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Diaphorina citri, an important pest and insect vector that can transmit the pathogenic bacteria Candidatus Liberibacter asiaticus, causing Huanglongbing disease, is one of many challenges in citrus agriculture. Integrated pest management by utilizing microorganisms is a wise and efficient alternative without damaging the environment. Utilization of Plant Growth Promoting Rhizobacteria (PGPR), such as Bacillus cereus and B. velezensis, is a potential strategy for the biological control of plant diseases or insect vectors. By inducing systemic resistance in plants, PGPR can enhance plant defense against diseases and insect pests while activating molecular and physiological changes in plants. This research aimed to determine the effect of B. cereus and B. velezensis on the plant growth and feeding behavior of D. citri. The height and volume of the plant canopy were observed periodically for 6 months, while the feeding behavior of D. citri was monitored using the Electrical Penetration Graph (DC-EPG). The results showed increased height and volume of the citrus plant canopy treated with B. cereus, indicating that B. cereus could act as a PGPR. The application of B. cereus and B. velezensis to citrus seedlings affected the feeding behavior of D. citri. D citri showed difficulty in penetrating the phloem tissue of citrus plants.

Huanglongbing or citrus greening in Asia caused by the pathogen Candidatus Liberibacter asiaticus (CLas) is one of the most devastating citrus diseases worldwide. This disease is one of the causes of decreased citrus production in Indonesia. Symptoms of huanglongbing in citrus plants in the field and greenhouses have different levels of severity. This study was conducted to detect CLas in several types of samples based on leaf symptoms using conventional and real-time PCR (qPCR). Three pairs of primers were used in this study, a pair of Las606/LSS for conventional PCR and two pairs for qPCR, namely Las931/LSS and Lj900F/Lj900R. The results showed that blotchy mottle is the most easily detected symptom of huanglongbing and found in fields and greenhouses. The Lj900F/Lj900R primer pair is more suitable for detecting CLas pathogens using qPCR than Las606/LSS based on the melting curve and Ct value that appear. qPCR detection is more accurate and sensitive even with lower DNA concentrations. The lower limit of Ct value of healthy leaf samples is 34.08. Citrus leaves are considered positive if the Ct value is less than 34.08. Ct value based on severity or scoring between HLB symptomatic leaves from the field and greenhouse showed a significant difference, i.e. the Ct value of symptomatic samples from the field was lower than that of greenhouse samples.

Hevea brasiliensis, a natural rubber producing species, is widely cultivated due to its high rubber yield potential. Natural rubber is synthesised in the rubber particles of laticifers. Latex diagnosis (LD) was established to characterise the physiological state of the laticiferous system by measuring its physiological parameters, i.e., sucrose, inorganic phosphorous (Pi), thiols and total solid content (TSC). Rubber clones are often classified in three groups i.e., quick starters, medium starters and slow starters. To better understand the genetic bases of latex yield, a biparental population was generated from a cross between the quick-starter clone PB 260 and the medium-starter clone SP 217. LD was performed during the peak latex production season and used to calculate sucrose loading. The agronomic and physiological parameters associated with latex yield led to the classification of genotypes according to the rubber clonal typology and to the identification of quantitative trait loci (QTL) using a high-density map. Inorganic phosphorous content was positively associated with yield during the first year of production thus enabling identification of quick-starter clones. In addition, the LD-based clonal typology led to determine the long-term yield potential and the use of appropriate ethephon stimulation. QTL analysis successfully identified several QTLs related to yield, sucrose, Pi and TSC. One QTL related to sucrose loading was identified in the same position as the QTL for sucrose on linkage group 1. To our knowledge, this is the first study to report QTL analysis for this trait. The use of a high-density map enables the identification of genes underlying QTLs. Several putative genes underlying QTLs related to yield, sucrose and TSC were identified.

Microbes produce various types of volatile organic compounds (VOCs) through metabolism, which can be used for diagnostic purposes. Microbes' types and classes of VOCs are very wide, including fatty acid derivatives (hydrocarbons, alcohols, and ketones), aromatic compounds, nitrogen-containing compounds, and volatile sulfur compounds. Microbial volatile organic compounds (VOCs) can also be divided into several chemical classes: alkenes, alcohols, ketones, benzos, pyrazines, sulfides, acids, esters, and terpenes. This study aimed to design primers for genes encoding volatile synthesis in Ralstonia syzygii subsp. celebesensis, which causes blood disease in the banana plant. Some of the genes involved are adc (acetone synthesis), adhP (ethanol synthesis), ilvA, nirBD (ammonia synthesis), mdcA (propionic acid synthesis), cysI (hydrogen sulfide synthesis), and speBC (putrescine synthesis). Primers were designed and examined for specificity in silico using Primer3Plus, Geneious Prime, and BLAST programs. The numbers of nine pairs designed primers were successfully amplifying the related nine VOC genes of R. syzygii subsp. celebesensis for qPCR.

Agroforestry is often seen as a sustainable land-use system for agricultural production providing ecosystem services. Intercropping with food crops leads to equal or higher productivity than monoculture and results in food production for industry and subsistence. Low rubber price and low labor productivity in smallholdings have led to a dramatic conversion of rubber plantations to more profitable crops. The literature analysis performed in this paper aimed at better understanding the ins and outs that could make rubber-based agroforestry more attractive for farmers. A comprehensive search of references was conducted in March 2023 using several international databases and search engines. A Zotero library was set up consisting of 415 scientific references. Each reference was carefully read and tagged in several categories: cropping system, country, main tree species, intercrop type, intercrop product, level of product use, discipline of the study, research topic, and intercrop species. Of the 232 journal articles, 141 studies were carried out on rubber agroforestry. Since 2011, the number of studies per year has increased. Studies on rubber-based agroforestry systems are performed in most rubber-producing countries, in particular in Indonesia, Thailand, China, and Brazil. These studies focus more or less equally on perennials (forest species and fruit trees), annual intercrops, and mixed plantations. Of the 47 annual crops associated with rubber in the literature, 20 studies dealt with rice, maize, banana, and cassava. Agronomy is the main discipline in the literature followed by socio-economy and then ecology. Only four papers are devoted to plant physiology and breeding. The Discussion Section has attempted to analyze the evolution of rubber agroforestry research, progress in the selection of food crop varieties adapted to agroforestry systems, and to draw some recommendations for rubber-based agroforestry systems associated with food crops.

Biofilms are major virulence factors formed by pathogenic bacteria to invade their host and maintain their colony. While biofilms usually develop on diverse solid surfaces, floating biofilms, also called pellicles, are formed at the air–liquid interface. To address the problem of biofilm formation by bacterial pathogens, honey has been extensively studied. However, information on the effect of honey on biofilm formation by plant pathogens is scarce. This study aimed to determine the effects of manuka honey on biofilm and pellicle formation by Pectobacterium brasiliense and analyze the expression of genes encoding proteins needed to form biofilm by using semiquantitative PCR and RT-qPCR. Treatment with 5% (w/v) of manuka honey significantly decreased biofilm and pellicle formation by P. brasiliense. RT-qPCR results showed that the expression of bcsA, fis, hrpL, and expI decreased 7.07-fold, 5.71-fold, 13.11-fold, and 6.26-fold, respectively, after exposure to 5% (w/v) manuka honey. Our findings reveal that manuka honey may effectively inhibit biofilm and pellicle formation.

Pisang abaka (Musa textilis) merupakan penghasil serat alam berkualitas tinggi dengan permasalahan utama penyakit layu fusarium oleh Fusarium oxysporum f. sp. cubense TR4. Penelitian ini bertujuan memperoleh bakteri pelarut silika (BPS), menentukan pengaruh aplikasi BPS dan pupuk silika untuk menghambat serangan fusarium serta memacu pertumbuhan tanaman pisang. Sebanyak enam isolat BPS diperoleh dari tanah rizosfer pisang abaka sehat, tiga di antaranya memiliki aktivitas antagonis terhadap F. oxysporum f. sp. cubense TR4. Empat perlakuan yang dicobakan menunjukkan keparahan penyakit layu fusarium yang tidak berbeda. Demikian juga keempat perlakuan tidak menunjukkan perbedaan pada peubah pertumbuhan yang diamati. Bakteri pelarut silika dan pupuk silika belum mampu mengendalikan F. oxysporum f. sp. cubense TR4. Oleh karena itu, pisang abaka terbukti rentan terhadap F. oxysporum f. sp. cubense TR4.

Biodiversity has been defined as the range of significantly different types of organisms and their relative abundance in an assemblage of community. The aim of this research was to understand about soil bacterial community after on biological control agents (BCA) treatments with various formulations. This research was conducted at Sleman Regency, Special Region of Yogyakarta and Faculty Agriculture of Universitas Gadjah Mada. The research conducted with culture dependent and culture independent methods to assess soil bacterial diversity. The results showed that soil bacterial diversity before and after treatment of biological control agent were different. Results from this research suggested different molecular methods regarding soil bacterial diversity based on their benefits and challenges.

