Metodologias para obtenção de resistência e/ou tolerância da soja à ferrugem-asiática

Abstract

RESUMOOs objetivos deste tra balho foram complementar os estudos dos mecanismos genéticos da resistência e tolerância da soja à ferrugemasiática e su gerir metodologias de melho ra me nto qu e perm ita m o a c ú mu lo de gen es ma ior es e m eno res. S eis ex pe rim ent os for a m r ea li za d os d u r a nt e t rê s sa fra s em Lo nd ri n a , P R , de 2 0 0 5 /0 6 a 2 0 0 7/0 8 , envolvendo cinco pa renta is e a s gerações deriva das Palavras-chave adicionais: Phakopsora pachyrhizi, Glycine Max, métodos de melhoramento, resistência à doença, melhoramento de soja.g en e s m en or e s n a p re sen ça de ge n es ma io r es. I sto é re sol v id o co nd u z ind o po pu l a ç õe s seg re ga n te s F 2 , F 3 e F 4 n u m er osa s pa ra m e lh o r a r a s c h a n c e s d e e n c on t r a r r e co m b in a ç õe s fa v o rá v e is e submetendo-as à pressã o do pa tógeno pa ra au menta r a frequ ência de genótipos resistentes/tolera ntes na popu la çã o F 4 ou F 5 qua ndo planta s individua is serã o seleciona das para forma ção de progênies. Consequ entemente, a frequ ência de progênies F 5 ou F 6 superiores possu idora s de a lelos nos genes menores e ma iores ta mbém será au mentada.The objectives of this work were to complement the studies on the genetic control of soybean resista nce to ru st and to suggest a breeding methodology that a llows the recombina tion a nd selection of soybea n genotypes ca rrying ma jor a nd minor genes for ru st resistance. Six experiments were carried out in Londrina, PR during three growing seasons from 2005/06 to 2007/08 involving five parents and their derived F 2 , F 3 and F 4 segregating populations. A completely randomized design was used with single plant hill-plots. The proposed Lima, W.F.; Prete, C.E.C.; Ribeiro, A.S.; Toledo, J.F.F. Methodologies for breeding towards resistance and/or tolerance of soybean the Asian rust. Summa Phytopathologica, v.38, n.1, p.67-72, 2012. methodologies wa re designed to overcome the difficu lties breeders fa ce while selecting for minor gene resista nce in the presence of major genes. This is dealt with by breeding large F 2 , F 3 and F 4 segregant populations to improve the changes of the favorable gene combinations to appear and increasing genotype homozygosis under pathogen pressure to enhance the frequency of the favorable genotypes in the populations F 5 populations. This will also increase the chances of superior F 6 to appear from plant selection in the popu lations.Keywords: Phakopsora pachyrhizi, Glycine Max, breeding methods, disease resistance, soybean breeding. ABSTRACTA soja (Glycine max (L.) Merrill) é a cultura com a maior área cultivada no Brasil. Na safra de 2010/2011 a área cultivada foi de 24,17 milhões de hectares, seguida pelo milho com 13,29 milhões de hectares e pela cana-de-açúcar com 8,03 milhões de hectares (6). O Brasil é o segundo produtor mundial de soja, sendo responsável por aproximadamente 27,7% da produção mundial (22).A ferrugem-asiática (Phakopsora pachyrhizi Syd. e P. Syd.) foi detectada pela primeira vez no Bras...

Soybean nutraceutical canonic inter-relations and its reflections on breeding

“…Variables for NP4 and SMP were similar for all genotypes studied. Findings different from the research by Lima et al (2012), who observed distinctions in SMP between parents, F2 and F3 generations. Families IRC3_159, IRC16_82, IRC19_62, and IRC36_152 satisfied the highest means for first pod insertion height (FPI), plant height (PH), and number of pods on main stem (NPS), whereas IRC1_194 satisfied the means for the number of pods on branches (NPB), number of branches (NBR), number of pods with 1 grain (NP1), number of pods with 2 grains (NP2) and number of pods with 3 grains (NP3) (Table 3).…”