Yellow Mosaic Research Articles

Evaluation of Three Cucurbitaceae Cultivars Resistant against Begomoviruses Based on Morphological Symptoms and Molecular Analysis

Cucurbitaceae is a group of annual horticultural crops with high economic prospects and benefits. The Faculty of Biology, Universitas Gadjah Mada has developed several new cultivars within the Cucurbitaceae family, such as the melon cultivar 'Hikapel', watermelon 'Citra Jingga', and butternut squash 'Citra Laga'. However, development of these cultivars has been hindered by yellow disease, typically triggered by Begomovirus infection. This study aimed to determine the morphological symptoms of yellow disease, to detect Begomovirus infection using molecular approach, and assess resistance levels of the three Cucurbitaceae cultivars. The method involved observing morphological symptoms in plants and measuring plant height. The degree of symptom severity was then converted into a vulnerability index (VI). The symptomatic leaf samples were tested using Krusty and Homer primer to confirm the symptoms caused by Begomovirus. The PCR results were sequenced and analyzed using Maximum Likelihood method in MEGA 11. The results showed that symptoms included curling tip of leaves, yellow mosaic on the leaves, and stunted growth in some plants, which were suggested as Begomovirus infection. Based on the Vulnerability Index (VI), the watermelon cultivar 'Hikapel' was considered susceptible to Begomovirus infection (VI = 85%), while the yellow squash 'Citra Laga' was moderately susceptible (VI = 57.5%). However, the watermelon 'Citra Jingga' was considered moderately resistant to this infection (VI = 50%). The presence of DNA the Begomovirus at three species Cucurbitaceae were characterized by a 550 bp band. The 'Hikapel' melon and 'Citra Laga' butternut were infected with Tomato leaf curl New Delhi virus (ToLCNDV), while the ‘Citra Jingga’ watermelon were infected with Squash leaf curl Philippine virus (SLCuPV).

Zucchini yellow mosaic virus-induced hypersensitive response is associated with pathogenesis-related 1 protein expression and confers resistance in watermelon.

The pathogenesis-related 1 gene of watermelon responds to the infection of ZYMV and contributes to the resistance of its host. Zucchini yellow mosaic virus (ZYMV; family Potyviridae) is a single-stranded positive-sense RNA virus that is a serious threat to cucurbits. Previously, we observed a hypersensitivity response (HR) in the systemic leaves of the 938-16-B watermelon line infected with ZYMV, distinct from the typical HR at infected sites. In this study, we confirmed that ZYMV accumulation in 938-16-B was significantly lower than in the susceptible line H1. Upon inoculation, the entry of ZYMV-eGFP into mesophyll cells is restricted into necrotic spots in leaves, indicating that resistance to ZYMV in 938-16-B is linked to the HR. Further, grafting experiments between 938-16-B and susceptible varieties were performed, and revealed an HR induction in susceptible varieties, suggesting the transfer of resistance signal(s) from 938-16-B to susceptible varieties. Through RNA-sequencing and proteomics analyses of the H1 scions on 938-16-B rootstock, a pathogenesis-related 1 (ClPR1) gene was identified. Specifically, ClPR1 expression is unique to ZYMV-infected 938-16-B. Repression of the expression of ClPR1 prevents an HR in 938-16-B. Conversely, overexpression of ClPR1 in susceptible varieties significantly reduces ZYMV accumulation, but an HR was not induced in susceptible line. Besides the virus, jasmonic acid (JA) can also trigger an HR in 938-16-B. Intriguingly, the expression of ClPR1 (Cla97C02G034020) is induced in both of 938-16-B and H1 by MeJA, rather than salicylic acid. These results suggest that HR is associated with the expression of ClPR1 and contributes to resistance to ZYMV in 938-16-B.