Chili anthracnose caused by Colletotrichum spp. is a significant disease of chili cultivation in Indonesia. The current taxonomic status of Colletotrichum spp. has been rearranged due to a well-developed molecular study. Several species of Colletotrichum were re-identified after being analyzed by a polyphasic approach. The polyphasic method in this research combines morpho-cultural and molecular identification using ITS-rDNA and GADPH region. The pathogenicity test would be more reliable in identifying the species complexes of Colletotrichum that are difficult to differentiate. This study applies a polyphasic approach to identify Colletotrichum species causing chili anthracnose, especially in fruits collected from chili fields in Yogyakarta, Indonesia, and observe its pathogenicity in wounded and unwounded inoculation. The results of those combination methods showed that isolates collected from chili fields in Yogyakarta were C. scovillei. The pathogenicity test revealed that the fungus caused anthracnose disease in wounded and unwounded OR Twist 42 chili fruits. The unwounded infection was confirmed by amplification of the ChEC3 pathogenicity gene 24 h after inoculation, showing that appressoria production may possess an essential role in the unwounded inoculation. This study revealed that C. scovillei does not always need a wound for its pathogenicity

Latex diagnosis is widely adopted in natural rubber-producing countries to optimize the natural rubber production through a physiological-based latex-harvesting system management. This study is the first bibliographical searching and meta-analysis on the variation of latex physiological parameters i.e. sucrose, inorganic phosphorus, thiols, and total solid content. The study used information extracted from 158 scientific papers. Descriptive statistics, agglomerative hierarchical clustering, and principal component analysis were performed to characterize applications of latex diagnosis, how often parameters are used and interpreted as well as the variation of its parameter values. From 158 papers, latex diagnosis parameters were used in 114 agronomy, 22 in physiology, and 22 in breeding papers. The agglomerative hierarchical clustering analysis indicated that sucrose and inorganic phosphorus contents were clustered together and total solid and thiols contents were located in another cluster. The average values of the total solid content, sucrose, inorganic phosphorus and thiols were 43.9%, 9.4 mM, 16.5 mM, and 0.52 mM, respectively. The percentage of interpretation is 63.3% for sucrose, 54.4% for inorganic phosphorus, 47.5% for thiols, and 41.1% for the total solid content. The low interpretation of thiols and total solid contents question their relevance in latex diagnosis. The low adoption of latex diagnosis in breeding could hinder the selection of activities leads to a limitation of selection for long-term high yielding and stress-adapted clones.

This study was aimed to confirms the Banana Bunchy Top Virus (BBTV) infection of ten banana accessions from Indonesia through PCR assay using primer of BBTV coat protein (CP) gene, also the sequences characteristics and phylogeny. Preliminary morphological results showed five acessions were positively infected with slight to severe intensity symptoms i.e. Pisang Berlin, Candi, Billa, Morosebo, and Mas Kripik; and five accessions were symptomless i.e. M. acuminata var. rutilifes and M. balbisiana, Pisang Ebung, Madu and Moseng. However, PCR results qualitatively confirms that all accessions were positively infected. Two sizes of amplicons were identified. Pisang Candi isolate was showing ±500 bp amplicons, whereas the others were ±1000-1100 bp. The total aligned and selected BBTV CP sequences of 36 accessions (bananas and other host species) was 450 nt. It was considered highly conserved (85.55%), low G+C content (41%), and high genetic similarities (92.47 to 100%). Phylogenetic analysis delineates isolates into two large groups, i.e. the Asian group (East Asia and South-east Asia) and the South Pacific group (South Asia, Africa and the Pacific). The findings of this study are usefull for broader applicability of further banana breeding program particularly for mitigation, selection and evaluation of banana with BBTV resistance.

The twisted disease is one of the essential diseases in shallots caused by Fusarium spp. This study aimed to study pathogenicity and identify Fusarium species isolated from shallot plants with twisted symptoms in Nganjuk and Bantul areas. The Fusarium isolates were identified and then tested for pathogenicity levels and the effect of the hormones GA3 and IAA on shallot symptoms. Molecular identification using NF2 and NF4 successfully identified one isolate of Fusarium oxysporum, three isolates of F. acutatum, and three isolates of F. solani. Each of these species produces different symptoms. Pathogenicity test showed that all isolates had disease incidence reaching 100%, except isolates of F. solani1 causing wilt and F. solani3 causing twisted have the lower disease incidence were 77.8% and 77.7%, respectively. The investigation caused twisted shallot related to different symptoms was tested using the Thin Layer Chromatography (TLC) method. The result indicates that all isolates did not find IAA hormone. In contrast, the hormone GA3 was found in F. solani2 and F. solani3 isolates, caused bulb rot and twisted disease, respectively. Detection of IAA, GA3, and other hormones in shallot plants showed different symptoms should be studied further.

Latex diagnosis (LD) is applied to optimize the natural rubber production and prevent tapping panel dryness (TPD), a physiological syndrome affecting latex production in Hevea brasiliensis. The reduced thiol content (RSH) is one of the biochemical parameters associated with the risk of TPD. However, RSH is difficult to interpret because of the influence of the environment. In order to better understand the regulation of antioxidants and to better interpret RSH, a key parameter of LD, this study analysed in latex both oxidised and reduced forms of ascorbic acid (AsA) and glutathione, and their cofactors as well as other latex diagnosis parameters in response to harvesting stress (tapping and ethephon stimulation) and TPD occurrence. The content of antioxidants in latex had a high variability among five rubber clones. The concentration in AsA was about ten times higher than GSH in laticifer, GSH accounting for about 50% of RSH. For short-term harvesting stress, RSH increased with tapping frequency and ethephon stimulation. TPD is associated with high latex viscosity and bursting of lysosomal particles called lutoids, as well as for several rubber clones with lower RSH and GSH contents. These results suggest that a high level of RSH shows the capacity of laticifer metabolism to cope with harvesting stress, while a drop in RSH is the sign of long stress related to lower metabolic activity and TPD occurrence. RSH remains an essential physiological parameter to prevent TPD when associated with reference data under low and high harvesting stress. This study paves the way to understand the role of AsA and GSH, and carry out genetic studies of antioxidants.

Phytophthora palmivora has a broad range of host plants. The expression of its pathogenicity-related genes in causing black pod rot disease on cacao in Indonesia has not been studied yet. This research was conducted to recognize relative expression of those genes using qPCR analysis. In planta experiment was carried out by inoculating representative three isolates on model plant (Nicotiana benthamiana) at the incubation periods of 24, 48, 72, and 96 h. The expressed genes were reconfirmed using conventional PCR and quantitatively analyzed using qPCR technique. The results showed that among eight target genes, four genes were actively expressed on the inoculated N. benthamiana, including CRN1, Pec1, Pec3, and RXLR5. Furthermore, qPCR analysis revealed that those genes were upregulated on the inoculated plants during incubation periods. In WNO1 and WAT1 isolates, the optimum expression was documented on the first day of incubation time, and then it was decreasing on the following days. However, the delay expression was exhibited by the pathogenicity-related genes in isolate BTG1. We assumed it as the general pathway of pathogenicity mechanisms in P. palmivora, since prior screening pathogenicity assay categorized that isolate BTG1 into moderate pathogenic, isolate WAT1 into high pathogenic, and isolate WNO1 into less pathogenic.

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) has been reported to cause ± 20–50% of rice yield loss around the world. Resistant varieties are used to control this disease, however due to rapid evolution of this pathogen, the resistances was broken down in a few years. This study is aimed to determine the role of nanochitosan in the expression of rice Xa21 and Xa1 resistant genes against Xoo. The BLB susceptible rice cultivar IR64, the Xoo isolate MAG2 and a 0.065% concentration of nanochitosan were used in this experiment. Application of nanochitosan was carried out within 1-week intervals starting at rice aged 2–10 weeks after transplanting. The expression of Xa21 and Xa1 genes against Xoo were analyzed using conventional PCR and qPCR methods at 0 and 4 days after Xoo inoculation followed by 4x scoring of disease symptoms in 1-week interval. The treatments used in this study included the mock one/inoculated with sterile distilled water, K (+)/ plants inoculated with Xoo, CNP (-)/ with nanochitosan and sterile distilled water inoculation, and CNP (+)/ with nanochitosan and Xoo inoculation. The results showed that the 0.0065% concentration nanochitosan application was able to increase the expression of Xa21 and Xa1 genes on CNP (-). Disease intensity and AUDPC values did not show any significant difference between K (+) and CNP (+). This study concluded that nanochitosan at 0.065% was able to increase the expression of rice Xa21 and Xa1 resistance genes. However, the gene expression was not able to significantly suppress the infection development of Xoo.

