scholarly journals Resistance Evaluation of Dominant Varieties against Southern Rice Black-Streaked Dwarf Virus in Southern China

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1501
Author(s):  
Shunkang Zhou ◽  
Yaling Zhao ◽  
Zhenyi Liang ◽  
Ruifeng Wu ◽  
Biao Chen ◽  
...  
Keyword(s):  
Southern China ◽  
Virus Titer ◽  
Incidence Rates ◽  
Dwarf Virus ◽  
Height Loss ◽  
Insect Vector ◽  
Long Distance ◽  
Rice Varieties ◽  
Plant Weight ◽  
Virus Acquisition

Southern rice black-streaked dwarf virus (SRBSDV), a Fijivirus in the Reoviridae family, is transmitted by the white-backed planthopper (Sogatella furcifera, WBPH), a long-distance migratory insect, and presents a serious threat to rice production in Asia. It was first discovered in China’s Guangdong Province in 2001 and has been endemic in the south of China and north of Vietnam for two decades, with serious outbreaks in 2009, 2010, and 2017. In this study, we evaluated the resistance of 10 dominant rice varieties from southern China, where the virus overwinters and accumulates as a source of early spring reinfection, against this virus by artificial inoculation. The results showed that in all tested varieties there was no immune resistance, but there were differences in the infection rate, with incidence rates from 21% to 90.7%, and in symptom severity, with plant weight loss from 66.71% to 91.20% and height loss from 34.1% to 65.06%. Additionally, and valuably, the virus titer and the insect vector virus acquisition potency from diseased plants were significantly different among the varieties: an over sixfold difference was determined between resistant and susceptible varieties, and there was a positive correlation between virus accumulation and insect vector virus acquisition. The results can provide a basis for the selection of rice varieties in southern China to reduce the damage of SRBSDV in this area and to minimize the reinfection source and epidemics of the virus in other rice-growing areas.

scholarly journals Dynamics of Southern rice black-streaked dwarf virus in Rice and Implication for Virus Acquisition

2013 ◽  
Vol 103 (5) ◽  
pp. 509-512 ◽  
Author(s):  
Keiichiro Matsukura ◽  
Tomomi Towata ◽  
Junichi Sakai ◽  
Masatoshi Onuki ◽  
Mitsuru Okuda ◽  
...  
Keyword(s):  
Southern China ◽  
Virus Titer ◽  
Viral Disease ◽  
Leaf Sheath ◽  
Dwarf Virus ◽  
Stunted Growth ◽  
Virus Acquisition ◽  
East And Southeast Asia ◽  
Polymerase Chain ◽  
The Relationship

A novel viral disease of rice caused by Southern rice black-streaked dwarf virus (SRBSDV) has spread throughout East and Southeast Asia since the mid-2000s. Outbreaks of this viral disease occur yearly in southern parts of Japan concurrently with overseas migration of the planthopper vector Sogatella furcifera from southern China during the rainy season (from late June to early July). We examined the dynamics (changes in titer and localization) of SRBSDV on rice using reverse-transcription real-time polymerase chain reaction and determined the relationship between virus titer in plants and virus acquisition by S. furcifera. Under a constant temperature of 27°C, a substantial increase of SRBSDV titer in the leaf sheath together with typical symptoms (stunted growth and twisting of leaf tips) was observed at 20 days after the end of a 7-day exposure of viruliferous S. furcifera. Approximately 40% of S. furcifera acquired SRBSDV through feeding for 5 days on rice plants that were infected following exposure to viruliferous vectors for 10 to 15 days. These results suggest that rice infected by S. furcifera can be a source of SRBSDV before the next generation of S. furcifera emerges.

scholarly journals Adverse Effects of Rice gall dwarf virus upon its Insect Vector Recilia dorsalis (Hemiptera: Cicadellidae)

