Pepper Yellow Leaf Curl Disease Research Articles

First report of pepper yellow leaf curl Thailand virus infecting hot chili in central Vietnam and Laos.

Hot chili pepper (Capsicum annuum) cultivation has been on the rise in South East Asia to meet export demands. In Thailand, the top chili exporter in South East Asia, chili production has been severely hampered by pepper yellow leaf curl disease (YLCD) caused by the begomovirus pepper yellow leaf curl Thailand virus (PepYLCThV) (Chiemsombat et al., 2018; Suwor et al., 2021). In the neighbouring countries of Laos and Vietnam, a limited survey of chili fields (200 plants in total) in Savannakhet (Savannakhet University campus, n = 150), Laos and Quang Nam province (Ka Dang commune, Dong Giang district, n = 50), central Vietnam in 2023 led to the finding of eight plants (5 in Laos and 3 in Vietnam) exhibiting YLCD-like symptoms, which included bright yellow color in young leaves and leaf curl and mosaic chlorosis in mature leaves (Fig. S1). Total DNA was extracted from leaves of two symptomatic plants (one from Savannakhet and one from Quang Nam) using a cetyltrimethylammonium bromide-based DNA extraction protocol (Doyle & Doyle, 1987; Nguyen et al., 2023). Next, PCR were performed using newly designed PepYLCThV-specific primers based on PepYLCThV sequences in GenBank (Table 1). PCR products of expected sizes were observed in samples with disease symptoms, but not from DNA extracted from C. annuum (cv. VA.99999) grown at the Institute of Biotechnology in Thua Thien Hue, Vietnam (Fig. S2). The amplicons were Sanger sequenced (Apical Scientific, Selangor, Malaysia) and the complete bipartite genome sequence of two isolates ('Sava01' from Laos and 'QNam01' from Vietnam) were obtained. The sequences of the DNA-A component from isolates 'Sava01' (GenBank PP437580) and 'QNam01' (GenBank PP437581) exhibited the highest sequence identity of 99.2% and 94.7% with the PepYLCThV isolate 'ChiangDaoS1' (GenBank OM677627), respectively (Table 2). Conversely, the sequences of the DNA-B component from the isolates 'Sava01' (GenBank PP437579) and 'QNam01' (GenBank PP437582) exhibited the highest similarity of 91.8% and 90.9% with the PepYLCThV isolate 'KKN601' (GenBank MW715820), respectively (Table 2). These results confirmed the presence of PepYLCThV in hot chili pepper plants exhibiting YLCD-like symptoms in central Vietnam and Laos. Infectious clones of PepYLCThV DNA-A and DNA-B (isolate 'QNam01') were created based on the pLX-AS vector as described by Pasin (2022), and transformed into Agrobacterium tumefaciens EHA105. The resulting bacteria were cultured in LB broth containing rifampicin (25 μg/mL) and kanamycin (50 μg/mL) at 28°C and used for agroinoculation of Nicotiana benthamiana (n = 6) and C. annuum (cv. VA.99999, n = 6) (4-6 leaf plants) as described by Pasin (2022). In all N. benthamiana plants, agroinoculation with both DNA-A and DNA-B infectious clones caused stunted growth, severe leaf curl, with yellow and white patches 21 days post inoculation (Fig. S3). In C. annuum plants, symptom expression, which included leaf curl and stunted leaves with yellow mosaic patterns, was observed in two out of six inoculated plants six weeks postinoculation (Fig. S3). PCR assays confirmed the presence of PepYLCThV DNA in N. benthamiana and C. annuum symptomatic leaves (Fig. S4). To our knowledge, this is the first report of pepper yellow leaf curl Thailand virus in hot chili pepper in Laos and central Vietnam. Appropriate containment and management strategies should be developed and implemented to control the spread of this disease in hot chili pepper crops in both countries.

The use of combination plant growth promoting rhizobacteria to control chili leaf curl disease in the field

Plant growth-promoting rhizobacteria (PGPR) is a promising technology for controlling viral diseases, including pepper yellow leaf curl disease (PYLCD) of chili pepper caused by Begomovirus infection. The objectives of this research were to investigate the effectiveness of PGPR containing Pseudomonas fluorescens PF1 and Bacillus polymyxa BG25, as well as their combination with other protective agents, to control PYLCD under field conditions in an endemic region. The treatments consisted of a single application of PGPR (a mixture of P. fluorescens PF1 and B. polymyxa BG25), guano tea, endophytic fungus H5, and neem oil; combination of PGPR with guano tea, endophytic fungus H5, and neem oil; conventional pesticide that relies on synthetic chemical insecticide sprayed weekly; and untreated plots. The experiment was arranged in a randomized block design with four replications. Treatment with PGPR alone was able to delay disease onset by 2.25 weeks, but it caused only a slight reduction in disease incidence. The combination of PGPR + guano tea and PGPR + endophyte H5 provided the best results in controlling PYLCD. The combination of PGPR + guano tea and PGPR + endophyte H5 delayed disease onset by 2.75 weeks and 3.25 weeks, respectively, and reduced disease incidence with effectiveness rates of 52.72% and 52.08%, respectively. These two treatment combinations gave the best performance for plant growth and yield.

