Variasi Virulensi Virus Tungro Bersumber Dari Inokulum Di Daerah Endemis Tungro Di Indonesia

Variations in virulence of tungro viruses from various inoculum sources in tungro endemic areas in Indonesia. Rice tungro disease is caused by virus which is effectively transferred by the green leafhopper. Reactions of resistant varieties to virus sources of inocula from 15 tungro endemic areas were employed as indicator of variations of virus virulence. The green leafhopper of Sukamandi's population was used as the vector and allowed to transfer viruses acquired from tungro's infected plants from 15 tungro endemic areas to five groups of virus resistant varieties based on parent source of resistance using free choice screening box method. The results showed that the most resistant variety was group V1-Tukad Petanu, followed by V4-Tukad Unda, V2-Tukad Balian and V3-Bondoyudo. Based on resistance test result group variety of V1-Tukad Petanu is recommended for 15 provinces source of incula except for Sulawesi Utara. Group variety of V4-Tukad Unda is not recommended to plant in Yogyakarta and Banten provinces. Group V2-Tukad Balian is not recommended to plant in Bali, Sulawesi Utara, Banten and Kalimantan Selatan provinces. Group V3-Bondoyudo is not recommended to plant in Jawa Tengah, Yogyakarta, and Banten provinces. There were variations in virus virulence among sources of inocula. Six virulence variants were identified, i.e. 001 (Jawa Barat, Nusa Tenggara Barat, Sulawesi Selatan, Jawa Timur, Lampung, Sulawesi Barat, Sulawesi Tengah, Sulawesi Tenggara, Papua), 011 (Jawa Tengah), 021 (Bali, Kalimantan Selatan), 051 (Yogyakarta), 071 (Banten) and 121 (Sulawesi Utara)

Karakteristik Wereng Hijau dan Epidemi Tungro di Kabupaten Garut, Provinsi Jawa Barat

Characteristics of Green Leaf Hoppers and Tungro Epidemic in Garut District, West Java Province. Tungro disease is one of the biotic constraints that may reduce crop yield potential of rice. The disease is caused by tungro virus that is spread by green leafhopper (GLH) Nephotettix virescens. GLH N. virescens is the most efficient vector of tungro virus among the others GLH. GLH was found in lowland to highland. The experiment was conducted in Garut district in the dry season 2012 and wet season 2012/2013. This study aims to determine the characteristics of GLH and Tungro epidemic in Garut District, West Java Province. Observations in the field include tungro disease intensity, GLH population density, and natural enemies populations, and the abiotic environment. Activities in the green house including adaptation test of GLH colonies from field to differential varieties resistant against GLH and virulence test of tungro virus to differential varieties resistant against tungro. The results in the fields showed that the GLH population density in the highlands Garut was relatively low. Likewise with tungro disease intensity at Garut in two cropping seasons had low intensity. Tungro attack depends on the effectiveness of GLH to transmit the virus. Although the GLH population was low but could transmit tungro virus effectively in the field. Natural enemies were most commonly founds in the highlands Garut was long jawed spiders Tetragnatha sp. The test results to the differential varieties resistant against GLH in green house suggested that adaptation of GLH colony from Garut was low and have not been able to break the resistance of GLH resistant varieties. While the test results to the differential varieties resistant against tungro showed that tungro virus from Garut was variants 071. That variant was highly virulent because it can break tungro resistant differential varieties except Tukad Petanu

Evaluasi Virulensi Virus Tungro dari Beberapa Daerah Endemi dan Uji Ketahanan Plasma Nutfah Padi

