Kyuri Green Mottle Mosaic Virus Research Articles

Kyuri green mottle mosaic virus detected for the first time in Turkey

Turkey is among the top 10 producers of cucumber, melon, watermelon, and squash in the world. Lately, seed-borne viruses have become a major issue in greenhouse and field-grown cucurbits. In this study, the incidence of kyuri green mottle mosaic virus (KGMMV) was determined in seeds from various species (cucumber, melon, watermelon, summer squash, bottle gourd, winter squash) of Cucurbitaceae. KGMMV detection in a total of 20 seed lots of each cucurbit species was done by enzyme-linked immunosorbent assay (ELISA) and RT-PCR. The highest virus incidence was 45% in melon followed by 25% in cucumber and 10% in squash. To the best of our knowledge, this is the first report of KGMMV in cucurbit crops in Turkey and this highlights the potential risk of KGMMV to commercial cucurbit seed lots.

Evolution of cucurbit-infecting tobamoviruses: Recombination and codon usage bias

Currently, there are seven cucurbit-infecting tobamoviruses comprising cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), cucumber fruit mottle mosaic virus (CFMMV), zucchini green mottle mosaic virus (ZGMMV), cucumber mottle virus (CMoV), watermelon green mottle mosaic virus (WGMMV), and Trichosanthes mottle mosaic virus (TrMMV). To gain more insights into their evolution, recombination analyses were conducted. Four CGMMV isolates and one KGMMV isolate were suggested to be recombinants. And there was an interspecies recombination event between CGMMV and ZGMMV. Phylogenetic incongruence was also observed for CGMMV and KGMMV. A probable ancestral pattern was inferred for the gene junction region between RdRp and MP. Codon usage bias analysis revealed that the viral genes had additional influence independent of compositional constraint. In codon preference, the seven viruses were both similar to and different from the host cucumber (Cucumis sativus). Moreover, the viruses were not deficient in CpG and UpA dinucleotides.

First Report of Natural Infection of Siraitia grosvenorii by Cucumber Green Mottle Mosaic Virus in China

Fruit of Siraitia grosvenorii (family Cucurbitaceae) are used as a sweetener in beverage and traditional herbal medicine production in China. Some viruses have been known to infect S. grosvenorii, such as papaya ringspot virus (PRSV), watermelon mosaic virus (WMV), and zucchini yellow mosaic virus (ZYMV) (Cai et al. 2001; Liao et al. 2005; Qin et al. 2005). In August 2017, six S. grosvenorii samples (nos. LHG-1 to LHG-6) that showed mosaic, chlorosis, and mottling of leaves were collected from Yongfu, Guangxi province, China. All symptomatic samples were tested by enzyme-linked immunosorbent assay (ELISA) in double antibody sandwich format for 10 known cucurbit-infecting viruses, including cucumber green mottle mosaic virus (CGMMV), cucumber mosaic virus, kyuri green mottle mosaic virus, PRSV, squash mosaic virus, tobacco mosaic virus (TMV), watermelon silver mottle virus, WMV, zucchini green mottle mosaic virus, and ZYMV. The sample LHG-1 with chlorosis and mottle symptoms reacted positively against the antisera of CGMMV and TMV (Adgen, U.K.) but negatively against antisera of the other viruses. The other samples were negative in ELISA for all viruses tested. Total RNA was extracted from the LHG-1 sample using TRIzol reagent (Takara Dalian, China) following the manufacturer’s instructions. Reverse transcription polymerase chain reaction (RT-PCR) assays using CGMMV-specific primer pair CGM1/CGM2 (Huang et al. 2007) and TMV-specific primers (Li et al. 2000) showed a positive RT-PCR product of the expected size (650 bp) for CGMMV but not for TMV. The amplicon was further cloned into pMD-18-T vector (Takara Dalian) and sequenced (GenBank accession no. MK858182). Sequence analysis revealed that the RT-PCR product showed 99% nucleotide identity to the sequences of CGMMV isolates available in GenBank (accession nos. HM008919, KY753928, KX883833, KP868654, KM873786, and MH271443). The virus in LHG-1 was therefore identified as an isolate of CGMMV and named as CGMMV-LHG. Additionally, to confirm the infectivity of CGMMV-LHG, leaf sap extract in phosphate buffer (0.1 M, pH 7.0) of LHG-1 was mechanically inoculated on leaves of S. grosvenorii and Lagenaria siceraria seedlings. Ten days after inoculation, S. grosvenorii produced symptoms similar to the diseased plants in the field, and systemic mosaic and vein-banding were observed on L. siceraria. The control seedlings inoculated with phosphate buffer remained symptomless. Presence of CGMMV in inoculated plants was confirmed by RT-PCR. To the best of our knowledge, this is the first report of CGMMV infection on S. grosvenorii under natural conditions. The virus can be transmitted by seeds, infects various cucurbit species, and causes yield losses all over the world (Liu et al. 2014; Wu et al. 2011). Use of virus-free seeds and seedlings will be helpful to control CGMMV in S. grosvenorii production areas.

