Cucurbit yellow stunting disorder virus (CYSDV), has recently been detected in different crops in India, including cucumber, bitter gourd, and watermelon. To investigate the distribution of emerging criniviruses, symptomatic round melon and wild melon plants were analyzed through transmission electron microscopy and RT-PCR. Long filamentous virions ( 850 nm in length) resembling criniviruses and 550 bp amplicons of RdRp gene specific to the genus Crinivirus were observed. The phylogeny using coat protein gene amino acid sequences of different criniviruses revealed grouping of round melon and wild melon isolates of this study with CYSDV isolates originating from Mexico. These isolates exhibited up to 100

The complete nucleotide sequence and genome organization of soybean yellow mottle mosaic virus severe strain causing bright yellow mosaic, mottling and puckering symptoms in soybean (Glycine max) from India was determined. The monopartite single stranded genomic RNA is 3974 nuclotides long and has the potential to encode six viral proteins viz., p25, p83, p8, p10, p39 and p25. The SYMMV-Sb isolate differed from mungbean strain with 69 nucleotides and nine aminoacids dispersed over the various ORFs. Comparative sequence analysis revealed that SYMMV-Sb shared 98% nt sequence identity at complete genome level and 96–100% at all ORFs level with SYMMV mungbean strain from India and 71–92% identity with SYMMV Korean soybean isolate, whereas it showed very low sequence identity with other tombusviridae members (2–53%). The phylogenetic analysis showed the clustering of SYMMV-Sb along with other members of genus Gammacarmovirus. The SYMMV-Sb isolate produced chlorotic blotches, mild and veinal mottling, necrosis and puckering symptoms in various leguminous host plants. The symptomatalogy of the soybean isolate was differed from mungbean strain as earlier induced severe symptoms on soybean and mild symptoms on mungbean.

Symptoms like bright yellowing, puckering of the leaf, vein banding, and vein thickening were observed on different cucurbit hosts at the experimental farm of Indian Agricultural Research Institute, New Delhi during Kharif 2019. Leaf-dip electron microscopy of the symptomatic leaves revealed the association of isometric virus particles measuring ~ 25 nm with bitter gourd and cucumber samples. The RT-PCR assay using polerovirus generic primers covering the partial RdRp, intergenic region, and partial CP region was resulted the amplicons of ~ 1.1 kb. Subsequent cloning, sequencing, and sequence analysis revealed the association of cucurbit aphid-borne yellows virus (CABYV) with bitter gourd (Momordica charantia) and cucumber (Cucumis sativus) plants. These results constitute the first report of CABYV infection on cucumber plants from India.

Thrips palmi is an important insect pest of vegetables and ornamental crops worldwide. Besides direct damage caused by feeding, it transmits several tospoviruses in a persistent-propagative manner. Eggs of T. palmi are microscopic and embedded within plant tissue by the sharp ovipositor of adult female. In the present study, an artificial oviposition setup has been standardized for T. palmi. Eggs of T. palmi were harvested in sterile water between two thin membranes. The developmental stages of T. palmi embryo were studied starting from oviposition up to hatching by inverted and confocal reflection microscopy. Energids were homogeneously distributed at an early stage of development. The anterior end of the egg curved with a constriction post 38 h. Initiation of tissue organization, mouthparts, appendages, compound eyes were observed at different time points. Appendages were well developed and segmentation was prominent post 70 h. The embryo was completely developed at around 80 h and hatched by 86 h post oviposition at 28 degrees C temperature. The study first time reports the embryonic development of T. palmi that would be helpful in detailed investigations of thrips developmental biology and evolution.

Culturing insect cells in vitro has witnessed remarkable growth in the past decades. Over 600 cell lines of dipteran, hemipteran, and lepidopteran insects have been reported so far. Besides its wide adoption for the production of recombinant proteins, viral pesticides, and vaccines, insect cell culture is increasingly being used as a tool for basic research in genetics, molecular biology, biochemistry, and virology. Since its first application in plant virus studies in 1956, insect cell culture has become an indispensable tool to study the complex and intimate interactions of plant viruses and their insect vectors. The in vitro cell cultures of several insect vectors of plant viruses including leafhoppers, planthoppers, aphids, thrips, and whiteflies have been successfully employed to understand the functions of viral proteins and receptor-mediated endocytosis into vector cells. This review summarizes the development of novel media and insect cell culture systems and their applications in plant virus research.