The Effects of Some Different Cultural Techniques on the Transmission and Infectious Development of Pepper Yellow Leaf Curl Indonesia Virus on Red Chili

<p>An experiment is conducted to investigate the effects of cultural techniques on pepper yellow leaf curl disease caused by <em>Pepper yellow leaf curl Indonesia virus</em> (PepYLCIV). The investigation is conducted in the area where the disease has been endemic and <em>Bemisia tabaci</em> is abundant. Four cultural techniques are applied in separate lands and cannot interfere with each other. The methods applied are seed treatment, intercropping, trap cropping, and physical barrier. Seeds harvested from infected plants are used for seed treatment experiments, and local farmers use commercial sources for other experiments. The results confirmed that PepYLCIV was a seed-borne virus affected by hot water treatment at 65<sup>o</sup>C for 30 minutes. Turmeric crude extract could reduce the incidence and severity of the disease. The tomato is a better intercrop than eggplant, mung bean, and soybean in reducing disease incidence, but their effects on disease severity and yield reduction were not significantly different. Basil and marigolds were better barrier crops compared to cosmos and zinnia. A 125 cm high physical barrier using 50 mesh cheesecloth could reduce the disease incidence, but not the lower ones. Under different cultural techniques, PepYLCIV causes a 40.00–52.32% chili yield reduction.</p>

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.

Relationship Between whitefly (Bemisia tabaci) Population and Pepper Yellow Leaf Curl Disease on Chili Plant Yield in The Field

Relationship Between whitefly (Bemisia tabaci) Population and Pepper Yellow Leaf Curl Disease on Chili Plant Yield in The Field

Estimation of the genetic parameters of hybridized peppers (Capsicum annuum L.) F2 progeny begomovirus resistance

Pepper is an essential vegetable commodity in Indonesia. Pepper yellow leaf curl disease caused by the infection Begomoviruses caused tremendous damage to pepper production in the country. The breeding process through crosses is necessary to produce Begomovirus resistance material to overcome the constraint. In this present study, we estimated the genetic parameters of hybridized F2 pepper under natural infected conditions. Two C. annuum accessions, BaPep-5 has resistance material for pepy-1 Begomovirus (locally called Perintis) and BaPep-4 as a susceptible parent (called Kencana) were crossed to produce F2 progenies. F2 generation from the cross as much as 500 plants were transplanted along with 200 plants of each parent as control to the field. The estimation results indicated that the high heritability value was found in the fruit weight per plant (51.31%), the number of fruits per plant (65.58%), the thickness of fruit flesh (92.24%), fruit stalk length (52.43%), and fruit diameter (96.83%), suggesting that these characters have a level of broad genetic diversity. Moreover, a 100% genotypic coefficient of variance (GCV) is observed in the fruit weight per plant, the number of fruits per plant, the thickness of fruit flesh, and fruit diameter meaning that these characters have a high level of genetic diversity broad. In addition, a 100% very broad phenotypic coefficient of variance (PCV) criteria is observed in fruit weight per plant, the number of fruits per plant, the thickness of fruit flesh, and fruit diameter, suggesting that these characteristics have a variety of appearances. Conclusively, fruit weight per plant, number of fruits per plant, the thickness of fruit flesh, and fruit diameter are the characters with high heritability values followed by very broad GCV and PCV values which potentially be inherited and can be used as a reference for selecting further Begomovirus resistance traits.

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.

