Pepper Yellow Leaf Curl Virus Research Articles

Leveraging Biotic Interaction Knowledge Graph and Network Analysis to Uncover Insect Vectors of Plant Virus

Background: Insect vectors spread 80% of plant viruses, causing major agricultural production losses. Direct insect vector identification is difficult due to a wide range of hosts, limited detection methods, and high PCR costs and expertise. Currently, a biodiversity database named Global Biotic Interaction (GloBI) provides an opportunity to identify virus vectors using its data. Objective: This study aims to build an insect vector search engine that can construct an virus-insect-plant interaction knowledge graph, identify insect vectors using network analysis, and extend knowledge about identified insect vectors. Methods: We leverage GloBI data to construct a graph that shows the complex relationships between insects, viruses, and plants. We identify insect vectors using interaction analysis and taxonomy analysis, then combine them into a final score. In interaction analysis, we propose Targeted Node Centric-Degree Centrality (TNC-DC) which finds insects with many directly and indirectly connections to the virus. Finally, we integrate Wikidata, DBPedia, and NCBIOntology to provide comprehensive information about insect vectors in the knowledge extension stage. Results: The interaction graph for each test virus was created. At the test stage, interaction and taxonomic analysis achieved 0.80 precision. TNC-DC succeeded in overcoming the failure of the original degree centrality which always got bees in the prediction results. During knowledge extension stage, we succeeded in finding the natural enemy of the Bemisia Tabaci (an insect vector of Pepper Yellow Leaf Curl Virus). Furthermore, an insect vector search engine is developed. The search engine provides network analysis insights, insect vector common names, photos, descriptions, natural enemies, other species, and relevant publications about the predicted insect vector. Conclusion: An insect vector search engine correctly identified virus vectors using GloBI data, TNC-DC, and entity embedding. Average precision was 0.80 in precision tests. There is a note that some insects are best in the first-to-five order. Keywords: Knowledge Graph, Network Analysis, Degree Centrality, Entity Embedding, Insect Vector

Response diversity and traits related to pepper yellow leaf curl disease resilience for resistant plants selection

Abstract. Sayekti TWDA, Syukur M, Hidayat SH, Maharijaya A, Sobir. 2023. Response diversity and traits related to pepper yellow leaf curl disease resilience for resistant plants selection. Biodiversitas 24: 5057-5064. Many chili species (Capsicum spp.) have been used and consumed, among them five species, namely Capsicum annuum, C. frutescens, C. chinense, C. baccatum and C. pubescens, are widely used. Most of these varieties are susceptible to Pepper Yellow Leaf Curl Disease (PYLCD) caused by Pepper yellow leaf curl virus (PYLCV) (Begomovirus, Geminiviridae). To control PYLCD, it is essential to gather resistant plant varieties to effectively shield cultivated plants from viral infections. An effective selection activity related to the target character is needed to get highly productive resistant plants. The objective of this study was to evaluate the relationship between resistance characters to crop production and to obtain appropriate selection criteria to increase the effectiveness of selecting resistant plants with good production. This study was conducted at Cikabayan Field, IPB University, Bogor, Indonesia. Twenty-nine genotypes of chili pepper were used, which consists of four species, including C. annuum, C. frutescens, C. chinense, and C. baccatum, arranged in a nested block design with three replications. The observed symptoms were yellowing of leaves followed by leaf malformations, but there were differences in the yellowing symptoms. From observation on visual symptoms, resistance characteristics, plant performance and productivity, there were differences in the response of each species to PYLCV attack. Correlation and path analysis results show that there was also differences in performance drop between C. annuum species and the non-C. annuum group. In C. frutescens, C. chinense, and C. baccatum, direct selection on resistance characters was able to increase the resistance level of selected plants while maintaining good crop production. Whereas for C. annuum species, the plant resistance level was not correlate with productivity reduction, so in the selection process, the percentage of yield decline needs to be considered to obtain resistant plants and maintain crop production.