Northwestern Himalayan common beans: A Treasure Trove for breeding resistant bean cultivars for multiple foliar pathogens

Common bean (Phaseolus vulgaris. L) is attacked by a lot of important foliar diseases like anthracnose, Bean Common Mosaic Virus, angular leaf spot, Bean Golden Yellow Mosaic Virus, and common bacterial blight. In the present study, we exploited anthracnose resistant germplasm of 122 common bean genotypes for the identification of broad spectrum and durable resistance for multiple foliar diseases. We utilized linked molecular markers and found some promising genotypes with 11 resistance genes. These genotypes possess significant potential as parental lines for gene pyramiding strategies, to enhance disease resistance in common beans. We also highlighted the need for new generation markers over SCAR markers to streamline genotypic screening and expedite the breeding of disease-resistant common bean varieties. Our phenotypic studies identified a few bean landraces highly resistant to the new BCMV NL-1n strain. Consequently, the genome wide association study also confirms the presence of already identified resistance genes. Additionally, our study reconfirms the presence of the recently identified bc-urgene in our material. The bean landraces of northern India contain novel regions associated with BCMV resistance on Pv03, Pv05, Pv04, Pv06, Pv07, Pv09, and Pv11. This study provides the list of bean genotypes that can be used to breed resistant cultivars and may also contain new resistance genes to a most important viral disease of common beans.

Molecular diversiry studies among blackgram genotypes for yellow mosaic virus resistance

Yellow mosaic disease (YMD), incited by a geminivirus. Mungbean Yellow Mosaic Virus (MYMV), is transmitted by whiteflies, poses a significant threat to various leguminous crops in India. This study focuses on identifying resistant sources and validating molecular markers for their efficacy in detecting YMV resistance in blackgram. In the present study, 150 blackgram genotypes were evaluated to identify resistant sources for YMD under natural field conditions and through molecular markers. Among the 150 genotypes, 22 (both resistant and susceptible) were selected based on field screening. These genotypes were validated using 15 molecular markers, including 8 simple sequence repeats (SSRs) and 7 gene-specific markers linked to MYMV resistance. The markers amplified a total of 48 alleles, with polymorphic information content (PIC) values ranging from 0.82 (CEDG67) to 0.21 (HSP), with an average value of 0.55. The highest PIC values were exhibited by markers CEDG67 (0.82), CEDG115 (0.81), and CEDG20 (0.74). Cluster analysis using DARWIN revealed that most phenotypically resistant genotypes grouped together, while susceptible genotypes formed separate clusters. The genotypes LBG 904, LBG 932, LBG 884, PU 1815, PU 1808, PU 1803, MASH 1008, MASH 114, VBN 10, and PU 31 exhibited resistance to YMV phenotypically. Among these, LBG 904, LBG 932, PU 1815, PU 31, and MASH 1008 produced a 162 bp resistant allele using the marker CEDG180. Similarly, the gene-specific marker DEF produced a 190 bp resistant allele in all the resistant genotypes, whereas the susceptible genotypes produced both 190 and 250 bp alleles. These identified genotypes can serve as valuable sources for MYMV resistance in blackgram breeding programs. Keywords: SSR markers, Blackgram, Diversity, MYMV

Effect of viruses infection symptoms on pollen viability in different horticultural crop species

A preliminary in vitro investigation was carried out to assess the impact of virus infection symptoms on in vitro pollen germination in different horticultural crop species. Pollen from healthy and virus-infected papaya (papaya ring spot virus—PRSV), gherkin (Ilar virus), okra (Ilar virus), bottle gourd (mosaic virus), chow-chow (mosaic virus), okra (yellow vein mosaic virus -YVMV), watermelon (mosaic), pumpkin (mosaic), watermelon (bud necrosis) and bitter gourd (yellow mosaic) flowers was collected, and pollen was extracted and to assessed viability in vitro via the hanging drop method. After incubation, the viability profiles of the pollen were computed. There was a significant reduction in the pollen germination profiles of pollen from infected plants compared to those from healthy plants. The impact of virus infection on pollen production, germination and viability is discussed in light of the overall reproductive ability of virus-affected plants.

