Sri Hendrastuti Hidayat

Deteksi dan Kajian Kisaran Inang Virus Penyebab Penyakit Daun Keriting Kuning Cabai

High incidence of Pepper yellow leaf curl virus (PepYLCV) was observed in Indonesia since early 2000. Disease incidence in Yogyakarta, Central and West Java reached 100% on Capsicum frutescens, but only 10-35% on C. annuum. As an exception, the disease incidence on C. annuum cv. TM 999 was in the range of 70-100%. The causal agent of the disease, PepYLCV, was detected by polymerase chain reaction. Viral specific DNA fragment of the size ~1600 bp and ~550 bp was amplified from infected plants using two pairs of geminivirus universal primers pAL1v1978/pAL1c715, and pAv494/pAc1048, respectively. The PepYLCV has an intermediate host range including plants belonging to the family of Solanaceae, Leguminosae, and Compositae. The species belonging to the families of Cucurbitaceae, Malvaceae, Chenopodiaceae, and Amaranthaceae were resistant to the virus. Physalis floridana, is very prospective as a propagation host for the geminivirus infecting pepper. Nicotiana spp., cucumber, watermelon, cotton, and Sida sp. could be used as a differential host. Besides, Capsicum frutescens cv. Cakra, tomato, N. benthamiana, N. glutinosa, and Ageratum conyzoides could be used as indicator plants for the geminivirus infecting pepper.

Transmission of Tomato leaf curl begomovirus by Two Different Species of Whitefly (Hemiptera: Aleyrodidae)

Whitefly-transmitted geminiviruses (WTGs) are economically important pathogens causing serious damage on tomato and chilli pepper in Indonesia. Geminiviruses are readily transmitted by its insect vector, sweetpotato whitefly (Bemisia tabaci). However, greenhouse whitefly (Trialeurodes vaporariorum), another species of whitefly, is commonly found together with B. tabaci in the field. Incidence of yellow leaf curl disease in tomato and chilli pepper is probably correlated with the population of whitefly complex. It is becoming important to find the role of T. vaporariorum in the spread of the disease. Therefore, research is conducted to study the characteristic relationship between tomato leaf curl begomovirus (ToLCV) and two species of whitefly. The two species of whitefly, B. tabaci and T. vaporariorum, was capable to transmit ToLCV although it was evidenced that B. tabaci is more effective as insect vector of ToLCV in tomato and chilli pepper. A single B. tabaci was able to transmit ToLCV to tomato with a minimum acquisition and inoculation access period of 10 h. Transmission of ToLCV by T. vaporariorum required at least 10 insects per plant with a minimum acquisition and inoculation access period of 24 h. The transmission efficiency will increase with longer acquisition and inoculation access period of the insect and the higher number of insect per plant.

Infeksi Cucumber Mosaic Virus dan Chili Veinal Mottle Virus terhadap Pertumbuhan dan Hasil Tanaman Cabai

A research was undergone to study the effect of single and double infection of Cucumber Mosaic Virus (CMV) and Chili Veinal Mottle Virus (ChiVMV) on the growth and yield of five chilli cultivars, i.e. Prabu, Taro, Jatilaba, Laris, and Keriting Bogor. Mechanical inoculation was conducted to transmit the virus. Infection of the virus was then confirmed with DAS-ELISA. Severe symptom was observed on plant given double infection compared to those given single infection. The rate of plant growth and the amount and weight of fruits were reduced. The type of interaction between CMV and ChiVMV on most chilli cultivar can be considered as interference and additive. Synergism interaction was only observed on cultivar Laris. Based on symptom expression and reduction on yield, it can be concluded that all chilli cultivars used in this study could not hold up the virus infection.