Molecular detection of Pepper yellow leaf curl virus, Tomato leaf curl virus, Tomato yellow leaf curl virus, and Mungbean yellow mosaic virus on eggplant, tomato, and pepper at different altitudes in East Java, Indonesia

The genus Begomovirus causes yellow disease is the most damaging and threatening for eggplant, tomato, and pepper production worldwide. Begomoviruses (Family Geminiviridae) are transmitted circulative persistent manner by Bemisia tabaci. This study aims to determine the variation of infection of several species of Begomoviruses in tomato, eggplant, and pepper at different altitudes in East Java. Molecular detection of infection Begomoviruses were discovered using PCR and four pairs of specific primers. Samples were collected at different altitudes in East Java (Kencong, Karangploso, and Pujon). The PCR was successfully applied to detect Pepper yellow leaf curl virus, Tomato leaf curl virus, and Tomato yellow leaf curl virus from tomato, eggplant, and pepper in Kencong. Tomato, eggplant, and pepper from all locations were not infected by Mungbean yellow mosaic virus. Symptoms of Begomovirus infection found in the samples from Kencong were more varied than those found in Karangploso and Pujon. The phylogenetic analysis’ findings revealed that the TYLCV Kencong shared the highest homologies with TYLCKaV pepper and eggplant from Indonesia; PepYLCV Kencong shared with PepYLCV Ageratum conyzoides from Indonesia; and ToLCV Kencong shared with ToLCNDV cucumber from Central Java. The molecular detection has shown that there are different combinations of Begomovirus infection at altitudes.

Seedling protection and barrier crops in chili pepper to reduce whitefly denseness and prevalence of pepper yellow leaf curl virus

Yellow leaf curl disease caused by pepper yellow leaf curl virus (PepYLCV) and transmitted by the whitefly (Bemisia tabaci), becomes the main problem in major horticultural crops, including chili pepper. The control of the insect vector is crucial to overwhelm the diseases. The experiment was designed to verify the efficacy of integrated vector and virus control focused on barrier crops and healthy seedling techniques on chili pepper to reduce whitefly crowdedness, the prevalence of the virus, and crop yield. This experiment used a randomized block design. The treatments were two kinds of seedlings, with and without seedling cover, combined with four kinds of borders i.e., maize, Sunn–hemp, screen (chiffon), and control (non-border). The result indicated that the use of protected seedlings was able to defend against the attack of B. tabaci and delay virus infection for about 2 weeks. The use of protected seedlings together with barrier crops (maize and sunn-hemp) reduced the number of pests, and PepYLCV damage up to 49.94 – 50.80%, and gave the highest yields. The positive correlation (r) between the population of B. tabaci and disease incidence was 0.925, whereas the correlation between disease incidence and yield crop was negative (r = -0.8886). These results will provide an advance of more valuable and practical methods for safeguarding chili pepper production.

The The Effect of Gamma Rays on Local Chilli Infected to Pepper Yellow Leaf Curl Virus Infection (Begomovirus)

Cabai merupakan salah satu komoditas hortikultura bernilai ekonomi tinggi di Indonesia. Cabai lokal Karo berbatang ungu merupakan cabai yang memiliki keunggulan produksi dan pertumbuhan vegetatif tinggi, namun sangat rentan terhadap penyakit virus keriting kuning oleh begomovirus. Salah satu upaya pengendalian begomovirus ialah dengan perakitan genotipe baru yang tahan melalui induksi iradiasi sinar gamma. Penelitian bertujuan mengkaji pengaruh iradiasi sinar gamma pada benih cabai lokal Karo berbatang ungu terinfeksi begomovirus untuk mendapatkan calon genotipe mutan yang tahan. Benih dari tanaman cabai terinfeksi begomovirus diberi perlakuan iradiasi sinar gamma dengan taraf dosis 150, 200, dan 250 Gy untuk mendapatkan tanaman mutan 1 (M1). Benih sehat dan benih berasal dari tanaman sakit tanpa perlakuan digunakan sebagai tanaman kontrol. Parameter yang diamati meliputi insidensi dan keparahan penyakit, AUDPC dan deteksi begomovirus pada tanaman M1 dan benih generasi kedua (M2). Perlakuan iradiasi sinar gamma taraf dosis 150 Gy pada benih cabai terinfeksi begomovirus menunjukkan rata-rata insidensi, keparahan penyakit, dan AUDPC paling rendah dibandingkan dengan perlakuan lainnya pada tanaman mutan M1 dan M2. Berdasarkan deteksi dengan PCR pada tanaman mutan M2, dari perlakuan dosis 150 Gy didapatkan 7 calon genotipe tahan begomovirus terbanyak di antara perlakuan lainnya.

