Jurnal Fitopatologi Indonesia
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Corynespora cassiicola Penyebab Noda Hitam pada Buah Pepaya
Get PDFSalah satu permasalahan yang dihadapi dalam produksi tanaman pepaya tersebut ialah penyakit noda hitam kelabu yang menyebabkan penampilan buah kurang menarik dan akhirnya menurunkan harga jual. Penelitian ini bertujuan mengisolasi, mengidentifikasi, dan menguji tingkat patogenisitas penyebab penyakit noda hitam pada pepaya varietas California. Identifikasi dilakukan berdasarkan karakter morfologi, sedangkan pengujian in vivo menggunakan rancangan acak lengkap dengan ulangan sebanyak lima kali. Perlakuan yang dicoba ialah letak buah vertikal (pertama, kedua, ketiga, keempat, dan kelima), semua buah diinokulasi cendawan patogen. Hasil penelitian menunjukkan bahwa gejala bercak kecil berwarna kekuningan hingga cokelat tua adalah penyakit noda hitam, yang disebabkan oleh cendawan Corynespora cassiicola. Cendawan C. cassiicola mempunyai koloni berwarna cokelat kehitaman, permukaan koloni halus dengan tepian yang rata, dan melengkung seperti beludru. Cendawan C. cassiicola memiliki konidiofor tegak, sedikit bengkok, bersepta, tunggal dan ada yang bercabang, berwarna cokelat, sedangkan konidium tunggal, sedikit bengkok, dan bersepta 2–12. Patogenisitas cendawan ini tergolong sedang. Masa inkubasi tercepat terjadi pada buah dengan letak vertikal keempat, luas serangan tertinggi pada buah dengan letak vertikal pertama, dan keparahan penyakit tertinggi ialah pada buah dengan letak vertikal pertama.Corynespora cassiicola Causes Black Spots on Papayas
One of the problems in papaya production is black spot disease which causes the appearance of the fruit to be less attractive and lowers the market price. This study aimed to isolate, identify, and determine the level of pathogenicity of the cause of black spot disease on papaya var. California. Identification was carried out based on morphological characters, while in vivo experiment was conducted using a completely randomized design with five replications. The treatment involved the vertical position of the fruits (first, second, third, fourth, and fifth), all fruit were inoculated with pathogenic fungi. The results showed that disease symptoms on papaya fruit involving small yellowish to dark brown spots is caused by the fungus Corynespora cassiicola. The fungus C. cassiicola has black-brown colonies, the surface of the colonies is smooth with flat edges, and curved like velvet. This fungus has a few upright conidiophores bent, septa, single and some are branched, brown, while the conidia are single, slightly bent, and septa 2–12. The pathogenicity of this fungus is moderate. The fastest incubation period occurred in fruit with the fourth vertical position, the largest disease spot areas was in the fruit in the first vertical position, and the highest disease severity was in the fruit with the first vertical position
The Potential of Bacillus subtilis subsp. subtilis RJ09 as a Biological Control Agent Against Leaf Spot Diseases on Clove
Get PDFCloves is one of the main plantation commodities and is native to Indonesia. Leaf spot disease with necrosis symptom is often found in clove plants. Interferences to photosynthesis caused by leaf spot disease can cause plant death. Bacillus is known to inhibit the development of pathogens through nutrient competition and antibiosis mechanism. This study aims to identify Bacillus sp. RJ09 through molecular approach and determine its potential in suppressing the development of Pestalotiopsis sp., the cause of clove leaf spot by in vitro examination. Identification of the fungus was carried out by observing the morphology which included the color of the colony, the shape and size of the conidium of the isolated fungus. Identification of Bacillus sp. RJ09 was performed by polymerase chain reaction (PCR) using a pair of primers that