Judul: Identification and multiplex reverse transcription polymerase chain reaction detection of viruses associated with mosaic symptom on patchouli (Pogostemon cablin Benth.).
Abstrak: Patchouli essential oil is one of sources of Indonesia foreign exchange, since Indonesia is the biggest supplier of patchouli oil in the world. One of obstacle on the patchouli production is viral infection. Virus(es) infecting patchouli plant has not been well known. Thus, the aim of presented work is to detect and identify virus(es) associated with mosaic symptom on patchouli either serologically or molecularly. Samples were collected from patchouli cultivation in Cicurug and Cijeruk (Sukabumi) and in Manoko (Lembang, Bandung) by taking 30 symptomatic and asymptomatic samples from each location. Serological test using four antisera to Cucumber mosaic virus (CMV), Cymbidium mosaic virus (CymMV), Potyvirus and Broad bean wilt virus 2 (BBWV2) were carried out to determine the incidence of virus infection. Further molecular detection of virus(es) was carried out by reverse transcription polymerase chain reaction (RT-PCR) and DNA sequencing. Multiplex RT-PCR was developed to provide rapid detection of those viruses used eight combination of primer concentrations (I, II, III, IV, V, VI, VII and VIII). Serology detections showed that BBWV2 and Potyvirus were detected in all sampling locations, CymMV was found in Cicurug and Manoko, while CMV was detected in Cicurug and Cijeruk. Potyvirus disease incidence was 100% in Manoko, 83.3% in Cicurug and 50.0% in Cijeruk. BBWV2 disease incidence was 100% in Manoko, 73.3% in Cicurug and 90.0% in Cijeruk. Disease incidence of CymMV in Manoko and Cicurug was 3.3% , while the incidence of CMV in Cicurug was 80.0% and 13.3% in Cijeruk. Each of primer pairs were able to amplify the coresponding viruses, which confirmed the serology detections. Nucleotide and amino acid sequence homology analysis showed that BBWV2 isolated from Manoko has a highest homology with BBWV2 from Singapore (natural host: Megakepasma erythroclamys / ME). BBWV2 from Manoko clustered with BBWV2 from Singapore (ME), China (pepper) and South Korea (red pepper) based on the nucleotide and amino acid sequences. CymMV from Manoko has a highest homology of nucleotide and amino acid sequences with CymMV from South Korea (Cymbidium). CymMV from Manoko clustered with CymMV from India (Phaius sp), Indonesia (Dendrobium), China (Cymbidium and vanilla), Thailand (Oncidium), Hawai (Dendrobium) and South Korea (Cymbidium) based on nucleotide sequence. While based on amino acid sequence, CymMV from Manoko clustered with CymMV from India (Phaius sp and vanilla), and Singapore (Dendrobium). Multiplex RT-PCR was succesfully amplified Potyvirus, BBWV2 and CymMV by using primer combination V, VI, VII and VIII. The multiplex RT-PCR can be applied to detect multiple viruses infection on patchouli simultaneously.
Keyword: Broad bean wilt virus 2, Cymbidium mosaic virus, mosaik, nilam

Judul: Telosma mosaic virus associated with mosaic disease of patchouli plant: identification and control approach
Abstrak: Patchouli oil (patchouli alcohol) produced by patchouli plant (Pogostemon cablin Benth.) is one of the raw materials of high value multifunctional perfume. However, in the process of cultivation and development of this commodities are attacked by plant pest organisms, especially diseases. Some important diseases of patchouli, which is now spread in Indonesia, namely budok, bacterial wilt, diseases caused by nematodes and viruses. This study aimed (1) to map the presence of mosaic disease on patchouli plantation in patchouli production centers of Indonesia, (2) to measure product reduction of patchouli plants due to mosaic disease, (3) to identify viruses associated with mosaic disease, (4) to identify aphid species found colonizing patchouli plants in the field, (5) to molecularly characterize viruses associated with mosaic disease on patchouli, (6) to analyze the genetic diversity among Telosma mosaic virus (TeMV) isolated from patchouli, (7) to determine the host range of TeMV, (8) to determine the relationship of the aphids colonizing patchouli plants with mosaic disease, and (9) to obtain virus-free patchouli seedling by apical meristem culture method and hot water treatment. The results show that the mosaic disease was found in all patchouli production areas of Java and Sumatra and two species of aphids, i.e. Aphis gossypii Glover and Brachycaudus sp. were found colonizing patchouli plants in all survey locations. Due to the mosaic disease, reduction of fresh herbs weight, dry herbs weight, oil content and the patchouli alcohol of patchouli in the first harvest was reached 35%, 40%, 9% and 5%, respectively. Based on the serological test, Potyvirus was found predominantly associated with the mosaic symptoms. Further identification based on nucleotide sequence of coat protein gene revealed that the species of Potyvirus is Telosma mosaic virus (TeMV). Host range and aphid transmission evaluation confirmed the association of Potyvirus with mosaic disease. This paper is the first report of occurence of TeMV in Indonesia. This virus will be easily to spread to any areas because patchouli plants are propagated by stem cuttings. In this study, a technique was also developed to produce virus-free cutting using apical meristem culture and hot water treatment on stem cutting. The patchouli plant has been propagated from apical meristem culture of 0.5-1 mm in sizes yielded 33.3-90.9% virus-free plants. Submersion of patchouli stem cutting in hot water of 50-60⁰C for 10-30 minutes could not eliminated TeMV. Apical meristem culture technique is potential to produce virus-free cutting of patchouli.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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