Assessment of Different Cucurbit Genotypes for Resistance to Zucchini Yellow Mosaic Virus (ZYMV)

Members of the Cucurbitaceae family, which includes species with quite different characteristics, have been used for food, medicine, and ornamental purposes for a long time. However, most plant diseases and pests cause yield and quality losses in cucurbits, and one of the most important of these diseases is zucchini yellow mosaic virus (ZYMV), which one of the most common potyviruses worldwide and causes serious yield losses in cucurbit production worldwide. Zucchini Yellow Mosaic Virus shows symptoms such as yellowing, mottling, curling, deformation, mosaic, shortening and thickening of the internodes, and may also cause loss of yield and quality. As widely known, there is no effective chemical control of viral diseases, and the use of resistant or tolerant varieties is the most effective solution. In this study, 92 watermelon genotypes, 14 zucchinis (pumpkin seeds) and 29 ornamental pumpkins collected from different parts of Türkiye were tested against ZYMV. Symptoms of ZYMV in different watermelon genotypes and pumpkins were observed for 21 days. Genotypes showing systemic infection after inoculation were evaluated on a scale of 0-5. Also, RT-PCR studies were carried out on selecting nine symptomless control plants, seven ZYMV-sensitive genotypes showing 5-scale value, one genotype with 1-scale value considered tolerant, and one genotype belongs to C. lanatus var. citroides. According to the results, it was determined that some watermelon and ornamental pumpkin genotypes could be considered as tolerant. Watermelon, which was having accession number PI560016, was found resistant to Turkish local strain of ZYMV. Although different susceptibility levels were detected between watermelon genotypes, all pumpkin genotypes were discovered to be susceptible to the Turkish local strain of ZYMV.

Understanding the origins, impacts, and remedies for mungbean yellow mosaic virus

Mungbean (Vigna radiata) is a crucial crop worldwide, especially in Asian countries, where it significantly contributes to agricultural yields. However, the Mungbean Yellow Mosaic Virus (MYMV), a begomovirus, causes substantial yield reductions. Despite ongoing efforts to identify resistant cultivars, most available varieties remain susceptible, potentially resulting in yield losses of up to 100%. In Pakistan, challenges such as inadequate irrigation, disease outbreaks, and poor-quality seed stocks exacerbate the impact of MYMV on mungbean production. Whiteflies (Bemisia tabaci) are the primary vectors for MYMV. Molecular characterization reveals that virus particles aggregate in the host nuclei, disrupting cell structure and leading to yield losses, with early infection stages resulting in more severe reductions. Efforts to manage MYMV include evaluating mungbean germplasm for resistance and emphasizing the importance of genetic resistance in disease control. Despite difficulties in developing resistant cultivars, ongoing research aims to reduce the impact of MYMV on mungbean production. This review explores the effect of MYMV on mungbean production, particularly in Pakistan, and examines the associated economic consequences. It also investigates the genetic susceptibility of mungbean cultivars, the influence of environmental conditions, and the dynamics of whitefly populations, which collectively contribute to MYMV incidence. The review highlights the correlation between whitefly populations and disease incidence and discusses strategies for managing MYMV and its vector. This paper provides a comprehensive overview of current approaches to develop sustainable and effective methods for mitigating MYMV-induced yield losses in mungbean cultivation.

Relationship between Whiteflies, Yellow Mosaic Severity, Weather and Crop Age in Soybean

Relationship between Whiteflies, Yellow Mosaic Severity, Weather and Crop Age in Soybean

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

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

Induced mutagenesis for resistance to mungbean yellow mosaic virus and yield traits in mungbean

The M0 ѕeedѕ of mungbean variety DGGV 2 treated with different doѕeѕ of ethyl methane ѕulphonate (EMЅ) at 0.1%, 0.2% and 0.3% concentrations were assessed for Mungbean Yellow Mosaic Virus (MYMV) in M2 generation during summer 2023 at University of Agricultural Sciences, Dharwad. Considering the yield superiority over check (Mean + 2 Standard Deviation) and highly resistant response to MYMV disease, out of 962 M2 plants 17 superior M2 plants were identified. The seed yield plant-1 in these identified mutants ranged from 21.9 to 32.0 g which is higher compared to the average yield of check DGGV 2 (11.7 g) during that season. Also, the other yield contributing traits such as number of productive branches, number of cluster plant-1, number of pods cluster-1, and number of pods plant-1 were observed to be higher in these mutants in comparison to check variety.