Colletotrichum sp., the causal agent of anthracnose disease, is one of the important pathogenic fungi in chili which can cause considerable yield losses, especially during the rainy season. This study aimed to identify the species of Colletotrichum isolates obtained from chili cultivation area in The Special Region of Yogyakarta Province both morphologically and molecularly. As a comparison, a Colletotrichum isolate obtained from Magelang Regency, Central Java Province was used as comparison isolate. From the isolation result, it was obtained 14 isolates of Colletotrichum that generally had conidia that were fusiform to cylindrical with two pointed or slightly blunt ends, or crescent shapes with a various size range between 9.02-19.38 µm x 2.37–8.57 µm. Based on morphological observations using UPGMA analysis, these 14 isolates could be divided into 4 groups with 7 different types. Representative isolates of each type in different groups and a comparison isolate were identified molecularly by multi-gene analysis using the ITS1-4, gapdh and tub2 genes. The result showed that B1, G1, K2 and Mg isolates were closely related to Colletotrichum scovillei, J1 with C. truncatum; S1 and S2 with C. siamense; and J2 with C. makassarii. From the pathogenicity test on wounded chili, it showed that C. scovillei and C. siamense isolates had higher virulence than C. truncatum and C. makassarii isolates.

Tea Mosquito Bug (TMB), Helopeltis bradyi (Hemiptera: Miridae) is one of the major pest infesting tea and cocoa plantations worldwide. Developing olfaction-based control methods was urges as an alternative to commonly used but non-environmental friendly chemical pesticides. However, the molecular mechanisms underlying TMB reception mechanism are still lacking. Here, we collected a pooled male and female TMB antennae for RNA extraction followed by sequencing using the BGISEQ-500 platform and de novo assembly. TMB antennae RNA-seq data yielded 32,142 unigenes with N50 and GC (%) were 2322 and 40.25; subsequently. The RNA-seq data are available in GenBank Sequence Read Archive (SRA) database with accession number SRR13327229. De novo transcriptome analysis had identified several genes involved in TMB odorant reception includes; 39 OBPs (odorant binding proteins), 10 CSPs (chemosensory proteins), 81 Ors (odorant receptors), 1 Orcos (co-receptors), 9 SNMPs (sensory neuron membrane proteins), 3 GRs (gustatory receptors) and 4 IRs (ionotropic receptors). Our study presents the first RNA seq for TMB antennae, which serve the primary molecular resources data, which will facilitate further research to develop olfaction-based control methods, potentially contribute to TMB management strategies.

Phytoplasma is known to be associated with plant diseases in about 300 plant species from various families. Information on the presence of phytoplasma in bananas as one of the pathogens that can cause disease in bananas in Indonesia has never been reported. This research was conducted with the aim to detect the presence of banana phytoplasma by the nested-PCR method and to identify phytoplasma obtained based on the sequence analysis of the 16S rRNA gene. Standard PCR was carried out using P1/P7 primary pairs, followed by nested-PCR using a pair of R16F2n/R16R2m23SR primers separately that could amplify the target 16S rRNA genes in a row at 1600 bp. BLAST analysis shows that the results of phylogenetic analysis of banana phytoplasmic nucleotide cv. manggala from Tasikmalaya and cv. Raja nangka from Banjar has a genetic relationship that is closer to lethal wilt oil palm Phytoplasma (Candidatus Phytoplasma asteris). This phytoplasma belongs to the 16SrI-B group (aster yellows).

Klebsiella sp. GMD08 is one of the bacteria that has the capability to dissolve insoluble inorganic phosphate into soluble phosphate ion through their organic acid production. Transposon is a genetic element agent usually used to generate mutant through mutagenesis. Thus it can be used to identify the genetic functions involved in those phosphate solubilizing mechanisms. This research was conducted to identify the genes of Klebsiella sp. GMD08 involved in phosphate solubilization through sequence detection obtained from a hyper-solubilizing phosphate mutant library. Mutation was conducted by inserting mini-Tn5 transposon hosted in Escherichia coli S17-1/λpir [pBSL202] into Klebsiella sp. GMD08 chromosome by the filter mating conjugation method. Trans conjugant mutant candidates were then qualitatively and quantitatively analyzed for their solubilizing ability to dissolve tricalcium phosphate [Ca3(PO4)2] using pikovskaya medium. The organic acid characteristics of transconjugant mutants were detected using High-performance liquid chromatography (HPLC). Meanwhile, suspected genes involved in phosphate solubilizing were detected using the sequencing method obtained from the transposon insertion result. Nucleotide Basic Local Alignment Search Tool (nucleotide BLAST) was used to identify the nucleotide base sequence similarity with the database. The results showed that PB116 and PB122 were the two main transconjugant mutants obtained from transposon mutagenesis which had higher tricalcium phosphate dissolving ability. Gluconic acid was the main organic acid produced by Klebsiella sp. GMD08 phosphate solubilizing mechanism. Moreover, arginine repressor (ArgR) and malate dehydrogenase gene (mdh) coding gene were involved in Klebsiella sp. GMD08 phosphate solubilizing mechanism.

Blood disease of Banana (BDB) is one of the prevalent disease caused by Ralstonia syzygii subsp. celebesensis (Rsc) which cause substantial loss on banana production in Indonesia. To date, the genetic basis of plant defense mechanism caused by blood disease in banana is not available. As a matter of fact, the knowledge of global gene expression will provide important information on plant response to the pathogen infection. Data from transcriptomic analysis in response to blood disease infection from Musa acuminata cv. Mas Kirana (AA group), representing the A genome, and Musa balbisiana cv. Klutuk (BB group), representing the B genome, were firstly reported. The transcriptome data discussed in this publication are accessible through NCBI's Gene Expression Omnibus with GEO Series accession number GSE138749. These data provide the basis for further investigation on the global gene expression which is pivotal to understand the mechanism of disease resistance from two banana genomes in response to blood disease infection. Keywords: Defense mechanism, Disease resistance, Gene expression, Pathogen, RNA-seq

The increasing production of banana is hampered by the spread of banana plant diseases, one of which is caused by a group of bacteria, including those of causing wilt diseases. In Indonesia, blood disease is one of the important banana wilt diseases since loss due to the infection can reach up to 50%. There are numerous publications on the pathogen identification causing banana blood disease based on the molecular approach, however to date, no detailed molecular data are available for the interaction of banana host plant against the pathogen. Here, we present three raw data sets of the total RNA-seq from the inoculated Musa balbisiana cutivar kepok (ABB genome) inoculated with Ralstonia syzigii subsp. celebesensis, Ralstonia solanacearum and mock. The data provide essential knowledge for differentiating the banana response against pathogen, reveal pathogenesis-related genes and gene functions in the plant system, and research development to design blood disease-resistance of banana as one of the management strategies. Raw reads of RNA-seq data can be found in NCBI's Sequence Read Archive (SRA) database with the accession number of SRR10547839 (RSC), SRR10547840 (RS), and SRR10547841 (Mock). Keywords: Banana, Leaf, Inoculated, Ralstonia syzygii subsp. celebesensis, Ralstonia solanacearum, Transcriptome

A survey to investigate the stem and bulb plant parasitic nematode at one of garlic area centre, in Temanggung, Central Java, Indonesia was conducted from Januaryto February 2018. Infected plant with specific symptoms, morphological and morphometric characters both of female and male of adult nematodes were used to describe a A1 quarantine plant parasitic nematode Ditylenchus dipsaci. Seven from nine observed locations were postively infected with population in average 2.67 nematodes per 100 g of soil and 2.67–189.33 per bulb. This is the first report of D. dipsaci from Indonesia and consequently further investigations were needed to know their distribution and also to confirm the origin of the nematode. Intisari Survei keberadaan nematoda parasit batang dan umbi dilakukan pada bulan Januari–Februari 2018 pada satu sentra penangkaran bawang putih di Temanggung, Jawa Tengah, Indonesia. Tanaman terinfeksi dengan gejala serangan yang spesifik, karakter morfologi dan morfometri nematoda betina dan jantan dewasa dipergunakan dalam identifikasi Ditylenchus dipsaci yang merupakan nematoda parasit tanaman yang termasuk OPTK A1 (Organisme Pengganggu Tanaman Karantina A1) di Indonesia. Sebanyak tujuh dari sembilan lokasi yang diamati mengindikasikan positif sebagai daerah sebaran nematoda tersebut dengan populasi rata-rata 2,67 ekor per 100 gram tanah dan 2,67–189,33 nematoda per umbi. Laporan pertama tentang nematoda D. dipsaci ini membawa konsekuensi perlunya penelitian lebih lanjut untuk mengetahui daerah sebaran dan juga konfirmasi dari mana nematoda tersebut berasal.