amplified gyrB gene region of ±1400 bp, followed by sequence analysis. The ability of Bacillus sp. RJ09 as a biological agent against fungi associated with leaf spot was determined using an in vitro double culture method. Pestalotiopsis sp. was found as the fungus associated with leaf spot disease and can cause black necrotic spots on the leaves. Molecular identification of Bacillus sp. RJ09 showed the highest similarity value of 99.40% with B. subtilis subsp. subtitles. In vitro dual culture showed B. subtilis subsp. subtilis RJ09 can inhibit the growth of Pestalotiopsis sp. colonies by 75%.Potensi Bacillus subtilis subsp. subtilis RJ09 sebagai Agens Pengendali Hayati Penyakit Bercak Daun Cengkih
Cengkih merupakan tanaman asli Indonesia yang menjadi salah satu komoditas utama sektor perkebunan. Penyakit bercak daun berupa nekrosis sering ditemukan pada tanaman cengkih. Gangguan terhadap fotosintesis yang disebabkan oleh penyakit bercak daun dapat menyebabkan kematian pada tanaman. Bacillus diketahui dapat menghambat perkembangan patogen melalui mekanisme persaingan nutrisi dan antibiosis. Penelitian ini bertujuan mengidentifikasi Bacillus sp. RJ09 secara molekuler dan mengetahui potensinya dalam menekan perkembangan Pestalotiopsis sp., penyebab bercak daun tanaman cengkih secara in vitro. Identifikasi cendawan dilakukan dengan mengamati morfologi yang meliputi warna koloni, bentuk, dan ukuran konidium cendawan hasil isolasi. Identifikasi Bacillus sp. RJ09 dilakukan dengan polymerase chain reaction (PCR) menggunakan sepasang primer yang mengamplifikasi wilayah gen gyrB sebesar ±1400 pasang basa (pb) yang dilanjutkan dengan analisis sikuen. Pengujian kemampuan Bacillus sp. RJ09 sebagai agens hayati terhadap cendawan yang berasosiasi dengan bercak daun dilakukan dengan metode kultur ganda in vitro. Hasil identifikasi cendawan bercak daun tanaman cengkih diperoleh Pestalotiopsis sp. yang dapat menyebabkan bercak nekrosis berwarna kehitaman pada daun. Hasil identifikasi molekuler Bacillus sp. RJ09 menunjukkan nilai kemiripan tertinggi 99.40% dengan B. subtilis subsp. subtilis. Pengujian in vitro menunjukkan B. subtilis subsp. subtilis RJ09 dapat menghambat pertumbuhan koloni Pestalotiopsis sp. sebesar 75%
Metode Termografi Inframerah untuk Deteksi Dini Pepper yellow leaf curl virus pada Tanaman Cabai
Get PDFPengamatan hama dan penyakit tanaman umumnya dilakukan dengan mencari gejala visual untuk setiap sasaran tertentu. Teknologi pertanian 4.0 mulai digunakan untuk pengembangan metode deteksi penyakit tanaman. Dilaporkan bahwa terdapat perbedaan warna dan suhu antara tanaman sakit dengan tanaman sehat yang dapat direkam oleh kamera termal. Penelitian ini bertujuan untuk mengetahui potensi kamera termal FLIR One Pro- IOS untuk merekam perbedaan warna dan suhu antara tanaman cabai terinfeksi virus dan tanaman sehat. Tanaman cabai di rumah kaca yang diinokulasi Pepper yellow leaf curl virus (PYLCV) mengalami kenaikan suhu pada 3 hari setelah inokulasi (HSI) (28.62 ℃) dibandingkan dengan tanaman yang tidak diinokulasi PYLCV (27.32 ℃). Perekaman citra digital sampel daun tanaman cabai dari lapangan menunjukkan suhu yang lebih tinggi pada tanaman yang terinfeksi beberapa jenis virus (Chilli veinal mottle virus, Pepper mottle virus dan PYLCV) dibandingkan yang terinfeksi virus secara tunggal. Rata-rata suhu terendah dan tertinggi tercatat pada sampel tanaman yang terinfeksi PepMV (17.74 ℃) dan terinfeksi campuran oleh PYLCV dan ChiVMV (25.68 ℃). Citra digital tanaman yang terinfeksi virus cenderung menunjukkan dominasi warna kuning terang, sedangkan tanaman bebas virus menunjukkan dominasi warna ungu gelap. Analisis lebih lanjut mengonfirmasi bilangan digital yang lebih tinggi untuk citra tanaman sakit dibandingkan dengan tanaman sehat. Metode termografi berpotensi menjadi metode deteksi dini karena dapat mendeteksi infeksi virus sebelum gejala visual muncul.
