Data/hora: 09/05/2024 10:35:59

Biblioteca(s): | Epagri-Sede.
Data corrente: | 18/10/2022
Data da última atualização: | 18/10/2022
Autoria: | SILVA, M. C. C. R.; CASTILHOS, R. V.; NESI, C. N.; SILVA, L. R. S.; BENTO, J. M. S.
Título: | Dalbulus maidis, the insect vector of Maize rayado fino virus (MRFV), does not distinguish between two maize genotypes in field conditions but seems to prefer asymptomatic plants.
Ano de publicação: | 2022
Fonte/Imprenta: | In: WORKSHOP BRASILEIRO DE EPIDEMIOLOGIA DE DOENÇAS DE PLANTAS, 6., 2022, Chapecó. Resumos... Brasília: Sociedade Brasileira de Fitopatologia, 2022. p. 43
Idioma: | Inglês
Conteúdo: | The corn leafhopper Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae) is the vector for the Maize rayado fino virus (MRFV), and recent studies have demonstrated its ability to discriminate different maize genotypes (Virla et al. 2010; Faria et al. 2021). When a persistently transmitted virus is involved in a plant-insect interaction, a series of modifications can also occur that aids transmission and dissemination process, involving changes in the insect vector's behavior (Mauck et al. 2012). This study aimed to verify the presence of D. maidis on MRFV-symptomatic and non-symptomatic plants of P4285 hybrid (resistant to order Lepidoptera) and SCS156 Colorado (an open pollination variety) in a field experiment. The incidence of MRFV diseased plants and plant production was also recorded in both genotypes. A field study was carried out in the second season after maize genotypes were sown at Epagri experimental field in Chapecó (Santa Catarina, Brazil) in January 2021. The experiment was set with 6 parcels for each genotype, with 6 rows of 5 m and spaced 0.8 m. Plants in the rows were spaced with 0.2 m. Corn leafhoppers were visually counted in the maize whorl at 9, 12, 14 and 16 days after sown (d.a.s.). When it was no longer possible to count the insects directly from the plant, yellow sticky traps were installed in the center of the plot at 1 m high on the 23rd d.a.s. The traps were replaced weekly, for three consecutive weeks. The number of D. maidis in the plant whorl or captured in the traps was not statistically different for P4285 hybrid or SCS156 Colorado. Maize plants were displaying symptoms of MRFV at 14 d.a.s. We evaluated the incidence of MRFV-symptomatic plants by observing 10 plants in the center of the plot. There were more MRFV diseased plants in P4285 than in Colorado (x&#773; = 2.50 and 0.16, respectively, P-value = 0.001). We counted the number of D. maidis in 10 MRFV-diseased plants in each plot, and there was more leafhoppers in asymptomatic plants than in symptomatic, disregarding the genotype (x&#773; = 7.3 and 5.4, respectively, P-value = 0.008). Plants (~12 each plot) with and without MRFV symptoms were tagged during experiment conduction, and their cobs were harvested during physiological maturation in order to check plant production. The production of each maize genotype was affected by MRFV disease, as SCS156 Colorado produced 42% less if MRFV symptomatic plants, while P4285 produced 45% less in comparison with asymptomatic plants. In conclusion, D. maidis seems not to distinguish between P4285 and SCS156 Colorado in field conditions. However, a higher incidence of MRFV in the hybrid was observed in the early days of the crop, which may be due to a shorter incubation period of the virus in planta. Insects were more numerous in asymptomatic plants of either genotype, suggesting either a preference for symptomless plants or a manipulation of the virus for spreading. In the end, MRFV affected the productivity of both maize genotypes.
Thesagro: | corn stunt disease complex; epidemiology; insect transmissiom; plant virus.
Categoria do assunto: | O Insetos e Entomologia
URL: | http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_54624.pdf
Registro original: | Epagri-Sede (Epagri-Sede)
Exemplares: | Epagri-Sede - (107586-1) - UPC - PL - DD -  -  -  - DIS