Kajian Plant Growth Promoting Rhizobacteria sebagai Agens Proteksi Cucumber Mosaic Virus dan Chilli Veinal Mottle Virus pada Cabai

This study was conducted to evaluate the effectiveness of plant growth promoting rhizobacteria (PGPR) in protecting chillipepper plant from infection of cucumber mosaic virus (CMV) and chilli veinal mottle virus (ChiVMV). Seven isolates of PGPR, i.e. BC1, BTP2H, BTP3G, BTP3O BTP1, BTP2D, and T1F were applied as seed treatment and soil drench. Plants height, number of branch, and fruits weight were measured every one and ten weeks after virus inoculation. Virus concentration in plants and disease incidence were confirmed by enzyme-linked immunosorbant assay (ELISA). Results showed that inoculation with PGPR improved the seed germination. Eight days after sowing, the percentage of PGPR treated seed germination reached 50-84%; whereas those of untreated seed reached only 18%. In general, PGPR treatment significantly reduced (p < 0.05) the effect of virus infection on plant growth. Two PGPR isolates, i.e. BTP1 and BTP2H, maintained fruit weight of infected plants as good as those of healthy plants. Based on ELISA, PGPR was able to inhibit the disease incidence. The BTP3O and BTP2D isolates even protected the plant from ChiVMV infection. Concentration of salicylic acid and peroxidase were relatively higher on plants treated with PGPR than those without PGPR treatment. This gave an indication that PGPR may act as induction agents for systemic acquired resistance. Therefore, PGPR treatment is a promising strategy to control viral diseases on chillipepper.

Detection and Host Range Study of Virus Associated with Pepper Yellow Leaf Curl Disease

Rojolele is one of Indonesian local variety from Javanica group that susceptible to yellow stem borer (Scirpophaga incertulas). Previous study showed that Rojolele can be cultured and regenerated in vitro. Two cry genes, cryIB-cryIAa were fused and introduced into rice cv. Rojolele in an attempt to improve resistance and to obtain durable resistance rice against the yellow stem borer. Two-week old embryogenic calli of Rojolele rice were inoculated with Agrobacterium tumefaciens harbored with binary vector pCAMBIA 1301, 1303, or 1304 carrying cryIB-cryIAa hybrid gene, hygromycin resistant gene (hpt), and -glucuronidase (gus) gene interrupted with an intron. The transformed calli were selected gradually on medium containing hygromycin (50, 100 mg/l) and regenerated on medium containing 0.5 mg/l IAA and 0.3 mg/l BAP. GUS activity in infected calli was detected by histochemical assay 3 days after inoculation. The highest (100%) transformation efficiency were obtained from calli transformed with pCAMBIA 1303 and 1304. Thirty four out of 77 transformed shoots were tested positive for the cryIB-cryIAa gene using PCR analysis. These shoots were grown in the soil to maturity and to collect the seeds. PCR analysis of the T1 progeny revealed that two out of six lines tested showed a Mendelian segregation pattern. These two lines were also potentially resistant to yellow stem borer based on bioassay in planta. Key words: cryIB-cryIAa hybrid gene, yellow stem borerRojolele is one of Indonesian local variety from Javanica group that susceptible to yellow stem borer (Scirpophaga incertulas). Previous study showed that Rojolele can be cultured and regenerated in vitro. Two cry genes, cryIB-cryIAa were fused and introduced into rice cv. Rojolele in an attempt to improve resistance and to obtain durable resistance rice against the yellow stem borer. Two-week old embryogenic calli of Rojolele rice were inoculated with Agrobacterium tumefaciens harbored with binary vector pCAMBIA 1301, 1303, or 1304 carrying cryIB-cryIAa hybrid gene, hygromycin resistant gene (hpt), and -glucuronidase (gus) gene interrupted with an intron. The transformed calli were selected gradually on medium containing hygromycin (50, 100 mg/l) and regenerated on medium containing 0.5 mg/l IAA and 0.3 mg/l BAP. GUS activity in infected calli was detected by histochemical assay 3 days after inoculation. The highest (100%) transformation efficiency were obtained from calli transformed with pCAMBIA 1303 and 1304. Thirty four out of 77 transformed shoots were tested positive for the cryIB-cryIAa gene using PCR analysis. These shoots were grown in the soil to maturity and to collect the seeds. PCR analysis of the T1 progeny revealed that two out of six lines tested showed a Mendelian segregation pattern. These two lines were also potentially resistant to yellow stem borer based on bioassay in planta. Key words: cryIB-cryIAa hybrid gene, yellow stem borer