Infrared Thermography for Early Detection of Pepper yellow leaf curl virus on Chili Plants
Observations of plant pests and diseases are generally carried out by looking for visual symptoms for each disease target. Agricultural technology 4.0 began to be used for the development of plant disease detection methods. It was reported that there were differences in color and temperature between diseased and healthy plants which could be recorded by a thermal camera. This study aimed to determine the potential of the FLIR One Pro-IOS thermal camera to record differences in color and temperature between viral-infected and healthy chili plants. Chili plants in the greenhouse that were inoculated with Pepper yellow leaf curl virus (PYLCV) experienced an increase in temperature 3 days after inoculation (28.62 ℃) compared to plants that were not inoculated with PYLCV (27.32 ℃). Digital image recording of chili leaf samples from the field showed that plants infected by multiple viruses (Chilli veinal mottle virus, Pepper mottle virus and PYLCV) has higher temperature than those infected with a single virus. The lowest and highest mean temperatures were recorded in plant samples infected with PepMV (17.74 ℃) and mixed infected by PYLCV and ChiVMV (25.68 ℃). Digital images of virus-infected plants tend to show a predominance of bright yellow, while virus-free plants showed a predominance of dark purple. Further analysis confirmed higher digital numbers for diseased plant images than healthy plants. The thermography method has the potential to be an early detection method because it can detect viral infection before visual symptoms appear
Cover Jurnal Fitopatologi Vol. 18 No. 2, Maret 2022
No full textThis editorial contains the front cover, editorial page, and back cover of the Indonesian Journal of Phytopathology Vol. 18 No. 2, Maret 2022This editorial contains the front cover, editorial page, and back cover of the Indonesian Journal of Phytopathology Vol. 18 No. 2, Maret 202
Seed Treatment with Pesticide, Bordeaux Mixture and Biological Agent for Ginger Rhizome-Borne Disease Suppression
Get PDFPenyakit puru akar yang disebabkan oleh nematoda dan busuk rimpang karena infeksi berbagai patogen banyak dijumpai pada rimpang jahe. Penelitian dilakukan untuk mengevaluasi pengaruh beberapa perlakuan benih terhadap penekanan kerusakan rimpang yang disebabkan oleh penyakit tersebut. Penelitian disusun menggunakan rancangan acak kelompok dengan 7 perlakuan rimpang, masing-masing diulang sebanyak 4 kali. Perlakuan rimpang jahe sebelum tanam terdiri atas perendaman dalam pestisida 1.5% (campuran streptomisin sulfat dan benomil), bubur Bordo (1% dan 2%), rizobakteri 10% (Bacillus pantotkenticus dan Trichoderma lactae) selama 24 jam; serta pelapisan dengan tepung karbosulfan ST (500 g untuk 4 kg rimpang) dan formula talk Fusarium non-patogenik (NP) (500 g untuk 4 kg rimpang). Rimpang jahe yang sudah diberi perlakuan ditanam pada medium tanam steril yang terdiri atas campuran tanah dan bubur Bordo 1% dan diamati sampai tanaman berumur 5 bulan. Perendaman rimpang dalam larutan pestisida dan formula rizobakteri, serta pelapisan rimpang dengan tepung karbosulfan ST dan formula Fusarium NP dapat menekan puru nematoda Meloidogyne dan busuk rimpang, serta umumnya menghasilkan viabilitas benih dan bobot segar dan atau bobot kering rimpang yang lebih baik. Kecuali bubur Bordo, empat perlakuan benih tersebut dapat dikembangkan untuk usaha penyediaan benih rimpang jahe sehat bermutu.Seed Treatment with Pesticide, Bordeaux Mixture and Biological Agent for Ginger Rhizome-Borne Disease Suppression
