Two Major Recessive Soybean Genes Conferring Soybean Rust Resistance

Abstract

Soybean rust (SBR) caused by Phakopsora pachyrhizi Syd. is currently the most threatening fungal disease of soybean [Glycine max (L.) Merr.] in the Americas. Development of resistant or tolerant cultivars is a major goal in several soybean breeding programs. Four loci, all carrying dominant alleles that confer a resistant phenotype, have been described. We investigated the genetic basis of the resistance in PI 200456 and PI 224270 by crossing each of them with a susceptible cultivar (CD 208). Phenotypic segregation ratios for F2 plants and F2:3 lines showed that the resistance in each resistant parent was controlled by a single recessive gene. A test for allelism demonstrated that these genes are non‐allelic. This is the first report of recessive genes controlling SBR resistance in soybean and may represent a different type of resistance for breeding programs aimed at development of more durable resistance.

Pathogenic Variation of Phakopsora pachyrhizi Isolates on Soybean in the United States from 2006 to 2009

“…The races and pathotypes identified in P. pachyrhizi are associated with specific resistance genes in soybean identified as Rpp I to -5 (3,7,13,14,19). Based on these studies, the resistant reaction was characterized by either an immune reaction or red-brown (RB) lesions without or with sparsely sporulating uredinia, while a susceptible reaction was characterized by tan (TAN) sporulating lesions.…”

Tolerância de genótipos de soja à ferrugem-asiática

“…portadores de genes maiores, ou ainda resistências ditas verticais, tem sido um grande desafio para a pesquisa (CALVO et al, 2008;PIEROZZI et al, 2008;MAPHOSA et al, 2013).…”

Taxa de aplicação e uso de surfactante siliconado na deposição da pulverização e controle da ferrugem da soja

“…Embora haja pesquisadores investigando resistência genética de cultivares de soja ao fungo P. pachyrhizi (CALVO et al, 2008;WALKER et al, 2011), ainda não estão disponíveis materiais resistentes a todas as raças desse patógeno (GOELLNER et al, 2010), sendo o controle com pulverizações fungicidas a alternativa mais viável na redução de perdas (LEVY, 2005). Uma das formas de maximizar a eficiência de produtos fito ssanitários é a utilização de adjuvantes em caldas de pulverização.…”