Characterisation and diagnosis of frangipani mosaic virus from India

Frangipani mosaic virus (FrMV) is known to infect frangipani tree (Plumeria rubra f. acutifolia) in India but the virus has not been characterized at genomic level and diagnosis is not available. In the present study, an isolate of FrMV (FrMV-Ind-1) showing greenish mosaic and vein-banding symptoms in P. rubra f. acutifolia in New Delhi was characterized based on host reactions, serology and genome sequence. The virus isolate induced local symptoms on several new experimental host species: Capsicum annuum (chilli), Nicotiana benthamiana, Solanum lycopersicum and S. melongena. N. benthamiana could be used as an efficient propagation host as it developed systemic mottle mosaic symptoms all round the year. The genome of FrMV-Ind-1 was 6643 (JN555602) nucleotides long with genome organization similar to tobamoviruses. The Indian isolate of FrMV shared a very close genome sequence identity (98.3 %) with the lone isolate of FrMV-P from Australia. FrMV-Ind-1 together with FrMV-P formed a new phylogenetic group i.e. Apocynaceae-infecting tobamovirus. The polyclonal antiserum generated through the purified virus preparation was successfully utilized to detect the virus in field samples of frangipani by ELISA. Of the eight different tobamoviruses tested, FrMV-Ind-1 shared distant serological relationships with only cucumber green mottle mosaic virus, tobacco mosaic virus, bell pepper mottle virus and kyuri green mottle mosaic virus. RT-PCR based on coat protein gene primer successfully detected the virus in frangipani plants. This study is the first comprehensive description of FrMV occurring in India.

Simultaneous multiplex PCR detection of seven cucurbit-infecting viruses

Two multiplex polymerase chain reaction (PCR) systems using dual priming oligonucleotide (DPO) primers were developed for the simultaneous detection of seven cucurbit-infecting viruses. One system allows for the detection of papaya ringspot virus, watermelon mosaic virus, and zucchini yellow mosaic virus, whereas the other permits the detection of cucumber green mottle mosaic virus, cucumber fruit mottle mosaic virus, kyuri green mottle mosaic virus, and zucchini green mottle mosaic virus. Viral species-specific DPO primers developed in this study detected as little as 10fg/μl of viral RNA under monoplex conditions and 10pg/μl of viral RNA under multiplex conditions. Multiplex PCR using the DPO primer sets was capable of amplifying viral genes at annealing temperatures ranging from 53°C to 63°C. Whereas the use of conventional primers gave rise to non-specific bands, the DPO primers detected target viral genes in the absence of non-specific amplification. When these DPO multiplex primer sets were applied to virus-infected cucurbit samples obtained in the field, multiple infection as well as single infection was accurately identified. This novel approach could also detect multiple viruses in infected seeds. The reliability of multiplex PCR systems using DPO primers for plant virus detection is discussed.