The purpose of this study was to evaluate the level of tungro virus virulence from some endemic areas, the suitability of planting resistant varieties, and resistance of rice germplasms. Tungro virus isolates were collected from tungro-endemic areas in North Sumatra, West Java, Central Java, South Sulawesi, West Sulawesi and Central Sulawesi. Tungro virus isolates were then inoculated using green leafhoppers Nephotettix virescens (Distant) to five differential varieties: Tukad Petanu, Bondoyudo, Kalimas, Tukad Balian, and Tukad Unda, and TN1 (as susceptible check). Level of virulence of tungro virus isolates and suitability planting of resistant varieties can be evaluated. Tungro virus isolate which has the highest virulence was used to test of resistant of rice germplasms. Results of tungro virulence test can be distinguished that there are 4 variants of virulence, namely: 073 (Subang, Bulukumba, Bantaeng, andWest Sulawesi isolates), 033 (Simalungun, Temanggung, and Palu), 031 (Kuningan andMagelang), and virulence 013 (Lanrang isolate). Tukad Petanu was still appropriate varieties to be planted in throughout the tungro-endemic areas (North Sumatra, West Java, Central Java, South Sulawesi, West Sulawesi, and Central Sulawesi). Bondoyudo variety still suitables to be planted in the areas of Simalungun, Kuningan, Magelang, Temanggung, Lanrang, and Palu. While Tukad Unda variety still have the suitability of planting for areas Kuningan, Magelang, and Temanggung. Between 100 assesions of germplasm which were tested to high virulence of tungro (073) one resistant assession has been identified (Deli assesion), and as many as 25 assesions showed moderately resistant reaction. Tujuan penelitian ini adalah untuk mengevaluasi tingkat virulensi virus tungro dari beberapa daerah endemi, kesesuaian tanam varietas tahan, dan ketahanan asesi plasmanutfah padi. Isolat virus tungro dikoleksi dari daerah endemi tungro di Sumut, Jabar, Jateng, Sulsel, Sulbar, dan Sulteng. Isolat-isolat virus tungro tersebut kemudian ditularkan menggunakan wereng hijauNephotettix virescens (Distant) pada 5 varietas diferensial yaitu Tukad Petanu, Bondoyudo, Kalimas, Tukad Balian, dan Tukad Unda, serta TN1 sebagai kontrol rentan. Tingkat virulensi isolat dan kesesuaian tanam varietas tahan kemudian dapat dievaluasi. Isolat tungro dengan virulensi yang paling tinggi selanjutnya digunakan untuk uji ketahanan asesi plasmanutfah padi sebagai bahan tetua tahan. Hasil uji virulensi tungro dapat dibedakan ada 4 varian virulensi, yaitu: 073 (isolat Subang, Bulukumba, Bantaeng, dan Polewali Mandar), 033 (isolat Simalungun, Temanggung, dan Palu), 031 (isolat Kuningan dan Magelang), dan virulensi 013 (isolat Lanrang). Varietas Tukad Petanu masih sesuai untuk ditanam di seluruh daerah endemi tungro (Sumut, Jawa Barat, Jawa tengah, Sulawesi Selatan, Sulawesi Barat, dan Palu). Varietas Bondoyudo masih mempunyai kesesuaian tanam di daerah Simalungun, Kuningan, Magelang, Temanggung, Lanrang, dan Palu. Sedangkan Varietas Tukad Unda masih mempunyai kesesuaian tanam untuk daerah Kuningan, Magelang, dan Temanggung. Dari sebanyak 100 asesi plasmanutfah yang diuji ketahanannya terhadap tungro virulensi tinggi (073) telah teridentifikasi satu asesi tahan (Deli), dan sebanyak 25 asesi yang menunjukkan reaksi agak tahan

Deteksi Keragaman Virus Tungro dari Beberapa Daerah Endemis di Indonesia dengan Teknik PCR-RFLP

Tungro is one of rice disease caused by two different viruses (rice tungro virus=RTV) i.e. Rice tungro bacilliform virus (RTBV) and Rice tungro spherical virus (RTSV) that are transmitted only by green leafhopper. Tungro had become a serious problem in several rice productions centre in Indonesia. Various components of management effort have been applied but they were inefficient in preventing the tungro disease development. Resistance variety is the most efficient component to tungro disease management. Complexity interactions of tungro disease components are mayor constraint in tungro disease management. Detection of molecular variability in rice tungro virus from several endemic areas in Indonesia were conducted by using PCR-RFLP technique. Existence of RTBV and RTSV in the infected plants collected from several endemic areas were successfully detected by PCR. The RFLP analysis with restriction enzymes BstYI and HindIII showed that there were significant difference among the RTSV originated from Java, Bali and Sulawesi. Tungro merupakan salah satu penyakit padi yang disebabkan oleh dua virus (rice tungro virus=RTV) yang berbeda yaitu Rice tungro bacilliform virus (RTBV) dan Rice tungro spherical virus (RTSV) yang keduanya hanya dapat ditularkan oleh wereng hijau.Tungro menjadi masalah serius di beberapa sentra produksi padi di Indonesia. Berbagai USAha pengendalian telah dilakukan tetapi belum dapat mencegah dan mengatasi perkembangan penyakit tungro secara efisien. Varietas tahan merupakan komponen pengendalian tungro yang paling efektif. Kompleksitasinteraksi penyebab penyakit tungro merupakan kendala utama dalam USAha pengendalian penyakit tungro. Melalui pendekatan molekuler telah dilakukan deteksi dan analisis keragaman virustungro dari beberapa daerah endemis di Indonesia. Berdasarkan analisis PCR dengan spesifik primer telah berhasil dideteksi keberadaan RTBV dan RTSV dari tanaman terinfeksi yang dikoleksi dari beberapa daerah endemis. Hasil analisis RFLP dengan enzim restriksi BstYI dan HindIII menunjukkan adanya keragaman genetik antaraRTSV yang berasal dariJawa,Bali dan Sulawesi

Keragaman Virulensi Dan Konstruksi Molekuler Virus Tungro Pada Padi Dari Daerah Endemis