Root knot caused by nematodes and rhizome rot due to infection by various pathogens is commonly found in ginger rhizomes. A study was conducted to evaluate the effect of several seed treatments on suppression of rhizome damage caused by these diseases. The experiment was arranged using a randomized block design with 7 rhizome treatments, each repeated 4 times. Ginger rhizome were given treatment before planting, i.e. soaking in 1.5% pesticides (a mixture of streptomycin sulfate and benomyl), Bordeaux mixture (1% and 2%), 10% rhizobacteria (Bacillus pantotkenticus and Trichoderma lactae) for 24 hours; and coating with carbosulfan ST flour (500 g for 4 kg rhizomes) and non-pathogenic Fusarium (NP) talc formula (500 g for 4 kg rhizomes). Ginger rhizomes were than planted in sterile planting medium consisting of a mixture of 1% Bordeaux mixture and soil; and observed until the plants reach 5 months old. Soaking the rhizomes in a solution of pesticides and rhizobacterial formulas, as well as coating the rhizomes with carbosulfan ST flour and Fusarium NP formulas could suppress root knot and rhizome rot; Those seed treatments also enhanced seed viability and plant growth (plant fresh weight and or rhizome dry weight). With the exception of Bordeaux mixture, these four seed treatments can be further used in the production of qualified and healthy ginger rhizome seed
Ketahanan Beberapa Varietas Padi Lokal terhadap Virus Tungro Isolat Muara
Get PDFPenyakit tungro merupakan salah satu penyakit penting pada tanaman padi karena menimbulkan gejala tanaman kerdil dan mampu menyebabkan kehilangan hasil yang nyata. Penanaman varietas tahan merupakan strategi pengendalian yang direkomendasikan untuk mengatasi penyakit tungro. Penelitian dilakukan untuk mencari sumber ketahanan genetik dari varietas padi lokal yang dapat digunakan dalam perakitan varietas tahan penyakit tungro. Percobaan disusun dalam rancangan penelitian deskriptif dengan teknik observasi. Observasi dilakukan terhadap 16 varietas padi lokal dengan setiap varietas terdiri atas 30 tanaman contoh sehingga jumlah keseluruhan tanaman yang digunakan sebanyak 480 tanaman. Isolat virus tungro dari pertanaman padi di Muara, Bogor diinokulasikan ke tanaman uji melalui serangga vektor wereng hijau (Nephotettix virescens). Hasil penelitian menunjukkan bahwa ketahanan varietas lokal bervariasi berdasarkan nilai indeks penyakit, insidensi penyakit dan penyusutan tinggi tanaman. Varietas TN1 merupakan varietas pembanding dengan reaksi rentan, sedangkan varietas padi lokal dibedakan atas tahan (‘Utri Merah’), moderat (‘Karau’, ‘Bekongan’, ‘Bujang Berinai’, ‘Srogel Abang’, ‘Pulut Garu’, ‘Randu Kisaran’, ‘Siredep’, ‘Katimpung’, ‘Pulut Sawijan’, ‘Dube’), moderat cenderung rentan (‘Blumbungan’, ‘Tjere bandung’, ‘Sempor’) dan rentan (‘Rumbai’). Semua varietas dapat terinfeksi (insidensi penyakit 27–76%), tetapi indeks keparahan penyakit sangat bervariasi (3–7). Semakin berat keparahan penyakit menyebabkan penyusutan tinggi tanaman semakin tinggi. ‘Srogel Abang’ merupakan varietas yang bermanfaat untuk perakitan varietas padi unggul tahan penyakit tungro karena bersifat moderat dengan persentase penyusutan tinggi tanaman yang rendah (36%) sehingga produktivitas tanaman masih dapat dipertahankan.Resistance of Several Local Rice Varieties to Isolate Tungro Virus from Muara