Detection of Kyuri Green Mottle Mosaic Virus from Soil by the Immunocapture Reverse Transcription Loop-mediated Isothermal Amplification Reaction

Detection of Kyuri Green Mottle Mosaic Virus from Soil by the Immunocapture Reverse Transcription Loop-mediated Isothermal Amplification Reaction

Application of Multiplex RT-PCR for Detection of Cucurbit-infecting Tobamovirus

Cucumber green mottle mosaic virus (CGMMV) and Kyuri green mottle mosaic virus (KGMMV) are seed borne viruses and they are also transmitted mechanically during agricultural practice and through water. Hence, these viruses have potential diseases widely distributed throughout the world. To detect different strains of CGMMV and KGMMV, several specific primers for each virus were designed for single and multiplex RT-PCR. The results of single and multiplex RT-PCR showed that CGMMV was detected in zucchini isolated in Bali-Indonesia, while KGMMV was detected both in zucchini isolated in Bali-Indonesia and Cucumis metuliferus isolated in Thailand. Furthermore, artificial co-infection of these two viruses was prepared and carried out using two different ways of viral RNAs extraction. Based on the results, it could be reported that viral RNAs for cDNA amplification by multiplex RT-PCR could be extracted from a mixture of infected leaves or separate extraction of each viruses infected leaves. In addition, results presented in this study demonstrated the application of multiplex RT-PCR to simultaneously detect CGMMV and KGMMV from cucurbit leaves using a mixture of four primers and its feasibility as a sensitive and rapid laboratory assay. Since, no multiplex RT-PCR technique has been described for the detection of CGMMV and KGMMV, this technique can be a good option for sensitive and reliable tool for detection of two major cucurbit infecting Tobamoviruses. Keywords : Cucurbit infecting Tobamovirus, multiplex RT-PCR, seed borne viruses

Immunocapture RT-PCR을 이용한 박과작물 종자전염 바이러스의 검출

Immunocapture reverse transcription polymerase chain reaction (IC-RT-PCR) was applied to the detection of Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), and Zucchini green mottle mosaic virus (ZGMMV) on Cucurbitaceae crops. These seed-borne tobamoviruses were accurately detected from the infected leaves and seeds by IC-RT-PCR. This method was estimated to be about 100 times more sensitive than ELISA, and also it allowed the direct confirmation of ELISA results by using the captured antigens from a completed ELISA microwell. This convenient and reliable method could be used routinely for large-scale field surveys or seed tests of Cucurbitaceae crops.

九州におけるキュウリ緑斑モザイクウイルス分離株の遺伝的多様性

To investigate the genetic diversity of Kyuri green mottle mosaic virus (KGMMV) in Kyushu, Japan, nine isolates collected from greenhouse-cultivated cucumbers from 2005 to 2009 were examined. All isolates showed mosaic and growth inhibition on cucumber plants after mechanical inoculation. Phylogenetic analyses of the nucleotide sequences of the coat protein (CP) and movement protein (MP) genes clustered the nine isolates into four groups. For the CP gene, one cluster consisted of two isolates and the other three clusters were closely related to the Yodo and Cucumber strains. This was not the case for the MP gene. Recombination analysis of the genomic region encoding MP and CP suggested that recombination events had occurred among isolates within the same cluster. These data indicate that there is a high genetic diversity among KGMMV populations in Kyushu and some isolates have been generated by recombination.

Molecular and Serological Characterization of Cucumber mottle virus, a New Cucurbit-Infecting Tobamo-like Virus.