Cucumber mosaic virus (CMV) has been recorded worldwide, infecting more than 1200 plant species including weeds. In this study, 23 samples of bell pepper, squash, tomato, ornamental (calla lily, French hydrangea, spider lily) and weeds (Arrowleaf dock, Spanish needle) hosts originating from Himachal Pradesh were examined. 20 of 23 samples were identified CMV positive based on electron microscopy, bio-assay, RT-PCR assay and sequence analyses of coat protein (CP) gene. The CMV-CP gene sequences from eight isolates cloned and sequenced in this study shared 96–100% amino acid sequence identities with CMV Subgroup I isolates. This study forms the first report of the natural occurrence of CMV on squash and a weed host, Arrowleaf dock (Rumex hastatus), in India as well as the occurrence of CMV Subgroup I in the cooler hilly regions of India. These findings suggest the expansion of the host range as well as ecological niche of CMV.

HomePlant DiseaseVol. 104, No. 11First Report of Natural Infection by Capsicum Chlorosis Virus on Amaryllis (Hippeastrum hybridum) Plants from India PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Natural Infection by Capsicum Chlorosis Virus on Amaryllis (Hippeastrum hybridum) Plants from IndiaY. B. Basavaraj, Jyoti Siwach, Ashwini Kumar, Ajay Bhattarai, Nayeem Qayoom, Virendra Kumar Baranwal, and Rakesh Kumar JainY. B. Basavaraj†Corresponding author: Y. B. Basavaraj; E-mail Address: rajayb@gmail.comhttp://orcid.org/0000-0002-9216-877XAdvanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author, Jyoti SiwachAdvanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author, Ashwini KumarAdvanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author, Ajay BhattaraiAdvanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author, Nayeem QayoomAdvanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author, Virendra Kumar Baranwalhttp://orcid.org/0000-0002-5251-0905Advanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author, and Rakesh Kumar Jainhttp://orcid.org/0000-0002-5074-8661Advanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, IndiaSearch for more papers by this author AffiliationsAuthors and Affiliations Y. B. Basavaraj † Jyoti Siwach Ashwini Kumar Ajay Bhattarai Nayeem Qayoom Virendra Kumar Baranwal Rakesh Kumar Jain Advanced Centre for Plant Virology (ACPV), Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110 012, India Published Online:17 Sep 2020https://doi.org/10.1094/PDIS-03-20-0537-PDNAboutSectionsView articlePDFPDF PlusSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleCapsicum chlorosis virus (CaCV) is a member of the genus Orthotospovirus, family Tospoviridae (Abudurexiti et al. 2019). In India, it was first identified on tomato (Kunkalikar et al. 2007) and thereafter on several other hosts belonging to different families (Basavaraj et al. 2017). Amaryllis or red trumpet lily (Hippeastrum hybridum Hort.; family Amaryllidaceae) is an ornamental plant being grown in the high ranges of the Western Ghats of India. In 2017 to 2018, chlorotic and necrotic ringspots rimmed by dark red margins, necrotic streaks, and sunken patches resembling the symptoms of tospovirus infection were observed on the leaves of amaryllis plants grown at the Indian Agricultural Research Institute, New Delhi, with an incidence of up to 36% (n = 18) out of 50 plants observed. In transmission electron microscopy, the symptomatic leaves revealed the presence of quasi-spherical virus-like particles measuring 80 to 120 nm in diameter. Direct antigen-coating enzyme-linked immunosorbent assay (ELISA) was performed using sap extracted from selected symptomatic (n = 11) and asymptomatic (n = 2) plants using the in-house raised polyclonal antibodies (pAb) to groundnut bud necrosis virus (GBNV) (Jain et al. 2005) and commercially available pAbs (Agdia, Elkhart, IN) to impatiens necrotic spot virus, iris yellow spot virus, and tomato spotted wilt virus. pAbs to the N protein of GBNV and watermelon silver mottle virus are known to react with GBNV, watermelon bud necrosis virus, and CaCV (Mandal et al. 2012). Thus, four symptomatic samples showed mild positive reactions with the pAbs to GBNV (with A405 0.86 to 1.12), suggesting the association of a tospovirus antigenically related to the serogroup IV. Bioassay was done with the sap from ELISA-positive plants by mechanical