Tungro disease is one of the important diseases in rice because it causes stunted plants and may induce significant yield losses. Planting resistant varieties is a recommended control strategy to overcome tungro disease. The research was conducted to find sources of genetic resistance from local rice varieties that can be used in breeding of tungro disease resistant varieties. The experiment was arranged in a descriptive research design with observational techniques. Observations were made on 16 local rice varieties with each variety consisting of 30 sample plants so that the number of plants used was 480 plants. The isolate of tungro virus collected from rice field in Muara, Bogor was inoculated to the test plants through the insect vector, green leafhopper (Nepothettix virescens). The results showed that the resistance of local varieties varied based on the value of disease index, disease incidence and plant height reduction. ‘TN1’ was the check susceptible variety against tungro virus, while the local rice varieties were differentiated into resistant (‘Utri Merah’), moderate (‘Karau’, ‘Bekongan’, ‘Bujang Bernai’, ‘Srogel Abang’, ‘Pulut Garu’, ‘Randu Range’, ‘Siredep’, ‘Katimpung’, ‘Pulut Sawijan’, ‘Dube’), moderate tend to be susceptible (‘Blumbungan’, ‘Tjere bandung’, ‘Sempor’) and susceptible (‘Rumbai’). All varieties can be infected (disease incidence 27 – 76%), but disease severity varies greatly (3–7). The more severe the disease, the higher the plant height reduction. ‘Srogel Abang’ is a variety that is useful for breeding rice varieties resistant to tungro disease because it showed moderate response with a low percentage of plant height reduction (36%) so that plant productivity can still be maintained
Potensi Isolat Bakteri Asal Gambut sebagai Agens Pengendali Nematoda Puru Akar Meloidogyne incognita
Get PDFNematoda penyebab puru akar (Meloidogyne spp.) merupakan parasit penting tanaman budi daya dan memiliki kisaran inang yang luas. Salah satu alternatif pengendalian fitonematoda yang potensial ialah pemanfaatan bakteri non-patogen. Penelitian ini bertujuan mengevaluasi potensi bakteri asal gambut sebagai agens pengendali biologi nematoda puru akar (M. incognita). Pengujian secara in vitro menggunakan filtrat 15 isolat bakteri terhadap M. incognita juvenil 2 (J2) dalam cawan petri. Sebanyak 4.5 mL filtrat bakteri dimasukkan ke dalam cawan petri berdiameter 5 cm, kemudian ditambahkan 50 individu J2 M. incognita dan diinkubasi pada suhu 27 ℃. Pengamatan mortalitas nematoda dilakukan pada 6, 12, dan 24 jam setelah perlakuan. Percobaan disusun dalam rancangan acak lengkap dengan 3 ulangan. Peubah yang diamati ialah persentase mortalitas serta lamanya waktu paparan dalam mematikan nematoda. Karakterisasi fisiologis yang dilakukan terhadap isolat bakteri meliputi uji produksi HCN dan enzim kitinase. Hasil penelitian menunjukkan bahwa 9 isolat bakteri yaitu: GA2 GAA1, GT1 GTA7, GT1 GTB3, GT1 GTB4, GT1 GTB6, GT1 GTB7, GT1 GTC2, GT1 GTC4, dan STDHC4 memiliki kemampuan nematisidal dengan mortalitas mencapai 83%–94%. Isolat bakteri GT1 GTB4 dan GT1 GTB7 memiliki homologi 99% dengan Serratia marcescens asal Cina, dan GT1 GTC2 memiliki homologi 99% dengan Streptomyces sp. AT67 asal Korea Selatan. Ketiga isolat tersebut mampu menghasilkan enzim kitinase dengan indeks lisis >1, namun semua isolat tidak ada yang menghasilkan senyawa HCN.Potential of Bacterial Isolates from Peat Land as Controlling Agent for the Root Knot Nematodes Meloidogyne incognita