Plant Disease ◽  
2016 ◽  
Vol 100 (4) ◽  
pp. 784-790 ◽  
Author(s):  
Yong Chen ◽  
Chengcong Lu ◽  
Manman Li ◽  
Wei Wu ◽  
Guohui Zhou ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Molecular Level ◽  
Southern China ◽  
Culture Method ◽  
Protein Product ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Direct Effects ◽  
Rice Gall Dwarf Virus ◽  
Polymerase Chain

Rice gall dwarf virus (RGDV), a plant reovirus that threatens rice production in Southeast Asia and Southern China, is transmitted by the leafhopper vector Recilia dorsalis in a persistent-propagative manner. To assess the direct effects of RGDV on R. dorsalis, we established an infected leafhopper population from eggs laid by viruliferous females using the water-soaked filter paper culture method. Life history parameters indicated that the virus was harmful to its vector in terms of all biotic indices, including reduced survival rate, emergence rate, fecundity, and longevity of adults, compared with a nonviruliferous control population. Those findings were supported by systematic monitoring of viruliferous rates of R. dorsalis in different overwintering generations. To better elucidate the adverse effects of RGDV on its vector, we measured fecundity at the molecular level using quantitative reverse-transcription polymerase chain reaction and Western blot assays, which revealed differential expression of vitellogenin (Vg) in viruliferous versus nonviruliferous adult females. We infer that RGDV reduced levels of Vg transcript and protein product, resulting in the lower fecundity of its vector. Overall, this study demonstrates how RGDV exerts an adverse effect on R. dorsalis, which hinders the expansion of viruliferous populations of the insect.

scholarly journals Plasma Epstein-Barr virus DNA and risk of nasopharyngeal carcinoma in a prospective seropositive population

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wen-Jie Chen ◽  
Wen-Na Xu ◽  
Hai-Yun Wang ◽  
Xiao-Xia Chen ◽  
Xue-Qi Li ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Epstein Barr Virus ◽  
Screening Program ◽  
Southern China ◽  
Incidence Rates ◽  
Cox Proportional Hazards ◽  
Barr Virus ◽  
Ebv Dna ◽  
Epstein Barr

Abstract Objective Plasma Epstein-Barr virus (EBV) DNA is considered a biomarker for nasopharyngeal carcinoma (NPC). However, its long-term role in NPC development is unclear. Materials and methods A total of 1363 participants seropositive for EBV VCA-IgA and EBNA1-IgA in a community-based NPC screening program in southern China were tested for plasma EBV DNA levels by real-time qPCR between 2008 and 2015. New NPC cases were confirmed by active follow-up approach and linkage to local cancer registry through the end of 2016. Cox proportional hazards regression analysis was performed to calculate the hazard ratios (HRs) for NPC risk with plasma EBV DNA. Results Thirty patients were newly diagnosed during a median 7.5 years follow-up. NPC incidence increased with the plasma EBV DNA load ranging from 281.46 to 10,074.47 per 100,000 person-years in participants with undetectable and ≥ 1000 copies/ml levels; the corresponding cumulative incidence rates were 1.73 and 50%. Furthermore, plasma EBV DNA loads conferred an independent risk for NPC development after adjustment for other risk factors, with HRs of 7.63 for > 3–999 copies/ml and 39.79 for ≥1000 copies/ml. However, the HRs decreased gradually after excluding NPC cases detected in the first 2 to 3 years and became statistically nonsignificant by excluding cases detected during the first 4 years. Conclusion Elevated plasma EBV DNA can predict NPC risk over 3 years. Monitoring plasma EBV DNA can be used as a complementary approach to EBV serological antibody-based screening for NPC.

scholarly journals HAND-FOOT-AND-MOUTH DISEASE EPIDEMIOLOGICAL STATUS AND RELATIONSHIP WITH METEOROLOGICAL VARIABLES IN GUANGZHOU, SOUTHERN CHINA, 2008-2012

2014 ◽  
Vol 56 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Tiegang Li ◽  
Zhicong Yang ◽  
Xiangyi Liu ◽  
Yan Kang ◽  
Ming Wang
Keyword(s):  
Negative Binomial ◽  
Southern China ◽  
Foot And Mouth Disease ◽  
Negative Binomial Regression ◽  
Incidence Rates ◽  
Mouth Disease ◽  
Meteorological Variables ◽  
High Morbidity ◽  
Weather Factors ◽  
Foot And Mouth