Enhancing Mungbean Resistance to Yellow Mosaic Virus: Insights from Biochemical Studies

Enhancing Mungbean Resistance to Yellow Mosaic Virus: Insights from Biochemical Studies

Biological and Molecular Characterization of a Korean Isolate of Clover Yellow Vein Virus Infecting Canavalia ensiformis

Jack bean (Canavalia ensiformis) is one of healthy products for fermented or functional food in Korea and is widely distributed and cultivated worldwide. During August 2022, Jack bean plants showing symptoms of yellow flecks, chlorosis, necrotic spots and mosaic were observed in Jangheung-gun, South Korea. By transmission electron microscopy, flexuous filamentous virus particles of approximately 750×13 nm in size were observed in the symptomatic leaf samples. The infection of a Korean isolate of clover yellow vein virus (ClYVV-Ce-JH) was confirmed using double antibody sandwich enzyme-linked sorbent assay, reverse transcription polymerase chain reaction and high-throughput sequencing. The complete genome sequence of ClYVV-Ce-JH consists of 9,549 nucleotides (nt) excluding the poly (A) tail and encodes 3,072 amino acids (aa), with an AUG start and UAG stop codon, containing one open reading frame that is typical of a potyvirus polyprotein. The polyprotein of ClYVV-Ce-JH was divided into ten proteins and each protein’s cleavage sites were determined. The coat protein (CP) and polyprotein of ClYVV-Ce-JH were compared at the nt and aa levels with those of the previously reported 14 ClYVV isolates. ClYVV-Ce-JH shared 92.62% to 99.63% and 93.39% to 98.05% at the CP and polyprotein homology. To our knowledge, this is the first report of a Korean isolate of ClYVV from Jack bean plants and the complete genome sequence of a ClYVV Jack bean isolate in the world.

Evaluation of Integrated Pest Management Against Yellow Mosaic Virus Disease in Blackgram

Evaluation of Integrated Pest Management Against Yellow Mosaic Virus Disease in Blackgram

Selection efficiency of molecular markers associated to Yellow Mosaic Virus (YMV) tolerance and identification of donors for earliness, yield and YMV tolerance in blackgram (Vigna mungo (L.) Hepper) using GT Biplot analysis

Selection efficiency of molecular markers associated to Yellow Mosaic Virus (YMV) tolerance and identification of donors for earliness, yield and YMV tolerance in blackgram (Vigna mungo (L.) Hepper) using GT Biplot analysis

Multi-trait stability index for identification of stable green gram (Vigna radiata (L.) Wilczek) genotypes with MYMV resistance

Multi-environment trials (MET) are crucial for selecting genotypes that are well-suited to different environmental conditions. Incorporating multiple traits in the analysis can provide more reliable recommendations for selecting genotypes with desirable traits, including resistance to the Mungbean Yellow Mosaic Virus (MYMV) and high yield potential. The use of a Multi-Trait Stability Index (MTSI) is a good approach for analyzing the stability of genotypes across multiple traits under MYMV stress. In the present investigation, the performance of thirteen green gram genotypes were evaluated for traits such as yield, plant height, number of branches per plant, and resistance to MYMV. The main objective of the study is to identify highly productive and stable mung bean genotypes resistant to MYMV. MTSI can be calculated by combining information on the performance of genotypes across multiple traits and environmental conditions to provide a single index that indicates the overall stability of genotypes across traits and environments. The results helped to identify two green gram genotypes (Yadadri and JNG-18) that were high-yielding with stable resistance to MYMV stress across multiple environmental conditions. This can provide useful information to breeders for the development of suitable genotypes against MYMV in the affected areas.