A new tobamo-like virus was isolated from a greenhouse-grown cucumber that showed severe mosaic distortion on leaves and fruit, in the southern part of Japan. The virus was tentatively designated Cucumber mottle virus (CuMoV) and further characterized. The size and antigenicity of the coat protein (CP) and the complete sequence of the genome were compared with those of the known cucurbit-infecting tobamoviruses: the W and SH strains of Cucumber green mottle mosaic virus (CGMMV), the C and Y strains of Kyuri green mottle mosaic virus (KGMMV), Cucumber fruit mottle mosaic virus (CFMMV), and Zucchini green mottle mosaic virus (ZGMMV). The CP of CuMoV migrated more slowly than those of CGMMV-W and -SH and KGMMV-C and -Y in sodium dodecyl sulfate polyacrylamide gel electrophoresis. In Western blot analysis, the CP of CuMoV cross-reacted weakly with antisera against CGMMV-W and did not react with antisera against KGMMV-Y. The overall nucleotide sequence of CuMoV had 62.5 to 63.5% identity with those of CGMMV-W, -SH, KGMMV-Y, CFMMV, and ZGMMV. The genome organization was characteristic of tobamoviruses, encoding a 131-kb protein, a 188-kb protein, a movement protein (MP), and CP in 5' to 3' order. In the phylogenetic analyses of the CP, CuMoV was placed in a separate lineage from CGMMV-W, -SH, KGMMV-C, -Y, CFMMV, and ZGMMV. The results indicate that CuMoV is a distinct tobamovirus species which represents a third sub-subgroup in the cucurbit-infecting tobamoviruses.

The Incidence of Virus Diseases on Melon in Jeonnam Province during 2000-2002

The occurrence and relative incidence of viruses including Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV), Papaya rings pot virus (PRSV), and Watermelon mosaic virus (WMV), Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), and Melon necrotic spot virus (MNSV) were surveyed from main melon (Cucumis melo L.) production areas in Jeonnam province during 2000-2002. Virus disease incidences of melon cultivating fields were 0% and 11% in spring and fall 2000; 40%, 2.1%, and 8.8% in spring, summer, and fall 2001; and 6.3 % in spring 2002 in main cultivated areas in Jeonnam province, respectively. Field disease incidences of melon virus infections were 0% and 18.8% in spring and fall 2000; 50%, 38.5%, and 82.6% in spring, summer, and fall 2001; and 47.4% in spring 2002, respectively. Total of 101 melon samples showing typical disease symptoms were collected from 2000 to 2002 and tested for virus infection by RT-PCR. Potyvirus-specific DNA fragments for WMV, ZYMV, and PRSV were amplified from 46, 5, and 4 samples, respectively. MNSV specific DNA fragment was amplified from 18 samples. CMV-specific DNA fragment was detected from only 3 samples.

박과 작물 종자전염 바이러스 3종(CGMMV, ZGMMV, KGMMV)의 간편한 동시진단 VC/RT-PCR 유전자 진단

박과 작물에 발생하는 종자전염성 막대형 바이러스인 CGMMV, KGMMV, ZGMMV 3종의 단독 및 동시 VC/RT-PCR 유전자 진단법을 개발하였다. CGMMV 등 3종의 바이러스에 대한 동시진단용 조합선발을 위하여 12조합 중에서 동시 진단용 프라이머 조합 CGMMV-C724, KGMMV-K513, ZGMMV-Z407A를 선발하였다. CGMMV등 3종에 대한 triplex VC/RT-PCR 유전자 진단법은 박, 수박, 오이, 멜론, 쥬키니 호박, 애호박, 담배(N. benthamiana) 작물의 식물체 즙액과 프라이머 간에 간섭현상 없이 특이적으로 진단되었다. The genetic diagnostic method of virion capture (VC)/RT-PCR was developed for the simultaneous detection of three rod shaped viruses of Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus(KGMMV) and Zucchini green mottle mosaic virus (ZGMMV) transmitted by seed in Cucurbit. Out of 12 primer combinations for the three tobamoviruses, a primer set of CGMMV-C724, KGMMV-K513 and ZGMMV-Z407A was useful for mono and triplex VC/RT-PCR. The triplex VC/RT-PCR for the three tobamovirus in Cucurbit could detect specifically without interference among primers and/or plant species of watermelon, gourd, cucumber, melon, pumpkin, squash and Nicotiana benthamiana.

