Mapeamento molecular do loco Rpp5 de resistência à ferrugem asiática da soja
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Data
2008-08-04
Autores
Morceli, Thaiza Galhardo Silva [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A ferrugem asiática da soja, causada pelo fungo Phakopsora pachyrhizi (Sidow & P. Sidow) foi relatada no Brasil ao final da safra 2001 e já nas safras seguintes, ocasionou severas perdas de produtividade. Cinco genes de resistência à ferrugem asiática da soja (Rpp1 a Rpp5) estão descritos na literatura. O objetivo geral deste trabalho foi identificar marcadores moleculares microssatélites ligados ao gene de resistência a P. pachyrhizi presente na linhagem de soja PI 200526. Uma população de plantas F2 derivada do cruzamento entre esta linhagem e a cultivar suscetível Coodetec 208, foi artificialmente inoculada e avaliada quanto à sua reação de resistência à ferrugem. Marcadores microssatélites foram testados nos genitores e em dois bulks contrastantes para possibilitar a identificação de possíveis marcadores ligados. Os três marcadores polimórficos que foram caracterizados como potencialmente associados com a resistência à ferrugem asiática foram, posteriormente, avaliados em toda a população. A resistência comportou-se como governada por um gene com dominância completa. O gene de resistência da PI 200526 foi mapeado no grupo de ligação N da soja, estando próximo ao marcador Sat_166. Existe grande possibilidade de que o gene mapeado neste estudo corresponda ao novo loco de resistência à ferrugem asiática da soja, denominado de Rpp5, recentemente descrito.
The Asian soybean rust caused by the Phakopsora pachyrhizi (Sidow & P. Sidow) fungus was related in Brazil at the end of 2001 crop year, and already in the following seasons, caused severe losses in productivity. Five distinct resistance genes to Asian rust (Rpp1 to Rpp5) are described. The main objective of this work was to identify microsatellite markers linked to a resistance gene to P. pachyrhizi present in the soybean line PI 200526. One population of F2 plants originated from the cross between this resistant line and the suscetible cultivar Coodetec 208 was artificially inoculated and evaluated for the Asian rust resistance. Microsatellite markers were tested on parents and in the two contrasting bulks to enable the identification of linked markers. The three polymorphic markers that were identified potentially associated with resistance to Asian rust were then evaluated throughout the progeny. The resistance showed to be governed by a gene with complete dominance. The resistance gene of PI 200526 was mapped on the soybean linkage group N, being close to Sat_166 marker. Possibly, the gene mapped on this linkage group is part of the new locus of resistance to Asian soybean rust, called Rpp5, recently described.
The Asian soybean rust caused by the Phakopsora pachyrhizi (Sidow & P. Sidow) fungus was related in Brazil at the end of 2001 crop year, and already in the following seasons, caused severe losses in productivity. Five distinct resistance genes to Asian rust (Rpp1 to Rpp5) are described. The main objective of this work was to identify microsatellite markers linked to a resistance gene to P. pachyrhizi present in the soybean line PI 200526. One population of F2 plants originated from the cross between this resistant line and the suscetible cultivar Coodetec 208 was artificially inoculated and evaluated for the Asian rust resistance. Microsatellite markers were tested on parents and in the two contrasting bulks to enable the identification of linked markers. The three polymorphic markers that were identified potentially associated with resistance to Asian rust were then evaluated throughout the progeny. The resistance showed to be governed by a gene with complete dominance. The resistance gene of PI 200526 was mapped on the soybean linkage group N, being close to Sat_166 marker. Possibly, the gene mapped on this linkage group is part of the new locus of resistance to Asian soybean rust, called Rpp5, recently described.
Descrição
Palavras-chave
Soja, Ferrugem asiática, Genes de resistência, Marcadores microssatélites, Seleção assistida, Resistance genes, Glycine max, Microsatellites markers, Assisted selection
Como citar
MORCELI, Thaiza Galhardo Silva. Mapeamento molecular do loco Rpp5 de resistência à ferrugem asiática da soja. 2008. iii, 68 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2008.