Determination of Begomovirus on chili plants (Capsicum sp.) in Buton and Muna Islands, Southeast Sulawesi, Indonesia

Abstract. Widodo CJ, Taufik M, Khaeruni A, Mallaranggeng R. 2023. Determination of Begomovirus on chili plants (Capsicum sp.) in Buton and Muna Islands, Southeast Sulawesi, Indonesia. Biodiversitas 24: 741-751. Begomovirus disease is one of the main factors inhibiting chili cultivation which could harm plants and result in crop failure. This study aimed to determine the symptoms of begomovirus disease in chili plants in Buton and Muna, Southeast Sulawesi. The methods used are disease incidence survey, insect vector observation, molecular identification using the polymerase chain reaction (PCR) technique, and Sanger sequencing (Applied Biosystem 3500). The survey was conducted in Southeast Sulawesi province, covering Bau-Bau City, Buton Regency, Central Buton, North Buton, Muna, and West Muna. The results showed that the incidence and severity of Begomovirus disease were observed highest in Buton islands, 73% and 49.5% (Buton City), followed by North Buton, Central Buton, and Buton, with the incidence and severity of Begomovirus, respectively, of 71.74% and 59.5%; 69.32% and 51.5%; and 68% and 61.5%. While in Muna Regency, 63.16% and 38.5%, West Muna, 73.79% and 53.50%. On the other hand, the highest percentage of the whitefly population was in Bau-Bau City, 24%, while the lowest was in West Muna, 15.5% supporting this observation. Furthermore, PCR analysis successfully amplified symptomatic isolates from Buton and Muna islands at a band length of 580 bp. On the other hand, Sanger sequencing analysis revealed the existence of the Indonesian Pepper Yellow Leaf Curl Virus (PepYLCIV) with more than 96% genetic homology to the Gene Bank data of MN094866 PepYLCIV Capsicum annuum Indonesia and MN738463 PepYLCIV Chili pepper Indonesian. This information is the first report of the presence of Begomovirus on the two islands.

Infrared Thermography for Early Detection of Pepper yellow leaf curl virus on Chili Plants

Infrared Thermography for Early Detection of Pepper yellow leaf curl virus on Chili Plants Observations of plant pests and diseases are generally carried out by looking for visual symptoms for each disease target. Agricultural technology 4.0 began to be used for the development of plant disease detection methods. It was reported that there were differences in color and temperature between diseased and healthy plants which could be recorded by a thermal camera. This study aimed to determine the potential of the FLIR One Pro-IOS thermal camera to record differences in color and temperature between viral-infected and healthy chili plants. Chili plants in the greenhouse that were inoculated with Pepper yellow leaf curl virus (PYLCV) experienced an increase in temperature 3 days after inoculation (28.62 ℃) compared to plants that were not inoculated with PYLCV (27.32 ℃). Digital image recording of chili leaf samples from the field showed that plants infected by multiple viruses (Chilli veinal mottle virus, Pepper mottle virus and PYLCV) has higher temperature than those infected with a single virus. The lowest and highest mean temperatures were recorded in plant samples infected with PepMV (17.74 ℃) and mixed infected by PYLCV and ChiVMV (25.68 ℃). Digital images of virus-infected plants tend to show a predominance of bright yellow, while virus-free plants showed a predominance of dark purple. Further analysis confirmed higher digital numbers for diseased plant images than healthy plants. The thermography method has the potential to be an early detection method because it can detect viral infection before visual symptoms appear.

