Data/hora: 01/06/2024 08:27:33

Biblioteca(s): 	Epagri-Sede.	
Data corrente: 	02/05/2024	
Data da última atualização: 	02/05/2024	
Autoria: 	CANALE, M. C.; ANDRADE, M. V. S.; GORAYEB, E. S.; ZINGER, L. K. C. R.; CÓL, M. C.; PONTE, E. M. D.; SILVA, F. N.	
Título: 	Natural infectivity of the corn leafhopper, Dalbulus maidis, with the Corn Stunting Complex pathogens in Santa Catarina, Brazil.	
Ano de publicação: 	2024	
Fonte/Imprenta: 	In: INTERNATIONAL EPIDEMIOLOGY WORKSHOP, 13., 2024, Foz do Iguaçú, PR. Abstracts... Viçosa, MG: UFV, 2024. p. 40	
Idioma: 	Inglês	
Conteúdo: 	The Corn Stunting Complex is a growing concern in Brazil, marked by numerous outbreaks
since 2015, particularly impacting Santa Catarina state. In the 2020/21 season alone, the
state experienced a significant drop in productivity from the usual 7.,7 t/ha to 5.,5 t/ha,
resulting in a 38% decrease in yieldproduction. This complex involves the Maize bushy stunt
phytoplasma (?Candidatus Phytoplasma asteris?), Corn stunt spiroplasma (Spiroplasma
kunkelii), and Maize rayado fino virus (MRFV), all persistently transmitted by the corn
leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae). We intended to verify the natural
infectivity of D. maidis with both mollicutes and the virus during the 2021/22 and 2022/23
maize crop years in Santa Catarina State. Yellow sticky traps were installed in 23 maize
crops in different municipalities. The traps were weekly replaced and addressed to the
laboratory during 40 weeks, from July to April, which comprehended interseason (before
maize sowing), main season (first planting period, in August or September, depending on the
location), second season (second sowing season, generally in January) and postharvest. D
maidis specimens were removed from the traps and up to 7 samples were set using insects
in triplicates for each location and week, and submitted to molecular diagnosis. Both
mollicutes and the virus were found infecting the leafhoppers. Comparable prevalence with
an average count of 11.96 insects positive to spiroplasma and 7.51 to phytoplasma occurred
in the 2021/22 maize crop year, with the second season exhibiting the highest incidence of
mollicute-infected insects. In the subsequent maize crop year (2022/23), MRFV emerged as
the dominant pathogen with an average count of 25.5, followed by spiroplasma (11.1), while
phytoplasma exhibited a lower prevalence at 5.9. The seasonal analysis revealed
heightened prevalence of viruses and phytoplasma during the second season, contrasting
with spiroplasma, which exhibited higher prevalence during the main season and
interseason. This exploratory analysis showed that D. maidis infectivity with the corn stunting
complex diseases pathogens associated with corn stunting disease complex diseases was
distinct between both assessed maize crop years. This suggests that natural infectivity of
this leafhopper vector may be associated with singular aspects of each year, such as
climate, which perhaps influence the epidemiology of this pathosystem. These results are
derived from Monitora Milho SC Program, an advisory system that aims to support the maize
productive sector of Santa Catarina state regarding the Corn Stunting Complex. This
information can be used in the future to design an accurate risk analysis to this pathosystem.	
Thesagro: 	cigarrinha-do-milho; infectividade; inseto vetor; molicutes; Monitoramento; vírus.	
Categoria do assunto: 	X Pesquisa, Tecnologia e Engenharia	
URL: 	http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_60784.pdf	
Registro original: 	Epagri-Sede (Epagri-Sede)	
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