Begomovirus infection has a significant impact of lowering chilli yield in Indonesia. A constraint of narrow genetic variability of chilli in Indonesia has made the mutation breeding program as a ...solution worth-pursuing in increasing the genetic variability. The objective of this study was to determine the LD50 point for each of the five irradiated chilli genotypes and the optimum dose of gamma irradiation in inducing chilli resistance to Begomovirus and other improved agronomical traits. The study was conducted in the Indonesian Vegetable Research Institute (IVEGRI) at Cikole-Lembang, elevation 1,200 m above sea level, from March to December 2013. Split plot design was used with genotype as main factor (Kencana, Lembang-1, SSP, Tanjung 2, Seloka) and irra-diation dosage as sub-factor (0, 200, 400, 600, 800 Gy). All treatments were replicated three times. The results showed that LD50 points of the five irradiated chilli genotypes were in the range of 422.64-629.68 Gy. There were some chilli genotypes in the population of M2 that had high coefficient variance genetic (CVG) and broad sense heritability (h2bs) value for disease incu-bation time. This could be used as resistance parameter to Begomovirus and improvement parameter of several agronomical traits.
Virus infection in chili plants may cause various symptoms. The complexity of the symptoms and human vision ability often become limiting factors during disease investigations. Digital image analysis ...is expected to become a method to assist in comprehensively describing the symptoms of plant viruses. A disease survey was conducted on cayenne pepper fields in Southeast Sulawesi Province to observe symptoms of virus infection virtually and to record the symptomatic plant using an RGB camera. The split-channel method is used to process images, followed by multidimensional scaling statistical analysis. Later on, viruses associated with plants were detected serologically. Single or mixed infection of Tobacco mosaic virus, Cucumber mosaic virus, Chili veinal mottle virus, and Pepper mottle virus was confirmed by plant leaves showing yellow-mosaic and mottle symptoms. The digital image analysis method could show variations in the characteristics of symptoms based on digital numbers in that cannot be recognized based on the observation of visual symptoms. A new approach to study the interactions between plant infecting viruses and their effects based on image analysis has also been developed during this research. This method needs to be further validated through testing under controlled conditions, such as inoculating plants with a predetermined type of virus.
Banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) is known as vector of Banana bunchy top virus (BBTV) that threatening production of banana worldwide. It was reported recently ...that P. nigronervosa and P. caladii is “cryptic species”. A good and proper identification is necessary to verify the correct species and its status. Research was conducted to identify and to find the host range of banana aphids in Java. Aphid collection was conducted in several locations in West Java, Central Java, and East Java. Eleven morphometric characters were analyzed to assess the morphometric variations among banana aphids. Morphological identification and principle component analysis (PCA) approach were conducted for accurate identification of banana aphids. Two species of aphids were found during the survey in Java, i.e. P. nigronervosa and P. caladii. P. nigronervosa mostly infested bananas (Musa spp.), and a few was found on heliconia (Heliconia sp.) and banana traveler (Ravenala madagascariensis). In contrast, P. caladii generally infested taro (Colocasia esculenta), turmeric (Curcuma longa), costus (Costus sp.), dumbcane (Dieffenbachia sp.), but rarely on bananas.
