Estudo de associação genômica ampla da resistência do germoplasma amphillo a Meloidogyne paranaensis
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Data
2022-09-06
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Universidade Federal de Viçosa
Resumo
O fitonematoide Meloidogyne paranaensis é uma das principais ameaças à cafeicultura. O desenvolvimento de cultivares de Coffea arabica resistentes a este patógeno é uma demanda urgente dos programas de melhoramento genético do cafeeiro. Progênies derivadas do germoplasma silvestre ‘Amphillo’ são consideradas potenciais fontes de resistência a M. paranaensis, porém, os mecanismos envolvidos nesta resistência ainda não foram elucidados. No presente trabalho, a resistência de diferentes progênies derivadas de Amphillo foi estudada e foram identificados marcadores moleculares associados a resistência. Por meio da Associação Genômica Ampla foram identificados marcadores SNP (Single Nucleotide Polymorphism) associados a genes potencialmente envolvidos no controle da resistência. Foram analisados 158 genótipos pertencentes a quatro progênies derivadas de cruzamentos entre germoplasma ‘Amphillo’ e linhagens da cultivar Catuaí Vermelho. Estes cafeeiros foram fenotipados para cinco caracteres relacionados à resistência, sendo eles as variáveis nota, número de ovos por grama de raiz, fator de reprodução e tipo de reação ao nematoide. Foram genotipados 7116 marcadores SNPs e após filtragens de qualidade foram selecionados 931 SNPs para condução do estudo de associação genômica ampla. Por meio do modelo linear misto foram identificados 12 SNPs com associações significativas com ao menos uma das variáveis avaliadas. Foram mapeados 18 genes sendo considerados aqueles nos quais os SNPs estão inseridos e os genes imediatamente mais próximos nos sentidos upstream e downstream. Os resultados obtidos fornecem subsídio para o desenvolvimento de marcadores para seleção assistida, para estudos sobre a herança genética e para elucidação de mecanismos moleculares envolvidos na resistência de C. arabica a M. paranaensis. Palavras-chave: Fitonematóide. Arquitetura Genética. Meloidogyne paranaensis.
The phytonematode Meloidogyne paranaensis is one of the main threats to coffee production. The development of Coffea arabica cultivars resistant to this pathogen is an urgent demand for coffee genetic breeding programs. Progenies derived from the wild germplasm 'Amphillo' are considered potential sources of resistance to M. paranaensis, however, the mechanisms involved in this resistance have not yet been elucidated. In the present work, the resistance of different progenies derived from Amphillo was studied and molecular markers associated with resistance were identified. Through the Genomic-Wide Association, SNP (Single Nucleotide Polymorphism) markers associated with genes potentially involved in resistance control were identified. A total of 158 genotypes belonging to four progenies derived from crosses between 'Amphillo' germplasm and lines of the cultivar Catuaí Vermelho were analyzed. These coffee plants were phenotyped for five characters related to resistance, being the variables note, number of eggs per gram of root, reproduction factor and type of reaction to the nematode. A total of 7116 SNP markers were genotyped and, after quality filtering, 931 SNPs were selected to conduct the genome-wide association study. Through the mixed linear model, 12 SNPs with significant associations with at least one of the evaluated variables were identified. Eighteen genes were mapped, considering those in which the SNPs are inserted and the genes immediately closest in the upstream and downstream senses. The results obtained provide support for the development of markers for assisted selection, for studies on genetic inheritance and for the elucidation of molecular mechanisms involved in the resistance of C. arabica to M. paranaensis. Keywords: Phytonematode. Genetic Architecture. Meloidogyne paranaensis.
The phytonematode Meloidogyne paranaensis is one of the main threats to coffee production. The development of Coffea arabica cultivars resistant to this pathogen is an urgent demand for coffee genetic breeding programs. Progenies derived from the wild germplasm 'Amphillo' are considered potential sources of resistance to M. paranaensis, however, the mechanisms involved in this resistance have not yet been elucidated. In the present work, the resistance of different progenies derived from Amphillo was studied and molecular markers associated with resistance were identified. Through the Genomic-Wide Association, SNP (Single Nucleotide Polymorphism) markers associated with genes potentially involved in resistance control were identified. A total of 158 genotypes belonging to four progenies derived from crosses between 'Amphillo' germplasm and lines of the cultivar Catuaí Vermelho were analyzed. These coffee plants were phenotyped for five characters related to resistance, being the variables note, number of eggs per gram of root, reproduction factor and type of reaction to the nematode. A total of 7116 SNP markers were genotyped and, after quality filtering, 931 SNPs were selected to conduct the genome-wide association study. Through the mixed linear model, 12 SNPs with significant associations with at least one of the evaluated variables were identified. Eighteen genes were mapped, considering those in which the SNPs are inserted and the genes immediately closest in the upstream and downstream senses. The results obtained provide support for the development of markers for assisted selection, for studies on genetic inheritance and for the elucidation of molecular mechanisms involved in the resistance of C. arabica to M. paranaensis. Keywords: Phytonematode. Genetic Architecture. Meloidogyne paranaensis.
Descrição
Tese de Doutorado defendida na Universidade Federal de Viçosa.
Palavras-chave
Café - Melhoramento genético, Café - Doenças e pragas, Café - Recursos do germoplasma, Nematoda
Citação
GONZALES, Rafael Vago. Estudo de associação genômica ampla da resistência do germoplasma amphillo a Meloidogyne paranaensis. 2022. 83 f. Tese (Doutorado em Genética e Melhoramento) - Universidade Federal de Viçosa, Viçosa-MG. 2022.