Fine mapping quantitative resistances to downy mildew in lettuce revealed multiple sub-QTLs with plant stage dependent effects reducing or even promoting the infection
| Autor: | Ningwen W. Zhang, Marieke J. W. Jeuken, K.T.B. Pelgrom, Rients E. Niks, Erik den Boer, Richard G. F. Visser |
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| Rok vydání: | 2013 |
| Předmět: |
PBR Non host and insect resistance
Genetic Markers disease resistance DNA Plant durable resistance Quantitative Trait Loci genetic dissection Plant disease resistance Genes Plant Chromosomes Plant leaf rust Laboratorium voor Plantenveredeling wild lettuce Genetics nonhost resistance Disease Resistance Plant Diseases Genetic dissection Bremia lactucae Peronospora biology backcross inbred lines fungi food and beverages Chromosome Mapping Stripe rust General Medicine trait locus qtl Lettuce biology.organism_classification Lactuca saligna Immunity Innate Plant Breeding Agronomy stripe rust Plant biochemistry Downy mildew bremia-lactucae EPS Agronomy and Crop Science PBR Non host en Insectenresistentie Biotechnology |
| Zdroj: | Theoretical and Applied Genetics, 126(12), 2995-3007 Theoretical and Applied Genetics 126 (2013) 12 |
| ISSN: | 1432-2242 0040-5752 |
| Popis: | Three regions with quantitative resistance to downy mildew of non-host and wild lettuce species, Lactuca saligna , disintegrate into seventeen sub-QTLs with plant-stage-dependent effects, reducing or even promoting the infection. Previous studies on the genetic dissection of the complete resistance of wild lettuce, Lactuca saligna, to downy mildew revealed 15 introgression regions that conferred plant stage dependent quantitative resistances (QTLs). Three backcross inbred lines (BILs), carrying an individual 30-50 cM long introgression segment from L. saligna in a cultivated lettuce, L. sativa, background, reduced infection by 60-70 % at young plant stage and by 30-50 % at adult plant stage in field situations. We studied these three quantitative resistances in order to narrow down their mapping interval and determine their number of loci, either single or multiple. We performed recombinant screenings and developed near isogenic lines (NILs) with smaller overlapping L. saligna introgressions (substitution mapping). In segregating introgression line populations, recombination was suppressed up to 17-fold compared to the original L. saligna × L. sativa F 2 population. Recombination suppression depended on the chromosome region and was stronger suppressed at the smallest introgression lengths. Disease evaluation of the NILs revealed that the resistance of all three BILs was not explained by a single locus but by multiple sub-QTLs. The 17 L. saligna-derived sub-QTLs had a smaller and plant stage dependent resistance effect, some segments reducing; others even promoting downy mildew infection. Implications for lettuce breeding are outlined. |
| Databáze: | OpenAIRE |
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