전남지역의 호박에 발생하는 바이러스 병 발생 실태

전라남도 호박 주산단지의 2000년 바이러스병 발생포장율은 노지재배 76.1%,억제재배 55%,반촉성재배는 발생이 없었으며, 포장별 이병주율은 반촉성재배 3.6%, 노지재배 100%이었다. 포장에서 채집된 시료에 대한 RT-PCR 검정결과 노지재배는 40점 시료 중 WMV 16점, ZYMV 10점, PRSV 2점이 각각 검출되었으며, WMV, ZYMV, PRSV의 2개 또는 3개 바이러스에 중복감염된 시료도 7점이었다. 억제재배는 21점 시료중 WMV 7점, ZYMV 6점, PRSV 6점, WMV와 PRSV의 2개 바이러스에 중복감염된 시료가 1점이었으며, CMV는 검출되지 않았다. Field disease incidences of squash virus diseases in Jeonnam province were estimated to be 76.1% and of delayed planting on August-September (retarding culture) and on February-March (semi-forcing culture) on glass house were 55.0% and 0%, respectively, in 2000. Disease incidences of individual squash plant within a field were 100% and 3.6%, respectively, in wild culture and retarding culture. Total of 61 samples suspected to be infected with viruses were collected in 2000 and tested by RT-PCR using specific oligonulceotide primer sets designed for the detection of Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), Zucchini yellow mosaic virus (ZYMV), Papaya ring spot virus (PRSV), Watermelon mosaic virus (WMV), and Cucumber mosaic virus (CMV). Each specific primer set for WMV, ZYMV, and PRSV amplified expected size of DNA fragments from 16, 10, and 2 samples in wild culture, respectively. Double or triple infection were observed in 7 samples tested. In contrast, each specific primer set for WMV, ZYMV, and PRSV confirmed virus infection from 7, 6, and 6 samples, respectively, in samples collected from semi-forcing culture. Double infection of WMV and PRSV was observed in only one sample. However, no DNA fragment was amplified from RT-PCR using CGMMV, KGMMV, and CMV specific oligonucleotide primer sets indicating no CGMMV, KGMMV, or CMV infection in squash fields in Jeonnam province in 2000.

プライマーカクテルを用いたＲＴ‐ＰＣＲによるキュウリおよびメロンに感染する８種ウイルスの検出法

Multiplex primers were calculated using a web-based program, muPlex in order to detect eight cucurbit-infecting viruses: Watermelon mosaic virus (WMV), Zucchini yellow mosaic virus (ZYMV), Cucumber mosaic virus (CMV), Kyuri green mottle mosaic virus (KGMMV), Papaya ringspot virus (PRSV), Melon yellow spot virus (MYSV), Cucumber green mottle mosaic virus (CGMMV), and Beet pseudo-yellows virus (BPYV). The predicted length of the amplified fragments ranged from 283 by to 1, 144 bp, and were distinct from each other. RT-PCR conducted using a mixture of all the primer pairs (primer cocktail) amplified the appropriate fragments corresponding to each virus species. Non-specific fragments were not observed. Two fragments were simultaneously amplified when RNA mixtures containing two distinct viral species were used as templates. However, if the concentration of one viral RNA was too high, the other virus could not be detected.

Molecular evidence supporting the confirmation of Maracuja mosaic virus as a species of the genus Tobamovirus and production of an infectious cDNA transcript

The complete genome sequence of maracuja mosaic virus (MarMV) was determined and analyzed. The full MarMV genome consisted of 6794 nucleotides, and this is the largest genome size among known tobamoviruses. The MarMV genome RNA contained four open reading frames (ORFs) coding for proteins of M(r) 126, 181, 34 and 18 kDa from the 5' to 3' end, respectively. The lengths of the 5' nontranslated region (NTR) and the 3' NTR were 54 and 177 nucleotides, respectively. Phylogenetic tree analysis revealed that these MarMV-encoded proteins are related to members of the Malvaceae- and Cucurbitaceae-infecting tobamoviruses. MarMV is different from other tobamoviruses and forms a new Passifloraceae-infecting subgroup. Western blot analysis showed that MarMV cross-reacted strongly with antibodies against Kyuri green mottle mosaic virus and Hibiscus latent Singapore virus. Synthesized capped transcripts from full-length cDNA of MarMV were infectious. These data clearly indicate that MarMV belongs to a separate species of the genus Tobamovirus.