Use of Serological-Based Assay for the Detection of Pepper yellow leaf curl Indonesia virus

Diseases caused by Pepper yellow leaf curl virus infection is considered to be emerging plant diseases in Indonesia in the last five years. One key factor for disease management is the availability of accurate detection of the virus in plants. Polyclonal antibody for Pepper yellow leaf curl Indonesia virus-Bogor (PYLCIV-Bgr) was produced for detection of the virus using I-ELISA and DIBA methods. The antibody was able to detect PYLCIV-Bgr from infected plants up to dilution 1/16,384 and cross reaction was not observed with Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV), and Chilli veinal mottle virus (ChiVMV). Positive reaction was readily detected in membrane containing Begomovirus samples from Yogyakarta (Kaliurang and Kulonprogo) and West Java (Bogor and Segunung). Infection of PYLCIV-Bgr in chillipepper, tomato, and Ageratum conyzoides was also confirmed using polyclonal antibody for PYLCIV-Bgr in DIBA. Polyclonal antibody for PYLCIV-Bgr is suggested to be included in disease management approach due to its good detection level.

Identifikasi Gejala dan Kisaran Inang Enam Isolat Begomovirus Cabai di Indonesia (Symptom and Host Range Identification of Six Chilli Begomovirus Isolate in Indonesia)

Perkembangan infeksi Begomovirus pada cabai di Indonesia tidak menutup kemungkinan adanya isolat baru yang berbeda gejala dan kisaran inangnya. Tujuan penelitian adalah melakukan identifikasi isolat Begomovirus cabai dari beberapa sentra produksi di Indonesia berdasarkan gejala dan kisaran inangnya. Penelitian dilakukan di Laboratorium dan Rumah Kasa Virologi Balai Penelitian Tanaman Sayuran (Balitsa) Lembang, dari Bulan Mei 2013 sampai dengan Agustus 2013. Isolat Begomovirus cabai diperoleh dari enam daerah, yaitu Leuwikopo-Bogor, Brebes, Magelang, Kediri, Blitar, dan Karangploso-Malang. Isolat Begomovirus cabai tersebut diisolasi dan dipelihara pada benih tanaman cabai sehat varietas Tanjung-2 dengan cara ditularkan melalui serangga vektor Bemisia tabaci nonviruliferous. Deteksi isolat Begomovirus cabai secara polymerase chain reaction (PCR) menggunakan sepasang primer universal pAL1v1978/pAR1c715. Identifikasi gejala dan kisaran inang dilakukan pada sembilan jenis tanaman indikator, yaitu cabai, tomat, terung, kacang panjang, buncis, mentimun, babadotan, caisim, dan bayam duri. Penelitian menggunakan rancangan acak kelompok dengan tiga ulangan. Amplifikasi PCR menggunakan primer universal pAL1v1978/pAR1c715 terhadap enam isolat Begomovirus cabai berhasil memperoleh fragmen DNA berukuran 1.600 kb. Isolat Begomovirus cabai asal Brebes, Magelang, Kediri, Blitar, dan Karangploso berhasil ditularkan pada tanaman indikator cabai, tomat, terung, mentimun, kacang buncis, kacang panjang, dan babadotan, namun tidak berhasil ditularkan pada tanaman caisim dan bayam duri. Pada tanaman cabai, isolat Begomovirus asal Brebes lebih virulen 3,3–10% untuk tingkat kejadian penyakit dengan masa inkubasi lebih cepat 2,7–3,7 hari dibandingkan isolat Begomovirus asal Bogor, Magelang, Kediri, Blitar, dan Malang. Untuk kepastian perbedaan enam isolat Begomovirus cabai secara molekuler, disarankan untuk analisis perunutan DNA. Keywords Begomovirus; Gejala; Kisaran inang; Virulen Abstract Possibility Begomovirus infection on chilli in Indonesia continually could appear a new isolate. The research was aimed at identifying chilli Begomovirus isolate from some chilli area in Indonesia according to their symptom dan host range. The research was conducted at virology’s Laboratory and Screen Net House of the Indonesian Vegetable Research Institute (IVEGRI), from May to August 2013. Chilli Begomovirus isolates from six area were collected, namely: Leuwikopo-Bogor, Brebes, Magelang, Kediri, Blitar, and Karangploso-Malang. All isolates were isolated and maintained to the healthy chilli seedling of Tanjung-2 variety transmitted by insect vector B. tabaci nonviruliferous. The molecular isolate detection by polymerase chain reaction (PCR) using a pair of universal primers pAL1v1978/pAR1c715. Nine indicator plants were used to identify their symptom and host range, namely chilli, tomato, eggplant, yardlong bean, bean, cucumber, ageratum, caisim, and wild spinach. A randomized block design was used with three replications. Amplification on six chilli Begomovirus isolates. Isolates from Brebes, Magelang, Kediri, Blitar, and Karangploso were succesfully transmitted to various indicator plants, i.e chilli, tomato, eggplant, cucumber, bean, yardlong bean, and ageratum weed, but failed on caisim and wild spinach. Isolate from Brebes was 3.3–10.0% more virulent (disease incident parameter) and 2.7–3.7% days shorter (incubation time parameter) than isolate from Bogor, Magelang, Kediri, Blitar, and Malang. DNA sequencing analysis is recommended to be done. Further DNA sequencing was recommended to confirm the moleculer diffferences among the six chilli Begomovirus isolates.