The root-knot nematodes (Meloidogyne spp.) is an important parasite of cultivated plants and have a wide host range. One of the potential alternative to controlling this pathogen is by utilizing non-pathogenic bacteria. This study aims to evaluate the potential of bacteria from peat as a biological control agent for the root-knot nematodes (M. incognita). In vitro testing was conducted by using filtrate of 15 bacterial isolates against M. incognita juvenile 2 (J2) in a 5 cm petri dish. Fivety juveniles (J2) of M. incognita were added to 4.5 mL of bacterial filtrate and incubated at 27 ℃. Nematode mortality was observed at 6, 12, and 24 hours after treatment. The experiment was arranged in a completely randomized design with three replications. The variables observed include the percentage of nematode mortality and the length of lethal exposure to nematodes. Physiological characterization test was carried out to the bacterial isolates including the production of HCN and chitinase enzymes. The results showed that nine bacterial isolates, that are GA2 GAA1, GT1 GTA7, GT1 GTB3, GT1 GTB4, GT1 GTB6, GT1 GTB7, GT1 GTC2, GT1 GTC4, and STDHC4 perform nematicidal activities with mortality level 83% to 94%. Three bacterial isolates, that are GT1 GTB4, GT1 GTB7, and GT1 GTC2 produce chitinase enzymes with lysis index above 1, but none of those isolates produce HCN. Bacterial isolates GT1 GTB4 and GT1 GTB7 had 99% homology with Serratia marcescens from China, and GT1 GTC2 had 99% homology with Streptomyces sp. AT67 from South Korea
Spesies Meloidogyne penyebab umbi berbintil kentang pada tiga sentra produksi di Sumatra
No full textMeloidogyne species, the pimple-like knot pathogen of potato tuber in three production centers in Sumatra
Nematoda puru akar (Meloidogyne spp.) merupakan penyebab ubi berbintil yang menurunkan kualitas dan kuantitas produksi kentang di wilayah Sumatra. Identifikasi spesies Meloidogyne diperlukan dalam merancang strategi pengendaliannya yang efektif. Penelitian ini bertujuan mendeteksi dan mengidentifikasi spesies Meloidogyne pada kentang secara morfologi, morfometri, dan molekuler. Sampel ubi kentang bergejala bintil, malformasi bentuk ubi, permukaan ubi tidak rata, serta permukaan ubi bergelombang dikumpulkan dari tiga sentra produksi kentang di wilayah Sumatra, yaitu Karo (Sumatra Utara), Solok (Sumatra Barat), dan Kerinci (Jambi). Ekstraksi nematoda dilakukan dengan teknik pembedahan jaringan ubi berbintil. Identifikasi morfologi dilakukan berdasarkan pola perineal nematoda betina. Pengukuran morfometri dilakukan terhadap juvenil 2 berdasarkan formula de Man. Identifikasi molekuler dilakukan dengan teknik PCR dilanjutkan dengan perunutan nukleotida dan analisis filogenetika. Tiga spesies Meloidogyne yang diidentifikasi ialah Meloidogyne arenaria, M. incognita, dan M. javanica. Amplifikasi DNA menggunakan primer spesifik CO1 berhasil mengamplifikasi pita DNA sebesar ±360 pb untuk M. arenaria, ±326 pb untuk M. incognita, dan ±170 pb untuk M. javanica. Hasil perunutan nukleotida menunjukkan bahwa isolat M. incognita asal Karo-Indonesia berkerabat sangat dekat dengan spesies sejenis dari negara Cina, Amerika Serikat, Vietnam, Inggris, Brazil, dan Afrika Selatan. M. javanica asal Solok-Indonesia berkerabat sangat dekat dengan spesies sejenis dari negara Amerika Serikat, Afrika, Cina, Jerman, dan Inggris.Meloidogyne species, the pimple-like knot pathogen of potato tuber in three production centers in SumatraThe root-knot nematode (Meloidogyne spp.) is the cause of pimple-like swelling symptoms, which results in a decrease in the quality and quantity of potato production in the Sumatra