Testing of Superiority and Resistance of Cayenne Pepper of Blaze 12 Variety to Pepper Yellow Leaf Curl Disease

Cayenne pepper is one of the important vegetables and has high economic value. This plant can be cultivated in various types of soil in the lowlands to the highlands. Chilies are very much liked by Indonesian people because of it is spicy and contains various nutrients and vitamins. The purpose of this study was to study and determine the productivity and resistance to yellow curly leaf disease of Blaze 12 varieties compared to comparison varieties. The demand for chili continues to increase from year to year but chili production is not optimal. Efforts to increase crop production have several obstacles related to seed quality, crop cultivation technique, pest and disease attacks. Pepper yellow leaf curl virus (PYLCV) is a disease that can reduce production and cause crop failure. One of the ways to improve seed quality is through a breeding process to support chili productivity and improve other characters such as resistance to disease.Testing of variety is a final stage in plant breeding before varieties are released and commercialized. The purpose of this study was to study and determine the productivity and resistance to yellow curly leaf disease of Blaze 12 varieties compared to comparison varieties. The results of the analysis variance showed a significant effect on the characters: leaf length, leaf width, fruit length, fruit diameter, skin thickness, weight per fruit, number of fruit per plant and yield per hectare. Resistance to yellow curl leaf disease of the Blaze 12 variety was as same as VP-3 and better than VP-1 and VP-2, which showed resistance with mild symptoms. The character of cayenne pepper yellow curl disease is closely related to leaf area.

Pencirian Genetik Pepper Yellow Leaf Curl Virus pada Tanaman Cabai Merah (Capsicum annuum) di Bengkulu

Chili is one of the horticultural commodities with increasing demand yearly. Rejang Lebong and Kepahiang regencies are the most significant chili-producing areas in Bengkulu. One of the crucial viruses in chili plants is Pepper yellow leaf curl virus (PYLCV). PYLCV virus infection in the vegetative phase can cause stunted plants and fail to bear fruit. This study aims to detect and genetically characterize PYLCV. Samples of chili plants were taken in these two districts using the purposive sampling method. Virus detection was carried out at the Genetics and Biotechnology Laboratory, Department of Biology. Extraction of viral DNA using the Cetyl Trimethyl Ammonium Bromide (CTAB) method. Rep and Trap gene amplification using universal primers of Bemovirus. SPG1 and SPG2. The PCR product was visualized on a 1.2% agarose gel in TAE.. Furthermore, the PCR products were sequenced in PT Genetics Science Indonesia. Virus gene sequences were aligned using Bioedit and MEGA X software. The results showed that of the 24 chili plants sampled in the study, 21 samples showed an amplicon with a size of ~ 900 bp, which follows the length of the amplicon based on the primer used. Of the 21 amplicon results, 6 of them were sequenced and genetically characterized. The results of the genetic characterization of the 6 samples showed the presence of 552 conservative sites (C) (75.6%), 178 variation sites (Vi) (24.4%), parsimony sites (Pi) (15.9%), and 70 singleton (S) sites (8.5%). The highest nucleotide base composition was thymine (T) with an average value of 30.1%, and the lowest was guanine (G) 21.9%, while the highest nucleotide combined composition was AT with an average value of 55%, the lowest was GC approximately 45%. The average genetic distance between samples was 0.13 (13%). Based on the phylogenetic tree, 6 samples were divided into two groups. Keywords: begomovirus, Bengkulu, Capsicum annuum

Fourier transform infrared spectrum pre-processing technique selection for detecting PYLCV-infected chilli plants

