Dr. Ir. Hadiwiyono, M.Si
NIP 196201161990021001Sebagai Staf Pengajar pada Fakultas Pertanian Lahir di Sleman, 16 Januari 1962
Riwayat Pendidikan:
S-1. Fak. Pertanian UNSOED. 1989.
Bidang Ilmu: Ilmu Hama/Penyakit Tanaman S-2. IPB Bogor. 1996.
Bidang Ilmu: Fitopatologi
S-3. Universitas Gadjah Mada. 2010. Bidang Ilmu: Fitopatologi
Judul Disertasi
BLOOD DISEASE OF BANANA: INFECTION AND GENETIC DIVERSITY OF THE PATHOGEN
PENYAKIT DARAH PISANG: INFEKSI DAN KEANEKARAGAMAN GENETIKA PATOGEN
Blood disease of banana caused by blood disease bacterium (BDB), the sequevar 10 in the phylotype IV of
Ralstonia solanacearum species complex, is a devastating disease of bananas in Indonesia. Previously, the disease was limited in South Sulawesi, now however the disease has been spread in 90% provinces of Indonesia. In the field, the disease incidence could reach over 80% in some banana orchards. The available control techniques didn’t solve the problem. Therefore, the development of effective control is still needed. Concerning with the development of effective control method, the factors determining infection and genetic diversity of BDB are important to be find out. The information is needed to develop the control techniques especially through reducing source of the inocula, protecting infection sites, and reducing infection development of the pathogen. This research was aimed to study on the diseased banana and infested soil as source of potential inocula, determining infection sites, the effects of community structure of endophytic bacteria, the infection development at different altitudes, and the genetic diversity of
Penyakit darah pada pisang yang disebabkan oleh blood disease bacterium
(BDB), sequevar 10 phylotype IV dalam kompleks spesies Ralstonia solanacearum,
merupakan penyakit yang mematikan pertanaman pisang di Indonesia. Penyakit ini semula ditemukan terbatas di Sulawesi Selatan, namun, sekarang telah tersebar di 90% provinsi di Indonesia. Di kebun tertentu, insidens penyakit bisa lebih dari 80%. Teknik pengendalian yang tersedia belum dapat memecahkan permasalahan, sehingga pengembangan teknik pengendalian yang efektif masih diperlukan. Informasi tentang faktor-faktor yang menentukan infeksi dan genetika patogen penting untuk dipelajari guna pengembangan strategi pengendalian penyakit yang efektif, misalnya melalui penurunan sumber inokulum, perlindungan tempat infeksi, dan menghambat perkembangan infeksi. Penelitian ini bertujuan untuk mendapatkan informasi tentang potensi tanaman sakit dan tanah terinfestasi sebagai sumber inokulum, tempat infeksi, pengaruh bakteri endofit dan ketinggian tempat terhadap perkembangan infeksi BDB, serta keanekaragaman genetika BDB dari beberapa lokasi pertanaman pisang di Indonesia.
Kajian sumber inokulum BDB dilakukan dengan deteksi patogen dari
BDB from different cultivars and localities in Indonesia.
The study on the potential inocula of BDB was conducted by detection of the pathogen and the disease assessment developing from the diseased banana, diseased plant debris, and infested soil after several periods of incubation. The BDB detection on the plant part was done by polymerase chain reaction (PCR) using a specific primer pair for BDB. The assessment of BDB inocula in the plant diseased debris and soil were carried out by planting susceptible cultivar Kepok Kuning as plant indicator. BDB suspension 108 cfu/ml
was inoculated on the flowers and root system with and without wounding to study the infection site of the pathogen into the host. The community structure of endophytic bacteria in the stem was studied by PCR-ribosomal intergenic spacer analysis (PCR-RISA) using a primer pair of S926f and L189r. The PCR-RISA products were visualized by 6% polyacrylamide gel electrophoresis and DNA staining with 0.2% silver nitrate solution. The infection development at different altitude was evaluated by incubating root inoculated banana seedlings at 100, 1,000, and 1,600 m above sea level. Wilting symptom development was observed weekly for 42 days. The genetic diversity of BDB was analysed by pulsed field gel electrophoresis (PFGE) using restriction enzyme of XbaI and a CHEF Mapper. DNA fragments were resolved using a 2.16s to 54.17s switching pulse over a linear ramp period of 19 h at 6 V/cm.
