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OPTIMASI PERLAKUAN EKSPLAN PADA KULTUR ORGAN VEGETATIF TANAMAN KARET (HEVEA BRASILIENSIS MUELL. ARG.) KLON PB 330
Get PDFPerkembangan sistem perbanyakan klonal melalui teknik kultur jaringan tanaman karet  masih terus dikaji. Embrio fase torpedo berhasil diperoleh pada tahun 2012 menggunakan eksplan petiol klon PB 330, namun persentasenya sangat rendah akibat ketidakstabilan kalus friabel yang diperoleh, dan adanya hambatan fase diferensiasi selanjutnya. Hambatan tersebut berupa tingginya tingkat kontaminasi dan intensitas browning. Serangkaian penelitian pendahuluan dilakukan dalam upaya optimasi perolehan kalus friabel yang lebih baik. Penelitian tersebut meliputi teknik sterilisasi untuk meminimalkan tingkat kontaminasi, teknik eliminasi browning, pemilihan bagian dan fase eksplan dan kombinasi zat pengatur tumbuh dalam media kultur. Rangkaian penelitian tersebut dilakukan di Laboratorium Bioteknologi, Fakultas Biologi, Universitas Gadjah Mada (UGM) dan Laboratorium Kultur Jaringan, Balai Penelitian Getas, sepanjang Oktober 2013 hingga Oktober 2017. Hasil penelitian menunjukkan bahwa beberapa optimasi perlakuan sumber eksplan berhasil dilakukan. Kontaminasi berhasil ditekan hingga 33% pada kultur petiol dengan perlakuan prasterilisasi perendaman eksplan dalam fungisida Dithane M-45 selama 24 jam, kemudian disterilisasi dengan NaClO 5,25% dan HgCl2 0,2%. Penurunan kontaminasi juga didukung dengan penempatan sumber eksplan di luar area pembibitan karet. Intensitas browning berhasil ditekan hingga 7,5% dengan merendam eksplan dalam larutan asam askorbat steril selama 30 menit sebelum tanam. Penurunan intensitas browning diperoleh dengan pemilihan fase eksplan yang tepat (pertengahan flush) dan minimal pelukaan pada eksplan. Penambahan auksin ganda NAA 0,1 ppm+2,4-D 1 ppm ke dalam media MS modifikasi dan menempatkan sumber eksplan di bawah kondisi ternaung berhasil meningkatkan persentase kalus friabel hingga 60%. Protokol tersebut perlu terus dioptimasi untuk mengetahui respon diferensiasi selanjutnya
PENGGUNAAN TZ SEBAGAI ANTI PRAKOAGULASI LATEKS PADA PROSES PEMBUATAN RSS DENGAN PENGGUMPAL ASAM FORMAT
Get PDFRibbed Smoked Sheet (RSS) adalah salah satu produk karet mentah berupa lembaran yang diproses dari lateks kebun dengan disertai pengasapan. Amonia biasa digunakan sebagai pengawet lateks agar tidak terjadi prakoagulasi sebelum dibuat RSS. Amonia mempunyai sifat basa sehingga berdampak pada penggunaan bahan penggumpal asam format dalam jumlah yang lebih banyak. Pengurangan jumlah bahan penggumpal perlu diteliti lagi dengan menggunakan pengawet sekunder yang tidak menaikkan pH yaitu Tetramethyl thiuram disulfide – zinc oxide (TZ). Tujuan dari penelitian ini adalah untuk mengurangi penggunaan amonia dengan penambahan pengawet sekunder TZ. Efektifitas penggunaan pengawet sekunder dievaluasi dari keawetan lateks, konsumsi bahan penggumpal dan karakteristik air limbah yang dihasilkan. Percobaan pengawetan lateks dilakukan pada skala laboratorium dengan konsentrasi amonia 0,05% dan memvariasikan dosis TZ 0,01; 0,02; 0,03; 0,04; 0,05% v/v. Sebagai pembanding lateks diawetkan dengan amonia saja dengan konsentrasi 0,1%. Hasil penelitian menunjukkan, bahwa dosis pengawet ammonia 0,05% dikombinasikan dengan TZ 0,03% adalah dosis yang optimum. Pada konsentrasi tersebut, lateks mengalami prakoagulasi setelah 17 jam. Konsumsi penggumpal asam format berkurang 24,41%. Karakteristik limbah cair pengolahan RSS berpengawet TZ 0,03% + NH3 0,05% adalah : BOD turun 7,9%; COD turun 21,5%; TSS turun 18%; pH 5,2; N-amonia turun 34,5%; N-total turun 12,5%; dan logam Zn naik 120%
PENGEMBANGAN TEKNIK SEROLOGI UNTUK DETEKSI DINI PENYAKIT JAMUR AKAR PUTIH (RIGIDOPORUS MICROPORUS) PADA TANAMAN KARET