transmission to amaryllis and cowpea (Vigna unguiculata cv. Pusa Komal) seedlings. Cowpea plants exhibited concentric chlorotic lesions followed by necrotic lesions at 5 to 7 days postinoculation, whereas the amaryllis plants exhibited symptoms as described above. To confirm the association of tospovirus species, total RNA was isolated from symptomatic leaves of amaryllis and cowpea plants using a PureLink RNA Mini Kit (Invitrogen, Carlsbad, CA). The isolated RNA (400 ng per 25-µl reaction) was subjected to cDNA synthesis using an IMPROM-II Reverse Transcription system (Promega, Madison, WI). The cDNA (2.0 µl per 25-µl reaction) was further subjected to RT-PCR with the generic primers of tospovirus (F, 5′-CCTTTAACAGTDGAAACAT-3′; R, 5′-CATDGCRCAAGARTGRTARACAGA-3′) (Chu et al. 2001) corresponding to a part of the L-RNA of tospoviruses (∼800 bp) using GoTaq Flexi DNA polymerase (Promega). Amplicons of the expected size of ∼880 bp were obtained from all four samples, cloned into the pGEM-T Easy Vector (Promega), and sequenced. The sequence (MT006242; 816 bp) showed up to 98 and 100% identities at nucleotide (nt) and deduced amino acid (aa) with the L-RNA sequence (KX108865) of the CaCV isolate of groundnut from Thailand. For further confirmation, the RT-PCR was performed using specific primers derived from the complete nucleocapsid (N) gene (828 bp) of CaCV (CaCV-BYB-F, 5′-ATGTCTAMCGTYAGGCAAC-3′; CaCV-BYB-R, 5′-TYACACYTCWATAGAWGTACTAG-3′), which resulted in the amplicons of ∼800 bp from the ELISA-positive samples (n = 4). The gel-purified amplicons were cloned and sequenced. The sequence (MT018563; 828 bp) showed 97% (nt) and 99% (aa) identities with the N gene sequence of CaCV isolate (KX757228) from Iran. These results confirmed infection by CaCV on amaryllis plants. Infection of amaryllis plants by CaCV was previously reported in Taiwan (Chen et al. 2009). To the best of our knowledge, this is the first report of CaCV infection on amaryllis or red trumpet lily in India. However, CaCV is known to infect other hosts that belong to the families Amaranthaceae, Apocynaceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, and Solanaceae in India (Basavaraj et al. 2017). This finding will help in understanding the expanded host range of CaCV.The author(s) declare no conflict of interest.References:Abudurexiti, A., et al. 2019. Arch. Virol. 164:1949. https://doi.org/10.1007/s00705-019-04253-6 Crossref, ISI, Google ScholarBasavaraj, et al. 2017. Page 445 in: A Century of Plant Virology in India. Springer, Singapore. https://doi.org/10.1007/978-981-10-5672-7_20 Crossref, Google ScholarChen, C. C., et al. 2009. Plant Dis. 93:1346. https://doi.org/10.1094/PDIS-93-12-1346A Link, ISI, Google ScholarChu, F. H., et al. 2001. Phytopathology 91:361. https://doi.org/10.1094/PHYTO.2001.91.4.361 Link, ISI, Google ScholarJain, R. K., et al. 2005. J. Virol. Methods 130:162. https://doi.org/10.1016/j.jviromet.2005.06.018 Crossref, ISI, Google ScholarKunkalikar, S. R., et al. 2007. Plant Health Prog. 8:37. https://doi.org/10.1094/PHP-2007-1204-01-BR Link, Google ScholarMandal, B., et al. 2012. Plant Dis. 96:468. https://doi.org/10.1094/PDIS-06-11-0520 Link, ISI, Google ScholarThe author(s) declare no conflict of interest.Funding: Funding was provided by ICAR-Indian Agricultural Research Institute.DetailsFiguresLiterature CitedRelated Vol. 104, No. 11 November 2020SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionPlants of Echinacea purpurea affected by Verticillium dahliae (A. Garibaldi et al.). Photo credit: M. L. Gullino. Spinach plant infected with Stemphylium leaf spot (K. A. Spawton et al.). Photo credit: M. T. McGrath. Metrics Downloaded 657 times Article History Issue Date: 30 Oct 2020Published: 17 Sep 2020First Look: 5 Jun 2020Accepted: 1 Jun 2020 Pages: 3086-3086 Information© 2020 The American Phytopathological SocietyFundingICAR-Indian Agricultural Research InstituteKeywordsAmarylliscapsicum chlorosis virusHippeastrum hybridumhost expansionnew host of CaCVornamental plantred trumpet lilyThe author(s) declare no conflict of interest.Cited ByFirst report of natural infection by two potyviruses on amaryllis (Hippeastrum hybridum) plants from India30 September 2021 | VirusDisease, Vol. 104Tospovirus Diseases of Ornamental Plants: Characterization, Identification, Diagnosis and Management14 November 2021