The results suggested that infection of BDB was affected by the source of potential inocula and the capability of penetration. The community structures of endophytic bacteria in the stem were different with the different infection development. Different infection development was found at different altitude.
All parts of individual diseased banana were potential as source of inocula since BDB detected from the point of the flower, brack, fruit pulp, fruit shelter/coat, fruit stalk, bunch
berbagai titik jaringan tanaman sakit, sisa tanaman sakit, dan tanah terinfestasi setelah beberapa periode inkubasi. Deteksi BDB pada bagian tanaman dilaksanakan dengan teknik polymerase chain reaction (PCR) menggunakan sepasang primer spesifik BDB, sedangkan kultivar pisang rentan, yaitu Kepok Kuning digunakan sebagai tanaman indikator pada uji virulensi isolat BDB dan inokulum infektif Kajian kemampuan penetrasi BDB dilakukan dengan inokulasi suspensi bakteri 108 cfu/ml pada bunga dan
sistem perakaran dengan dan tanpa pelukaan pada bonggol pisang. Evaluasi pengaruh bakteri endofit terhadap perkembangan infeksi BDB dalam tanaman yang takbergejala dan bergejala, dilakukan dengan teknik PCR-ribosomal inter genic spacer analysis (pCR-RISA) menggunakan primer S926f dan L189r. Visualisasi hasil PCR-RISA dilakukan dengan elektroforesis gel poliakrilarnida 6% dan perwarnaan DNA dengan larutan perak nitrat 0,2%. Bibit pisang terinokulasi ditumbuhkan di dataran dengan ketinggian 100, 1.000, and 1.600 m di atas permukaan laut untuk evaluasi pengaruh ketinggian ternpat terhadap perkernbangan infeksi BDB. perked1bangan intensitas kelayuan dilakukan mingguan selama 42 hari. Keanekaragarnan genetika BDB didasarkan pada analisis pulsed field gel electrophoresis (pFGE) menggunakan enzirn restriksi Xbal dan alat CHEF Mapper.
Fragrnen DNA dipisahkan dengan suatu pergantian pulsa antara 2,16 sarnpai 54,17 detik dengan kenaikan linier selama 19 jam pada 6 V/cm.
peduncle, middle peduncle, basal peduncle, leaf lamina, midrib, petiole, corm, and root. The inocula in the diseased plant debris and infested soil were infectious for 5-6 months after incubation. The longer incubation period the lesser of the potential inoculum source of diseased plant debris and infested soil. The bigger with fresher infected tissue showed the higher population of BDB as the inoculum source. Declining the inoculum potentiality post incubation was slower in Vertisol soil than those in Andosol and Regorol soil.
Based on the inoculation results showed that BDB was able to infect the plant through the flowers. The infection was able to develop through on the flowers leading to both fruit development and undevelopment. BDB detection using PCR was positive and the symptom appeared on 1 and 3 weeks post inoculation respectively. The infection was also able to develop through the root system inoculation. However, the infection through the wounded corm developed more intensively than that of the unwounded one.
The results showed that 33,3-41,7 % of asymptomatic bananas from endemic area positively contained BDB. The community structure of endophytic bacteria in the asymptomatic infected banana was different from that of the symptomatic one. One DNA band at about 400 bp was frequently found on the asymptomatic banana which was not found on the symptomatic one. Therefore the related bacterium might involve in the suppression of the symptom.
Based on the artificial inoculation on the banana seedlings showed that BDB infection could develop at the altitudes of 100 to 1600 m above sea level (asl). Therefore, the risk of BDB infection at the altitudes should be considered where banana grows and the insect-transmitters are available.
