Karakterisasi biologi dan analisis sekuen gen coat protein cucumber green mottle mosaic virus (CGMMV) isolat Indonesia

LIANA, Alin, Dr. Budi Setiadi Daryono, M.Agr.Sc

2010 | Tesis | S2 Biologi

Labu-labuan merupakan tanaman yang banyak dibudidayakan di Indonesia sebagai tanaman musim kemarau. Namun, budidaya labu-labuan seringkali mengalami gangguan akibat infeksi virus yang dapat mengurangi hasil produksinya. Cucumber green mottle mosaic virus (CGMMV), merupakan anggota Genus Tobamovirus yang dilaporkan telah menginfeksi tanaman labu-labuan di Indonesia. Gejala yang dapat diamati di antaranya adalah mosaik dan belang pada daun, tanaman menjadi kerdil, dan perubahan bentuk pada daun dan buah. Penelitian ini bertujuan untuk mengetahui keberadaan, karakteristik biologi dan molekuler CGMMV yang diisolasi dari tanaman labu-labuan di Daerah Istimewa Yogyakarta (DIY), dan mengetahui hubungan kekerabatan CGMMV isolat Indonesia dengan isolat CGMMV dari berbagai negara berdasarkan kesamaan sekuen gen coat protein (CP). Survei dan koleksi sampel dilakukan di beberapa lahan pertanian di Sleman dan Kulon Progo, DIY selama bulan Maret sampai Juni 2009. Hasil analisis serologi dua sampel daun gambas (Luffa acutangula) positif terinfeksi CGMMV, dan selanjutnya disebut isolat CGMMV-ILa. Uji kisaran inang CGMMV-ILa terhadap beberapa tanaman indikator, menunjukkan adanya necrotic local lesion pada Chenopodium amaranticolor, Chenopodium quinoa, dan Momordica charantia. Gejala mosaik ditemukan pada Citrullus lanatus, Cucumis sativus, Luffa acutangula, dan Nicotiana tabacum var. virginia, dan gejala klorotik ditemukan pada Cucumis melo, tetapi CGMMV-ILa tidak menginfeksi Lycopersicon esculentum. CP CGMMV-ILa diketahui memiliki berat molekul 16 kDa pada uji SDS-PAGE. Sepasang primer CGMMV diperlukan untuk melakukan sekuen nukleotida CGMMV-ILa. Nukleotida dengan panjang 500bp berhasil diamplifikasi dengan RTPCR. Hasil sekuen nukleotida kemudian dibandingkan dengan beberapa isolat CGMMV yang lain, dan diperoleh indeks similaritas pada kisaran 81%. Berdasarkan hasil yang diperoleh, dapat disimpulkan bahwa CGMMV-ILa yang diisolasi dari tanaman gambas, merupakan anggota Genus Tobamovirus.

Cucurbits grow throughout the Java island of Indonesia as dry season crops. However, the cucurbits cultivation has been faced with virus infections that reduce their production. Cucumber green mottle mosaic virus (CGMMV), which a member of the Genus Tobamovirus, has been reported infecting cucurbits in Indonesia. The most common symptoms of infected plants are leaf mosaic and mottling, growth stunting and malformation of leaf and fruit. The purposes of this research were to find out the occurrence of CGMMV infecting cucurbits in Daerah Istimewa Yogyakarta (DIY) and to identify the biological and molecular characterization. Survey and samples collection were conducted in several fields in Sleman and Kulon Progo, DIY during March – June 2009. Serological analysis confirmed that two angled loofah (Luffa acutangula L.) were positively infected by a virus related to Cucumber green mottle mosaic virus (CGMMV), and called CGMMV-ILa isolate. The reaction of indicator plants to CGMMV-ILa were the necrotic local lesion on Chenopodium amaranticolor, Chenopodium quinoa, and Momordica charantia. The mosaic symptoms on Citrullus lanatus, Cucumis sativus, Luffa acutangula, Nicotiana tabacum var. virginia, and the chlorotic symptoms on Cucumis melo, but the CGMMV-ILa did not infect Lycopersicon esculentum. The coat protein (CP) of purified CGMMV-ILa detected with molecular weight of about 16 kDa by SDSPAGE analysis. Viral and complementary CGMMV-specific primer sets were designed for spanning the genome using previously reported CGMMV sequence. About 500bp of Coat protein (CP) gene of CGMMV-ILa was amplified by RT-PCR. The nucleotide sequence of CP gene of CGMMV-ILa shared 81% identities with several isolate of CGMMV. Based on these result, we identified CGMMV-ILa as a CGMMV isolate of Luffa acutangula, a member of Tobamovirus.

Kata Kunci : CGMMV,Labu,labuan,Coat protein,RT,PCR, cucurbits, coat protein