Pre-processing is a crucial step in analyzing spectra from Fourier transform infrared (FTIR) spectroscopy because it can reduce unwanted noise and enhance system performance. Here, we present the results of pre-processing technique optimization to facilitate the detection of pepper yellow leaf curl virus (PYLCV)-infected chilli plants using FTIR spectroscopy. Optimization of a range of pre-processing techniques was undertaken, namely baseline correction, normalization (standard normal variate, vector, and min–max), and de-noising (Savitzky-Golay (SG) smoothing, 1st and 2 derivatives). The pre-processing was applied to the mid-infrared spectral range (4000 – 400 cm−1) and the biofingerprint region (1800 – 900 cm−1) then the discrete wavelet transform (DWT) was used for dimension reduction. The pre-processed data were then used as an input for classification using a multilayer perceptron neural network, a support vector machine, and linear discriminant analysis. The pre-processing method with the highest classification model accuracy was selected for the further use in the processing. It was seen that only the SG 1st derivative method applied to both wavenumber ranges could produce 100% accuracy. This result was supported by principal component analysis clustering. Thus, we have demonstrated that by using the right pre-processing technique, classification success can be increased, and the process simplified by optimization and minimization of the technique used.

Genotyping-by-sequencing-based QTL mapping reveals novel loci for Pepper yellow leaf curl virus (PepYLCV) resistance in Capsicum annuum.

Disease caused by Pepper yellow leaf curl virus (PepYLCV) is one of the greatest threats to pepper (Capsicum spp.) cultivation in the tropics and subtropics. Resistance to PepYLCV was previously identified in a few Capsicum accessions, but no resistance QTLs have been mapped. This study aimed to elucidate the genetics of PepYLCV resistance in C. annuum L. Augmented inoculation by the viruliferous whitefly Bemisia tabaci was used to evaluate parental lines and an F2 segregating population derived from a cross between resistant C. annuum line LP97 and susceptible C. annuum line ECW30R. Final evaluation was performed six weeks after inoculation using a standardized 5-point scale (0 = no symptoms to 4 = very severe symptoms). A high-density linkage map was constructed using genotyping-by-sequencing (GBS) to identify single-nucleotide polymorphism (SNP) markers associated with PepYLCV resistance in the F2 population. QTL analysis revealed three QTLs, peplcv-1, peplcv-7, and peplcv-12, on chromosomes P1, P7, and P12, respectively. Candidate genes associated with PepYLCV resistance in the QTL regions were inferred. In addition, single markers Chr7-LCV-7 and Chr12-LCV-12 derived from the QTLs were developed and validated in another F2 population and in commercial varieties. This work thus provides not only information for mapping PepYLCV resistance loci in pepper but also forms the basis for future molecular analysis of genes involved in PepYLCV resistance.

Infeksi Ganda Pepper Yellow Leaf Curl Virus dan Chilli Veinal Mottle Virus dalam Menimbulkan Penyakit Daun Kuning Keriting Cabai

Yellow leaf curl disease is the primary disease in chili plants with up to 100% losses. Detection from the field showed a mixed infection between Geminivirus or Pepper Yellow Leaf Curl Virus (PYLCV) and several viruses, including Chilli Veinal Mottle Virus (ChiVMV) and Cucumber mosaic Virus (CMV). Therefore, this study aimed to determine the role of PYLCV and ChiVMV dual infection in influencing the development of chili yellow leaf curl disease. This study used a completely randomized design (CRD) with six treatments and ten replications. The treatments used were multiple Geminiviruses and ChiVMV infections simultaneously, before ChiVMV co-infection, after Geminivirus infection, single infection and whithout infection viruses. The results showed that the presence of ChiVMV infection before, after, and concurrently with Geminiviruses infection could increase the yellow leaf curl disease intensity and reduce plant height and wet weight growth. The mean scale value of ChiVMV infection before, after, and concurrently with Geminiviruses infection were 3.38, 3.90 and 3.58 compared to single Geminiviruses infection (scale of 3.20) and single ChiVMV (scale of 1.33). The interaction analysis of ChiVMV and geminiviruses infections based on the percentage reduction in plant growth height and wet weight showed additive interaction. ChiVMV co-infection further exacerbated the incidence of yellow leaf curl diseases in chilies.