region. Identification of the Meloidogyne species is necessary for designing its effective control strategies. This study aimed to detect and identify Meloidogyne species in potatoes morphologically, morphometry, and molecularly. Potato tubers with pimple-like swelling symptoms, tuber shape malformations, uneven tuber surface, and corrugated tuber surface were collected from 3 potato production centers in Sumatra, i.e., Karo (North Sumatra), Solok (West Sumatra), and Kerinci (Jambi). Nematode extraction was conducted by a surgical technique of spotted tuber tissue. Morphological identification was conducted based on the perineal patterns of females. Morphometric measurements were carried out on juvenile 2 based on the de Man formula. Molecular identification was conducted by PCR technique, followed by nucleotide sequencing and phylogenetic analysis. Three species of Meloidogyne identified were Meloidogyne arenaria, M. incognita, and M. javanica. DNA amplification using a CO1-specific primer successfully amplified DNA bands of ±360 bp for M. arenaria, ±326 bp for M. incognita, and ±170 bp for M. javanica. The sequencing results showed that M. incognita isolates from Karo-Indonesia were very closely related to M. incognita isolates from China, the United States, Vietnam, the United Kingdom, Brazil, and South Africa. M. javanica isolates from Solok-Indonesia were very closely related to M. javanica from the United States, Africa, China, Germany, and the United Kingdom
Karakterisasi Cendawan Rizosfer Kebun Jeruk Organik dan Potensinya dalam Menghambat Pertumbuhan Botryodiplodia theobromae dan Colletotrichum gloeosporioides
Get PDFCharacterization of Soil Rhizospheric Fungi on Citrus Plantation and Their Potential to Inhibiting the Growth of Botryodiplodia theobromae and Colletotrichum gloeosporioidesThe rhizosphere soil around the roots of citrus plants has microorganisms, one of which is a fungus. The aim of this study was to identify the rhizosphere fungi of Siam Pontianak organic citrus gardens and their potential to inhibit the growth of the pathogenic fungi Botryodiplodia theobromae and Colletotrichum gloeosporioides. The characterization of the fungus was carried out by evaluating its growth at different temperatures, humidity and pH levels, then an antagonist test was performed on C. gloeosporioides and B. theobromae. The fungi obtained from the rhizosphere of Siam Pontianak citrus organic farming were Fusarium sp., Fusidium sp., Penicillium sp., Trichoderma sp. All rhizosphere fungi grow optimally at pH 4.5–5.5, temperature 20–30 ℃ and humidity 60–80%. The fungus Penicillium sp. had the highest ability to inhibit the growth of C. gloeosporioides (83.66%), while Trichoderma sp. able to inhibit the growth of the highest pathogen B. theobromae (92.04%). Further studies are needed before applying the obtained fungal isolates as biocontrol agents for C. gloeosporioides and B. theobromae.Tanah rizosfer di sekitar akar tanaman jeruk mempunyai mikroorganisme salah satunya ialah cendawan. Tujuan penelitian ialah mengidentifikasi cendawan rizosfer kebun jeruk siam pontianak organik serta potensinya dalam menghambat pertumbuhan cendawan patogen Botryodiplodia theobromae dan Colletotrichum gloeosporioides. Karakterisasi cendawan dilakukan dengan mengevaluasi pertumbuhannya pada suhu, kelembapan, dan tingkat pH yang berbeda, selanjutnya dilakukan uji antagonis terhadap C. gloeosporioides dan B. theobromae. Cendawan yang diperoleh dari rizosfer pertanian organik jeruk siam pontianak ialah Fusarium sp., Fusidium sp., Penicillium sp., dan Trichoderma sp. Seluruh cendawan rizosfer tumbuh optimal pada pH 4.5–5.5, suhu 20–30 ℃, dan kelembapan 60–80%. Cendawan Penicillium sp. mempunyai kemampuan tertinggi menghambat per-tumbuhan C. gloeosporioides (83.66%), sedangkan Trichoderma sp. mampu menghambat pertumbuhan patogen B. theobromae optimal (92.04%). Studi lebih lanjut diperlukan sebelum pengaplikasian isolat cendawan yang diperoleh sebagai agens biokontrol C. gloeosporioides and B. theobromae
