivitas perbanyakan vegetatif kultur jaringan sengon toleran karat tumor serta stabilitas sifat toleran bibit sengon hasil perbanyakan kultur jaringan setelah diinokulasi kembali dengan spora penyakit karat tumor. Seleksi genetik dilakukan di persemaian, rumah kaca dan laboratorium kultur jaringan Balai Besar Penelitian dan Pengembangan Bioteknologi dan Pemuliaan Tanaman Hutan, Yogyakarta. Materi seleksi berasal dari 40 populasi dari Wamena, Hubikosi, Kuluru dan Solomon. Inokulum patogen yang digunakan adalah spora segar 2 populasi U. tepperianum pada ketinggian 400 mdpl. dari Tridadi (Tr) dan 800 mdpl. dari Kaliurang (Kr). Seleksi 800 semai di persemaian dibandingkan dengan seleksi 800 plantlet, famili semai terseleksi digunakan sebagai materi seleksi sel kalus in vitro dan materi perbanyakan kultur jaringan. Hasil uji 1) menunjukkan inokulasi secara langsung spora patogen pada semai terbukti efektif untuk seleksi sengon toleran karat tumor. 100 % dari 3 famili semai asal Wamena yaitu famili 2, 6 dan 35 toleran terhadap 2 populasi inkulum sampai dengan umur semai 2 tahun. Gejala serangan spora karat tumor asal Tr lebih tinggi dibandingkan asal Kr. Populasi Wamena mempunyai tingkat serangan paling rendah dibandingkan Kuluru, Solomon maupun Hubikosi. Hasil uji 2) menunjukkan sel kalus famili 2 individu 4, famili 6 individu 5 dan famili 35 individu 5 mempunyai nilai indeks toleransi tertinggi. Filtrat gall karat tumor mengandung steroid, saponin dan terpenoid namun alkaloid tidak berperan dalam sistem pertahanan sengon. Hasil analisis 3) menunjukkan Dark substrate content dapat digunakan sebagai penanda anatomi. Hasil analisis 4) menunjukkan aktivitas enzim kitinase, β-1,3-glukanase dan total fenol efektif sebagai penanda biokimia. Hasil analisis 5) menunjukkan identitas alel dan alel prifat efektif sebagai penanda molekuler sengon putatif toleran maupun tidak toleran karat tumor. Hasil uji 6) menunjukkan kultur jaringan efektif digunakan pada perbanyakan vegetatif sengon toleran karat tumor dengan koefisien perbanyakan tertinggi 2,5 (90 hari dikultur) pada media MS dengan pengayaan BAP 2 mg/l dan NAA 0,5 mg/l. Inokulasi kembali semai sengon hasil perbanyakan kultur jaringan mempunyai stabilitas tinggi (100 %) berdasarkan tidak terbentuknya gall karat tumor sampai dengan umur semai 6 bulan di persemaian.

For the past few decades, the widespread disease of gall rust on sengon (F. moluccana) trees has affected most areas in Indonesia. U. tepperianum (Sacc.) McAlp. has been identified as the cause of the disease. The use of biotechnology to selectively choose genetically disease tolerant seeds is considered to be more effective, accurate and accelerate in acquiring superior plant than that of conventional methods. The aim of this research is to conduct a genetic selection on sengon putatively tolerant to the gall rust disease caused by U. tepperianum. The genetic selection has been done directly in vivo and indirectly in vitro, through: 1) inoculation effectiveness test by directly injecting pathogen spore to seedlings for the selection of tolerant sengons to gall rust in vivo, 2) effectiveness test on gall rust filtrate for sengon callus cell selection in vitro, 3) anatomy analysis on sengon tissue culture acquired from genetic selection, 4) chitinase enzyme, β-1,3-glucanase, and total phenol endogenous activity analysis from the sengon seedling, 5) identification of allele and private allele that are tolerant or intolerant to gall rust, and 6) vegetative multiplication effectiveness test by tissue culture method on tolerance stability in sengon seedlings after re-inoculation with gall rust spore. The genetic selection has been done individually at the nursery and the tissue culture laboratory of the Balai Besar Penelitian dan Pengembangan Bioteknologi dan Pemuliaan Tanaman Hutan, Yogyakarta. Experimental subjects are 40 families from Wamena, Hubikosi, Kuluru, and Solomon. The pathogen inoculant was made of fresh spores from 2 populations of U. tepperianum with original environmental heights of 400 mdpl. from Tridadi (Tr) and 800 mdpl. from Kaliurang (Kr). Selection for the 800 seedlings at the nursery were compared to a selection of 800 plantlets, the chosen seedling family were then used as the experimental subject of callus cell selection in vitro and tissue culture. Results from tests 1) shows that three seedling families; family 2 and 6 from Hubikosi and family 35 from Wamena, are 100% tolerant towards 2 inoculant populations until the seedling reaches two years old. Symptoms due to gall rust spores from Tridadi are more severe to that from Kaliurang. The Wamena population has the lowest number of gall rust spore attacks compared to Kuluru, Solomon, or Hubikosi. Results from tests 2) shows that Callus cell selection results identifies family 2 individual 4, family 6 individual 5, and family 35 individual 5 has the highest tolerance index values. Gall rust filtrate contains steroid, saponin and terpenoids but alkaloid does not function as a sengon defence mechanism. Results from analysis 3) shows that dark substrate contents could be used as anatomycal marker. Results from analysis 4) shows that chitinase enzyme, β-1,3-glucanase and total phenol activity efective as the biochemical marker. Results analysis 5) shows that the identity of allele and private allele are efective as a sengon molecular marker for the assumed tolerant or intolerant to gall rust. Results from tests 6) shows that tissue culture technique was efective on the vegetative multiplication of gall rust tolerant sengons with the highest multiplication coefficient of 2,5 (90 days cultured) on MS media with an enrichment of BAP 2 mg/l and NAA 0,5 mg/l. Re-inoculation of sengon seedlings resulting from the tissue culture multiplication has a high stability (100%) based on gall rust not forming until the seedling reaches 6 months old at the nursery.

Kata Kunci : sengon, gall rust, genetic selection, tolerant, anatomycal marker, biochemical marker, molecular marker, tissue culture