Morphological response and genetic variability of four species of chili pepper (Capsicum spp.) under infection of pepper yellow leaf curl virus

Abstract. Sayekti TWDA, Syukur M, Hidayat SH, Maharijaya A. 2021. Morphological response and genetic variability of four species of chili pepper (Capsicum spp.) under infection of pepper yellow leaf curl virus. Biodiversitas 22: 4758-4765. Chili pepper has various types and species, but only five known species are commonly used and consumed. Most cultivated chili is susceptible to various plant diseases, one of which is Pepper yellow leaf curl disease (PYLCD) caused by Pepper yellow leaf curl virus (PYLCV) (Begomovirus, Geminiviridae). To control PYLCD, resistant variety assembly is required to prevent virus infection in cultivated plants. From this research, testing on four chili species is expected to provide information regarding the resistance and performance of chili peppers to conditions infected with PYLCV. This study was conducted at Dramaga Bogor, West Java, Indonesia in two experimental units: planting under virus-free conditions (as control) and virus-infected conditions. Each experimental unit was carried out using a single factor Randomized Complete Block Design (RCBD) with three replications. Twenty-nine genotypes of chili pepper were used consisted of four species, including C. annuum, C. frutescens, C. chinense, and C. baccatum. Of the 29 genotypes tested, thirteen genotypes in the resistant, nine genotypes in moderate resistant, two genotypes in moderate susceptible, three genotypes in the Susceptible, and two genotypes in the highly susceptible category. The heritability, genotypic coefficient of variance (GCOV) and phenotypic coefficient of variance (PCOV) value obtained from testing for all characters is high, ranging from 65.16-99.12%, 14.87-82.60%, and 15.77-84.45%, respectively. Most of the genotypes from C. chinense showed good resistance to PYLCV. In general, by considering the category of the resistance level and other characters such as productivity, ‘Jolokia’ (C. chinense), ‘Anies’ (C. annuum) and ‘Bonita’ (C. frutescens) can be ascertained as potential candidate sources of resistance to PYLCV.

Resistance Analysis of CRISPR/Cas9 Genome-Edited Chili M2 Mutant Lines against Pepper Yellow Leaf Curl Viral Disease

<p>Pepper yellow leaf curl virus (PepYLCV) infection transmitted by silverleaf whitefly (Bemisia tabaci [Gennadius]) can decrease chili pepper yield up to 100%. At this moment, there is no chili pepper variety resistant to PepYLCV available. Genome editing approach through CRISPR/Cas9 is an effort to develop variety resistance to the viral infection. The purpose of this study was to obtain M2 lines developed by CRISPR/Cas9 system on proliferating cell nuclear antigen (PCNA) gene for resistance to PepYLCV. A total of four M2 lines (C47-7, L84-2, L84-23, and L120-19) consisting of 60 chili plants were tested for their resistance to PepYLCV. PCR analysis was performed to detect the presence (infection) of the virus. The results showed that a total of 35 plants derived from the four lines were resistant to PepYLCV. They consisted of 7 plants from C47-7 line, 11 plants from L84-2 line, 9 plants from L84-23 line, and 8 plants from L120-19 line. PCR analysis confirmed that the resistant plants obtained from this study were negatively infected by the virus. Since not all tested plants were resistant to virus infection, the PCNA gene allele in these resistant lines were most likely heterozigotes. Sequencing of PCNA gene of the resistant lines is needed to confirm that the resistance phenotypes obtained was due to mutation of the gene. Therefore, further selection needs to be performed to obtain stable and PepYLCV-resistant lines.</p>

Effect of Fermentation Extracts against Bemisia tabaci on Chilli Pepper (Capsicum annuum)