Sebagian besar petani bawang merah di Indonesia menggunakan umbi sebagai bahan perbanyakan meskipun banyak penyakit diketahui ditularkan melalui umbi. Perlakuan air atau udara panas pada organ aktif ...seperti biji atau umbi adalah metode yang umum digunakan untuk menghasilkan tanaman bebas virus. Penelitian ini dilakukan untuk mendapatkan umbi bawang merah bebas virus melalui perlakuan air panas dikombinasikan dengan kultur jaringan. Deteksi virus sebelum perlakuan menggunakan Dot immuno binding assay (DIBA) untuk memastikan infeksi genus Potyvirus (Onion yellow dwarf virus/OYDV), Carlavirus (Shallot latent virus/SLV dan Garlic common latent virus/GCLV) dari umbi. Penelitian disusun menggunakan rancangan acak lengkap dengan tiga faktor, yaitu kultivar (Sumenep dan Bima Curut), suhu (45 °C, 50 °C, dan suhu kamar), dan waktu pemanasan (15 dan 30 menit). Secara umum, perlakuan air panas yang dikombinasikan dengan kultur jaringan tidak memengaruhi kemampuan tumbuh dan jumlah daun planlet. Berdasarkan deteksi virus menggunakan RT-PCR, suhu 45 °C selama 15 menit mampu mengeliminasi 100% Potyvirus dan Carlavirus pada bawang merah ‘Bima Curut’; sedangkan pada bawang merah ‘Sumenep’ perlakuan air panas pada suhu 50 °C selama 15 menit mampu mengeliminasi 100% Potyvirus dan 33.33% Carlavirus.
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.
Manzila I, Priyatno TP, Nugroho K, Terryana RT, Lestari P, Hidayat SH. 2020. Molecular and morphological characterization of EMS-induced chili pepper mutants resistant to Chili veinal mottle virus. ...Biodiversitas 21: 1448-1457. Chili veinal mottle virus (ChiVMV) is a major prevalent virus that potentially reduces the yield of chili pepper by more than 50% in Indonesia. Therefore, the development of a ChiVMV-resistant cultivar is necessary to ensure satisfactory chili pepper production. Mutation breeding is a promising tool available to produce virus-resistant plants via the induction of new alleles due to point mutations within the existing chili germplasm. This research was conducted to assess the genetic variation of ten promising (M6) EMS-induced mutant lines of chili pepper (Capsicum annuum L.) potentially resistant to ChiVMV by their morphological characteristics and SSR profile, as well as identify potential mutants based on agronomic traits. The ten chili pepper mutant lines used in the present study were derived from the shoot tips of a Gelora cultivar treated with 0.5% ethyl methanesulfonate (EMS) as a chemical mutagen. The performance of the respective promising chili pepper mutant lines both at a molecular and morphological level was observed. Phenotypic analysis showed that all the promising chili pepper mutant lines underwent significant morphological changes. Of these, the phenotype coefficient variation (PCV) values were higher than the genotype coefficient variation (GCV) values for all the traits observed. High heritability (h2) was found for the canopy area, length of the fruit stalk, fruit weight, fruit weight per plant, thick fruit flesh, leaf width, leaf length, and fruit storage duration. A total of 52 alleles were detected from the five polymorphic SSR loci with 5.2 average alleles/loci. A dendrogram was generated and revealed two groups with five mutants clustered separately from their parents which could be valuable for further improvement.
Single image-NDVI method for early detection of mosaic symptoms in Capsicum annuum
Mosaics are a symptom of a disease often found in red chilies (Capsicum annuum) and is generally caused by viral ...infections such as the Tobacco mosaic virus. Severe infection can cause stunting and significant yield loss. Serological and molecular detection is a common detection method for plant viruses although they are time-consuming, relatively inefficient for large samples, and are destructive to plants. On the other hand, direct symptoms observation is hampered by human visual abilities and latent symptoms in virus infection. Therefore, detection method based on the plant’s ability to absorb and reflect various spectrums of sunlight, such as the normalized difference vegetation index (NDVI), has the potential to be developed. This study aims to evaluate the potential of a single image-NDVI as an NDVI variant for the early detection of mosaic symptoms in red chilies. The main activity involved image recording of chili plants that were not inoculated (V0) and inoculated (V1) by the virus, and given minimal nutrients (M) using an unmodified RGB camera and lens filter to capture blue and Near-Infrared light reflection. Furthermore, image processing is carried out using the Photo Monitoring plugin on the Fiji-ImageJ application. The recording was done one day after inoculation (dai) until the symptoms were visible. The results showed that there was an increasing trend in the integrated NDVI value in all treatments. Howewer, the increasing trend in V1 was not significant compared to V0 and M. The difference in the mean value of integrated NDVI between V1 was very significant compared to V0 (at 5 dai) and M (at 1 dai). This method’s level of sensitivity, specificity, and accuracy ranges from 80–90% at 5 dai.