Relationship between viruliferous Bemisia tabaci population and disease incidence of Pepper yellow leaf curl Indonesia virus in chili pepper

Abstract. Temaja IGRM, Selangga DGW, Phabiola TA, Khalimi K, Listihani L. 2022. Relationship between viruliferous Bemisia tabaci population and disease incidence of Pepper yellow leaf curl Indonesia virus in chili pepper. Biodiversitas 23: 5360-5366. Bemisia tabaci Genn is an important pest in horticulture crops. Until today, B. tabaci has always been found in chili pepper and causes damage. In addition to a direct injury to the chili pepper, it is also the vector of Begomovirus. There is no research till date regarding the relationship between B. tabaci with Begomovirus which caused damage to chili pepper crops. Thus, the aim of this research was to analyze the interaction between B. tabaci population with the disease incidence of Begomovirus on chili peppers crops, as well as the percentage of viruliferous B. tabaci. This research noted B. tabaci population dynamics, disease incidence of pepper yellow leaf curl disease, and the percentage of viruliferous B. tabaci via PCR by using Begomovirus universal primer and DNA analysis confirmation. The highest imago population occurred at 6 WAP with the average density 27.21 imago/yellow sticky card, while the highest nymph population occurred at 8 WAP with the average density of 4.26 nymph/leaf. The high population of B. tabaci nymph and imago caused the incidence of Begomovirus disease to reach 83.07% at 12 WAP. Result showed that high population of B. tabaci accelerated the speed of virus in the field. The confirmation result of Begomovirus in B. tabaci body showed that the virus was Pepper yellow leaf curl Indonesia virus (PYLCIV). The highest homology obtained was between PYLCIV isolates from Sekaan, Bangli with isolates from Bayung Gede, Bangli which ranged from 99.6 to 99.8%. Further phylogenetic analysis showed that PYLCIV isolates from Sekaan, Bali formed a group with the isolate from Bayung Gede, Bangli, which was from a different group with other isolates. This proved that B. tabaci carries and transmits PYLCIV to chili peppers in Bali.

Distribution and Identification of Pepper yellow leaf curl Indonesia virus Infecting Chili Pepper in Bali Island

Yellow leaf curl disease in chili pepper has been reported in Bali Island since the early 2012. Research was conducted to identify the virus causing this disease and disease distribution in Bali. Field survey was carried out to observe disease intensity and to collect field samples from several chili pepper growing areas in Bali (Karangasem, Bangli, Tabanan, and Gianyar). Begomovirus identification from field samples was then conducted by polymerase chain reaction method using universal primers SPG1/SPG2, followed by an analysis of the amplified target DNA sequences. The incidence of pepper yellow leaf curl disease reached 100% at all sites and disease severity reached 18%−87%. Begomovirus specific DNA fragment measuring 912 bp was successfully amplified from 12 field samples. Sequence analysis of DNA fragments showed the highest homology with Pepper yellow leaf curl Indonesia virus (PYLCIV). Further phylogenetic analysis confirmed the relationship between PYLCIV isolates from Bali and various PYLCIV isolates from Indonesia.

Genetic variance and heritability estimation of hybridized pepper plants (Capsicum annuum L.) F2 progeny for begomovirus resistance in growth stage

Pepper is widely cultivated as a condiment and cash crop in Indonesia. However, Pepper yellow leaf curl disease (PepYLCD) caused by begomovirus is currently seriously affect the domestic pepper production. Breeding for begomovirus resistance material by crossing is currently necessary to overcome the constraint. The present study is aimed to determine the resistance of pepper (C. annuum) plants F2 progenies to begomovirus infection in the growth stage. Two local C. annuum accessions, BaPep-5 as a resistance donor for pepy-1 begomovirus resistance gene (locally called Perintis) and BaPep-4 as a susceptible parent (locally called Kencana) were crossed to generate F2 progenies. The research was conducted in Agricultural Extension Training Centre (BLPP) Saree and Horticulture Laboratory of Syiah Kuala University from February to July 2020. 500 F2 progenies were transplanted to the field along with 15 plants of each parent as control. The result suggested that plant height and crown width had the highest broad sense heritability value, whereas the dichotomous height, stem diameter, secondary branch, and tertiary branch had the lowest broad sense heritability value. Coefficient of genetic variance and coefficient of phenotypic variance from overall characteristics were relatively low which suggest the narrow sense to slightly narrow sense heritability.

Resilience response to yellow leaf curl disease and identification of resistance gene analogs (RGA) in pepper (Capsicum annuum)