Tungro is an important disease of rice, constraining to the rice production in Indonesia. Tungro is caused by the infection of two different viruses namely tungro bacilliform virus (RTBV) and tungro spherical virus (RTSV). Both viruses are only transmitted by green leafhoppers, especially Nephotettix virescens in a semipersistent manner. The variation of tungro viruses from different areas had been reported, and there is a specific relationship between resistance variety and tungro virus isolate. It is important therefore, to study the virulences and the genetic diversities of tungro viruses derived from the endemic areas in Indonesia. This study was aimed to identify the virulence and the molecular diversity of tungro viruses from endemic areas in Indonesia. Susceptible variety TN1 was used in the study. Surveys and collection of the infected plants and green leafhoppers were conducted in some tungro endemic areas, including: West Java, Central Java, Yogyakarta, Central Sulawesi, West Sulawesi, South Sulawesi, Bali and West Nusa Tenggara. Artificial virus transmission using test tube method was used in the virulence test. Green leafhoppers caught from the field were used as vector transmitters. The virulence of tungro viruses was determined based on diseases indexes (DI). Results showed that the virulence of tungro viruses varied among region in the endemic areas in Indonesia. The Central Java virus isolate was the most virulence; however, not all isolates from endemic areas in the island of Java were more virulent than those from outside of Java. The presence of RTBV and RTSV was detected in the infected TN1 plants. The existences of molecular diversities of tungro viruses from the endemic areas were observed. The relationship between combination of DNA bands of RTBV and RTSV with the virulence in endemic areas outside of Java was more complex than it was in West Java and Central Java. The molecular diversities of tungro viruses were not correlated with the geographic difference of the endemic areas, nor with the virulences

Evaluation of bottom-up and top-down strategies for aggregated forecasts: state space models and arima applications

Abstract. In this research, we consider monthly series from the M4 competition to study the relative performance of top-down and bottom-up strategies by means of implementing forecast automation of state space and ARIMA models. For the bottomup strategy, the forecast for each series is developed individually and then these are combined to produce a cumulative forecast of the aggregated series. For the top-down strategy, the series or components values are first combined and then a single forecast is determined for the aggregated series. Based on our implementation, state space models showed a higher forecast performance when a top-down strategy is applied. ARIMA models had a higher forecast performance for the bottom-up strategy. For state space models the top-down strategy reduced the overall error significantly. ARIMA models showed to be more accurate when forecasts are first determined individually. As part of the development we also proposed an approach to improve the forecasting procedure of aggregation strategies

MAGGnet: an international network to foster mitigation of agricultural greenhouse gases.

Research networks provide a framework for review, synthesis and systematic testing of theories by multiple scientists across international borders critical for addressing global-scale issues. In 2012, a GHG research network referred to as MAGGnet (Managing Agricultural Greenhouse Gases Network) was established within the Croplands Research Group of the Global Research Alliance on Agricultural Greenhouse Gases (GRA). With involvement from 46 alliance member countries, MAGGnet seeks to provide a platform for the inventory and analysis of agricultural GHG mitigation research throughout the world. To date, metadata from 315 experimental studies in 20 countries have been compiled using a standardized spreadsheet. Most studies were completed (74%) and conducted within a 1-3-year duration (68%). Soil carbon and nitrous oxide emissions were measured in over 80% of the studies. Among plant variables, grain yield was assessed across studies most frequently (56%), followed by stover (35%) and root (9%) biomass. MAGGnet has contributed to modeling efforts and has spurred other research groups in the GRA to collect experimental site metadata using an adapted spreadsheet. With continued growth and investment, MAGGnet will leverage limited-resource investments by any one country to produce an inclusive, globally shared meta-database focused on the science of GHG mitigation

Pertumbuhan Populasi dan Oviposisi Wereng Hijau, Nephotettix Virescens Distant (Hemiptera: Cicadellidae) Berkaitan dengan Saat Padi Keluar Malai

Effects of early and late-maturing varieties of rice on the population growth of N. virescens was investigated during the wet season crop of 1994/1995, and dry season crop of 1995 in the experimental fields of Research lnstitute for Rice in Sukamandi. A pot experiment to observe oviposition rate of N. virescens on both varieties was conducted in screen house in the dry season crop of 1995. The population fluctuation of N. virescens on both varieties as well as number of eggs of the first generation at 8 weeks aftertransplanting were similar. The population density increased during early growth stage of rice from immigrant generation to the first generation and decreased thereafter. The peak emergence of adults of the first generation on early maturing variety occured after the flowering stage, on the otherhand on late maturing variety the peak emergence of adults occured before the flowering stage. Adult N. virescens laidmore eggs on early maturing variety after flowering stage than that on late maturing variety before flowering stage (p< 0.01; t-test) in the pot experiment. Those field and pot experiment facts indicated that the first generation of adult emigrant influenced the population fluctuation in the fields, because the density of predator, Lycosa, was lower in the early maturing variety than in the late maturing variety in the wet season crop of 1994/1995 and it was similar in the dry season crop of 1995