Some extract of the banana plants parts have been identified to produce a compound that has efficacy as traditional medicine and human virus inhibitor. There was no previous report on the use of the banana flower as the plants antiviral sources for plant pathogen. The objective of this study was to identify the potency of two types of the banana flower as the Tobamovirus inhibitor substance. The antiviral was prepared from the extract of Ambon banana (Musa acuminata Colla) flower and Klutuk banana (Musa balbisiana Colla) flower, as the comparison extract of Mirabilis jalapa L. leaf which is widely known to have antiviral on various plant viruses was used. This study applied the Complete Randomized Design with three replications. Collected data includes the virus incubation period and the inhibitor power upon the local necrotic symptom on indicator plant. Results of this study showed that the extract of Ambon and Klutuk banana flower was able to inhibit the Tobamovirus with inhibition levels of 86.34% and 91.22%. Intisari Beberapa ekstrak bagian tanaman pisang diketahui memiliki kandungan senyawa yang berkhasiat sebagai obat tradisional dan zat yang dapat menghambat virus manusia. Belum pernah dilaporkan penggunaan bunga pisang sebagai sumber antiviral terhadap virus tumbuhan. Penelitian ini bertujuan untuk mengetahui potensi ekstrak bunga dua jenis pisang sebagai zat penghambat Tobamovirus. Antiviral disiapkan dari ekstrak bunga pisang Ambon (Musa acuminata Colla) dan pisang Klutuk (Musa balbisiana Colla), sebagai pembanding digunakan ekstrak daun Mirabilis jalapa L. yang sudah banyak diketahui mengandung antiviral pada berbagai virus tumbuhan. Penelitian ini dirancang menggunakan Rancangan Acak Lengkap dengan 3 ulangan. Data yang dikumpulkan meliputi masa inkubasi virus dan daya hambat gejala nekrotik lokal pada tanaman indikator. Hasil penelitian menunjukkan bahwa ekstrak bunga pisang jenis Ambon dan Klutuk mampu menghambat Tobamovirus dengan tingkat penghambatan sebesar 86,34% dan 91,22%.

Fusarium oxysporum f. sp. cubense tropic race 4 (Foc TR4) strain which belong to Vegetative Compatibility Group (VCG) 01213 is the most devastating disease in global banana production. Validation of specific primer sets using the positive control (Foc TR4). In total, 50 isolates of Foc are collected from several banana production regions in Indonesia represent the group of VCG, races, genotype, cultivars, which are confirmed as Foc based on the tested using FocEf3 primer set, except Cjr-2 and Lmp-4 isolates. Foc-1/Foc-2 could amplify 34 Foc isolates included in Foc race 4. Three specific primer sets i.e. TR4-F/TR4-R, Six-1c, and TR4-F2/TR4-R1 are used to classify Foc isolates into Foc tropic race 4. TR4-F/TR4-R is known have the highest specificity as it could amplify 35 Foc isolates including positive controls (Foc TR4) compared to the other primer sets (Six-1c and TR4-F2/TR4-R1). This research indicates that there are a large number of diversity strains found in Foc isolates to be studied for further research. Race 4 of Foc (STR4 or TR4) is known to be widespread in several regions in Indonesia. Therefore, specific primer set development needs to be done to detect Foc TR4 and the most damaging strains on Foc TR4 based on molecular data. Intisari Fusarium oxysporum f. sp. cubense ras 4 tropika (Foc TR4) yang termasuk ke dalam kelompok VCG 01213 merupakan patogen yang paling merusak dalam produksi tanaman pisang secara global. Validasi primer spesifik berbasis PCR menggunakan kontrol positif (Foc TR4). Total, 50 isolat Foc dikoleksi dari beberapa daerah produksi pisang di Indonesia mewakili VCG, ras, genotipe dan kultivar yang dikonfirmasi sebagai isolat Foc berdasarkan pengujian menggunakan primer FocEf3, kecuali isolat Cjr-2 dan Lmp-4. Foc-1/Foc-2 dapat mengamplifikasi 34 isolat Foc yang termasuk ke dalam Foc ras 4. Selanjutnya tiga pasang primer spesifik yaitu TR4-F/TR4-R, Six-1c, dan TR4-F2/TR4-R1 digunakan untuk mengelompokkan isolat-isolat tersebut ke dalam isolat Foc ras 4 tropika. TR4-F/TR4-R diketahui memiliki spesifitas tertinggi karena dapat mengamplifikasi sebanyak 35 isolat Foc termasuk kontrol positif (Foc TR4) dibandingkan dengan primer lainnya (Six-1c dan TR4-F2/TR4-R1). Penelitian ini menunjukkan bahwa terdapat sejumlah besar keragaman strain yang terlihat pada isolat-isolat Foc tersebut untuk dapat dipelajari lebih lanjut. Ras 4 dari Foc (STR4 atau TR4) diketahui tersebar luas pada beberapa daerah di Indonesia. Oleh karena itu, perlu dilakukan pengembangan primer spesifik untuk mendeteksi Foc TR4 dan strain yang paling merusak pada Foc TR4 berdasarkan data molekuler.

The presence of bacterial panicle blight disease caused by Burkholderia glumae have been reported to infect rice plants in Indonesia. There have been no reports of yield losses due to B. glumae infection, but this pathogen is seed-borne so that it can increase the spreading potential to other areas. This study aims to determine the spread of the disease area of bacterial panicle blight in Java and to detect B. glumae based on ITS region of 16-23S rDNA. Methods for this research include surveys and random sampling of rice seeds directly from farmers and the Food Crop and Horticulture Center, Agriculture Office of Yogyakarta. The bacteria were isolated using S-PG selective medium, then DNA extraction was performed and amplified using a pair of primers BGF 5’-ACACGGAACACCTGGGTA-3’ and BGR 5’-TCGCTCTCC CGAAGAGAT-3’. 101 isolates were obtained from 21 seed samples consisting of 11 rice varieties from nine regions in Java that has different morphological characteristics. The eight isolates were detected as B. glumae by using ITS primers, i.e., isolates ChgCM.4, IRP.3, IRP.6b, InSB.1a, InSB.2a, InSB.3a, InSB.5a, and InSB.6a. The eight isolates were isolated from seed samples of Cirebon, Purworejo and Banyuwangi. This study shows that bacterial panicle blight disease has found in several rice varieties and locations in Java, and the ITS primer can be used for early detection of B. glumae in rice seed samples. Intisari Penyakit hawar malai yang disebabkan oleh bakteri patogen Burkholderia glumae mulai banyak dilaporkan menginfeksi tanaman padi di Indonesia. Belum ada laporan mengenai kerugian akibat infeksi B. glumae di Indonesia, namun sifatnya yang tular benih dapat meningkatkan potensi menyebar ke wilayah lain. Penelitian ini bertujuan untuk mengetahui wilayah sebar penyakit hawar malai di Jawa dan mendeteksi secara molekuler berdasarkan urutan basa gen 16-23S rDNA internal transcribed spacer (ITS). Metode yang dilakukan meliputi survei dan pengambilan sampel biji padi secara acak langsung dari petani dan UPT Balai Pengembangan Perbenihan Tanaman Pangan dan Hortikultura, Dinas Pertanian Yogyakarta. Sampel biji padi diisolasi menggunakan media selektif S-PG, kemudian dilakukan ekstraksi DNA, dan diamplifikasi menggunakan primer BGF 5’-ACACGGAACACCTGGGTA-3’ dan BGR 5’-TCGCTCTCC CGAAGAGAT-3’. Hasil survei di lapangan diperoleh 21 sampel biji yang terdiri dari 11 varietas padi dari sembilan wilayah di Jawa. Hasil isolasi diperoleh 101 isolat dan masing-masing isolat tersebut memiliki karakteristik morfologi yang berbeda. Delapan isolat dari total isolat yang diuji terdeteksi B. glumae menggunakan primer ITS, yaitu isolat ChgCM.4, IRP.3, IRP.6b, InSB.1a, InSB.2a, InSB.3a, InSB.5a, dan InSB.6a. Kedelapan isolat tersebut merupakan hasil isolasi sampel biji dari wilayah Cirebon, Purworejo, dan Banyuwangi. Hasil penelitian menunjukkan bahwa penyakit hawar malai bakteri sudah terdeteksi pada varietas padi di beberapa lokasi wilayah Jawa, dan penggunaan primer ITS dapat digunakan untuk deteksi dini B. glumae pada sampel biji padi secara molekuler.

Six isolates of Rhizoctonia solani, i.e. two isolates collected from infected rice plants and four isolates from laboratory collection were studied by using morphological characters and molecular analysis. Un-weighted pair group method with arithmetic mean dendogram constructed based on cluster analysis showed that these isolates were grouped into three clusters at the 0.77 similarity coefficient. Cluster I consisted of BA, BNJ, and NBR isolates with 100% similarity and indicated that those were from AG 1 IA sub group, cluster II consisted of BND, and cluster III consisted of SL1 and SL2. Mycelium was very light brown or whitish with few and moderate sclerotia except SL1 and SL2. Molecular characterization showed that BA, BNJ, and NBR were amplified at 140 bp using Rs1F/Rs2R specific primer for R. solani AG1 IA. All isolates were amplified between 350−400 bp using Rhsp1 primer, meanwhile SL1 and SL2 were not amplified using AG2sp and AG22sp2 primers. Based on Maximum Likelihood tree analysis showed that SL1 and SL2 had high similarity based on ITS sequence data. Intisari Enam isolat Rhizoctonia solani yang berasal dari tanaman padi bergejala dan koleksi laboratorium diuji secara morfologi dan molekuler. Analisis UPGMA dengan koefisien persamaan 0,77 menunjukkan bahwa enam isolat tersebut terbagi atas tiga klaster. Klaster I terdiri atas isolat BA, BNJ, dan NBR dengan kesamaan 100% dan menunjukkan bahwa isolat tersebut berasal dari subgrup AG 1 IA , klaster II yakni isolat BND, dan klaster III terdiri atas isolat SL1 dan SL2. Miselium berwarna putih hingga cokelat muda dengan jumlah sklerotia sedang, kecuali isolat SL1 dan SL2. Uji keragaman secara molekuler menunjukkan bahwa isolat BA, BNJ, dan NBR teramplifikasi pada kisaran 140 bp dengan menggunakan primer Rs1F/Rs2R yang merupakan primer spesifik dari R. solani AG1 IA. Seluruh isolat teramplifikasi pada kisaran 350−400 bp dengan menggunakan primer Rhsp1, sedangkan isolat SL1 dan SL2 keduanya tidak teramplifikasi oleh primer AG2sp dan AG22sp2. Analisis Maximum Likelihood tree berdasar data sekuen ITS menunjukkan bahwa isolat SL1 dan SL2 memiliki tingkat kesamaan yang tinggi.