This experiment was aimed to determine the effects of application of fermentation extracts on the development of pepper yellow leaf curl and whitefly on chilli. Experiment arranged in a completely randomized block design with four treatments (water as control, fermentations extracts named TSNGlu, BP4, and BP4Glu). The results showed symptoms in the form of curling of young leaves. The color of the leaves was relatively green. Yellow symptoms commonly found when severe were not found in the experiment. The symptoms of severe disease are marked in yellow at the top of the leaf and remain green at the bottom. The laboratory used 350 lux (underexposed light) so the symptoms become slight. ack of light intensity made plants etiolated and could not carry out photosynthesis properly. Each experiment consisted of 4 fermentation extract treatments. Each treatment. Overall, all treatments without fermentation and also AUDPC of the disease did not significantly affect the treatment of fermented extract both the incidence and severity of the low pepper yellow leaf curl virus. The treatment by spraying did not significantly affect the population of whitefly, except at 7 days after infestation, inversely proportional to the spraying treatment by means of discharge significantly affected from 14 days after infestation. The increase in plant height spray treatment did not have a significant effect and for spraying treatment with extraction of fermentation did not significantly affect the canopy area of ​​the plant canopy.

Polymorphics SSR Markers of Chilli Parental and Breeding Lines in Chilli Resistance to Pepper Yellow Leaf Curl Virus (PYLCV)

Aksesi cabai IPBC12 telah diketahui memiliki gen ketahanan dominan terhadap PYLCV dan dapat dimanfaatkan sebagi donor gen untuk perakitan varietas cabai tahan PYLCV. PYLCV merupakan salah satu virus patogen penting pada pertanaman cabai di Indonesia. Identifikasi marka SSR polimorfik pada populasi persilangan antara IPBC12 dan varietas Yuni dilakukan untuk mendapatkan marka yang dapat digunakan untuk seleksi progeni hasil persilangan dan terpaut dengan sifat ketahanan terhadap PYLCV. Sebanyak 20 marka SSR dianalisis polimorfismenya pada dua tetua persilangan, kemudian marka yang polimorfik diuji pada galur generasi F1 dan F2. Hasil penelitian menunjukkan ada empat marka polimorfik pada kedua tetua persilangan, tetapi ketika diuji pada galur-galur keturunannya hanya 3 marka (CaBR61, CaBR64, dan CaBR98) yang polimorfik. Berdasarkan analisis marka, 14 galur F1 terkonfirmasi hasil persilangan antar aksesi IPBC12 dan varietas Yuni. Marka yang secara konsisten mendeteksi penurunan alel dari kedua tetua pada progeni F1 adalah CaBR61. Marka tersebut berpotensi sebagai marka seleksi galur-galur hasil persilangan pada tanaman cabai. Analisis molekuler pada galur-galur F2 tidak mendapatkan keterpautan antara marka dengan sifat ketahanan. Perlu analisis lebih lanjut menggunakan jumlah marka yang mencukupi dan tersebar merata dalam genom cabai untuk memetakan gen ketahanan terhadap PYLCV pada populasi persilangan antara aksesi IPBC12 dan varietas Yuni.
 Kata kunci: aksesi IPBC12, Capsicum annuum, seleksi berpandu marka, varietas Yuni

Gas Chromatography-Mass Spectrometry Analysis of Compounds Emitted by Pepper Yellow Leaf Curl Virus-Infected Chili Plants: A Preliminary Study

Pepper yellow leaf curl virus (PYLCV) is a threat to chili plants and can significantly reduce yields. This study aimed as a pilot project to detect PYLCV by analyzing compounds emitted by chili plants using gas chromatography-mass spectrometry (GC-MS). The samples investigated in this research were PYLCV-infected and PYLCV-undetected chili plants taken from commercial chili fields. The infection status was validated by using a polymerase chain reaction (PCR) test. A headspace technique was used to extract the volatile organic compounds emitted by plants. The analysis of GC-MS results began with pre-processing, analyzing sample compound variability with a boxplot analysis, and sample classification by using a multivariate technique. Unsupervised multivariate technique principal component analysis (PCA) was performed to discover whether GC-MS could identify PYLCV-infected or not. The results showed that PYLCV-infected and PYLCV-undetected chili plants could be differentiated, with a total percent variance of the first three principal components reaching 91.32%, and successfully discriminated between PYLCV-infected and PYLCV-undetected chili plants. However, more comprehensive studies are needed to find the potential biomarkers of the infected plants.