Penapisan Aktinomiset Rizosfer Tanaman Liliaceae sebagai Agens Pengendali Hayati Fusarium oxysporum f. sp. cepae
Get PDFPenyakit moler yang disebabkan oleh Fusarium oxysporum f. sp. cepae merupakan salah satu penyakit penting pada tanaman bawang merah. Aktinomiset memiliki potensi sebagai agens pengendali hayati F. oxysporum f. sp. cepae karena kemampuannya dalam memproduksi senyawa bioaktif. Penelitian ini bertujuan mengevaluasi dan menyeleksi isolat-isolat aktinomiset yang dapat menekan pertumbuhan F. oxysporum f. sp. cepae dan memacu pertumbuhan tanaman bawang merah. Penelitian dibagi menjadi empat tahap, yaitu: isolasi, seleksi, karakterisasi, dan identifikasi isolat aktinomiset yang potensial. Sebanyak 43 isolat berhasil diisolasi dari tanaman Liliaceae dan sebanyak 14 isolat berhasil diseleksi berdasarkan hasil uji keamanan hayati. Hasil uji antagonisme menunjukkan bahwa 14 isolat menghasilkan penghambatan terhadap F. oxysporum f. sp. cepae sebesar 3.67%–53.67%. Di antara 14 isolat tersebut, sebanyak 13 isolat mampu memproduksi enzim kitinase dengan indeks kitinolitik sebesar 0.31–1.38. Lima isolat terpilih yaitu: ABF42, ABF59, ACF45, AEF35, dan AEF45, mampu melarutkan fosfat dan memproduksi IAA dengan konsentrasi 24.82–82.88 ppm, namun hanya tiga isolat yang mampu memfiksasi nitrogen. Berdasarkan sikuen gen 16S rRNA, lima isolat tersebut berturut-turut teridentifikasi sebagai: Streptomyces rameus, S. lydicus, S. panaciradicis, S. seoulensis, dan S. fuscichromogenes.Screening of Liliaceae Rhizosphere Actinomycetes as Biological Control Agents of Fusarium oxysporum f. sp. cepae
Fusarium basal rot caused by F. oxysporum f. sp. cepae is one of the major diseases of shallot in Indonesia. The use of biocontrol agents is one alternative method for controlling this disease. Actinomycetes isolates have the potential as biological control agents for F. oxysporum f. sp. cepae because of its ability to produce bioactive compounds. This study aims to evaluate and select actinomycete isolates with the ability to inhibit the growth of F. oxysporum f. sp. cepae and potentially promote the growth of shallot crops. The study was divided into four stages: i.e. isolation, selection, characterization, and identification of the potential isolates. Forty-three isolates of actinomycetes were successfully isolated from Liliaceae plants, and 14 isolates were selected based on the results of the biosafety test. Antagonism test showed that 14 isolates produced inhibition of F. oxysporum f. sp. cepae by 3.67%–53.67%. Among them, 13 isolates produced chitinase enzyme with a chitinolytic index of 0.31–1.38. Five selected isolates, i.e., ABF42, ABF59, ACF45, AEF35, and AEF45, were able to solubilize phosphate and produced IAA at the concentration range of 24.82–82.88 ppm, but only three isolates were able to grow on media without nitrogen. Based on the sequences of 16S rRNA, the five isolates were identified as Streptomyces rameus, S. lydicus, S. panaciradicis, S. seoulensis, dan S. fuscichromogenes