Get PDFPenyakit Jamur Akar Putih (JAP) yang disebabkan oleh Rigidoporus microporus merupakan salah satu penyakit penting pada tanaman karet. Penyakit ini dapat menimbulkan kerugian besar karena mengakibatkan kematian tanaman dan tambahan biaya yang cukup tinggi untuk pengendalian penyakit tersebut. Oleh karena itu, usaha pencegahan melalui deteksi dini akan lebih efektif dan ekonomis dari pada pendekatan kuratif. Deteksi dini gejala penyakit JAP secara konvensional masih sulit dilakukan, dan baru diketahui secara pasti ketika serangan patogen sudah sampai pada tahap lanjut (stadia berat). Upaya mempercepat deteksi ini membutuhkan teknologi yang praktis dan mudah diadopsi oleh para pekebun. Perangkat teknologi untuk mendeteksi adanya materi protein dapat dilakukan melalui pemeriksaan antibodi yang berada di dalam serum. Tujuan dari penelitian ini adalah mengembangkan teknik serologis untuk mendeteksi gejala serangan dini penyakit jamur akar putih. Hasil penelitian menunjukkan bahwa produksi antibodi untuk mendeteksi JAP dapat diperoleh dengan mengimunisasi ayam petelur dengan ekstrak kasar fruiting body (AgF) atau miselium (AgM) sebanyak dua kali dengan interval 3 hari. Antibodi hasil reaksi inokulasi ekstrak badan buah (AbF) dan ekstrak miselium (AbM) dapat mengenali AgM dan AgF dengan tingkat reaksi yang berbeda. AbM tidak dapat secara spesifik mendeteksi adanya infeksi JAP melalui daun dan kurang sensitif mendeteksi miselium di tanah. Sebaliknya AbF dapat mendeteksi tanaman terserang JAP melalui daun dan dapat mendeteksi miselium di dalam tanah
SINTESIS DAN KARAKTERISASI KOMPOSIT KARET ALAM/SELULOSA DENGAN VARIASI JENIS SELULOSA
Get PDFKaret alam dan selulosa merupakan dua material yang memiliki kompatibilitas yang sangat berbeda. Karet alam bersifat nonpolar sedangkan selulosa bersifat polar. Kombinasi antara karet alam dengan selulosa diharapkan akan menjadi komposit dengan kekuatan yang lebih tinggi. Konsep penguatan bahan polimer, seperti karet alam dengan bahan pengisi selulosa, terjadi akibat peningkatan interaksi karet-bahan pengisi. Penelitian ini bertujuan untuk mengetahui pengaruh beberapa jenis selulosa terhadap sifat fisik komposit yang dihasilkannya. Sebanyak tiga jenis selulosa digunakan dalam penelitian ini yaitu serbuk selulosa dari tandan kosong kelapa sawit, selulosa onggok dari limbah pati singkong, dan CMC (Carboxy Methyl Cellulose). Bahan selulosa digiling dalam mesin giling terbuka bersama dengan karet alam dan bahan-bahan lainnya menggunakan dua jenis bahan penyambung (coupling agent) yaitu hexamine/resorcinol dan anhidrida maleat. Hasil penelitian menunjukkan bahwa CMC memberikan hasil sifat fisik yang relatif lebih baik dibandingkan dengan dua jenis selulosa lainnya terutama dalam hal kuat tarik, pampatan tetap, dan ketahanan pantul komposit yang dihasilkannya. Sementara itu hexamine/ resorcinol lebih kompatibel digunakan sebagai bahan penyambung dibandingkan anhidrida maleat.Â
THE PERFORMANCE OF IRR SERIES RUBBER CLONES ON TRIAL SCALE AND IN COMMERCIAL PLANTATIONS
No full textIncrease of rubber productivity is the main factor for rubber commodities to remain competitive and profitable under fluctuating rubber prices. The use of Superior rubber clones is one of the most important technological components that contribute significantly to increase productivity. The superiority of a clone is determined by the genotype and environment of plant growth factors. The physical and biological environment conditions affect the growth and production of plants. The exposure to various agro-ecosystem conditions is required to select of superior clones with good stability or adaptation to specific environments, to ensure optimum productivity. Rubber breeding and selection activities in Indonesia had been covered four generations and produced several potential clones. The fourth-generation rubber clones have great genetic progress in terms of potential for rubber production and fast growth. The fourth-generation rubber clones are of IRR series 100, 200, 300 and 400. The performance of superior rubber clones is evaluated based on data from Small Scale Clone Trials (SSCT), Promotion Plots Trials, and Large Scale Clone Trials (LSCT)/Adaptation Trials. Some clones of IRR series 100 and 200 such as IRR 112, IRR 118, IRR 220 and IRR 230 can be recommended for planting. The clones IRR 112 and IRR 220 have a good stabilized of growth and production on normal to high rainfall environments, while, IRR 118 and IRR 230 have good growth and production in low rainfall (dry) conditions. IRR 118 and IRR 230 are moderately susceptible to Corynespora leaf fall disease. Some of the IRR 300 and 400 series clones have vigourus growth and high production on SSCT,  Promotion Plot Trials and LSCT. These are IRR 302, IRR 309, IRR 406, IRR 420, IRR 425, and IRR 429. The development of these clones on the commercial scale could be done gradually by considering the suitability for different plant growth environments.Keywords:      Hevea brasiliensis, breeding and selection, growth and productivity, IRR series clone