Radio-sensitivity test of gamma irradiation of local chilli pepper seeds (Capsicum annum L.)

Chilli pepper is a strategic horticultural commodity for its economic, nutritional, and medicinal values and is used as a spice in a variety of cuisines all over the world. Induced mutation by gamma ray’s irradiation has been used to increase chilli resistance and quality. The objective of this study was to determine the optimum dose of gamma irradiation in inducing resistance in putative mutation(M1) on chilli pepper seeds. The seeds induced were infected by Pepper Yellow Leaf Curl Virus (PYLCV) and were irradiated with 0, 25, 50, 100,150,200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, and 1000Gy. The plants (M1) were observed for their seed germination, leaf length, leaf width, and plant height. The results indicated that the best LD50 irradiation was 288.269 Gy (y = 82.7847+ 0.0698x + 0.0002x2 + 2.0082x3). The results also revealed that plants irradiated with doses 150, 200, and 250 Gy were selected to be planted in the field.

Effect of Screen House on Disease Severity and Coat Protein Diversity of Begomovirus-infected Capsicum frutescens L. ‘Cempluk’ from Indonesia

Chili can be infected by Begomovirus through whiteflies (Bemisia tabaci) serving as a vector insect. Begomovirus infection causes dwarf plants and yellow curly leaves. The molecular detection of Begomovirus coat protein gene may serve as a preliminary identification of Begomovirus. This study was conducted to observe the differences in the symptom severity of Begomovirus infection in chilies (Capsicum frutescens L. ‘Cempluk’) planted inside and outside a screen house. This study also observed whether or not using a screen house in chili farming affects the diversity of the coat protein of Begomovirus. Symptom observation and sampling were conducted in Madurejo, Prambanan, Sleman. Molecular detection was performed by amplifying the coat protein (CP) gene using the universal primer Krusty and Homer. Results showed 7 plant samples with DNA bands ± 550 bp and confirmed that the plants were positively infected with Begomovirus. The amplified bands were purified and sequenced. The nucleotide sequences were analyzed using BLASTn, followed by phylogenetic analysis using MEGA. Planting chili in the screen house resulted in low disease severity and good crop conditions. The coat protein sequence showed different strains of Begomovirus infected the chili plants inside and outside the screen house. Pepper yellow leaf curl Indonesia virus (PepYLCIV) was found inside the screen house while PepYLCIV [Ageratum] was dominant outside the screen house. Both strains are closely related to other Pepper yellow leaf curl virus (PepYLCV) from various regions in Indonesia. Optical manipulation using an ultraviolet screen or screen house was effective in reducing Begomovirus infection and improving plant performance.

Molecular diversity of Pepper Yellow Leaf Curl Virus (PepYLCV) Infecting Capsicum annuum in West Sumatra

In recent years, Pepper Yellow Leaf Curl Disease (PepYLCD) is one of the most common diseases affecting chili cultivation in Indonesia, including West Sumatra. In 2019, Pepper Yellow Leaf Curl Virus (PepYLCV) damaged chili plants and have lost yields of up to 100%. The controlling of this PepYLCV that has been carried out so far is less effective because the virus often mutates. In 2019, PepYLCV damaged the chili crop and resulted in 100% yield loss. The controls that have been done so far are less effective, especially because the virus mutates frequently. Genome editing is one of the solutions to control the PepYLCV attacks. For that purpose, information of the genome sequence of the PepYLCV is necessary. This study was aimed to obtain the size of the PepYLCV-APWS genome and the differences in its genomic sequence characteristics with other PepYLCV isolates in West Sumatra. The results showed that PepYLCV has a genome size of 2743 bp. This PepYLCV-APWS isolate had molecular diversity with two other isolates from West Sumatra, PepYLCV TDWS and PepYLCV PSSWS respectively 91% and 92%.