Sugarcane Mosaic Virus Research Articles

Registration of ‘UFCP 87‐0053’ Sugarcane for Use as a Biofuel Feedstock

‘UFCP 87‐0053’ (Reg. No. CV‐166; PI 674425) sugarcane (Saccharum spp.) cultivar was released by the USDA‐ARS, Canal Point (CP), FL, and the University of Florida (UF) for its potential use in cellulosic ethanol production. UFCP 87‐0053 is a high‐fiber sugarcane clone, which was developed to produce genetic diversity in a feedstock for cellulosic ethanol production in Florida. The UFCP 87‐0053 clone results from a CP cross of unknown parents, yet it can be distinguished molecularly, and is genotypically distinct, from other energy cane cultivars released concurrently. UFCP 87‐0053 is highly resistant to smut (caused by Sporisorium scitamineum). in field conditions, with significantly lower infestation than the reference cultivar L 79‐1002. Following both naturally occurring environmental and artificial inoculations. UFCP 87‐0053 was also resistant, or moderately resistant, to several other sugarcane diseases, including brown rust (caused by Puccinia melanocephala Syd. and P. Syd.), orange rust [P. kuehnii (Kruger) E. Butler], leaf scald [caused by Xanthomonas albilineans (Ashby) Dawson], and Sugarcane mosaic virus. Mean dry biomass yield of UFCP 87‐0053 was approximately 5% greater than L 79‐1002. Plant composition of UFCP 87‐0053 was similar to L 79‐1002. UFCP 87‐0053 was released to be cultivated on marginal or sandy soils of Florida for cellulosic ethanol production.

First Report of Sugarcane mosaic virus Infecting Columbus Grass (Sorghum almum) in the United States

First Report of <i>Sugarcane mosaic virus</i> Infecting Columbus Grass (<i>Sorghum almum</i>) in the United States

First Report of Sugarcane mosaic virus group IV Isolates from the Corn Production Fields in China

First Report of <i>Sugarcane mosaic virus</i> group IV Isolates from the Corn Production Fields in China

Occurrence and distribution of potyviruses infecting sorghum in Kaduna and Kano States, Nigeria

Field surveys were conducted during the 2012 wet season in five Local Government Areas (LGAs) each of Kaduna and Kano States, Nigeria, to determine the incidence of potyviruses infecting sorghum. Sorghum leaves (n = 450) showing mosaic, streak, dwarfism and asymptomatic ones were collected from 30 fields. Based on the fields, the virus disease incidence in Kaduna State was 19.3, 17.1, 53.7, 35.4 and 32.7% for Sabon Gari, Giwa, Lere, Kubau and Makarfi LGAs, respectively. In Kano State, the incidence was 13.3, 32.9, 28.9, 34.3 and 50.9% for Tsanyawa, Minjibir, Wudil, Sumaila and Garun Malam LGAs, respectively. Enzyme-linked immunosorbent assay (ELISA) was employed in the detection of the viruses. There was overall incidence of Sorghum mosaic virus 2.8%, Maize dwarf mosaic virus 2.0%, Sugarcane mosaic virus 3.3% and unidentified potyvirus 4.2% from the two states.

Occurrence of maize lethal necrosis in Ecuador: a disease without boundaries?

Maize plants displaying severe mosaic, chlorosis and, in some cases, necrosis were observed in two provinces of Ecuador. Shotgun sequencing of cDNA obtained from double-stranded RNA extracted from symptomatic samples revealed the presence of Sugarcane mosaic virus (SCMV) and Maize chlorotic mottle virus (MCMV), two components of maize lethal necrosis. In 2015, a survey conducted in Los Rios, Manabi and Guayas, major maize production areas in the country, showed that the two viruses were present in a significant number of plants. Mixed infections were detected and associated with severe symptoms. MCMV was also detected in two hybrid seed lots, a significant finding for the epidemiology of the disease in Ecuador. The report of maize lethal necrosis, today the most significant virus disease of maize, in Ecuador is of great concern for producers in the South American continent because of the potential of an epidemic as that observed in east Africa in recent years.

