Identitas dan Keragaman Genetik Begomovirus yang Berasosiasi dengan Penyakit Keriting pada Tomat Berdasarkan Teknik Polymerase Chain Reaction (PCR)- Restriction Fragment Length Polymorphism (RFLP) Tri J. Santoso 1 , Sri H. Hidayat 2 , M. Herman 1 , H. Aswidinnoor 3 , dan Sudarsono 3 1 Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian, Jl. Tentara Pelajar 3A, Bogor 16111 2 Departemen Proteksi Tanaman, Fakultas Pertanian Institut Pertanian Bogor, Kampus Darmaga, Bogor 16680 3 Departemen Agronomi dan Hortikultura, Fakultas Pertanian Institut Pertanian Bogor, Kampus Darmaga, Bogor 16680 ABSTRACT Identities and Genetic Diversities of Begomoviruses Associated with Leaf Curl Disease of Tomato Based on the Polymerace Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) Technique. Tri J. Santoso, Sri H. Hidayat, M. Herman, H. Aswidinnoor, and Sudarsono. Begomoviruses, members of the Geminivirus, are considered as emerging plant viruses. This was due to the increasing incidences and severities of the diseases in a number of economically important crops, including tomato. Genetic diversities of the Begomovirus isolates infecting tomato (Lycopersicon esculentum) of several areas in Indo- nesia were analyzed by using Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) technique. A 1500 base pairs of PCR fragments amplified by using degenerate primers for Begomovirus was digested using four restriction enzymes, i.e., DraI, EcoRI, RsaI, and PstI. The pattern of RE digested fragments of 8 Begomovirus isolates and the predicted RFLP fragments of the Begomo- virus isolates in the GeneBank database were used to deter- mine the genetic identities and diversities among the isol- ates. Positive results of the PCR amplifications proved that diseased tomato plant samples collected from 8 locations in Java and Sumatra were infected with at least one Begomo- virus isolate. The PCR amplification products, which were digested using the four restriction enzymes indicated the presence of polimorfisms among the DNA fragments of the Begomovirus isolates. Identifications of the Begomovirus indicated that the Brastagi, Bogor, Sragen, Ketep, and Boyo- lali isolates were Tomato Leaf Curl Virus (ToLCV); the isolates from Malang and Blitar isolates were Ageratum Yellow Vein Virus (AYVV), while one isolate from Kaliurang was Tomato Yellow Leaf Curl Virus (TYLCV). Results of the phylogenetic analysis of the 8 Begomovirus isolates based on Begomoviruses from the DNA database indicated that they belonged to three different groups. Key words: Begomovirus, tomato leaf curl, genetic diversity, PCR-RFLP technique. Hak Cipta © 2008, BB-Biogen PENDAHULUAN Dalam dasawarsa terakhir ini di berbagai daerah di Indonesia dilaporkan muncul serangan penyakit ke- riting daun pada tanaman tomat dan cabai. Hasil pe- nelitian yang dilakukan menunjukkan bahwa penyakit tersebut disebabkan oleh infeksi Begomovirus dari kelompok geminivirus dan famili Geminiviridae (Aidawati et al. 2005, Hidayat et al. 1999). Penurunan hasil akibat serangan penyakit keriting daun pada ta- naman di daerah Bogor, Jawa Barat dan sekitarnya di- laporkan dapat mencapai 50-70% (Sudiono et al. 2001). Di Indonesia, kejadian penyakit keriting akibat infeksi Begomovirus pada pertanaman tomat dapat mencapai 90-100%. Infeksi penyakit keriting daun ini dilaporkan dapat menyebabkan penurunan hasil hing- ga 50-100% (AVRDC Centerpoint Newsletter-spring 2003 issue) dibandingkan dengan tanaman tomat se- hat. Selain tanaman tomat, Begomovirus juga meng- infeksi beberapa tanaman lain, seperti kacang-kacang- an, mentimun, cabai, dan ubi kayu baik di daerah tro- pis maupun subtropis (Polkela et al. 2005, Rodriguez et al. 2006). Pada berbagai tanaman, infeksi virus dapat me- nyebabkan munculnya gejala fisiologis yang sama de- ngan kekurangan unsur hara tertentu (Agrios 1997). Selain itu, keakuratan identifikasi patogen yang me- nyerang merupakan salah satu faktor yang berpenga- ruh terhadap keberhasilan pengendalian penyakit pa- da tanaman (Agrios 1997). Dengan demikian, tersedia- nya metode deteksi patogen yang menyerang tanam- an perlu dikembangkan. Deteksi dan identifikasi Begomovirus yang me- nyerang tanaman dapat dilakukan antara lain dengan pengamatan gejala yang muncul pada tanaman ter- infeksi, penggunaan teknik serologi dan Polymerase Chain Reaction-Restriction Fragment Length Poly- morphism (PCR-RFLP) untuk berbagai gen pada ge- nom virusnya. Jika hanya berdasarkan gejala atau tek- nik serologi, kesalahan deteksi Begomovirus yang menginfeksi tanaman dapat terjadi karena adanya Jurnal AgroBiogen 4(1):9-17