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Banana bunchy top disease is caused by the Banana bunchy top virus (BBTV), which is a species of the genus Babuvirus in the family Nanoviridae. In this study, we collected 61 isolates of BBTV from Sumatra Island. The sequences of DNA-R and DNA-S of 61 samples and DNA-U3 of 37 samples were determined. Although the Sumatra population has different sequences in the stem-loop region in DNA-U3

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Analisis genetik  isolat-isolat  cendawan Fusarium  oxysporum f. sp. cubense (Foc) VCG 01213/16 penyebab penyakit layu pada tanaman pisang menunjukkan adanya keragaman yang nyata. Penelitian bertujuan mempelajari keragaman virulensi isolat-isolat yang terkelompok dalam VCG 01213/16, berasal dari berbagai daerah dan varietas pisang yang berbeda.  Penelitian dilakukan di Laboratorium Penyakit dan Rumah Kasa Balai Penelitian Tanaman Buah Tropika (Balitbu Tropika) Solok, dari bulan Maret sampai dengan Juni 2009. Rancangan yang digunakan ialah acak kelompok dengan 10 perlakuan dan tiga ulangan, masing-masing perlakuan terdiri atas 10 tanaman. Perlakuan terdiri atas 10 isolat Foc VCG 01213/16 yang berasal dari varietas pisang dan lokasi berbeda. Tanaman uji ialah benih pisang Barangan hasil perbanyakan kultur jaringan. Hasil penelitian menunjukkan bahwa terdapat keragaman virulensi 10 isolat Foc VCG 01213/16 yang dinilai dari perbedaan masa inkubasi, persentase serangan, dan indeks keparahan penyakit pada bonggol dan daun pisang Barangan. Sembilan isolat Foc yang diuji mempunyai virulensi yang tinggi. Masa inkubasi berkisar antara 13,98 dan 16,80 hari, persentase serangan 93,33-100%, dan indeks keparahan penyakit pada bonggol dan daun masing-masing berkisar 3,46-5,35 dan 4,68-5,41. Isolat Foc VCG 01213/16 yang berasal dari Jabung-Lampung Timur dan diisolasi dari pisang varietas Ambon Kuning (isolat F) menunjukkan virulensi yang relatif lebih rendah dibanding sembilan isolat  Foc lainnya dengan masa inkubasi 30,27 hari, indeks keparahan penyakit pada bonggol dan daun masing-masing sebesar 2,14 dan 3,76.  Hasil penelitian ini bermanfaat dalam memberikan informasi tentang biologi F. oxysporum f. sp. cubense sebagai dasar untuk penyusunan teknik pengendalian yang tepat.<br /><br /><br />Genetic analysis of isolates of the Fusarium oxysporum f. sp. cubense (Foc) that are grouped in VCG 01213/16, as the causal agent of wilt disease in banana plants showed a considerable variation. This research aimed to study the variation in virulence of isolates that are grouped in VCG 01213/16 from different varieties of banana and regions. The study was conducted in the Protection Laboratory and the Screenhouse of Indonesian Tropical Fruit Research Institute (ITFRI) Solok, from March to June 2009. A randomized block design was used in this research with 10 treatments and three replications. Each treatments consisted of 10 banana plants. The treatment was 10 Foc isolates belonging to VCG 01213/16 originating from different varieties of banana and locations. Barangan plantlets produced from tissue culture propagation were used as the planting material. The results showed that there were high variations in virulence among 10 Foc isolates in VCG 01213/16 based on variables of the incubation period, percentage of wilt, and disease severity index on corm and leaves of Barangan variety. Nine of the 10 Foc isolates tested were highly virulent isolates. The incubation period ranged from 13.98 to 16.80 days, the percentage of wilt from 93.33 to 100%, and the disease severity index of corm and leaves ranged from 3.46 to 5.35 and from 4.68 to 5.41, respectively. The Foc VCG 01213/16 isolates originated from Jabung, East Lampung and from Ambon Kuning variety (isolate F) shown relatively low virulence than others isolates that the incubation period was 30.27 days and the disease severity index on the corm and leaves was 2.14 and 3.76, respectively. This result provides useful information on biology of F. oxysprum f. sp. cubense to find out the best control method of the pathogen.<br /><br />

Fusarium wilt is the most destructive disease on banana. One of control measures that can be performed to control this disease is by increasing plant immunity. The aim of this study was to find out the disease resistance profile of banana to fusarium wilt through resistance induction with Salicylic acid. This study was performed at Plant Pest and Disease Laboratory, Indonesian Tropical Fruit Research Institute, started from May to December 2018. Banana cultivars used in this study were cv. Barangan and Raja Kinalun at pre-planting stage. The treatments were the induction methods consisted of control (sterile water), Salicylic acid spraying to entire part of plant and the root soaking with 5 mM Salicylic acid solution. The plants were artificially inoculated with F. oxysporum f.sp cubense VCG 01213/16 (TR4). Each treatment was repeated 3 times with 10 plants for each treatment unit. The result showed that. banana cv. Barangan inoculated with Foc (control) was highly susceptible while cv. Raja Kinalun in the same treatment had moderate resistant criterion. Salicylic acid can induce resistance to fusarium wilt disease on cv Barangan with moderate resistant criterion compared to highly susceptible on its positive control.