Registration of ‘CPSG‐3481’ Sugarcane

‘CPSG‐3481’ (Reg. No. CV‐165, PI 676023) sugarcane (a complex hybrid of Saccharum spp.) cultivar was developed through cooperative research conducted by the Shakarganj Sugar Research Institute in Pakistan and the USDA‐ARS Sugarcane Field Station in the United States and released to growers for loam soils in Pakistan in September 2012. CPSG‐3481 was developed from a biparental cross (CP 81‐1238 × CP 85‐1308) made at Canal Point (CP), FL, USA, in December 1992, and selection process was made at the Shakarganj Sugar Research Institute, Punjab, Pakistan, in 2001–2011. CPSG‐3481 was commercially released by the variety evaluation committee of sugarcane scientists from the public and private sectors in the sugarcane production region (Punjab, Pakistan) in 2012 because of its high cane and sucrose yields and high commercial recoverable sucrose on loam soils and its acceptable levels of resistance to red rot (caused by Colletotrichum falcatum Went), brown rust (caused by Puccinia melanocephala Syd. &amp; P. Syd.), pokkah boeng (caused by Fusarium moniliforme J. Sheldon), Sugarcane mosaic virus, and smut (caused by Ustilago scitaminea Syd. &amp; P. Syd.) in Pakistan. Based on results of nine harvests of three crops (plant cane, first ratoon, and second ratoon) in the final‐stage replicated yield trials conducted at three locations on loam soils and compared with a reference cultivar HSF‐240, CPSG‐3481 had 19.4% higher (p &lt; 0.030) cane yield, 19.7% higher (p &lt; 0.001) commercial recoverable sucrose, 43.0% higher (p &lt; 0.001) sucrose yield, and 19.4% greater (p &lt; 0.001) economic index.

Molecular Variability and Distribution of Sugarcane Mosaic Virus in Shanxi, China.

BackgroundSugarcane mosaic virus (SCMV) is responsible for large-scale economic losses in the global production of sugarcane, maize, sorghum, and some other graminaceous species. To understand the evolutionary mechanism of SCMV populations, this virus was studied in Shanxi, China. A total of 86 maize leaf samples (41 samples in 2012 and 45 samples in 2013) were collected from 4 regions of Shanxi.ResultsDouble-antibody sandwich (DAS)-ELISA and RT-PCR showed 59 samples (30 samples in 2012 and 29 samples in 2013) to be positive for SCMV, from which 10 new isolates of SCMV were isolated and sequenced. The complete genomes of these isolates are 9610 nt long, including the 5′ and 3′ non-coding regions, and encode a 3063-amino acid polyprotein. Phylogenetic analyses revealed that 24 SCMV isolates could be divided on the basis of the whole genome into 2 divergent evolutionary groups, which were associated with the host species. Among the populations, 15 potential recombination events were identified. The selection pressure on the genes of these SCMV isolates was also calculated. The results confirmed that all the genes were under negative selection.ConclusionsNegative selection and recombination appear to be important evolutionary factors shaping the genetic structure of these SCMV isolates. SCMV is distributed widely in China and exists as numerous strains with distinct genetic diversity. Our findings will provide a foundation for evaluating the epidemiological characteristics of SCMV in China and will be useful in designing long-term, sustainable management strategies for SCMV.

The complete genome sequences of two naturally occurring recombinant isolates of Sugarcane mosaic virus from Iran.

Sugarcane mosaic virus (SCMV) is the most prevalent virus causing sugarcane mosaic and maize dwarf mosaic diseases. Here, we presented the first two complete genomic sequences of Iranian SCMV isolates, NRA and ZRA from sugarcane and maize. The complete genome sequences of NRA and ZRA were, respectively, 9571 and 9572 nucleotides (nt) in length, excluding the 3'-terminal poly(A) tail. Both isolates contained a 5'-untranslated region (UTR) of 149 nt, an open reading frame of 9192 nt encoding a polyprotein of 3063 amino acids (aa), and 3'-UTR of 230 nt for NRA and 231 nt for ZRA. SCMV-NRA and -ZRA genome nucleotide sequences were 97.3 % identical and shared nt identities of 79.1-92 % with those of other 21 SCMV isolates available in the GenBank, highest with the isolate Bris-A (AJ278405) (92 and 91.7 %) from Australia. When compared for separate genes, most of their genes shared the highest identities with Australian and Argentinean isolates. Phylogenetic analysis of the complete genomic sequences reveals that SCMV can be clustered to three groups. Both NRA and ZRA were clustered with sugarcane isolates from Australia and Argentina in group III but formed a separate sublineage. Recombination analysis showed that both isolates were intraspecific recombinants, and represented two novel recombination patterns of SCMV (in the P1 coding region). NRA had six recombination sites within the P1, HC-Pro, CI, NIa-Vpg, and NIa-pro coding regions, while ZRA had four within the P1, HC-Pro, NIa-Pro, and NIb coding regions.

Synergistic infection of two viruses MCMV and SCMV increases the accumulations of both MCMV and MCMV-derived siRNAs in maize.