PENGARUH INFEKSI VIRUS MOSAIK TERHADAP PRODUKSI DAN KADAR MINYAK TIGA VARIETAS NILAM

Purwoceng ( Pimpinella pruatjan Molk.) berkhasiat aprodisiak dengan bahan aktif antara lain steriod, saponin dan ber-gaptin. Penelitian dilakukan di KP. Gunung Putri, bertujuan untuk menge-tahui hubungan cekaman defisit air dengan pembentukan bahan aktif penting pada purwoceng. Pada kegiatan penelitian ini dilakukan dua pengujian yaitu respon pembentukan bahan aktif terhadap peningkatan level cekaman defisit air pada tiga fase pertumbuhan tanaman (3, 5, dan 7 bulan), dan kandungan bahan aktif purwoceng pada kondisi tingkat ketersediaan air tanah di level 80% kegiatan lapang (KL), 60% KL, 50% KL, dan 40% KL, dengan meng-gunakan rancangan acak kelompok, 6 ulangan, pada intensitas cahaya 55%. Hasil penelitian menunjukkan bahwa periode cekaman defisit air berpengaruh terhadap pembentukan bahan aktif pur-woceng. Periode cekaman defisit air 21-38 hari berpengaruh terhadap kandung-an bahan aktif steroid, saponin dan bergapten. Periode cekaman defisit air selama 21-24 hari pada purwoceng berumur tiga bulan menghasilkan kan-dungan stigmasterol dan sitosterol ter-tinggi. Cekaman ringan dengan potensial air pada jaringan daunantara 5-12 bar menghasilkan kandungan bahan aktif steroid dan saponin tertinggi pada tujuh bulan setelah tanam (BST). Perlakuan cekaman defisit air selama 2 bulan dengan pengaturan ketersediaan air tanah setara 60% KL menghasilkan bahan aktif stigmasterol (0,121%), sitos-terol (0,087%) tertinggi pada tanaman purwoceng berumur lima bulan, sedang-kan empat bulan cekamans defisit air dengan 50% KL menghasilkan kandung-an saponin (0,149%) tertinggi pada umur tanaman tujuh bulan.Penyakit mosaik tercatat sebagai salah satu faktor pembatas dalam produksi tanaman nilam ( Pogostemon cablin ). Penelitian ini dilakukan untuk mengukur pengaruh infeksi virus penyebab penyakit mosaik terhadap produksi dan kadar minyak tanaman nilam. Bahan yang digunakan dalam penelitian ini adalah tiga varietas unggul tanaman nilam yaitu Sidikalang, Lhokseumawe dan Tapak Tuan. Infeksi Potyvirus berhasil dideteksi pada varietas Tapak Tuan dan Lhok-seumawe berdasarkan hasil metode ELISA. Pengukuran berat terna basah, terna kering, kadar minyak dan kadar patchouli alcohol (PA) yang dilakukan pada tanaman berumur enam bulan menunjukkan terjadinya penurunan produksi dan kadar minyak. Penurunan tertinggi berat terna basah, terna kering, kadar minyak dan kadar PA berturut-turut dapat mencapai 34,65, 40,42, 9,09 dan 5,06%.Pengaruh pemupukan terhadap intensitas serangan penyakit budok, dan pertum-buhan tanaman nilam telah dilakukan di daerah endemik penyakit budok di Nagari Situak Pasaman Barat sejak Juli 2009 sampai Maret 2010. Perlakuan disusun dalam Rancangan Acak Kelompok 8 perlakuan dan 4 ulangan. Perlakuan yang diuji adalah pupuk NPK (PL) 250 