Abstract. Ayu DK, Maharijaya A, Syukur M, Hidayat SH. 2021. Resilience response to yellow leaf curl disease and identification of resistance gene analogs (RGA) in pepper (Capsicum annuum). Biodiversitas 22: 4731-4739. Pepper yellow leaf curl disease (PYLCD) caused by infection of Begomovirus is a serious threat to pepper production worldwide. Identification of the resistance gene analogs (RGA) and resilience response of pepper against PYLCD is needed especially for selection resistance genotype. Evaluation of resistance response involving 28 pepper genotypes was carried out through transmission of Begomovirus using whitefly (Bemisia tabaci) as vector. The result showed that IPB C12 and F4-012328-6-3 were potential resistance genotypes. A total of 15 R gene analogs (CaRGA) containing NBS motif, namely CARGA1 to CARGA15, were identified by degenerated PCR amplification and database mining. The alignment of deduced amino acid sequence revealed conservation of subdomains Ploop (GKTT), kinase2 (LVVLDDV), RNBSB/kinase3 (IILTTR) and GLPL. BLASTp analysis indicated that 15 RGA showed high homology at deduced amino acid level with R gene identified such as whitefly resistance protein Mi-1.2, Pvr 9 gene for potyvirus, Begomovirus resistance protein, TRGA15 and RGA 13 for putative late blight resistance. Phylogenetic analysis exhibited that isolated sequences distinguished into CNL-NBS groups. These pepper RGA could be considered as candidate sequences of resistance genes.

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.

A recessive gene pepy-1 encoding Pelota confers resistance to begomovirus isolates of PepYLCIV and PepYLCAV in Capsicum annuum.

A begomovirus resistance gene pepy-1, which encodes the messenger RNA surveillance factor Pelota, was identified in pepper (C. annuum) through map-based cloning and functional characterization. Pepper yellow leaf curl disease caused by begomoviruses seriously affects pepper (Capsicum spp.) production in a number of regions around the world. Ty genes of tomato, which confer resistance to the tomato yellow leaf curl virus, are the only begomovirus resistance genes cloned to date. In this study, we focused on the identification of begomovirus resistance genes in Capsicum annuum. BaPep-5 was identified as a novel source of resistance against pepper yellow leaf curl Indonesia virus (PepYLCIV) and pepper yellow leaf curl Aceh virus (PepYLCAV). A single recessive locus, which we named as pepper yellow leaf curl disease virus resistance 1 (pepy-1), responsible for PepYLCAV resistance in BaPep-5 was identified on chromosome 5 in an F2 population derived from a cross between BaPep-5 and the begomovirus susceptible accession BaPep-4. In the target region spanning 34kb, a single candidate gene, the messenger RNA surveillance factor Pelota, was identified. Whole-genome resequencing of BaPep-4 and BaPep-5 and comparison of their genomic DNA sequences revealed a single nucleotide polymorphism (A to G) located at the splice site of the 9th intron of CaPelota in BaPep-5, which caused the insertion of the 9th intron into the transcript, resulting in the addition of 28 amino acids to CaPelota protein without causing a frameshift. Virus-induced gene silencing of CaPelota in the begomovirus susceptible pepper No.218 resulted in the gain of resistance against PepYLCIV, a phenotype consistent with BaPep-5. The DNA marker developed in this study will greatly facilitate marker-assisted breeding of begomovirus resistance in peppers.

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%.

Validating Plant Genes Involved in Pepper Yellow Leaf Curl Indonesia Virus Infection Using VIGS in Model Plant Nicotiana benthamiana

<p>Pepper yellow leaf curl disease caused by Pepper yellow leaf curl Indonesia virus (PepYLCIV) has become a challenge to chili pepper cultivation. Development of resistant variety by utilizing recessive resistance gene is expected to control the disease in the field. This study aimed to validate three plant genes, namely deltaCOP, hsc70, and BAM1, in PepYLCIV infection by applying Virus-induced Gene Silencing (VIGS) in a model plant, wild type Nicotiana benthamiana. PepYLCIV and construct of Tobacco rattle virus (TRV) which induced silencing of each gene were co-inoculated into N. benthamiana plants through agroinfiltration. Gene expression and the relative amount of viral DNA were determined by quantitative reverse transcription PCR (qRT-PCR) and quantitative PCR (qPCR), respectively, at 15 days post inoculation. The results showed a decreased level of deltaCOP, hsc70, and BAM1 expressions to 66.4%, 53.0%, and 47.0%, respectively, compared to that in the control (100%). Silencing of the three genes decreased the accumulation of PepYLCIV to 0.1%, 18.4%, and 63.0%, respectively, compared to that in the control. deltaCOP and hsc70 genes were indicated to be involved in the viral infection and could be good candidate genes for obtaining chili pepper varieties resistant to PepYLCIV. This result affirmed that the reverse genetics technique could be an alternative approach for identifying plant genes involved in viral infection, including PepYLCIV. The use of an infectious clone in this study allows the virus inoculations could be carried out without rearing and maintaining its natural vector, hence reduces the risk of virus transmission to healthy plants.</p>

The pET-Rep recombinant plasmid construction and geminivirus Rep [C1] gene expression in Escherichia coli strain BL21