The co-infection of Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV) can cause maize lethal necrosis. However, the mechanism underlying the synergistic interaction between these two viruses remains elusive. In this study, we found that the co-infection of MCMV and SCMV increased the accumulation of MCMV. Moreover, the profiles of virus-derived siRNAs (vsiRNAs) from MCMV and SCMV in single- and co-infected maize plants were obtained by high-throughput sequencing. Our data showed that synergistic infection of MCMV and SCMV increased remarkably the accumulation of vsiRNAs from MCMV, which were mainly 22 and 21 nucleotides in length. The single-nucleotide resolution maps of vsiRNAs revealed that vsiRNAs were almost continuously but heterogeneously distributed throughout MCMV and SCMV genomic RNAs, respectively. Moreover, we predicted and annotated dozens of host transcript genes targeted by vsiRNAs. Our results also showed that maize DCLs and several AGOs RNAs were differentially accumulated in maize plants with different treatments (mock, single or double inoculations), which were associated with the accumulation of vsiRNAs. Our findings suggested possible roles of vsiRNAs in the synergistic interaction of MCMV and SCMV in maize plants.

Genetic diversity of maize accessions for maizelethal necrosis disease resistance

Maize is among the most preferred crop in Tanzania and other parts of the world. However, its production has been facing a number of challenges. Maize Lethal Necrosis Disease (MLND) is a new challenge in Eastern Africa. The control of MLND is said to be complicated as it is caused by a combination of more than one virus viz. Maize Chlorotic Mottle Virus (MCMV) and Sugarcane Mosaic Virus (SCMV). Stakeholders agree that the priority is to identify MLND resistant maize varieties. Genetic diversity provides the source of traits required against maize production challenges such as MLND. The study of genetic diversity in maize accessions often involves characterizing morphological plant characteristics as well as molecular marker techniques to study variation at DNA level. This review explores different literatures that address the importance of genetic diversity and the possibility of generating information towards obtaining potential materials against maize challenges and MLND in particular.

Association mapping resolving the major loci Scmv2 conferring resistance to sugarcane mosaic virus in maize

Sugarcane mosaic virus (SCMV) is one of the most damaging virus diseases in maize. Two major loci, Scmv1 and Scmv2, have been identified in many studies across a broad spectrum of germplasm by linkage mapping. In this study, we undertook a genome-wide association study (GWAS) in a maize association panel comprising 504 diverse inbred lines with over 556,000 SNP markers in three environments. Extensive phenotypic variation of resistance to SCMV was observed in the association panel. GWAS identified five genes significantly associated with resistance to SCMV. A cluster of four genes was detected near or within the Scmv2 region on chromosome 3 (bin 3.05). GRMZM2G116204, which encoded auxin binding protein and resided within the fine-mapped Scmv2 region, was predicted as the most likely candidate gene for Scmv2. In conclusion, we found that GWAS along with linkage analyses are effective approaches to the mapping of resistance to SCMV and to the subsequent identification of causal genes.

Maize-Pathogen Interactions: An Ongoing Combat from a Proteomics Perspective.

Maize (Zea mays L.) is a host to numerous pathogenic species that impose serious diseases to its ear and foliage, negatively affecting the yield and the quality of the maize crop. A considerable amount of research has been carried out to elucidate mechanisms of maize-pathogen interactions with a major goal to identify defense-associated proteins. In this review, we summarize interactions of maize with its agriculturally important pathogens that were assessed at the proteome level. Employing differential analyses, such as the comparison of pathogen-resistant and susceptible maize varieties, as well as changes in maize proteomes after pathogen challenge, numerous proteins were identified as possible candidates in maize resistance. We describe findings of various research groups that used mainly mass spectrometry-based, high through-put proteomic tools to investigate maize interactions with fungal pathogens Aspergillus flavus, Fusarium spp., and Curvularia lunata, and viral agents Rice Black-streaked Dwarf Virus and Sugarcane Mosaic Virus.