Identification of Resistance Gene for Mungbean Yellow Mosaic Virus (MYMV) in Resistant Mungbean Genotypes through RGA Markers

Identification of Resistance Gene for Mungbean Yellow Mosaic Virus (MYMV) in Resistant Mungbean Genotypes through RGA Markers

Identification of Barley yellow mosaic virus Isolates Breaking rym3 Resistance in Japan.

In early spring 2018, significant mosaic disease symptoms were observed for the first time on barley leaves (Hordeum vulgare L., cv. New Sachiho Golden) in Takanezawa, Tochigi Prefecture, Japan. This cultivar carries the resistance gene rym3 (rym; resistance to yellow mosaic). Through RNA-seq analysis, Barley yellow mosaic virus (BaYMV-Takanezawa) was identified in the roots of all five plants (T01-T05) in the field. Phylogenetic analysis of RNA1, encompassing known BaYMV pathotypes I through V, revealed that it shares the same origin as isolate pathotype IV (BaYMV-Ohtawara pathotype). However, RNA2 analysis of isolates revealed the simultaneous presence of two distinct BaYMV isolates, BaYMV-Takanezawa-T01 (DRR552862, closely related to pathotype IV) and BaYMV-Takanezawa-T02 (DRR552863, closely related to pathotype III). The amino acid sequences of the BaYMV-Takanezawa isolates displayed variations, particularly in the VPg and N-terminal region of CP, containing mutations not found in other domains of the virus genome. Changes in the CI (RNA1 amino acid residue 459) and CP (RNA1 amino acid residue 2138) proteins correlated with pathogenicity. These findings underscore the importance of monitoring and understanding the genetic diversity of BaYMV for effective disease management strategies in crop breeding.

Identification and Bioinformatics Analysis of Coat Protein Gene of a Strain of Zucchini Yellow Mosaic Virus

Identification and Bioinformatics Analysis of Coat Protein Gene of a Strain of Zucchini Yellow Mosaic Virus

Selection efficiency of molecular markers associated to Yellow Mosaic Virus (YMV) tolerance and identification of donors for earliness, yield and YMV tolerance in blackgram (Vigna mungo (L.) Hepper) using GT Biplot analysis

Selection efficiency of molecular markers associated to Yellow Mosaic Virus (YMV) tolerance and identification of donors for earliness, yield and YMV tolerance in blackgram (Vigna mungo (L.) Hepper) using GT Biplot analysis

Viral complexity of tomatoes yellow mosaic and leaf curl diseases in lowland and highland areas

AbstractYellow mosaic and leaf curl diseases caused by whitefly‐transmitted begomo virus genera are important problems in tomato (Solanum lycopersicon L.) production in Indonesia, particularly on Java Island. The aims of this survey are to assess the percentages of disease incidence (DI) and disease severity index (DSI), evaluate the spread and complexity of begomovirus and crinivirus infections responsible for yellow mosaic and leaf curl diseases in tomato plants, and identify the species of whitefly insect vectors and their cryptic biotypes in tomato production centers located on Java Island, Indonesia. A total of 43 locations in East, Central, and West Java were surveyed during the dry season from July 2022 to September 2022. Disease incidence and severity were determined by observing 200 samples of tomato plants from five points at each location, with 40 plants per point of land. A total of 116 whitefly samples in microtubes and 215 symptomatic leaf samples were collected. The genus begomovirus and crinivirus infecting tomato were identified by PCR and RT‐PCR using genus‐specific primers. Similarly, whitefly species and their cryptic biotypes were identified by PCR using MCoI gene‐specific primers. Results showed that DI and DSI remarkably differed between the lowlands (66%–89%) and highlands (33%–62%) in the provinces of Central Java and West Java. Furthermore, PCR analysis of 215 infected tomato showing the symptoms of yellow mosaic and curly leaf revealed that three begomoviruses, one crinivirus and their mixed combination both begomoviruses, one crinivirus has been detected in all the samples. Similarly, the whitefly insect vector Bemisia tabaci biotype Q was identified in all areas, whereas Trialeurodes vaporariorum was found only in the East Java and Java highlands, respectively.