Sugarcane yellow leaf virus (SCYLV) is a distinct member of the Polerovirus genus of the Luteoviridae family. SCYLV is the major limitation to sugarcane production worldwide and presently occurring in most of the sugarcane growing countries. SCYLV having high genetic diversity within the species and presently ten genotypes are known to occur based on the complete genome sequence information. SCYLV is present in almost all the states of India where sugarcane is grown. Virion comprises of 180 coat protein units and are 24-29 nm in diameter. The genome of SCYLV is a monopartite and comprised of single-stranded (ss) positive-sense (+) linear RNA of about 6 kb in size. Virus genome consists of six open reading frames (ORFs) that are expressed by sub-genomic RNAs. The SCYLV is phloem-limited and transmitted by sugarcane aphid Melanaphis sacchari in a circulative and non-propagative manner. The other aphid species namely, Ceratovacuna lanigera, Rhopalosiphum rufiabdominalis, and R. maidis also been reported to transmit the virus. The virus is not transmitted mechanically, therefore, its transmission by M. sacchari has been studied in different countries. SCYLV has a limited natural host range and mainly infect sugarcane (Sachharum hybrid), grain sorghum (Sorghum bicolor), and Columbus grass (Sorghum almum). Recent insights in the protein-protein interactions of Polerovirus through protein interaction reporter (PIR) technology enable us to understand viral encoded proteins during virus replication, assembly, plant defence mechanism, short and long-distance travel of the virus. This review presents the recent understandings on virus biology, diagnosis, genetic diversity, virus-vector and host-virus interactions and conventional and next generation management approaches.

Background To date, four thrips vectors have been reported to transmit five different tospoviruses in India. Their identification at an early stage is crucial in formulating appropriate pest management strategies. Since morphometric key-based thrips identification based on the adult stage is time-consuming, there is a need to develop diagnostic tools which are rapid, accurate, and independent of developmental stages. Here, we report a multiplex PCR assay to identify four major thrips vectors viz. Thrips palmi, T. tabaci, Scirtothrips dorsalis, and Frankliniella schultzei present in India. Results Cytochrome oxidase subunit III and internal transcribed spacer region 2 were utilized to design species-specific primers. Of 38 pairs of primers tested, primer pairs AG35F-AG36R, AG47F-AG48R, AG87F-AG88R, and AG79F-AG80R amplified 568 bp, 713 bp, 388 bp, and 200 bp products from the DNA templates of T. palmi, S. dorsalis, T. tabaci, and F. schultzei, respectively at same PCR conditions. The specificity of the primer pairs was validated with a large number of known specimens and no cross-reactivity was observed with other thrips species. The multiplex PCR assay with a cocktail of all the four primer pairs detected four thrips vectors efficiently and could discriminate all of them concurrently in a single reaction. Conclusion The multiplex PCR reported in this study could identify the major thrips vectors reported in India. The assay will be useful in ascertaining distribution profile of major thrips vectors, disease epidemiology, screening large samples, and quarantine.

Tilletia indica is an internationally quarantined fungal pathogen causing Karnal bunt of wheat. The present study carried out that the whole genome of T. indica was sequenced and identified transposable elements, pathogenicity-related genes using a comparative genomics approach. The T . indica genome assembly size of 33.7 MB was generated using Illumina and Pac Bio platforms with GC content of 55.0%. A total of 1737 scaffolds were obtained with N 50 of 58,667 bp. The ab initio gene prediction was performed using Ustilago maydis as the reference species. A total number of 10,113 genes were predicted with an average gene size of 1945 bp out of which functionally annotated genes were 7262. A total number of 3216 protein-coding genes were assigned in different categories. Out of a total number of 1877 transposable elements, gypsy had the highest count (573). Total 5772 simple sequence repeats were identified in the genome assembly, and the most abundant simple sequence repeat type was trinucleotide having 42% of total SSRs. The comparative genome analysis suggested 3751 proteins of T . indica had orthologs in five fungi, whereas 126 proteins were unique to T . indica . Secretome analysis revealed the presence of 1014 secretory proteins and few carbohydrate-active enzymes in the genome. Some putative candidate pathogenicity-related genes were identified in the genome. The whole genome of T . indica will provide a window to understand the pathogenesis mechanism, fungal life cycle, survival of teliospores, and novel strategies for management of Karnal bunt disease of wheat.