One effort to increase domestic sugar production is through the extension of sugarcane growing area outside Java island. The status of sugarcane disease outside Java, particularly those caused by ...virus(es), has not been evaluated yet; where virus diseases are able to decrease sugarcane productivity. Therefore, the aim of this research was to identify the sugarcane major viruses and their distributions in Lampung and South Sulawesi. Field survey and leaf sampling was collected from Lampung Tengah District, in Lampung Province and three districts in South Sulawesi Province i.e., Bone, Gowa, and Takalar. Virus detection was performed by reverse transcription-polymerase chain reaction (RT-PCR) method using specific primers for Sugarcane mosaic virus (SCMV), Sugarcane streak mosaic virus (SCSMV), and Sugarcane yellow leaf virus (SCYLV). Results indicated that symptoms variation was observed in the field. The highest disease incidence and severity was found in Lampung, i.e. 100% and 61.6771.67%, respectively; whereas the lowest disease incidence and severity was found in Takalar, i.e. 570% and 545%, respectively. The disease incidence and severity of viral diseases tend to be low in dry and low rain fall conditions. This information might be helpful for the extensification program of sugarcane development in supporting the sugar self-sufficiency program.
A survey on several cucumber cultivation areas in West Java, Central Java, Yogyakarta, and East Java found many plants showing typical Begomovirus symptoms such as yellow mosaic, cupping, and vein ...banding. This study was aimed to determine disease frequency, detection and molecular characterization of the causal virus of those symptoms on cucumber in Java. Sampling was conducted by purposive sampling by collecting 50 symptomatic plants from each location in West Java (Indramayu, Subang, and Bogor), Central Java (Brebes and Klaten), Yogyakarta (Kulon Progo), and East Java (Nganjuk, Kediri, and Tulungagung). The detection and disease frequency was determined based on DIBA test using a specific antiserum of Tomato leaf curl New Delhi virus (ToLCNDV) and Squash leaf curl virus (SLCV). The identification of nucleic acid was conducted by PCR using specific primer of ToLCNDV and SLCV, DNA cloning, and sequencing. The results of serological detection showed the disease frequency of ToLCNDV and SLCV ranged from 92.77-100% and 78.33-93.3%, respectively. PCR using specific primer of ToLCNDV successfully amplified the coat protein gene at a size of 600 bp from all samples. Homology nucleotide and amino acid sequences among ToLCNDV Java isolate ranging from 95.6-99.2% and 99.7-100%. ToLCNDV isolates Java had highest nucleotide and amino acid sequences similarity with cucumber isolate from Klaten, Indonesia (AB613825) ranging from 96.1-98.1% and 99.7-100%, and was considered as “Indonesia” strain. SLCV not amplified on all samples by PCR using specific primer, indicating it might not present yet on cucumber in Java.
Epiphytic yeasts have the potency as antagonistic agents against various pathogens of post-harvest products. Anthracnose is a major disease of chilli that causes high economic loss. This research was ...objected to study the antagonism mechanism of epiphytic yeast isolates that have the antagonistic potency against anthracnose pathogen on chilli (Colletotrichum acutatum). Twenty-two isolates of epiphytic yeasts, isolated from chilli leaves and fruit, were tested. The characterization of the antagonism was carried out by antibiosis, anti-fungus volatile production, and chitinolytic activity tests. The results showed that all tested isolates did not have antibiosis mechanism against C. acutatum. All isolates produced volatile compounds which inhibited the colony growth of C. acutatum. Four isolates showed high relative inhibition rate, i.e. isolates B32DEP (35.68%), B30DEP (37.52%), B23DEP (38.52%), and B29DEP (45.42%). Fourteen isolates showed chitinolytic activities. Three of them had high chitinolytic activities, i.e. B12DEP, B2DEP, and G237DEP.
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