KARAKTERISASI DAN TANGGAPAN TANAMAN INANG TERHADAP VIRUS KERDIL PISANG

RUTH FETI RAHAYUNIATI, Dr. Ir. Sedyo Hartono, M.P.; Prof. Dr. Ir. Soesamto Somowiyarjo, M.Sc.; Prof. Dr. Ir. Siti Subandiyah, M.Agr.Sc.

2021 | Disertasi | DOKTOR ILMU PERTANIAN

Penyakit kerdil pisang merupakan salah satu penyakit yang paling merusak tanaman pisang. Penyakit disebabkan oleh Banana bunchy top virus (BBTV). Penelitian ini bertujuan untuk (1) Menentukan karakter BBTV di Indonesia secara molekuler berdasarkan letak geografisnya dan (2) menentukan tanggapan tanaman pisang terhadap infeksi BBTV. Untuk mencapai tujuan tersebut, maka dilakukan: (1) survei untuk menentukan distribusi penyakit dan pengambilan sampel tanaman bergejala kerdil baik pada tanaman pisang maupun inang lainnya (2) identifikasi patogen dengan PCR berdasarkan DNA R BBTV, (3) analisis bioinformatika isolat BBTV berdasarkan DNA R, DNA S, DNA C, dan DNA N serta pengelompokan berdasarkan letak geografisnya, (4) analisis kisaran inang BBTV melalui inokulasi buatan pada tanaman non pisang, (5) analisis kerentanan tanaman pisang terhadap infeksi BBTV. Hasil analisis menunjukkan bahwa distribusi penyakit kerdil dan virus BBTV telah merata di seluruh wilayah di Indonesia, dan terdapat penambahan daerah sebaran baru selama periode 1998-2019, yaitu provinsi Sulawesi Selatan, Sulawesi Utara, Nusa Tenggara Barat, Nusa Tenggara Timur, Maluku Utara dan Papua. BBTV di Indonesia memiliki panjang nukleotida berkisar 1014 nt-1104 nt. BBTV tersebut dapat dikelompokkan berdasarkan letak geografisnya menjadi klaster Sumatera, Bengkulu, Jawa, Bali, Nusa Tenggara Barat (Sumbawa), Nusa Tenggara Timur (Timor), Sulawesi Utara, Maluku Utara. Setiap anggota dalam klaster memiliki perbedaan 0,2-1,5%. Selain menginfeksi tanaman pisang, BBTV mampu menginfeksi tanaman jahe, kunyit, kencur dan lengkuas. Hal tersebut membuktikan bahwa tanaman tanaman tersebut dapat berfungsi sebagai inang alternatif bagi BBTV. Analisis kerentanaman tanaman pisang, menunjukkan bahwa tanaman pisang mas, Cavendish, raja, dan kapok rentan terhadap BBTV dengan nilai kerentanan 2,9-3. Sedangkan M. acuminata subsp. halabanensis (0,006), subsp. malacensis (0,772), dan subsp. longipetiolata (0,981), sehingga dapat dikatakan pisang liar tersebut bersifat toleran. Pada penelitian ini, pisang tanduk dan klutuk wulung bersifat tahan terhadap BBTV, dengan tingkat kerentanan 0. Sehingga, tanaman pisang tanduk, klutuk wulung, dan halabanensis dapat digunakan sebagai sumber gen ketahanan tanaman pisang pada pengembangan pisang tahan BBTV. Kata kunci: BBTV, karakterisasi, distribusi, inang alternatif, kerentanan

The bunchy top disease is one of the most devastating diseases of bananas. The disease is caused by the Banana bunchy top virus (BBTV). This study aims to (1) determine the character of BBTV in Indonesia molecularly based on its geographical location and (2) determine the response of bananas to BBTV infection. To achieve these goals, the following were carried out: (1) surveys to determine disease distribution and sampling of plants with stunted symptoms on banana and other hosts (2) identification of pathogens by PCR based on RBBTV DNA, (3) bioinformatics analysis of BBTV isolates based on DNA R, DNA S, DNA C, and DNA N as well as grouping based on their geographical location, (4) analysis of BBTV host range through artificial inoculation on non-banana, (5) analysis of banana susceptibility to BBTV infection. The results of the analysis show that the distribution of dwarf disease and BBTV virus has been evenly distributed throughout Indonesia, and there were added new distribution areas during the period 1998-2019, namely the provinces of South Sulawesi, North Sulawesi, West Nusa Tenggara, East Nusa Tenggara, North Maluku, and Papua. BBTV in Indonesia has nucleotide lengths ranging from 1014 nt to 1104 nt. The BBTV can be grouped based on its geographical location into clusters of Sumatra, Bengkulu, Java, Bali, West Nusa Tenggara (Sumbawa), East Nusa Tenggara (Timor), North Sulawesi, North Maluku. Each member in the cluster has a difference of 0.2-1.5%. In addition to infecting bananas, BBTV can infect ginger, turmeric, kencur, and galangal. This proved that these plants role as an alternative host for BBTV. Analysis of the susceptibility of banana plants showed that the mas, Cavendish, raja, and kapok banana plants were susceptible to BBTV with a susceptibility value of 2.9-3. Meanwhile, M. acuminata subsp. halabanensis (0.006), subsp. malacensis (0.772), and subsp. longipetiolata (0.981), it showed that the wild banana is tolerant. In this study, pisang Tanduk and Klutuk Wulung were resistant to BBTV, with a susceptibility level of 0. Thus, pisang Tanduk, Klutuk Wulung, and halabanensis could be used as a source of banana plant resistance genes in the development of BBTV resistant bananas. Key words: BBTV, characterization, distribution, alternative host, susceptibility

Kata Kunci : BBTV, characterization, distribution, alternative host, susceptibility