Melon thrips ( Thrips palmi ) is the principal insect pest of vegetable and ornamental plants worldwide. In addition to inflicting feeding injuries on host plants, they act as vectors of economically damaging tospoviruses. Application of insecticides and host plant resistance has proven largely ineffective in the management of T. palmi . However, increasingly, genetic knowledge is being successfully utilized to manage insect pests. A number of recent studies have enriched the genetic database of T. palmi . In this review, we report on genetics of T . palmi for species identification and to study its populations structure. For example, a DNA polymorphism analysis of global T. palmi populations has revealed the existence of 29 haplotypes. The T. palmi population can be divided into three lineages based on phylogenetic analysis. A high maximum intraspecific distance is indicative of cryptic species within T. palmi populations. Regarding climate adaptability, the upregulation of trehalose biosynthesis genes, and genes encoding several heat-shock proteins is expected to enable T. palmi thermal adaptation to both cold and hot conditions. Genetics of T . palmi has shown that resistance to conventional insecticides like cypermethrin appears to be linked to mutations in the sodium channel. On the other hand, resistance to imidacloprid appears to be a result of cytochrome P450-mediated detoxification. T . palmi genes potentially involved in tospovirus transmission are also reviewed and new molecular tools for genetic study presented. Molecular modeling and docking analyses of groundnut bud necrosis virus glycoprotein demonstrated protein–protein interactions with T. palmi vacuolar ATP synthase E subunit, cathepsin, clathrin, adaptor protein 2, and enolase. Overall, a better knowledge of T. palmi genes will assist elucidation of thrips identification, means of adaptation in diverse ecological niches, mechanisms of insecticide resistance, and transmission of plant viruses. This data will be an invaluable tool for integrated thrips management.

The first draft genome sequence of the pearl millet blast pathogen Magnaporthe grisea PMg_Dl from India is presented. The genome information of M. grisea will be useful to understand the Magnaporthe speciation, genetic diversity, environmental adaptation, and pathogenic and host range determinants.

Among 10 proteins encoded by Papaya ringspot virus (PRSV), only coat protein (CP) has been studied extensively from mainly the papaya-originated isolates i.e. PRSV-P. In this study, besides CP, the helper component proteinase (HC-pro) and nuclear inclusion protein-a (NIa-pro) coding regions from 19 PRSV-P and -W isolates originating from different geo-climatic locations and hosts were analyzed. Unlike CP, both HC-pro and NIa-pro did not reveal the variability in their length. HC-pro and NIa-pro sequences revealed less than 10% deduced amino acid (daa) diversity worldwide, the CP was found highly variable (up to 20% daa diversity). Highest variability in CP sequence was noticed among the cucurbit-originating PRSV-P Indian isolates, especially from Warm semi-arid climate, which was attributed to a large number of aa insertions/deletions. However, papaya-originating PRSV-P isolates from the Oceanic climate were less variable (up to 5% daa diversity). In NIa-pro, besides already known host/pathotype-specific switching of aa Lys/Asp27, switching of Lys27 → Arg27 and Asp27 → Glu27 was identified within P and W pathotypes. Additionally, a novel aa switching from Ser/Met134 → Thr134 between P and W pathotypes respectively was identified. The phylogeny of PRSV isolates was largely based on the geo-climatic locations and hosts. Through recombination detection analysis, three recombinant isolates were detected based on both NIa-pro and CP sequences, which possessed cucurbit-originated PRSV (either -P or -W) isolates as one of their parents (either major or minor.) Patterns of codon usage among the three protein coding sequences generated further revealed that the CP gene is under maximum selection pressure (with six sites) followed by NIa-pro gene (with one site). This investigation shows that the genetic recombination between the isolates originating from different hosts and geo-climatic locations as well as mutations are the significant mechanisms playing their role in generating diverse populations of PRSV.

