<p>Rice ragged stunt virus (RRSV) is transmitted by brown planthopper in the persistent manner. This disease in recent years has become a serious problem in Indonesia and some other countries, such as China, Vietnam, Philippines, and Thailand. Disease control is usually conducted by the vector control using insecticides, so often causes an environmental pollution. An alternative control method is using the environmentally friendly of resistant varieties. The purpose of this study was to determine the level of preference of brown planthopper (BPH) to some varieties and rice germplasms, the resistance of several varieties against rice ragged stunt virus (RRSV) disease and its effectiveness as an inoculum source of virus (RRSV). A total of 15 varieties of rice were used in preference test of BPH and resistance test to RRSV. The test for resistance varieties to RRSV was conducted by transmission of 2nd instar of BPH for 3 days of acquisition feeding period, 10 days incubation period and 24 hours inoculation period with population density of 3 BPH/plant. Disease index was calculated and used to determine the level of plant resistance. Varieties that showed resistant, moderately resistant and susceptible responses were selected and were used as a source of inoculum to be transmitted on to TN1 variety susceptible check variety to know the effectiveness of varieties as source of virus inoculum. The results showed that of the 15 varieties tested, Situ Bagendit, Utri Merah, Mentik Wangi, Mahsuri, and Inpari 1 each was less favored by BPH to settle and to multiply. Mentik Wangi, Tetep, Utri Merah, and Swarnalata each showed resistant response to RRSV. Transmission test to susceptible variety (TN1) showed that the variety of Situ Bagendit, Inpari 13, Mentik Wangi, and Tetep each has a fairly low effectiveness as a source of inoculum as indicated by the lower percentage of infection and disease index on the transmited test plants.</p>

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Abstract. Subiastuti AS, Hartono S, Daryono BS. 2019. Detection and Identification of Begomovirus infecting Cucurbitaceae and Solanaceae in Yogyakarta, Indonesia. Biodiversitas 20: 738-744. Begomovirus genome has high plasticity that led to evolve rapidly. Begomovirus is one of a remarkably successful group of emerging viruses as the results from combination of many factors. Planting systems in Indonesia which often overlapping two or more plant species in one land has high possibility for occurring mixed infection. It is also suggested has high contribution to increase Begomovirus diversity. The aim of this research is to do preliminary identification of Begomovirus infected-Solanaceae and Cucurbitaceae in Yogyakarta based core coat protein (CP) gene sequence. A total of 50 melon, 50 chili, 30 eggplants, and 30 watermelon samples which showed Begomovirus symptoms were observed from several fields in Yogyakarta and Purworejo, Indonesia during 2016. Almost 90% of infected samples for each plant were tested by PCR and showed positive for Begomovirus. Based on coat protein (CP) gene nucleotide sequence identity, Begomovirus infected Solanaceae in Indonesia has close relationship with Pepper yellow leaf curl Indonesia virus (PepYLCIV) and Tomato yellow leaf curl Kanchanaburi virus (TYLCVKaV), while in Cucurbitaceae has close relationship with Squash leaf curl China virus (SLCCV) Tomato leaf curl New Delhi virus (ToLCNDV). All collected isolates showed highest sequence identity with isolates from South-East Asia and China. However, further analysis that including full genome characterization is still needed to explain Begomovirus evolution in Indonesia.

Research on technical efficiency of organic rice farming was conducted in Tampang PENDAHULUANSektor pertanian adalah sektor yang paling berdampak dengan adanya perubahan iklim, akibat bergesernya musim dan berubahnya pola curah hujan. Meningkatnya temperatur akan berdampak terhadap percepatan penguapan, baik dari tanah maupun tanaman, sehingga tanaman akan rentan terhadap kekurangan air yang pada akhirnya akan menurunkan hasil, bahkan sampai pada gagal panen.Laboratorium Iklim di Institut Pertanian Bogor menyatakan bahwa selama kurun waktu 1981-1990, setiap kabupaten di Indonesia setiap tahunnya mengalami penurunan produksi padi 100.000 ton; dan pada kurun waktu 1992-2000, jumlah penurunan ini meningkat menjadi 300.000 ton (UNDP Indonesia, 2007).Perubahan iklim merupakan proses alami yang bersifat tren yang terus menerus dalam jangka panjang. Oleh karena itu diperlukan suatu strategi untuk antisipasi dan penyiapan adaptasi dalam rangka menghadapi perubahan iklim dan mengembangkan pertanian yang tahan terhadap perubahan