Based on the PFGE analysis of 26 BDB isolates, showed that the bacteria in Indonesia were relatively homogeneous. However the isolates were able to be
dan Regosol.
Berdasarkan hasil inokulasi menunjukkan bahwa BDB dapat menginfeksi melalui bunga yang membentuk maupun yang tidak membentuk buah. BDB terdeteksi positip dengan PCR dan gejala muncul berturut-turut pada 1 dan 3 minggu setelah inokulasi pada bunga. BDB juga dapat menginfeksi melalui inokulasi pada sistem perakaran pisang, namun, pelukaan bonggol meningkatkan infeksi BDB.
Hasil penelitian menunjukkan bahwa 33,3-41,7 % pisang takbergejala dari lahan endemi terinfeksi BDB. Hasil analisis dengan
polymerase chain reaction-ribosomal intergenic spacer region analysis (PCR-RISA), menunjukkan bahwa kamunitas bakteri endofit pisang terinfeksi yang takbergejala berbeda dengan pisang terinfeksi yang bergejala. Bakteri endofit dengan dengan ciri fragrnen DNA sekitar 400 bp, sering dijumpai pada pisang terinfeksi yang takbergejala, sehingga diduga berperan pada penghambatan infeksi BDB.
Hasil inokulasi buatan pada bibit pisang menunjukkan bahwa infeksi BDB
dapat berkembang mulai dari dataran rendah (100 m) sampai dataran tinggi (1.600 m) di atas permukaan laut (dpl). Oleh karena itu, perlu diwaspadai risiko ledakan serangan
BDB pada kisaran ketinggian tempat tersebut, terutama apabila tersedia sumber inokulum dan serangga penyebar BDB.
Analisis pulsed field gel electrophoresis (pFGE) pada 26 isolat BDB
menurunkan pola fragmen yang relatif homogen, namun, sejumlah isolat tersebut dapat terkelompokkan menjadi 5 pulsed field gel strain (galur pfg) yang tidak berhubungan dengan kultivar inang maupun daerah asal isolat BDB.
Berdasarkan kesimpulan tersebut maka penelitian lebih lanjut yang disarankan adalah: 1) identifikasi serangga pengunjung bunga yang secara empirik sebagai penular
BDB, 2) mempelajari potensi bakteri endofit untuk pengendalian BDB, dan 3) mempelajari pengaruh sifat-sifat tanah yang secara empirik mempengaruhi ketahanan hidup inokulum BDB. Kesimpulan penelitian mengimplikasikan bahwa pengendalian penyakit darah pada pisang dapat dilakukan secara terpadu dengan komponen pengendalian yang antara lain sebagai berikut: 1) mencegah penyebaran BDB
grouped into 5 pfg strains which were not related to the host cultivar and area of origin of the isolates.
Based on the results, feather information should be studied, are : 1) identification of the flower visitor insects being empirically as BDB-disseminator, 2) effect of the soil properties to survival of the BDB inocula, 3)study on potentiality of the endophyte bacterium of banana for biological control of BDB. The conclusions imply that BDB should be controlled in integrated system with the control components which could be developed, among of them are: 1) avoidance of BDB spread brought in diseased plant organs including the fruits and leaves, 2) avoidance of planting in endemic land without effective eradication or plant rotation at least for a year, 3) elimination of inocula in diseased plant debris through chopping into fine bits and accelerating decomposition of the debris, 4) prevention of insect transmitting with cutting the bud immediately after no flowers developing the fruits and protecting the flowers from visiting transmitter insects, such as bagging the bud immediately using blue plastic before the flowers are opened, 5)prevention of infection through the root system with elimination of inocula in the soil and control of the wounder microb, such as by biological control and soil amendment, 6) reducing infection with avoiding wounding on the root system and through cultivation tools, such as by tool disinfestations, 7) avoidance of sucker use from endemic area for propagating materials, although the banana clusters are looking healthy.