Geminivirus Rep [C1] gene produces a replication protein [Rep] that interacts with Retinoblastoma-related protein [RBR] when Geminivirus infect the plants. That interactions interfere with RBR and transcription factor function. So the mechanism of chili plant defense against symptoms of Pepper Yellow Leaf Curl Disease is blocked. The NPR1 gene is a transcriptional co-activator involved in the regulation defense mechanism of Systemic Acquired Resistance [SAR] in chili plants. In silico, Rep protein blocks the SAR mechanism that is regulated by the NPR1 gene. This study aimed to obtain a construction of pET-28a+ plasmid expression recombinant Rep [C1] gene and Rep protein that can be expressed in E.coli BL21. This research is useful to study the interaction of Geminivirus with transcription co-activator in chili plants. The construction was done by ligating plasmid and Rep genes which have been cut using restriction enzymes BamHI and SacI. The construction of a recombinant pET-Rep plasmid is confirmed by amplification and verification of the nucleotide sequence through sequencing techniques. Nucleotide sequence verification results proved that the Rep [C1] gene is successfully constructed into a pET-28a+ plasmid with proper position and orientation. The pET-Rep recombinant proceeds to the expression test using the E.coli BL21 host. Expression was performed using the induction method with IPTG. Proteins Rep is purified using the MagnehisTM Protein Purification System. Rep protein is visualized with SDS-PAGE. Visualization showed that Rep protein was successfully expressed in E.coli BL21 where protein size is estimated of 41,03 kDa in size.

The threat of seed-transmissible pepper yellow leaf curl Indonesia virus in chili pepper

Recently, chili pepper (Capsicum annuum) plants in Indonesia have been devastated by a notorious bipartite begomovirus infection named Pepper yellow leaf curl Indonesia virus (PepYLCIV), which causes a distinct decrease in chili pepper production. Pepper yellow diseases have been known since early 2000; however, the spread of this virus thus far is distressing. These diseases can reduce chili yields by 20–100% in Indonesia. As previously known, begomovirus can be transmitted through whitefly to several host plants from the families Solanaceae, Compositae, and Leguminosae. In the field, a single plant was observed with severe symptoms of pepper yellow leaf curl disease, while other plants in the same field were asymptomatic and healthy. The observation leads to the possibility that the virus can be transmitted from previously infected chili pepper plants through seeds, as begomovirus transmission through seeds has been reported before. This study was conducted using seeds from chili peppers infected with viruses from different places in Indonesia. Whole seeds, embryos, and seedlings from PepYLCIV infected seeds were investigated in this study by performing viral genome DNA extraction, uracil DNA glycosylase-PCR, and sequencing analysis. Results revealed that both DNA-A and DNA-B of PepYLCIV in seeds and embryos of infected chili pepper plants were detected. The results also showed that 25–67% of PepYLCIV DNA-A and 50–100% of DNA-B were detected from seedlings grown from infected chili pepper seed collected from different location, thus confirming PepYLCIV as a seed-transmissible virus in chili pepper plants.

Determination of Endophytic Fungi as Induce Resistance Agent of Chilli Pepper Against Pepper Yellow Leaf Curl Disease

Pepper yellow leaf curl disease caused by Pepper yellow leaf curl virus becomes a major problem on chilli pepper in Indonesia since 2000. Endophytic fungi has the potency to suppress plant diseases by acting as induced resistant agent. The objective of this research was to determine the effect of endophytic fungi application on incidence of yellow leaf curl disease of chilli pepper. Four isolates of endophytic fungi, i.e. Cercospora nicotianae isolate H5, Curvularia sp. isolate H12, Fusarium sp. isolate AC-2.7 and AC-4.5 were applied as seed treatment and leaf spray on 2 chilli varieties, ‘Biola’ and ‘Luwes’. Observations of incubation period showed that delayed symptom occurred on application of Fusarium sp. isolate AC-2.7 and Curvularia sp. isolate H12. Disease incidence reached 100 % in all treatments. Less severe symptom was observed on application of Curvularia sp. isolate H12. Most plants infected by PYLCIV showed obvious symptoms of yellow mosaic, leaf curling and stunting. Plant productivity analysis showed that application of Fusarium sp. isolate AC-2.7 resulted higher fruit weight and this treatment may induce tolerant response of the plants to PYLCIV infection. Initial effort to evaluate endophytic fungi as biocontrol agents for pepper yellow leaf curl disease should be studied further.

Begomoviruses Associated to Pepper Yellow Leaf Curl Disease in Thailand

Begomoviruses Associated to Pepper Yellow Leaf Curl Disease in Thailand

Leaf surface characters related to resistance against pepper yellow leaf curl disease

Leaf surface characters related to resistance against pepper yellow leaf curl disease