The new disease on garlic (Allium sativum) and shallot (A. cepa L. aggregatum group) have been found in several production centers of garlic and shallot in Tawangmangu and Temanggung, Central Java. The infected plants showed symptoms of leaf blight accompanied by chlorosis. The objective of this study was to determine the pathogen that causes leaf blight and chlorosis based on the phenotypic characterization and gyrB gene sequences analysis. The research started from the isolation of pathogen, physiological and biochemical test, DNA extraction, and sequence analysis of gyrB using gyrB 01-F and gyrB 02-R primer. The results showed that the isolated bacterial pathogen have a yellow pigment, slimy colonies with regular borders, convex, gram-negative, non-spore, facultative anaerobic, motile, catalase production, indole production, and acid production from D-glucose, D-mannitol, sucrose, and lactose. From the pathogenicity test, it was found that the bacteria produced the typical symptom of leaf blight. Characterization of pathogens based on gyrB gene sequence revealed that the pathogen was placed in the group of Pantoea ananatis. Intisari Penyakit baru pada bawang putih (Allium sativum) dan bawang merah (A. cepa L. aggregatum group) telah ditemukan di beberapa sentra produksi bawang putih dan bawang merah di Tawangmangu dan Temanggung, Jawa Tengah. Tanaman yang terinfeksi menunjukkan gejala hawar daun disertai klorosis. Tujuan penelitian untuk mengetahui karakter patogen berdasarkan fenotipik dan sekuen gen gyrB. Penelitian dimulai dengan isolasi bagian tanaman yang sakit, uji fisiologi dan biokimia, ekstraksi DNA dengan metode CTAB/NaCl dan amplifikasi gen gyrB menggunakan primer gyrB 01-F and gyrB 02-R. Hasil uji menunjukkan koloni berlendir, cembung, pigmen berwarna kuning, gram negative, tidak berspora, aerob fakultatif, motil, produksi katalase, indol, membentuk asam dari D-glukosa, D-monnitol, sukrosa dan laktosa, dan patogenesitas positif. Karakterisasi patogen berdasarkan sekuen gen gyrB, menunjukkan patogen hawar daun berkerabat dekat dengan Pantoea ananatis.

Ralstonia solanacearum species complex phylotype IV strains, which have been primarily isolated from Indonesia, Australia, Japan, Korea, and Malaysia, have undergone recent taxonomic and nomenclatural changes to be placed in the species Ralstonia syzygii. This species contains three subspecies; Ralstonia syzygii subsp. syzygii, a pathogen causing Sumatra disease of clove trees in Indonesia, Ralstonia syzygii subsp. indonesiensis, the causal pathogen of bacterial wilt disease on a wide range of host plants, and Ralstonia syzygii subsp. celebesensis, the causal pathogen of blood disease on Musa spp. In Indonesia, these three subspecies have devastated the cultivation of susceptible host plants which have high economic value. Limited knowledge on the ecology and epidemiology of the diseases has hindered the development of effective control strategies. In this review, we provide insights into the ecology, epidemiology and disease control of these three subspecies of Ralstonia syzygii.

Shallot (Allium cepa L. Aggregatum group) is usually cultivated vegetatively. As a result, viruses tend to accumulate within the host plants and spread to healthy plants every crop cycle, reducing yield and bulb quality. There are a very limited number of studies about the elimination of shallot viruses through heat treatment. The objective of this research was to eliminate shallot viruses through heat treatment to produce virus-free plantlets. The leaves of Biru Lancor with specifc visual virus symptoms were detected by Reverse Transcription–Polymerase Chain Reaction (RT-PCR). Then bulbs of Biru Lancor that were positively infected by viruses were used as materials for heat treatment. The treatments were a control (without treatment), electric treatment at 15 mA for 10 minutes, heat treatment in an incubator at 37°C for 4 weeks, heat treatment in a waterbath at 45°C for 60 minutes, and combination of heat treatment in an incubator at 37°C for 4 weeks and heat treatment in a waterbath at 45°C for 60 minutes. After being subjected to heat treatment, the pseudo stem were cultivated in the MS Medium + 1 mg/L BAP + 1 mg/L IBA.Virus detection by RT-PCR was conducted 28 days after planting using samples of leaves from each plantlet. The results of this research showed that the treatments of electric treatment at 15 mA for 10 minutes and combination of heat treatment in the incubator at 37°C for 4 weeks and heat treatment in the waterbath at 45°C for 60 minutes could suppress the incidence of Shallot latent virus (SLV) until 100%. Heat treatment might have an important role in the degradation of virus particles by boosting Virus-Induced Gene Silencing (VIGS) as plant responses to virus infection.

Fusarium wilt, caused by Fusarium oxysporum f.sp. cubense (Foc), is one of the most destructive diseases of banana and has spread in many plantation areas in Indonesia. Until today, the effective ways to control banana fusarium wilt disease have not yet been found. Some studies indicated thatAllium spp. could be used to suppress plant diseases caused by Fusarium. Allium spp. are important horticultural crops which are generally cultivated in some areas in Indonesia. This research was conducted to determine the effect of several species ofAllium spp. intercropped with banana to improve soil suppressiveness against banana fusarium wilt disease. The results showed that up to 12 months after planting, from 3 species ofAllium spp. (A. tuberosum/ Chinese leek, A. fistulosum/ bunching onion, and A. cepa var. aggregatum/ shallot) intercropped with banana Ambon Kuning (AAA) cultivar, Chinese leek and shallot were able to suppress the incidence of fusarium wilt disease of banana by 46 and 33% respectively. Soil analysis on the rhizosphere of banana intercropped with Chinese leek and shallot had lower population of total Fusarium compared to the other treatments. Analysis of fluorescein diacetate (3’.6’-diacetylfluoerescein) or FDA also showed that total microbial activity in the rhizosphere of banana intercropped withAllium spp. was also lower compared to control treatment (without intercropping). The observation of the effect ofAllium spp. extracts on Foc showed that Allium spp. extracts were able to suppress the development of the colony and spore germination of Foc in vitro. INTISARI Layu Fusarium, yang disebabkan oleh Fusarium oxysporum f.sp. cubense (Foc), merupakan salah satu penyakit tanaman pisang yang paling merusak dan telah tersebar di berbagai daerah di Indonesia. Sampai saat ini cara yang efektif untuk mengendalikan penyakit layu fusarium pisang belum ditemukan. Beberapa penelitian menunjukkan bahwa Allium spp. dapat dipergunakan untuk menekan penyakit tumbuhan yang disebabkan oleh Fusarium. Allium spp. adalah tanaman hortikultura penting yang banyak dibudidayakan di Indonesia. Penelitian ini dilakukan untuk mengetahui pengaruh beberapa spesiesAllium spp. yang ditumpangsarikan dengan tanaman pisang untuk meningkatkan supresifitas tanah dalam menekan penyakit layu fusarium pisang. Hasil pengamatan menunjukkan bahwa sampai 12 bulan setelah tanam, dari 3 spesiesAllium spp. (A. tuberosum/kucai, A. fistulosum/loncang, dan A. cepa var. aggregatum/bawang merah) yang ditumpangsarikan dengan pisang kultivar Ambon Kuning (AAA), kucai dan bawang merah mampu menekan insidensi penyakit layu fusarium pisang berturut-turut sebesar 46% dan 33%. Analisis tanah rhizosfer pisang yang ditumpang sari dengan kucai dan bawang merah menunjukkan populasi total Fusarium yang lebih rendah daripada perlakuan lainnya. Analisis fluorescein diacetate (3’.6’-diacetylfluoerescein) atau FDA juga menunjukkan bahwa aktivitas total mikrobia pada rhizosfer pisang yang ditumpang sari dengan Allium spp. lebih rendah jika dibandingkan dengan perlakuan kontrol (tanpa tumpang sari). Pengamatan pengaruh ekstrak Allium spp. terhadap Foc menunjukkan bahwa ekstrak Allium spp. mampu menekan perkembangan koloni dan perkecambahan spora Foc secara in vitro.