DEVELOPMENTAL DYNAMICS OF ACTIVITY AND EXPRESSION OF SUCROSE-METABOLIZING ENZYMES IN HEVEA BRASILIENSIS LEAVES
No full textSucrose-metabolizing enzymes in plant leaves are maily investigated in temperate species, and rarely along with expression and sugar analyses. Here, we investigated the activity and expression of sucrose-metabolizing enzymes as well as the sugars in the leaves of Hevea brasiliensis, a tropical tree species widely cultivated for natural rubber. Sucrose, fructose and glucose as the major and quebrachitol as the minor sugars were detected in Hevea leaves at its four developmental stages (I to IV). Fructose and glucose contents increased until stage III, and decreased strongly at maturation (IV). Sucrose contents increased continuously throughout the development. Alkaline/neutral invertase activity remained stable in developing leaves (I to III) with values comparable to those of vacuolar and cell wall invertases. Sucrose synthase (cleavage direction) activity was higher than the three invertases in developing leaves, corroborated by its high transcript levels. All sucrose-cleaving enzymes depressed their activities markedly at maturation, corresponded well to a transcript decline for most encoding genes. Sucrose phosphate synthase (SPS) and sucrose synthase (synthesis direction) activites were low in mature leaves, the former of which being contradictory to its high transcript levels at maturation. In conclusion, the sucrose-metabolizing enzymes contained in Hevea leaves exhibit discrepancies from those in other plants.Keywords: Hevea brasiliensis, leaf development, sucrose-metabolizing enzymes, sugar content, enzyme activity, gene expression
ISOLATION, PURIFICATION AND INACTIVATION MECHANISM OF CASSIICOLIN PRODUCED BY CORYNESPORA CASSIICOLA
No full textThe Corynespora leaf fall disease (CLFD) caused by Corynespora cassiicola (Ber.&Curt.) is the second important disease after South American Leaf Blight (SALB). The toxin produced by the pathogens is the important pathogenic factor. In order to obtain the cassiicolin of the pathogenic strains in domestic rubber tree, the production conditions of the toxin of HC-10 were optimized and the crude toxin was then concentrated and purified. In addition, detoxification mechanism of the antagonistic endophytic bacteria, inorganic salts and fungicides against the toxin were performed. Then the production conditions and the stability of the toxin of HC-10 were determined. The conditions of improved Fries 3 medium, 25°C, lighted 12 h, cultured 10 d, 160 rpm speed and 4 of initial pH of medium were most conducive to the formation of toxin; a certain relevance among temperature, UV and different concentrations of the toxin with the activity of toxin existed. The crude toxin was concentrated and purified by using of dialysis, freeze-dried, ammonium sulfate precipitation, as well as technologies such as ion-exchange chromatography and polyacrylamide gel electrophoresis. The molecular weight of the toxin protein was about 14.4 KDa, and 10 inorganic salts were used to inactivate the crude toxin produced by Corynespora cassiicola. The results showed that the growth of mycelial and the germination of spores were inhibited strongly by CuSO4•5H2O, FeCl3 and FeSO4•6H2O at a concentration of 2~5 mg/mL. KMnO4 could inactivate the toxin well at a concentration of 0.5 mg / mL with a wilting rate of 2.04%; FeCl3 was the second with the wilting rate of 3.97%. Five fungicides were used to inactivate the toxin, and the results showed that carbendazim is the most effective fungicide with EC50 =0.2243 μg/mL, followed by prochloraz amine with EC50 0.0.4797 μg/mL.Keywords: Corynespora cassiicola, Hevea brasilensis, cassiicolin, inactivation, toxin, fungicide, rubber, carbendazim, prochloraz amin