Registration of ‘UFCP 82‐1655’ Sugarcane

‘UFCP 82‐1655’ (Reg. No. CV‐164; PI 673050), a high fiber and low sucrose sugarcane, also called energy cane (a complex hybrid of Saccharum sp.), was developed through the collaborative effort of the University of Florida (UF) and the USDA‐ARS, Canal Point (CP) for its potential use in cellulosic ethanol production in Florida. UFCP 82‐1655 has moderate to high resistance against smut (caused by Sporisorium scitamineum). UFCP 82‐1655 did not have any natural infestation of brown rust (caused by Puccinia melanocephala H. &amp; P. Sydow), orange rust (caused by P. kuehnii), mosaic (caused by Sugarcane mosaic virus) and leaf scald [caused by Xanthomonas albilinenas (Ashby) Dawson]. Dry biomass yield (soluble plus insoluble dry weight) of UFCP 82‐1655 was not significantly different from ‘L 79‐1002’. Averaged across different crop cycles (plant cane, first ratoon, second ratoon, and third ratoon) at three locations in Florida (Citra, Tecan and Lykes Bros. farms), mean dry biomass yield of UFCP 82‐1655 was 32.7 Mg ha−1 compared with 30.6 Mg ha−1 for the reference check, L 79‐1002. Plant composition (% fiber) of UFCP 82‐1655 is composed of 41.7% cellulose, 27.9% hemicellulose, 22.6% lignin, 2.6% nonstructural ash, 2% structural ash, and 1.6% structural protein, which is quite similar to L 79‐1002. UFCP 82‐1655 is released to enhance genetic diversity and to improve disease resistance in energy cane.

Characterization of Sugarcane Mosaic Virus Scmv1 and Scmv2 Resistance Regions by Regional Association Analysis in Maize.

Sugarcane Mosaic Virus (SCMV) causes one of the most severe virus diseases in maize worldwide, resulting in reduced grain and forage yield in susceptible cultivars. In this study, two association panels consisting of 94 inbred lines each, from China and the U.S., were characterized for resistance to two isolates: SCMV-Seehausen and SCMV-BJ. The population structure of both association panels was analyzed using 3072 single nucleotide polymorphism (SNP) markers. The Chinese and the U.S. panel were both subdivided into two sub-populations, the latter comprised of Stiff Stalk Synthetic (SS) lines and Non Stiff Stalk Synthetic (NSS). The relative kinships were calculated using informative 2947 SNPs with minor allele frequency ≥ 5% and missing data ≤ 20% for the Chinese panel and 2841 SNPs with the same characteristics were used for the U.S. panel. The Scmv1 region was genotyped using 7 single sequence repeat (SSR) and sequence-tagged site (STS) markers, and 12 SSR markers were used for the Scmv2 region in the U.S. panel, while 5 of them were used for the Chinese panel. For all traits, a MLM (Mix Linear Model) controlling both population structure and relative kinship (Q + K) was used for association analysis. Three markers Trx-1, STS-11, and STS-12 located in the Scmv1 region were strongly associated (P = 0.001) with SCMV resistance, and explained more than 16.0%, 10.6%, and 19.7% of phenotypic variation, respectively. 207FG003 located in the Scmv2 region was significantly associated (P = 0.001) with SCMV resistance, and explained around 18.5% of phenotypic variation.

Genome-wide association and genomic prediction of resistance to maize lethal necrosis disease in tropical maize germplasm.

Key messageGenome-wide association analysis in tropical and subtropical maize germplasm revealedthatMLND resistance is influenced by multiple genomic regions with small to medium effects.The maize lethal necrosis disease (MLND) caused by synergistic interaction of Maize chlorotic mottle virus and Sugarcane mosaic virus, and has emerged as a serious threat to maize production in eastern Africa since 2011. Our objective was to gain insights into the genetic architecture underlying the resistance to MLND by genome-wide association study (GWAS) and genomic selection. We used two association mapping (AM) panels comprising a total of 615 diverse tropical/subtropical maize inbred lines. All the lines were evaluated against MLND under artificial inoculation. Both the panels were genotyped using genotyping-by-sequencing. Phenotypic variation for MLND resistance was significant and heritability was moderately high in both the panels. Few promising lines with high resistance to MLND were identified to be used as potential donors. GWAS revealed 24 SNPs that were significantly associated (P < 3 × 10−5) with MLND resistance. These SNPs are located within or adjacent to 20 putative candidate genes that are associated with plant disease resistance. Ridge regression best linear unbiased prediction with five-fold cross-validation revealed higher prediction accuracy for IMAS-AM panel (0.56) over DTMA-AM (0.36) panel. The prediction accuracy for both within and across panels is promising; inclusion of MLND resistance associated SNPs into the prediction model further improved the accuracy. Overall, the study revealed that resistance to MLND is controlled by multiple loci with small to medium effects and the SNPs identified by GWAS can be used as potential candidates in MLND resistance breeding program.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-015-2559-0) contains supplementary material, which is available to authorized users.