kg/ha, pupuk kandang (Po) 20 t/ha, kompos nilam (Kn) 10 t/ha, kombinasi (PL + Po), (PL + Kn), (Po + Kn,) (PL + Po + Kn) dan kontrol (tanpa pupuk). Hasil pene-litian menunjukkan bahwa semua perla-kuan memberikan pengaruh positif dalam menekan serangan penyakit budok, pem-berian pupuk NPK 250 kg/ha + pupuk kandang 20 t/ha + kompos nilam 10 t/ha mampu menekan intensitas serangan budok sekitar 48,49% dan menghasilkan pertumbuhan tanaman lebih baik dibanding perlakuan lain dengan rataan tinggi tanaman 96,83 cm, jumlah cabang primer 27,50 buah, diameter tajuk 104,98 cm dan produksi terna 1187,50 g/rumpun, hasil ini tidak berbeda nyata dengan pemberian pupuk kandang 20 t/ha + pupuk NPK 250 kg/ha dan pemberian pupuk kandang 20 t/ha + kompos 10 t/ha, tapi berbeda nyata dengan perlakuan kontrol dengan rataan tinggi tanaman 69,58 cm, jumlah cabang primer 19,50 buah, diameter tajuk 65,27 cm dan produksi terna 552 g/rumpun.

Deteksi Begomovirus pada Cabai Secara Cepat melalui Isolasi Genom DNA

Pepper yellow leaf culr disease has been widely spreading in Indonesia, especially in Special Province of Yogyakarta and Central Java since 2000. The disease is difficult to control because its fast spreading over in the field by the vector. To prevent epidemic of the disease, early detection method of the causal agent is needed. The aim of the research was to detect the causal agent of the pepper yellow leaf curl disease by isolating the DNA genome. Using the Guanidine-alkaline method, two specific fragments of the DNA were produced approximately at 2600 bp and 1600 bp. The DNA fragments were similar with the DNA genome of Begomovirus. The method applied in this study is faster and easier for early detection of the Begomovirus in infected crop than detection by the Polymerase chain reaction (PCR).

Cucumber Mosaic Virus and Chili Veinal Mottle Virus Infection on Growth and Yield Component of Chilli

The term of allelopathy refers to chemical interactions (inhibitory or stimulatory) between plants, between plants and microorganisms, and between microorganisms. The wealth of information on the processes, procedures, and practices of allelopathy has contributed to understanding this field of science. Recently, researches of allelopathy have been conducted in laboratory, greenhouse, and field with multifaceted standpoint in some concerning area: (i) allelochemicals identifications and screening test; (ii) ecological and physiological aspects of allelopathy; (iii) genetic studies and the possibilities of using plant breeding or genetic manipulation to enhance allelopathic varieties; (iv) the use of allelopathic potential in the biological control, including as natural pesticide, of weeds and plant diseases as eco-friendly approach for sustainable agriculture scheme. Key words: Allelochemicals, biological control, sustainable agriculture