Incidence and Distribution of Virus Diseases on Cucumber in Jeonnam Province During 1999-2002

Disease incidences of cucumber virus diseases in Jeonnam province were 52.5%, 16.1%, 35.2%, and 50.9% in 1999, 2000, 2001, and 2002, respectively. Rod- and flexuous rod-shaped virus particles were observed with the frequencies of 63.2% and 10.5%, respectively from the samples collected in 1999 under EM observation. Rod-shaped virus particles are considered as tobamovirus while flexuous rod shaped particles are considered as potyviruses. To further confirm their nature, total of 312 diseased virus samples were collected from 2000 to 2002, and tested by RT-PCR. Disease incidences of tobamoviruses including Cucumber green mottle mosaic virus and Kyuri green mottle mosaic virus were 48.7% and 3.8%, respectively while those of potyviruses including Zucchini yellow mosaic virus, Papaya ringspot virus, and Watermelon mosaic virus were 15.7%, 9.3%, and 5.1%, respectively. Interestingly, Cucumber mosaic virus was hardly detected. About 5.8% of tested samples were infected with more than one virus. Tobamovirus infection was consistently observed from September to December regardless of planting time, whereas infection of potyviruses was observed in many cucumber cultivating areas where it was planted in September and October.

Construction of Antibodies for Detection and Diagnosis of Cucumber green mottle mosaic virus from Watermelon Plants

We immunized BALB/c mice with purified Cucumber green mottle mosaic virus isolate HY1 (CGMMV-HY1). Through the selection of positive clones that were grown on the HAT medium, four sensitive monoclonal clones (CG99-01, CG99-02, CG99-03, and CG99-04) were selected from 500 Hypoxanthine-guanine phosphoribosyltransferase positive hybridoma cells. Four sensitive clones of CGMMV-HYI were determined as IgM type of the subclass of mouse immunoglobulins Ig group. The titer of monoclonal antiserum against CGMMVHY1 was estimated 1:12,800 by the indirect ELISA. Although monoclonal antibodies (MAbs) from CG99-01 and from CG99-04 cross-reacted with Zucchini green mottle mosaic virus and Kyuri green mottle mosaic virus, MAb from the cell line CG99-03 was highly specific to CGMMV. No MAbs cross-reacted with Cucumber mosaic virus-Fny. Only CG99-04 reacted with Pepper mild mottle virus weakly and CG99-02 reacted with both CGMMV and KGMMV. CGMMV was detected from the rind of watermelon fruit by DAS-ELISA of CGMMV-HY1, but not from the flesh of watermelon. Average seed transmission rate of CGMMV in watermelon was from symptomatic watermelon collected from 5 regions of Gyeongnam province. CGMMV was detected by DAS-ELISA with specific MAb of CGMMVHY1 periodically from root stock, during the sequential process for nursery seedling in Haman. Necrotic spots on cotyledons of root stock seedling progressed to reveal the typical symptomatology on the primary leaves of scion upon grafting. Here, we have established MAb based ELISA system, which could accurately detect CGMMV from watermelon seeds, nursery seedlings, transplants and field samples from greenhouse or open out door field as well.