BIOLOGICAL CONTROL OF CORYNESPORA CASSIICOLA CAUSING CORYNESPORA LEAF FALL DISEASE (CLF) ON RUBBER TREE BY BACILLUS THURINGIENSIS (T3)
No full textBacillus thuringiensis (T3) isolated from foliage and sapwood of Hevea brasiliensis is demonstrated to have biological control potential against CLF disease caused by Corynespora cassiicola. Pathogenicity of C. cassiicola is caused by the toxin, cassiicolin. This toxin is encoded by cassiicolin gene (cas). Screening of cas genes was conducted with twenty C. cassiicola isolates from Vietnam e by using PCR method. Two isolates were classified as cas2 and the remaining as cas0. C. cassiicola isolate containing cas2 gene (CoryQN01) was inoculated on detached rubber leaves with and without the treatment of B. thuringiensis (T3) bacterial isolate at various time intervals. The results indicated that cassiicolin gene expression was down-regulated under treatment with B. thuringiensis (T3). Keywords: antifungal ability, Corynespora cassiicola, cas gene, Bacillus thuringiensi
FRACTIONATION OF HEVEA BRASILIENSIS LATEX BY CENTRIFUGATION: (i) A COMPREHENSIVE DESCRIPTION OF THE BIOCHEMICALCOMPOSITION OF THE 4 CENTRIFUGATION FRACTIONS
No full textBiochemical components naturally occurring in Hevea latex are known to impact both superior and inferior properties of natural rubber (NR) but the mechanisms are still not well elucidated up to now. Thus, we established a systematic study to identify and locate the main biochemical components of latex that might drive NR quality inconsistency and dynamic structuration. Fresh latex from RRIM600 and PB235 clones were fractionated into 4 fractions, including  cream,  skim,  C-serum and lutoids,  through  successive  centrifugation  steps performed at various accelerations (g). The fractions were further analyzed to provide a comprehensive description of the biochemical composition in comparison with original whole latex. Comparison on a dry weight basis showed that skim was twice more concentrated in lipids and proteins than cream. For non-rubber fractions, lutoid was the richest in lipids, protein and minerals (mainly K and Mg). Similarly, serum also contained high protein and mineral content but no lipids. Nevertheless,  when considering the mass balance of each fraction in order to identify the main location of each analyte, the obtained picture was different. Qualitatively, it was noticed that the profiles of biochemical component of fractions were not uniform and dissimilar to that of the original latex. This information is essential to further study the quantitative impact of each component on NR structure and properties.Keywords: biochemical components, fractionation, hevea latex, non-isoprene componen
NITRIC OXIDE IMPROVES GROWTH AND PHYSIOLOGICAL ATTRIBUTES OF RUBBER (Hevea brasiliensis) UNDER DROUGHT AND HEAT STRESS CONDITIONS
No full textCultivation of Hevea is being extended to non–traditional areas of Sri Lanka where extreme climatic conditions like drought and high temperature are the major impediments limiting the crop performance. Nitric oxide (NO) is a signaling molecule which has proved to be protective against damages provoked by abiotic stresses. In this work, we studied the effect of NO donor sodium nitroprusside (SNP) on the response of Hevea to drought and heat stresses. There was a significant increase in net photosynthesis (Pr) and chlorophyll content (Cc) in drought imposed plants treated with SNP as compared to those devoid of SNP treatment under heat stress condition in the glass house. Girth and physiological attributes viz., Pr, stomatal conductance (gs) and leaf water potential (Ψ) of the field grown plants treated with SNP increased as compared to control. Therefore, exogenous SNP proved to be beneficial in improving growth and physiological attributes of Hevea under stress conditions.Keywords: growth, physiological attributes, rubber, sodium nitroprusside, drought stres