Spesies Colletotrichum telah banyak dilaporkan sebagai agens penyebab penyakit antraknosa pada tanaman jeruk. Importasi buah jeruk dari beberapa negara produsen ke Indonesia berpotensi membawa masuk ...spesies Colletotrichum yang belum dilaporkan terdapat di Indonesia. Penelitian dilakukan untuk mengidentifikasi spesies Colletotrichum yang terbawa melalui impor jeruk dan mengevaluasi potensinya menginfeksi tanaman hortikultura dan perkebunan penting di Indonesia. Sebanyak 7 isolat Colletotrichum diisolasi dari buah jeruk impor asal Cina, Pakistan dan jeruk lokal asal Indonesia. Isolat-isolat Colletotrichum tersebut diamati karakter morfologi dan molekulernya serta patogenisitasnya pada tanaman jeruk, cabai, karet, dan kakao. Analisis filogenetik dilakukan dengan metode analisis multilokus gen (multilocus sequence analysis) dengan mengombinasikan lokus gen ITS, ACT, TUB2, dan GAPDH. Identifikasi isolat Colletotrichum menghasilkan satu spesies grup C. boninense kompleks spesies (C. karstii), 3 spesies grup C. gloeosporioides kompleks spesies (C. fructicola, C. gloeosporioides sensu stricto, dan C. siamense). Isolat Colletotrichum asal jeruk Indonesia diidentifikasi sebagai C. gloeosporioides s.s. Strain C. fructicola mampu menginfeksi cabai, sedangkan strain C. karstii menginfeksi cabai, dan kakao. Strain C. gloeosporioides s.s. dan C. siamense memiliki kisaran inang yang lebih luas yaitu cabai, karet, dan kakao. Beberapa spesies Colletotrichum yang terbawa oleh buah jeruk impor berpeluang menjadi patogen pada beberapa tanaman penting di Indonesia, yaitu cabai, karet, dan kakao.
Virus infection is one of the major constraints in garlic production since the viruses are readily accumulated on vegetative propagation material (bulbs). This research aimed to detect garlic common ...latent virus (GCLV), shallot latent virus (SLV), onion yellow dwarf virus (OYDV), and leek yellow stripe virus (LYSV) infecting local garlic as seed bulb and imported garlic as consumption bulb. Seed bulb samples were obtained from seed breeders in several garlic growing centers in Indonesia. In contrast, consumption bulb samples were obtained from plant quarantine warehouses and three local markets in Bogor. Some bulb samples were used for morphological observations, and some were germinated in the laboratory until the leaves emerged. Leaves were collected for virus detection by RT-PCR using specific primers for GCLV, SLV, OYDV, and LYSV. Seed and consumption bulbs have differences in their morphological characteristics, especially in the type of neck hardness and the size of the bulb diameter. OYDV and LYSV infections were successfully detected in seed and consumption bulbs, while SLV was only found in consumption bulbs. Nucleotide sequence analysis showed that SLV from consumption bulbs formed one group, GCLV from seed bulbs formed one group, while OYDV and LYSV from seed and consumption bulbs were in different groups, indicating that the viruses came from different strains. Further research through high-throughput detection methods and providing virus-free planting material are needed to anticipate the spread of new strains of garlic viruses in Indonesia.
Pepper yellow leaf curl disease caused by Pepper yellow leaf curl virus becomes a major problem on chilli pepper in Indonesia since 2000. Endophytic fungi has the potency to suppress plant diseases ...by acting as induced resistant agent. The objective of this research was to determine the effect of endophytic fungi application on incidence of yellow leaf curl disease of chilli pepper. Four isolates of endophytic fungi, i.e. Cercospora nicotianae isolate H5, Curvularia sp. isolate H12, Fusarium sp. isolate AC-2.7 and AC-4.5 were applied as seed treatment and leaf spray on 2 chilli varieties, ‘Biola’ and ‘Luwes’. Observations of incubation period showed that delayed symptom occurred on application of Fusarium sp. isolate AC-2.7 and Curvularia sp. isolate H12. Disease incidence reached 100 % in all treatments. Less severe symptom was observed on application of Curvularia sp. isolate H12. Most plants infected by PYLCIV showed obvious symptoms of yellow mosaic, leaf curling and stunting. Plant productivity analysis showed that application of Fusarium sp. isolate AC-2.7 resulted higher fruit weight and this treatment may induce tolerant response of the plants to PYLCIV infection. Initial effort to evaluate endophytic fungi as biocontrol agents for pepper yellow leaf curl disease should be studied further.
Listihani, Hidayat SH, Wiyono S, Damayanti TA. 2019. Characteristic of Tobacco mosaic virus isolated from cucumber and tobacco collected from East Java, Indonesia. Biodiversitas 20: 2937-2942. ...Tobacco mosaic virus (TMV) is a newly emerging virus infecting cucumbers in Java, Indonesia. The basic characters of the TMV isolated from cucumber need further study to investigate its differences with that from tobacco. Thus, the research aimed to study the character of both isolates based on their biological, symptomatology and nucleic acid of coat protein (CP) gene properties. The TMV isolates from both cucumber and tobacco were able to infect similar indicator plants with differing symptom expressions, especially on eggplant. Homology of nucleotide and amino acid of coat protein gene among isolates were about 90.3% and 91.0%, and homology to other isolates was about 87.6 to 93.8% and 89.3 to 96.8%, respectively. There were 17 amino acid differences in the CP gene which is presumed to differentiate those two isolates. Phylogenetic analysis CP gene sequences compared with corresponding isolates in GenBank showed the two isolates separated in different clades. The cucumber isolate from Kediri is closely related to tomato isolate from China in clade I, while tobacco isolate from Jember closely related to tobacco isolate from China in clade IIindicating the existence of two differ TMV variants. It will increase the difficulty to manage TMV in the fields.
PDF