A New Source of Resistance to Cucumber Green Mottle Mosaic Virus in Melon

Cucumber green mottle mosaic virus (CGMMV), which is easily transmitted via foliage contact, soil contamination, and seeds, is one of the major diseases affecting melon (Cucumis melo L.). However, no commercial cultivars resistant to CGMMV are available. In melon, only the symptomless carrier-type accessions ‘Phoot’ and ‘Kachri’ (var. momordica Duthle and Fueler) have been reported to be resistant to CGMMV. Therefore, to identify CGMMV-resistant accessions, 152 melon accessions were screened for resistance to CGMMV by mechanical inoculation. Only plants of the Korean accession ‘Chang Bougi’ (var. makuwa Makino) were resistant to the SH isolate (CGMMV-SH). The influences of temperature on symptom development and CGMMV accumulation in ‘Chang Bougi’ plants were studied. At 24°C, no symptoms were observed in the upper leaves of ‘Chang Bougi’ plants at 25 days after inoculation. In contrast, at 30°C, chlorotic spots were observed in the upper leaves from 15 to 20 days after inoculation. Under greenhouse conditions at an average temperature of 27.3°C, mosaic and chlorotic spots were observed in the upper leaves of ‘Chang Bougi’ plants from 30 days after inoculation. The accumulation patterns of CGMMV in the inoculated portions of ‘Chang Bougi’ and ‘Perlita’ (susceptible control) cotyledons were almost identical. CGMMV was detected in the uninoculated portions of ‘Perlita’ cotyledons from 4 days after inoculation, but was not detected in the uninoculated portions of ‘Chang Bougi’ cotyledons until 10 days after inoculation. Symptoms were observed, and the virus was detected in the upper leaves of ‘Chang Bougi’ plants inoculated with the watermelon isolate (CGMMV-W) or Kyuri green mottle mosaic virus (KGMMV). These results indicate that virus movement was restricted and that growth at 30°C enhances symptoms in this accession. Moreover, the resistance to CGMMV in this accession was specific to the SH isolate.

Screening for resistance to Kyuri green mottle mosaic virus in various melons

AbstractAmong many species in the genus Tobamovirus, Kyuri green mottle mosaic virus (KGMMV) is known as a major seed‐borne virus infecting cucurbit plants, including melon, which possesses no known resistance. The identification of genetic resistance to KGMMV in Indonesia (KGMMV‐YM) in melons is of economic importance. Thus, 45 melon cultigens collected from 17 Asian countries were screened by manual virus inoculation and resistance to KGMMV‐YM was examined by visual observation, enzyme‐linked immunosorbent assay and reverse transcription‐polymerase chain reaction (RT‐PCR). The results show that resistance to KGMMV‐YM was found in ‘Mawatauri’, ‘Kohimeuri’, PI 161375 and PI 371795, and analysis by RT‐PCR showed the presence of KGMMV‐YM in susceptible cultigens as early as 3 days after leaf inoculation.

Biological and Molecular Characterization of Melon‐Infecting Kyuri Green Mottle Mosaic Virus in Indonesia

AbstractMelon (Cucumis melo L.) plants showing fruit deformation and mosaic symptoms were found in Java, Indonesia, in 2001. Leaf dips of the symptomatic melon tissue revealed rod‐shaped viral particles 300 × 18 nm in size. Biological and serological data described in this study indicate that the virus belonged to the genus tobamovirus and was related to the kyuri green mottle mosaic virus (KGMMV). The genome of the virus has been completely sequenced, consisting of 6512 nucleotides and was compared in detail with KGMMV‐C1 and KGMMV‐Y. The sequence of their 5′‐ and 3′‐ non‐coding regions (NCRs) were 91% and 94% identical to KGMMV‐C1, and only 82% and 95% identical to KGMMV‐Y respectively. The amino acid sequence of the shorter and longer RNA replicase components, movement protein and coat protein were 94%, 91%, 95% and 94% identical to KGMMV‐C1 and 93%, 89%, 91% and 85% identical of KGMMV‐Y respectively. The results from phylogenetic analysis of the coding regions revealed that KGMMV‐YM is a new strain of KGMMV. This is the first report of the complete nucleotide sequence and analysis of genome organization for KGMMV isolated in anywhere in South‐East Asia.