Hand-foot-and-mouth disease (HFMD) is becoming one of the extremely common airborne and contact transmission diseases in Guangzhou, southern China, leading public health authorities to be concerned about its increased incidence. In this study, it was used an ecological study plus the negative binomial regression to identify the epidemic status of HFMD and its relationship with meteorological variables. During 2008-2012, a total of 173,524 HFMD confirmed cases were reported, 12 cases of death, yielding a fatality rate of 0.69 per 10,000. The annual incidence rates from 2008 to 2012 were 60.56, 132.44, 311.40, 402.76, and 468.59 (per 100,000), respectively, showing a rapid increasing trend. Each 1 °C rise in temperature corresponded to an increase of 9.47% (95% CI 9.36% to 9.58%) in the weekly number of HFMD cases, while a one hPa rise in atmospheric pressure corresponded to a decrease in the number of cases by 7.53% (95% CI -7.60% to -7.45%). Similarly, each one percent rise in relative humidity corresponded to an increase of 1.48% or 3.3%, and a one meter per hour rise in wind speed corresponded to an increase of 2.18% or 4.57%, in the weekly number of HFMD cases, depending on the variables considered in the model. These findings revealed that epidemic status of HFMD in Guangzhou is characterized by high morbidity but low fatality. Weather factors had a significant influence on the incidence of HFMD.

scholarly journals A novel method for transmitting southern rice black-streaked dwarf virus to rice without insect vector

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Lu Yu ◽  
Jing Shi ◽  
Lianlian Cao ◽  
Guoping Zhang ◽  
Wenli Wang ◽  
...  
Keyword(s):  
Dwarf Virus ◽  
Insect Vector ◽  
Novel Method

Grassy Weeds and Corn as Potential Sources of Barley yellow dwarf virus Spread Into Winter Wheat

Plant Disease ◽  
2020 ◽  
pp. PDIS-05-20-1004
Author(s):  
Mahnaz Rashidi ◽  
Regina K. Cruzado ◽  
Pamela J. S. Hutchinson ◽  
Nilsa A. Bosque-Pérez ◽  
Juliet M. Marshall ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Barley Yellow Dwarf Virus ◽  
Rhopalosiphum Padi ◽  
Virus Titer ◽  
Yellow Dwarf ◽  
Dwarf Virus ◽  
Virus Spread ◽  
Weed Species ◽  
Barley Yellow Dwarf ◽  
Yellow Dwarf Virus

Barley yellow dwarf virus (BYDV) is an important vector-borne pathogen of cereals. Although many species of grasses are known to host BYDV, knowledge of their role in virus spread in regional agroecosystems remains limited. Between 2012 and 2016, Idaho winter wheat production was affected by BYDV. BYDV-PAV and the bird cherry-oat aphid (BCOA) (Rhopalosiphum padi L.) vector were commonly present in the affected areas. A series of greenhouse bioassays were performed to examine whether two types of corn (Zea mays L.), dent and sweet, and three commonly found grassy weeds, downy brome (Bromus tectorum L.), green foxtail (Setaria viridis L.), and foxtail barley (Hordeum jubatum L.), can be inoculated with BYDV (species BYDV-PAV) by BCOA and also act as sources of the virus in winter wheat. BCOA successfully transmitted BYDV-PAV to both corn types and all weed species. Virus titers differed between the weed species (P = 0.032) and between corn types (P = 0.001). In transmission bioassays, aphids were able to survive on these host plants during the 5-day acquisition access period and later successfully transmitted BYDV-PAV to winter wheat (var. SY Ovation). Transmission success was positively correlated with the virus titer of the source plant (P < 0.001) and influenced by weed species (P = 0.028) but not corn type. Overall, the results of our inoculation and transmission assays showed that the examined weed species and corn types can be inoculated with BYDV-PAV by BCOA and subsequently act as sources of infections in winter wheat.

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