Bacterial fruit blotch (BFB) caused by Acidovorax citrulli is a serious seedborne disease in Cucurbitaceae causing 90-100% yield losses. The aim of this study was to explore BFB symptom on melon and also to detect A. citrulli infection in commercial seed and symptomatic fruits from the field in Yogyakarta Special Region province and its surrounding using DAS-ELISA method. Samples include melon from Sleman, Bantul, Kulon Progo, Gunung Kidul, Magelang, Purworejo regencies while commercial seeds i.e. Action 434, Glamour and Mai 116 were collected. DASELISA detection method used reagent set from Agdia. Based on the field observation, this study found melon commercial fruit shares similar symptom with BFB, which showed discrete oily dark green spots, while the netting failed to develop over necrotic areas, resulting in smooth sunken spots. DAS-ELISA detection revealed that samples collected from Jetak village, district of Mungkid, Magelang and from Bligo village, district of Ngluwar, Magelang and in commercial seed Mai 116 were positively infected by A. citrulli. INTISARI Bacterial fruit blotch (BFB) merupakan penyakit penting pada famili Cucurbitaceae yang disebabkan oleh Acidovorax citrulli. Penyakit ini dilaporkan dapat menurunkan hasil mencapai 90-100%. Tujuan dari penelitian ini adalah untuk mengetahui gejala penyakit BFB pada melon dan deteksiA. citrulli pada benih komersial dan sampel buah bergejala dengan metode DAS-ELISA di DIY dan sekitarnya. Pengambilan sampel dilakukan di kabupaten Sleman, Bantul, Kulon Progo, Gunung Kidul, Purworejo dan Magelang. Selain dari lapangan, diuji pula benih melon komersial yaitu Action-434, Glamour dan Mai 116. Metode deteksi dengan ELISA menggunakanreagent set dari Agdia. Dari hasil pengamatan di lapangan ditemukan buah melon dengan gejala yang mirip dengan gejala BFB yaitu adanya becak berwarna hijau tua kebasahan pada permukaan buah, jaring tidak terbentuk sempurna dan pada bagian daging buah di bawah becak tadi membusuk. Hasil deteksi dengan DAS-ELISA mengindikasikan bahwa A. citrulli terdeteksi pada sampel yang berasal dari desa Bligo, kecamatan Ngluwar dan desa Jetak, kecamatan Mungkid, kabupaten Magelang, serta pada benih komersial MAI 116.

Virus infection on shallots may cause mosaic of leaves and plant dwarf. It is very important to know the identity of the virus as a requirement in determining viral disease management strategy. The research is subjected to identify seed- transmitted viruses from shallot bulbs. Detection of virus from bulb was conducted by growing on test, followed by mechanical inoculation on shallot cultivar Biru Bantul, Chenopodium amaranticolor, and Nicotiana tabacum and morphological observation of virus particle by electron microscope. About 2 weeks after inoculation symptoms was observed, i.e. mosaic and dwarf on shallot cultivar Biru Bantul, local necrotic on C. amaranticolor, but symptomless on N. tabacum. Filamentous particles of 650 nm and 800 nm in length was observed under electron microscope from plants with mosaic and dwarfing symptom, respectively. This indicated the presence of 2 different seed-transmitted viruses on infected shallots. Two species of shallot viruses, i.e. Shallot latent carlavirus (SLV) and Onion yellow dwarf potyvirus (OYDV) was most likely the main seedborne viruses on shallot bulb. Identification based on nucleic acid and protein sequence analysis is necessary for further confirmation

A study to determine the prevalence and distribution of plant parasitic nematodes associated with banana was undertaken in banana growing areas at four districts (Bantul, Gunung Kidul, Kulon Progo, and Sleman) of Yogyakarta Special Province. Seven genera of plant parasitic nematodes were found on these area: Criconemoides, Helicotylenchus, Hoplolaimus, Meloidogyne, Pratylenchus, Radopholus, and Rotylenchulus. Genera Hoplolaimus and Meloidogyne were distributed at all districts and occurring in soil and root samples of banana cultivars, Ambon, Kepok, Koja, Klutuk, Raja, Tanduk, and Uter, respectively. Four genera, Hoplolaimus, Meloidogyne, Pratylenchus, and Radopholus were dominant and were found with high level of population than the others on each district. Pratylenchus mostly was found on banana cv Kepok with average population 348,2–2057,3 nematodes on total samples of 5g banana root and 100g soil. Penelitian untuk mengetahui keberadaan dan sebaran nematoda parasit tumbuhan yang menyerang tanaman pisang dilakukan dengan survei di empat daerah kabupaten (Bantul, Gunung Kidul, Kulon Progo, dan Sleman) yang berada di wilayah Daerah Istimewa Yogyakarta. Ditemukan tujuh genera nematoda parasit yang menyerang pisang yaitu: Criconemoides, Helicotylenchus, Hoplolaimus, Meloidogyne, Pratylenchus, Radopholus, dan Rotylenchulus. Genera Hoplolaimus dan Meloidogyne tersebar merata di semua daerah dan didapatkan pada masing-masing sampel akar dan tanah pada hampir semua kultivar pisang: Ambon, Kepok, Koja, Klutuk, Raja, Tanduk, dan Uter. Empat genera yang dominan dengan tingkat populasi tinggi di setiap daerah adalah Hoplolaimus, Meloidogyne, Pratylenchus, dan Radopholus. Nematoda Pratylenchus banyak ditemukan pada pisang kultivar Kepok dengan rata-rata populasi 348,2– 2057,3 nematoda pada setiap total sampel 5 g akar dan 100 g tanah.

Blood disease of banana is one of the most serious banana disease in Indonesia. Although the disease has became the subject of quarantine it eventually spread and found in most provinces in Indonesia. The aim of this research were to identify the blood disease bacterium (BDB) using morphological observation, biochemical assay, pathogenicity testing of hosts range using infectivity titration and rapid detection by Polymerase Chain Reaction (PCR). The results showed that the blood disease bacterium could be differentiated from Ralstonia solanacearum race 2, the causal agent of Moko disease and R. solanacearum tobacco isolates. BDB isolates were not able to hydrolyze gelatin, Tween 80, starch, and were not able to produce nitrite from nitrate. They were only able to produce acid from galactose and glycerol. The pathogenicity test indicated that the BDB was only able to infect the banana/plantain and was not able to infect tomato, eggplant, and chili. Rapid detection using PCR method showed that the 121F/R primers was able to amplify the BDB genome and was not able to amplify the genome of R. solanacearum tobacco isolates. Penyakit darah pada pisang masih merupakan kendala utama dalam budidaya pisang di Indonesia. Walaupun patogen penyakit darah sudah merupakan OPT karantina, namun saat ini penyakit sudah tersebar di seluruh provinsi di Indonesia. Penelitian ini bertujuan untuk mengidentifikasi bakteri penyebab penyakit darah dengan karakterisasi morfologi, biokimia, kisaran inang, dengan infectivity titration dan deteksi cepat menggunakan PCR. Hasil penelitian menunjukkan bahwa bakteri penyakit darah (BDB) dapat dibedakan dengan Ralstonia solanacearum ras 2, penyebab penyakit Moko dan R. solanacearum isolat tembakau. Isolat BDB tidak dapat menghidrolisis gelatin, Tween 80, pati dan tidak dapat menghasilkan nitrit dari nitrat. Bakteri ini hanya menghasilkan asam dari galaktosa dan gliserol. Hasil uji patogenisitas menunjukkan bahwa bakteri penyakit darah (BDB) hanya dapat menginfeksi pisang dan plantain dan tidak dapat menginfeksi tomat, terung dan cabai. Deteksi cepat dengan PCR menunjukkan bahwa primer 121F/R dapat mengamplifikasi genom bakteri penyakit darah (BDB) dan tidak dapat mengamplifikasi R. solanacearum isolat tembakau.