Plant virus-based vectors provide attractive and valuable tools for rapid production of recombinant protein in large quantities as they produce systemic infections in differentiated plant tissues. In the present study, we engineered the Soybean yellow mottle mosaic virus (SYMMV) as a gene expression vector which is a promising candidate for systemic expression of foreign proteins in French bean plants. Full virus vector strategy was exploited for insertion of foreign gene by inserting MCS through PCR in the circular pJET-SYMMV clone. To examine the ability of the SYMMV vector system, GFP gene was cloned after the start codon of coat protein (CP) so that its expression was driven by the SYMMV-CP subgenomic promoter. When in vitro run off SYMMV-GFP transcript was mechanically inoculated to French bean leaves, good level of GFP expression was observed through confocal microscopy up to 40 dpi. Expression of heterologous protein was also confirmed through ISEM, DAC-ELISA and RT-PCR with specific primers at 20 dpi. The recombinant SYMMV construct was stable in in vitro runoff transcript inoculated plants but the inserted GFP was lost in progeny virion inoculated plants. The system developed here will be useful for further studies of SYMMV gene functions and exploitation of SYMMV as a gene expression vector.

Necrosis disease incited by tobacco streak virus (TSV) causes significant yield losses in sunflower in the tropics and sub-tropics. Genetic engineering of sunflower through deployment of the coat protein gene of TSV (TSV-CP) was attempted along with neomycin phosphotransferase gene (nptII) for selection of putative transformants on kanamycin. Split cotyledons from decoated mature seeds were used as target tissues for Agrobacterium tumefaciens-mediated transformation and putative transformed shoots were obtained with an average frequency of 3.3%. Presence of the introduced transgene was identified by PCR; expression was determined through RT-PCR, northern blot analysis and quantitative Real-time PCR (qRT-PCR); stable integration was ascertained through Southern blot analysis of plants in T0 to T4 generations. Out of 102 positive T0 events, 20 events were carried to T1 generation from which five events (CP-S-237, CP-S-247, CP-S-481, CP-S-648 and CP-S-753) were advanced till T4 generation. Challenge inoculations of plants of event No 481 showed resistance to necrosis disease and plants grew to maturity in TSV-CP transgenics while control plants (untransformed) showed mortality within 1–2 weeks following inoculation. Expression analysis of the TSV-CP and nptII genes in different tissues at flowering and seed setting stages revealed constitutive expression of the transgene till seed maturation. One event (No 481) was selected for transfer of the TSV-CP gene into agronomically superior genotypes.

The genome of Ralstonia solanacearum CaRs_Mep, a race 4/biovar 3/phylotype I bacterium causing wilt in small cardamom and other Zingiberaceae plants, was sequenced. Analysis of the 5.7-Mb genome sequence will aid in better understanding of the genetic determinants of host range, host jump, survival, pathogenicity, and virulence of race 4 of R. solanacearum.

The whole-genome assembly of a unique rice isolate from India, Magnaporthe oryzae RMg-Dl that causes blast disease in diverse cereal crops is presented. Analysis of the 34.82 Mb genome sequence will aid in better understanding the genetic determinants of host range, host jump, survival, pathogenicity, and virulence factors of M. oryzae.

Nucleotide sequence of a distinct soybean yellow mottle mosaic virusisolate from Vignaradiata (mungbean isolate, SYMMV-Mb) from India was determined and compared with othermembers of the family Tombusviridae. The complete monopartite single-stranded RNA genome of SYMMV-Mb consisted of 3974nt with six putative open reading frames and includes 5' and 3' untranslated regions of 35 and 254nt, respectively. SYMMV-Mb genome shared 75% nt sequence identity at complete genome level and 67-92% identity at all ORFs level with SYMMV Korean and USA isolates (soybean isolates) followed by CPMoV, whereas it shared very low identity with other tombusviridae members (5-41%). A full-length infectious cDNA clone of the SYMMV-Mb placed under the control of the T7 RNA polymerase and the CaMV35S promoters was generated and French bean plants on mechanical inoculation with in vitro RNA transcripts, p35SSYMMV-O4 plasmid and agroinoculation with p35SSYMMV-O4 showed symptoms typical of SYMMV-Mb infection. The infection was confirmed by DAC-ELISA, ISEM, RT-PCR and mechanical transmission to new plant species. Further testing of different plant species with agroinoculation of p35SSYMMV-O4 showed delay in symptoms but indistinguishable from mechanical sap inoculation and the infection was confirmed by DAC-ELISA, RT-PCR and mechanical transmission to new plants. The system developed here will be useful for further studies on pathogenecity, viral gene functions, plant-virus-vector interactions of SYMMV-Mb and to utilize it as a gene expression and silencing vector.