Stable Introduction of Plant-Virus-Inhibiting Wolbachia into Planthoppers for Rice Protection (original) (raw)
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Journal of Asia-Pacific Entomology, 2015
Members of the genus Wolbachia are a group of endosymbiotic bacteria that infect a wide range of arthropods and cause reproductive alterations in their hosts. A survey of these endosymbionts in leafhoppers and planthoppers in rice agroecosystems from 20 provinces in 4 different geographic regions of Thailand was carried out during January 2012 to December 2013. Most species were collected from growing rice fields among 5 habitat types surveyed from the Central and the Northeast regions. Infections of Wolbachia were screened by using polymerase chain reaction with wsp, ftsZ, 16S rRNA and groE gene primers and distinguished between A and B supergroup using wsp primers. Species of 15 leafhoppers and 18 planthoppers were collected and identified with 1, 14, 2, 14, 1 and 1 sp. representing the family Aphrophoridae, Cicadellidae, Cixiidae, Delphacidae, Lophopidae and Meenoplidae, respectively. Wolbachia were detected in 1377 of 1849 individuals (74.5%) representing 17 of 33 species (51.5%) of leafhoppers and planthoppers. Wolbachia had not been previously reported from Oliarus sp., Pyrilla perpusilla, Sogatella kolophon and S. vibix. The relative densities of Wolbachia within each individual were determined using quantitative real-time PCR and the result showed that the small brown planthopper Laodelphax striatellus had the highest Wolbachia density. These findings indicated that Wolbachia are distributed throughout leafhoppers and planthoppers from Thailand, suggesting that Wolbachia dynamics in nature may be affected by ecological factors.
Elsevier , 2015
This study examines the utility of resistant varieties and their associated resistance genes against brown planthopper, Nilaparvata lugens (Stål), populations from South and South East Asia. A collection of 39 rice accessions that included resistant, tolerant and susceptible varieties and breeding lines were examined for performance against populations of N. the Philippines (2). Planthopper virulence varied between regions; however only 6 varieties were generally less damaged than the susceptible check Taichung Native 1 (TN1) among !50% of the test populations. Each of these 6 varieties contained multiple resistance genes. One further variety, also with multiple resistance genes, and a modern cultivar (possibly with the Bph3 gene) were moderately effective against the South Asian populations, whereas a traditional variety with the Bph6 gene was effective against South East Asian populations. Bph1, bph2, bph5, bph7, bph8, Bph9, Bph10 and Bph18 were ineffective against most planthopper populations. Bph20, Bph21, and Bph17 have potential to be used in resistance breeding in both South and South East Asia, whereas BPH25 and BPH26 have potential for use in South Asia. The results indicate that only a few of the currently available resistance genes will be effective in monogenic rice lines; but that pyramiding of two or more genes with strong to weak resistance could improve resistance strength and durability as apparent with the most resistant, traditional varieties. Strategies to avoid planthopper adaptation to resistant rice varieties are discussed.
Risk assessment for rice planthopper and tungro disease outbreaks
Crop Protection, 1996
processes used in the management of two major pests of Asian rice production, namely, the brown planthopper (BPH) Nilaparvatu lugens. and rice tungro virus disease (RTVD), which is transmitted primarily by green leafhoppers, Nephotettix spp. BPH exhibits quite different population dynamics and behaviour in the tropical and the temperate parts of its range, and this has important implications for its management. In the tropics, BPH is usually regarded as a secondary pest which becomes a problem only due to misuse of insecticides. Thus the risk of inadvertently inducing resurgence by the planthoppcr must be considered when attempting to control other rice pests. In temperate rice systems, the number of immigrants entering the crop and the temperature during the growing season arc the main driving variables determining BPH population size. Hcrc decisions can be made both in response to early warnings of planthopper immigration and in response to monitoring of populations during the cropping period. With RTVD (which occurs only in tropical systems), measures to prevent plant-to-plant spread of the disease within a crop are relatively incffcctivc.
HAYATI Journal of Biosciences, 2021
Brown planthopper biotype 1, 2, 3 and a representative field population are required for resistance screening of promising rice lines in Indonesia, but the current biotype stocks has shown deviation in virulence patterns. The objectives of this study were to develop a set of brown planthopper populations with differential virulence and to investigate their genetic variability using SSR marker. Females originated from two field populations were selected on variety Mudgo (carries Bph1 gene) or ASD7 (bph2 gene) using honeydew excretion as the virulence parameter. Selection cycles resulted in population T, M, A, and R, which was raised and adapted on variety TN1 (carries no Bph gene), Mudgo, ASD7, and Rathu Heenathi (Bph3, Bph17), respectively. Population R was the most virulent as expected and can be used to represent a field population, but the remaining populations still showed high virulence level. AMOVA and PCoA results based on analysis with 38 SSR primer pairs revealed partial ge...