Banana bunchy top disease (BBTD) can be caused by the infection of two different viruses, Banana bunchy top virus (BBTV) or Abaca bunchy top virus (ABTV). Both viruses can be transmitted persistently by aphid Pentalonia nigronervosa Coq. The research was conducted to detect and to differentiate the virus bypolymerase chain reaction-restriction fragment length polymorphism (PCRRFLP) techniques. Infected plants were collected from Yogyakarta (Sleman, Yogyakarta city, Bantul, Gunung Kidul, and KulonProgo). Nucleon Phytopure DNA Extraction Kit method was used to extract the total DNA of infected plants. Universal primers of Common DNA region (S-CRF and S-CRR) and specific primers DNA-R (C1-CRF and CI-CRR) were used for PCR amplification. PCR products were analyzed by RFLP technique using the restriction enzyme of DraI. The results reconfirm previous reports that bunchy top disease of banana in Yogyakarta is caused by BBTV. The ABTV was not detected in this present study. Based on the RFLP analysis it was concluded that BBTV collected in this study could be divided into three groups. Group 1 consisted of BBTV isolate from Sleman and Yogyakarta city with two fragments DNA of 400 and 388 bp. Group 2 consisted of isolate BBTV from Kulon Progo and Gunung Kidul with three fragments DNA of 400, 388, and 323 bp. Group 3 consisted of isolate from Bantul with two fragments DNA of 723 and 376 bp. Further study on the complete characteristics of these groups is still needed. Penyakit kerdil pisang dapat disebabkan oleh infeksi virus yang berbeda yaitu Banana bunchy top virus(BBTV) atau Abaca bunchy top virus (ABTV). Kedua virus tersebut ditularkan secara persisten oleh kutu daun Pentalonia nigronervosa Coq. Penelitian ini bertujuan untuk mendeteksi dan membedakan virus dengan polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Tanaman terinfeksi dikoleksi dari Yogyakarta (Sleman,Kota Yogyakarta, Bantul, Gunung Kidul, dan Kulon Progo). Metode Phytopure DNA Extraction Kit dan CTAB digunakan untuk mengisolasi DNA total. Primer universal Common DNA region (S-CRF/S-CRR) dan primer spesifik DNA-R BBTV(C1-CRF danCI-CRR) digunakan dalam amplifikasi dengan PCR. Produk PCRBBTV dianalisis dengan teknik RFLP menggunakan enzim restriksi Dra I. Hasil penelitian memperkuat laporan sebelumnya bahwa penyakit kerdil pisang di Yogyakarta disebabkan oleh BBTV, dan belum ditemukan ABTV. Berdasarkan analisis RFLP, BBTV dapat dibedakan menjadi tiga kelompok. Kelompok 1 yaitu BBTV isolat Sleman dan Kota Yogyakarta dengan dua fragmen DNA berukuran sekitar 400 dan 388 bp. Kelompok 2 yaituBBTV isolat Kulon Progo dan Gunung Kidul dengan tiga fragmen DNA berukuran sekitar 400, 388, dan 323 bp. Kelompok 3 yaitu BBTV isolat Bantul dengan dua fragmen DNA berukuran sekitar 723 dan 376 bp. Penelitian tentang karakterisasi dari ketiga kelompok tersebut masih diperlukan.

One of the obstacles that was encountered in the banana cultivation is blood disease. Blood diseases is caused by Ralstonia solanacearum that is subsequently revised to become blood disease bacteria (BDB). Until now the control of banana blood disease is very difficult. Control of banana blood disease with chemical injections and soil treatment is not effective. This study was aimed to obtain Kepok Kuning cultivar banana seedlings which was resistant towards blood disease obtained from in vitro selection by using BDB growing filtrate and induced resistance by inoculation of antagonistic endophytic bacteria.The observation of Kepok Kuning banana explants treated with various concentrations of BDB growing filtrate showed that the percentage of living explants decreased to 83.33% when the BDB growing filtrate concentration increased to 15%. Treatment of banana explants with BDB growing filtrate also affected the number of roots, shoots, and leaves. Treatment with a single antagonistic endophytic bacteria suppressed the intensity of banana blood disease to 0% in comparison with the mixture of antagonistic endophytic bacteria if Kepok Kuning banana explants were not treated with BDB growing filtrate. When Kepok Kuning banana explants were treated with BDB growing filtrate, the intensity of banana blood disease suppressed to 0% after the high concentration of BDB growing filtrate and the antagonistic endophytic bacteria mixture were applied. Salah satu kendala yang dihadapi dalam usaha budidaya pisang adalah adanya penyakit darah. Penyakit darah disebabkan oleh bakteri Ralstonia solanacearumyang selanjutnya direvisimenjadi bakteri darah pisang (Blood Disease Bacteria orBDB). Sampai saat ini pengendalian penyakit darah pisang sangatsukar dilakukan. Pengendalian penyakit darah dengan suntikan bahan kimia dan perlakuan tanah tidak efektif untuk diaplikasikan. Penelitian ini bertujuan untukmendapatkan bibit pisang kultivar Kepok Kuning yang tahan penyakit darah yang diperoleh dariseleksi in vitro dengan menggunakan filtrat pertumbuhan BDB dan induksi ketahanan melalui inokulasi jasad renik endofitik yang bersifat antagonis. Hasil pengamatan terhadap eksplan pisang Kepok Kuning yang diperlakukan dengan berbagai konsentrasi filtrat BDB menunjukkan bahwa pada eksplan yang diperlakukan dengan filtrat pertumbuhan BDB, persentase tumbuhnya akan berkurang hingga 83,33% jika konsentrasifiltrat pertumbuhanBDBmencapai 15%. Selain itu perlakuan planlet pisang dengan filtrat pertumbuhan BDB akan mempengaruhi jumlah akar, tunas, dan daun. Perlakuan dengan jasad renik endofitik antagonis secara tunggal mampu menekan intensitas penyakit darah hingga 0% jika dibandingkan dengan perlakuan campuran apabila sebelumnya eksplan pisang Kepok Kuning tidak diperlakukan dengan filtrat pertumbuhan BDB. Apabila sebelumnya planlet pisangKepokKuning diperlakukan dengan filtrat pertumbuhan BDB maka mampu menekan intensitas penyakit darah hingga 0% jika konsentrasi filtrat pertumbuhanBDBsemakin tinggi dan diperlakuan campuran jasad renik endofitik.

Ralstonia syzygii is one of important pathogens of cloves. This study was aimed at obtaining pure culture of R. syzygi from diseased plant tissue samples. The acterium was isolated from infected clove plantations in Ungaran, Central Java. It had the ability to make clove seedlings show symptoms and then die 41 days after inoculation. The reisolated bacterium also showed its ability to kill clove seedlings after 17 days. The bacterium is gram negative, able to ultilize glucose, sucrose, maltose, mannitol, sorbitol, dulcitol, and glycerol, able to hydrolyze starch, grow well at 27oC, able to catalyze and release water and oxygen from hydrogen peroxyde (H2O2) and aerobically. Ralstonia syzygii merupakan salah satu patogen penting pada tanaman cengkeh. Penelitian ini dilakukan untuk mendapakan isolat murni R syzygii dari jaringan tanaman terinfeksi. Bakteri diisolasi dari pertanaman cengkeh sakit yang berasal dari daerah Ungaran, Jawa Tengah. Bakteri menunjukkan kemampuan untuk menyebabkan bibit tanaman cangkeh sakit dan kemudian mati 41 hsi. Bakteri hasil reisolasi juga menunjukkan kemampuannya menyebabkan sakit dan kematian pada bibit tanaman cengkeh setelah 17 hsi. Bakteri yang diperoleh bersifat gram negatif, mampu memanfaatkan glukosa, sukrosa, maltosa, manitol, sorbitol, dulsitol, dan gliserol, mampu menghidrolisis pati, tumbuh baik pada suhu 27o C, mampu mengkatalisis dan melepaskan air dan oksigen dari hydrogen peroxide (H2O2) dan bersifat aerob.

Response of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) on citrus leaves treated with horticultural and agricultural mineral oil (HMO & AMO) was evaluated under laboratory condition in choice and non-choice trials. Combination of HMO and AMO at concentration of 0 up to 2% was applied to citrus leaves. Mineral oil applications significantly reduced the proportion of D. citri stayed on citrus leaves for feeding with the proposed mechanisms: 1) oils covered leaves thus hampered it for releasing volatile compounds, 2) oil film preventing the direct contact of tarsus or palpus to leaf surfaces, and 3) the volatile compounds produced by mineral oils also blended with plant volatiles in the atmosphere and reduced the probability of olfactory receptors capturing the olfactory cues for locating the feeding site. Mineral oils also increased the mortality of D. citri due to the refusion for feeding on the treated citrus leaves. The effect of AMO was more prominent than HMO. Tanggapan Diaphorina citri Kuwayama (Hemiptera: Psyllidae) pada daun jeruk yang diperlakukan dengan minyak mineral (HMO dan AMO) dievaluasi dengan metode pilihan maupun tanpa pilihan di laboratorium. Kombinasi antara HMO dan AMO pada konsentrasi 0% sampai dengan 2% diaplikasikan pada daun jeruk. Minyak mineral secara nyata menurunkan proporsi D. citri hinggap untuk makan pada daun jeruk, yang mungkin disebabkan oleh mekanisme: 1) minyak melapisi daun sehingga tidak mampu melepaskan senyawa volatil, 2) lapisan minyak menghalangi kontak langsung antara tarsus atau palpus pada permukaan daun, dan 3) senyawa volatil dari minyak bercampur dengan volatil tanaman di udara sehingga menurunkan probabilitas reseptor olfaktori menangkap sinyal penanda lokasi inang. Minyak mineral juga meningkatkan mortalitas, akibat dari penolakan makan pada daun jeruk yang diperlakukan. Pengaruh AMO lebih besar dari pada HMO.

