Resistência da seringueira ao mal das folhas e modelagem no patossistema Hevea sp. – Microcyclus ulei através dos parâmetros monocíclicos
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2014-02-28
Autores
Bevenuto, João Alberto Zago [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O maior entrave à expansão da heveicultura no Brasil é a doença conhecida por mal das folhas causada pelo fungo Microcyclus ulei, cujos sintomas ocorrem nas folhas jovens, causando intensas desfolhas, diminuindo a produção de látex e até mesmo a morte em plantas suscetíveis. Consiste numa ameaça constante aos plantios do Oriente. Com a evolução dos programas de melhoramento genético tradicional, atualmente são utilizados clones híbridos interespecíficos, os quais são mais produtivos e apresentam melhor resistência aos patógenos. Através dos programas de melhoramento genético tradicional, não houve progresso significativo quanto à resistência ao mal das folhas, devido à seleção serem dirigida para clones com resistência completa. Neste patossistema a resistência horizontal (RH) e resistência vertical (RV) podem agir simultaneamente, sendo complexa e de difícil quantificação. Este trabalho teve como objetivo caracterizar o tipo de lesão foliar do patossistema Hevea sp. x M. ulei, verificar a suscetibilidade clonal aos patógenos, analisar a freqüência de infecção visando quantificar a resistência no patossistema Hevea sp. x M. ulei e sugerir clones diferenciadores de seringueira além de quantificar as raças de M. ulei no Brasil. Os parâmetros monocíclicos (período latente e diâmetro de lesão) são aplicáveis na quantificação de resistência no patossistema Hevea sp. x M. ulei. O período de latência teve pouca variação entre os clones. O diâmetro de lesão teve variação ampla entre os clones, sendo um parâmetro discriminante para a resistência horizontal e resistência vertical. Várias raças deste patógeno foram descritas no Brasil, baseada em uma série de clones diferenciadores. Diante disso foi utilizado testes com 11 clones diferenciadores já conhecidos na literatura: MDF 180, Fx 3844, Fx 985, Fx 4098, Fx 2261, Fx 2804, Fx 3899, IAN 6158, IAN 3087,...
The biggest barrier to expansion of rubber cultivation in Brazil is the disease known as leaf blight caused by the fungus Microcyclus ulei whose symptoms occur in young leaves, causing severe defoliation, reducing the production of latex and even death in susceptible plants. Is a constant threat to the plantations of the East. With the evolution of traditional breeding programs currently interspecific hybrid clones are used, which are more productive and have better resistance to pathogens. Through traditional breeding programs, there was no significant progress for resistance to leaf blight, due to selection be directed to clones with complete resistance. This pathosystem horizontal resistance (HR) and vertical resistance (VR) can act simultaneously, being complex and difficult to quantify. This study aimed to characterize the type of leaf injury pathossystem Hevea sp. x M. ulei verify clonal susceptibility to pathogens, to analyze the frequency of infection to quantify the resistance in the pathosystem Hevea sp. x M. ulei and suggest different clones of rubber and quantifies the races of M. ulei in Brazil. Monocyclic parameters (latent period and lesion diameter) are applicable in the quantification of resistance in the pathosystem Hevea sp. x M. ulei. The latency period had little variation among clones. The diameter of the lesion was wide variation between the clones, being a discriminant parameter for horizontal resistance and vertical resistance. Several races of this pathogen have been described in Brazil, based on a number of clones’ differentiators. Grounded on the reactions of 11 different clones already known in the literature: MDF 180, Fx 3844, Fx 985, Fx 4098, Fx 2261, Fx 2804, Fx 3899, IAN 6158, IAN 3087, IAN 717 and PA 31 containing the species Hevea brasiliensis, Hevea benthamiana and Hevea pauciflora, we performed an analysis grouping for the binary data referring to virulence ...
The biggest barrier to expansion of rubber cultivation in Brazil is the disease known as leaf blight caused by the fungus Microcyclus ulei whose symptoms occur in young leaves, causing severe defoliation, reducing the production of latex and even death in susceptible plants. Is a constant threat to the plantations of the East. With the evolution of traditional breeding programs currently interspecific hybrid clones are used, which are more productive and have better resistance to pathogens. Through traditional breeding programs, there was no significant progress for resistance to leaf blight, due to selection be directed to clones with complete resistance. This pathosystem horizontal resistance (HR) and vertical resistance (VR) can act simultaneously, being complex and difficult to quantify. This study aimed to characterize the type of leaf injury pathossystem Hevea sp. x M. ulei verify clonal susceptibility to pathogens, to analyze the frequency of infection to quantify the resistance in the pathosystem Hevea sp. x M. ulei and suggest different clones of rubber and quantifies the races of M. ulei in Brazil. Monocyclic parameters (latent period and lesion diameter) are applicable in the quantification of resistance in the pathosystem Hevea sp. x M. ulei. The latency period had little variation among clones. The diameter of the lesion was wide variation between the clones, being a discriminant parameter for horizontal resistance and vertical resistance. Several races of this pathogen have been described in Brazil, based on a number of clones’ differentiators. Grounded on the reactions of 11 different clones already known in the literature: MDF 180, Fx 3844, Fx 985, Fx 4098, Fx 2261, Fx 2804, Fx 3899, IAN 6158, IAN 3087, IAN 717 and PA 31 containing the species Hevea brasiliensis, Hevea benthamiana and Hevea pauciflora, we performed an analysis grouping for the binary data referring to virulence ...
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Palavras-chave
Seringueiras – Doenças e pragas, Microcyclus ulei, Melhoramento genetico, Fungos na agricultura, Fungi in agriculture
Como citar
BEVENUTO, João Alberto Zago. Resistência da seringueira ao mal das folhas e modelagem no patossistema Hevea sp. – Microcyclus ulei através dos parâmetros monocíclicos. 2014. v, 53 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agronômicas de Botucatu, 2014.