Relationship between Planthoppers (Nilaparvata lugens and Sogatella furcifera) anc Rice Diseases
Korean Journal of Applied Entomology, 1985
The locational preference of the brown planthopper (BPH) Nilaparvata lugens () and the whitebacked plant hopper (WBPH) Sogatella furcifera(Horvath) was studied on rice cultivars IR22 and IR36 as an integral part of subsequent research on insect-fungal pathogen relationships. The BPH was observed to stay consistently on the basal portion while the WBPH showed a general preference for the upper portion regardless of varieties, rice growth stages and insect population density levels. The habitat preference of both species (BPH and WBPH) was found not to be affected by the presence of the other species when both species are present on the same host plant Five rice cultivars with different reactions to BPH biotype 2 were used in the study on BPH-Rhizoctonia solani relationship: IR22 and TN1 (susceptible); Triveni and ASD7 (moderately resistant); and IR42 (resistant). Test plants were inoculated with R. solani (Kuhn) days after insect infestation. Sheath blight disease severity/incidence ...
Journal of insect science, 2020
Wolbachia is a maternally inherited bacterium ubiquitous in insects that has attracted interest as a prospective insect pest-control agent. Here, we detected and characterized Wolbachia in the leafhoppers Matsumuratettix hiroglyphicus (Matsumura) (Cicadellidae: Hemiptera) and Yamatotettix flavovittatus Matsumura (Cicadellidae: Hemiptera), insect vectors of the phytoplasma that cause white leaf disease in sugarcane. The 16S rRNA and wsp gene markers revealed that Wolbachia was not present in the M. hiroglyphicus but naturally occurs in Y. flavovittatus. Additionally, the infection rates in adult leafhoppers ranged from 0 to 100% depending on geographic location. Moreover, Wolbachia was detected in the eggs and first-to fifth-instar nymphs of Y. flavovittatus. A phylogenic tree of Wolbachia indicated that it resided in the monophyletic supergroup B clade and clustered in the Ori subgroup. Furthermore, fluorescence in situ hybridization revealed that Wolbachia localized to the egg apices, randomly distributed in the egg cytoplasm, and was concentrated in the nymph and adult bacteriomes, as well as occasional detection in the thorax and abdomen. To the best of our knowledge, the present study is the first to demonstrate the prevalence of Wolbachia in the leafhopper Y. flavovittatus. The obtained results would provide useful information for the future development of Wolbachia as a biological control agent for the leafhopper vectors.
Trends in Sciences
Rice ragged stunt virus, which was transmitted by the brown planthopper (Nilaparvata lugens Stål), was an economically important rice plant pathogen, and caused the yield losses of 10 - 100 % in Thailand and Asian rice cultivation areas. The purpose of this research was to assess the infectivity survival and the transmissibility of Rice ragged stunt virus from the frozen infected rice leaf tissues to the hosts, and the efficiency detection by the indirect enzyme-linked immunosorbent assay on nitrocellulose membranes. The result was shown that rice virus was successfully acquired from the infected rice leaf frozen samples at –20 °C (7 days and 10 months) by the insect vectors, which the reactions can be clearly detected on the nitrocellulose membranes. The efficiencies of the insect vector inoculated, and the rice plant transmitted were 60 - 100 % and 20 - 100 %, and the direct variations with increasing of the viral-minimal latent period at the 3 and 10 days after inoculation, respe...
Journal of Invertebrate Pathology, 2020
Wolbachia is a maternally inherited bacterium of insects that can affect host reproduction and fitness. We examined the effect of Wolbachia infection on the life history and reproductive traits of the leafhopper Yamatotettix flavovittatus, which is a vector of the phytoplasma that causes white leaf disease in sugarcane. This investigation was performed using Wolbachia-infected and uninfected leafhopper lineages. Results revealed that Wolbachia infection did not significantly affect the survival of nymphal stages, male longevity, and sex ratio. However, Wolbachia-infected lineages had prolonged immature development periods and female longevity. In intrapopulation crosses, Wolbachia infection had no significant effects on occupation success, number of eggs laid, and female offspring, but the effect on egg-hatching varied. In interpopulation crosses, Wolbachia infection had no significant effect on occupation success and female offspring, but it did affect the number of eggs laid and egg-hatching rates. Assortative pairings regarding infection status resulted in normal egg deposition and hatching, whereas disassortative pairings resulted in lower egg deposition and no hatching. Wolbachia was thus shown to be highly vertically transmitted (>98% of the tested individuals). Our findings provide additional data on the interactions between Wolbachia in insect hosts. This evidence of perfect maternal transmission and strong reproductive incompatibility highlights the importance of further studies on the use of Wolbachia as a biological control agent for the leafhopper vector.
Japanese journal of tropical agriculture, 1995
An avirulent green leafhopper (GLH) population was introduced and reared on a mixed cropping of two rice cultivars, IR42 and Pankhari 203. Although the GLH population required 43 days to complete the first generation, the time was reduced to about 30 days in the third and subsequent generations, which was close to the time required by the populations reared on the susceptible cultivar, TN1. This adapted GLH population was able to survive on IR42 and Pankhari 203, and to transmit both rice tungro bacilliform virus and rice tungro spherical virus to IR42, but only rice tungro bacilliform virus to Pankhari 203. The mixed cropping of two GLH-resistant cultivars was not considered to be effective for suppressing or delaying the development of varietal resistancebreaking populations of the GLH.