Registration of ‘UFCP 78-1013’ Sugarcane Cultivar

Sugarcane (a complex hybrid of Saccharum sp.) cultivar UFCP 78-1013 (Reg. No. CV-162; PI 673049) was developed through the collaborative efforts of the University of Florida (UF) and the USDA-ARS, Canal Point (CP), and released for its potential use in cellulosic ethanol production in Florida. Biomass is the most favorable characteristic of a potential feedstock for cellulosic ethanol production and must be improved in cultivars adapted to Florida conditions should cellulosic ethanol prove feasible for energy production. Averaged across eight location-years of field trials, mean dry biomass yield of UFCP 78-1013 was numerically greater than the reference check, ‘L 79-1002’. Plant composition of UFCP 78-1013 is similar to L 79-1002. The parents for UFCP 78-1013 are the sugarcane cultivar CP 68-1067 (female parent) and S. spontaneum line SES 602 (male parent). UFCP 78-1013 has moderate to high resistance against smut (caused by Sporisorium scitamineum) with significantly lower infestation than L 79-1002, under both natural environmental conditions and artificial inoculation. UFCP 78-1013 did not have symptoms of brown rust (caused by Puccinia melanocephala H. & P. Sydow), orange rust (caused by P. kuehnii), mosaic (caused by Sugarcane mosaic virus) or leaf scald [caused by Xanthomonas albilineans (Ashby) Dowson] during field evaluations. UFCP 78-1013 is adapted to marginal or sandy soils of Florida.

First report of Sugarcane streak mosaic virus in Iran

Sugarcane is one of the most economically important crops in south-western Iran and viral diseases such as those caused by Sugarcane mosaic virus (SCMV) have caused yield losses in some fields. A survey was conducted in Khuzestan province…

Maize Lethal Necrosis (MLN), an Emerging Threat to Maize-Based Food Security in Sub-Saharan Africa.

In sub-Saharan Africa, maize is a staple food and key determinant of food security for smallholder farming communities. Pest and disease outbreaks are key constraints to maize productivity. In September 2011, a serious disease outbreak, later diagnosed as maize lethal necrosis (MLN), was reported on maize in Kenya. The disease has since been confirmed in Rwanda and the Democratic Republic of Congo, and similar symptoms have been reported in Tanzania, Uganda, South Sudan, and Ethiopia. In 2012, yield losses of up to 90% resulted in an estimated grain loss of 126,000 metric tons valued at $52 million in Kenya alone. In eastern Africa, MLN was found to result from coinfection of maize with Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV), although MCMV alone appears to cause significant crop losses. We summarize here the results of collaborative research undertaken to understand the biology and epidemiology of MLN in East Africa and to develop disease management strategies, including identification of MLN-tolerant maize germplasm. We discuss recent progress, identify major issues requiring further research, and discuss the possible next steps for effective management of MLN.

Genetic diversity of viruses associated with sugarcane mosaic disease of sugarcane inter-specific hybrids in China

In this study, we investigated 78 sugarcane samples with severe mosaic symptoms collected from four provinces of southern China: Guangxi, Yunnan, Hainan, and Guangdong, which cover nearly 85 % of commercial sugarcane planting zones in China. Using RT-PCR, sequencing and phylogenetic analysis, we identified 72 hybrid sugarcane samples containing causal agents of sugarcane mosaic disease. Among these, 66 virus isolates were identified as Sorghum mosaic virus (SrMV) (84.6 %), four were identified as Sugarcane streak mosaic virus (SCSMV) (5.1 %), and two were identified as Sugarcane mosaic virus (SCMV) (2.6 %). The isolates of SrMV were classified into three subgroups: I, II, and III with a 95 % similarity level. The two largest subgroups, SrMV I containing 36 sugarcane mosaic diseases isolates (46.2 %), and SrMV III containing 20 isolates (25.6 %), were prevalent in Guangdong and Guangxi provinces; however, SrMV II containing five isolates (6.4 %) did not exhibit any close association with geographical distribution. The popular sugarcane cultivar, ROC22, was found to be infected with all the three subgroup types of SrMV. According to our knowledge, this is the first reported detection of the co-infection of SrMV and SCSMV in Saccharum hybrid (YN-bs-9). Recombination analysis indicated recombination between different isolates mostly occurring in Yunnan and Guangxi provinces among the SrMV I group. This study provides insight into the species diversity and geographical distribution of causal agents of sugarcane mosaic disease, and provides the basis for its identification, prevention, and future control efforts.

First Report of Lethal Necrosis Disease Associated With Co-Infection of Finger Millet With Maize chlorotic mottle virus and Sugarcane mosaic virus in Kenya

First Report of Lethal Necrosis Disease Associated With Co-Infection of Finger Millet With <i>Maize chlorotic mottle virus</i> and <i>Sugarcane mosaic virus</i> in Kenya