One of the major constraints of banana plantation in Indonesia is the occurrence of fusarium wilt disease caused by Fusarium oxysporum f.sp. cubense. The pathogen produced series of cell wall degradation extracellular enzymes which have important roles in pathogenicity. Many studies have been conducted to know the role of degrading enzyme banana pectin is the major component of cell wall. Many pectinolytic enzymes such as polygalacturonase and others have been isolated from many fungal plant pathogens. The study was aimed to know the role of polygalacturonase towards the virulence of race 4 of F. oxysporum f.sp. cubense. The result showed that from 10 isolates of race 4 of F. oxysporum f.sp. cubense, the most virulent isolate was Lmp1 followed by Srg1, Bgl6, Mln1, Bgl3, A13, Bnt2, Gnk3, Kjg1 dan Wsb5. This was indicated by high and low percentage of wilting leaves of banana cultivar Cavendish when they were inoculated with these isolates. Incubation period varied from 3 to 6 weeks after inoculation SDS-PAGE showed that polygalacturonase, mostly PG1 and PG2, was secreted by these isolates, whereas PG3 was only found in growing cultures of Gnk3 and Wsb5 isolates. Detection of polygalacturonase activity with diffusion agar and reducing sugar methods showed that the activity of polygalacturonase secreted by F. oxysporum f.sp. cubense in the growing culture had no correlation with the virulence of the fungal pathogen. Salah satu kendala utama dalam budidaya pisang di Indonesia adalah gangguan penyakit layu fusarium yang disebabkan oleh jamur Fusarium oxysporum f.sp. cubense. Jamur patogen ini menghasilkan serangkaian enzim ekstraselular pendegradasi dinding sel yang berperan dalam patogenesis. Beberapa penelitian telah dilakukan untuk mengetahui peran enzim yang mendegradasi pektin, yang merupakan komponen penting dinding sel tanaman. Beberapa enzim pektinolitik seperti poligalakturonase dan yang lainnya telah berhasil diisolasi dari berbagai spesies jamur penyebab penyakit tanaman. Penelitian ini bertujuan untuk mengetahui peranan poligalakturonase terhadap virulensi ras 4 F. oxysporum f.sp. cubense. Hasil penelitian menunjukkan bahwa dari 10 isolat F. oxysporum f.sp. cubense, yang mempunyai virulensi tertinggi hingga yang terendah berturut-turut adalah Lmp1, Srg1, Bgl6, Mln1, Bgl3, A13, Bnt2, Gnk3, Kjg1 dan Wsb5. Hal ini ditunjukkan dengan tinggi-rendahnya nilai persentase daun layu yang ditimbulkan oleh isolat-isolat tersebut pada bibit pisang kultivar Cavendish. Masa inkubasi bervariasi dari 3 hingga 6 minggu setelah inokulasi. Uji SDS-PAGE menunjukkan bahwa pada filtrat pertumbuhan isolat jamur-jamur patogen ini disekresikan poligalakturonase (PG) terutama PG1 dan PG2, sedangkan PG3 hanya dijumpai pada filtrat pertumbuhan isolat Gnk3 dan Wsb5. Adapun hasil deteksi aktivitas poligalakturonase dengan metode difusi agar serta gula reduksi menunjukkan bahwa aktivitas poligalakturonase yang disekresikan oleh F. oxysporum f.sp. cubense di dalam filtrat pertumbuhannya tidak berhubungan dengan virulensi jamur patogen tersebut.

Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is the vector of citrus greening (Huanglongbing) bacterium and the most serious impediment to citrus culture. Classical biological control of this psyllid vector should contribute to suppress their population. This research was conducted to determine the performance of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae) when they were fed with D. citri. The larval performance index of M. sexmaculatus on D. citri compared with Aphis craccivora Koch (Hemiptera: Aphididae) diet was 1.3.M. sexmaculatus fed with D. citri had lower fitness than those fed with A. craccivora as shown by longer larval stadium, lower adult dry weight, less number of egg produced and lower percentage of egg hatched. M. sexmaculatus grew best at the temperature of 27oC. Employing the exclusion procedure under field condition,M. sexmaculatus could reduce the population of D. citri up to 90%. These findings showed that theM. sexmaculatus could be a potential predator in reducing D. citri, particularly when the more preferred prey A. craccivora was not present. Diaphorina citri Kuwayama (Hemiptera: Psyllidae) merupakan kelompok Psyllid yang menularkan penyebab penyakit Huanglongbing yang sangat berbahaya pada tanaman jeruk. Pengendalian hayati klasik telah banyak memberikan kontribusi dalam pengendalian di lapangan. Penelitian ini dilakukan untuk melihat penampilan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae) dengan pakan D. citri. Indeks penampilan larva M. sexmaculatus dengan pakan D. citri dibandingkan dengan Aphis craccivora Koch (Hemiptera: Aphididae) adalah 1,3. M. sexmaculatus yang diberi pakan D. citri menunjukkan penurunan kebugaran dibandingkan jika diberi pakan A. craccivora seperti yang ditunjukkan dengan stadium larva lebih lama, penurunan berat kering serangga dewasa, telur yang dihasilkan lebih sedikit, dan penurunan jumlah telur yang menetas. Menggunakan metode eksklusi pada kondisi lapangan, M. sexmaculatus mampu menurunkan populasi D. citri sampai 90%. M. sexmaculatus berkembang baik pada suhu 27oC. Hasil penelitian ini menunjukkan bahwa M. sexmaculatus berpotensi untuk menurunkan populasi D. citri, terutama jika inang utamanya A. craccivora tidak ditemukan.

Patchouli mottle virus (PatMoV) is the most severe disease pathogen and causes substantial losses in many patchouli-producing regions in Indonesia. Serological detection tool for the disease was developed in this research. Virus isolation was conducted on Chenopodium amaraticolor resulted on the homogenous local lesions 6 days after inoculation. Virus purification was obtained from 200g inoculated leaves resulted on 2 ml virus solution with the concentration of 1 mg/ml. Polyclonal antibodies were produced on rabbits. Harvested antiserum was used for further virus detection by Indirect-Enzyme linked Immunosorbent assay (I-ELISA) and dot-immunobanding assay (DIBA) techniques. The antibodies were positively reacted with purified viruses, infected field collection of patchouli, and inoculated C. amaranticolor. On the other hand un-inoculated C. amaranticolor samples and healthy patchouli generated from tissue cultures gave negative reaction with the antibodies. This is the first report of cheap practical antibody production for PatMoV detection in Indonesia.

A research on the pathogenicity of Xanthomonas campestris pv. citri, the causal agent of citrus canker, has been carried out to study the growth characteristics of the pathogen on some media, physiological characteristics, and the role of extracellular protein on the bacterial pathogenicity. Extracellular protein of X. campestris pv. citri was extracted using ammonium sulfate precipitation. The extracted protein samples were electrophoresed on 10% polyacrilamide gel in the presence of sodium dodecyl sulfate at 15 mA/150 V for 1.5-2 hrs. Pathogenicity assay was conducted by infiltration of bacterial cell and extracellular protein suspension into citrus leaf tissues. The results showed that X. campestris pv. citri was able to grow well on all media. It possess specific protein with molecular weight of 25.71 KDa. Bacterial cell and extracellular protein of X. campestris pv. citri were able to produce typical symptoms of canker, while other closely related Xanthomonas campestris pathovars were only able to produce hypersensitive reaction on citrus leaves.

Coconut isolate of Phytophthora palmivora DNA was extracted from sporangium and mycelium using SDS and Proteinase-K method. Sporangium and mycelium were harvested from liquid and solid culture of Potato Dextrose medium. The result of the study showed that the DNA extracted from sporangium and mycelium of 8 days solid culture was seen as distinct band. On the other hand, the dNA from sporangium and mycelium of 24 days old liquid culture was fragmented with smear band appearance. Key words: DNA, Phytophthora palmivora

Purple blotch disease caused by Alternaria porri (Ell.) Cif. is one of the most important diseases on shallots. The farmers have been using fungicides as a reliable control method, however, the chemical control method has to be considered for the negative effect on the environment and the danger to the other species and causes the resistance to a certain pesticide. Therefore, it is important to develop other method that is safe, effective, and efficient, like the use of climatic data to decide the control strategy. The result of the study on ecology of purple blotch disease carried out at the experimental station in Kramat-Tegal, Kledung-Temanggung, and KP4 Kalitirto in dry and rainy season (1991/1992) suggested that climatic factors played on important role on the daily conidium dissemination of Alternaria porri and on the intensity of purple blotch disease. Daily conidium dissemination which was one of the important component in the epidemy of purple blotch disease was influenced by the temperature, relative humidity, and the wind velocity. Conidium dissemination was occurred both during the day and night and at 10.00 am-14.00 pm when the air temperature and wind velocity were high with low relative humidity, conidium dissemination was maximum. On the other hand, at 22.00 pm – 02.00 am there was minimum conidium dissemination. The result on the effects of leaf wetness period on disease intensity suggested that high humidity was not the only factor caused disease infection but it has to be supported by the presence of thin film water on the leaf surface at least for 4 hours since the attachment of the conidia on the leaves. Key words: purple blotch, climatic factor, Alternaria porri, shallot