Identification of QTLs conferring resistance to downy mildew in legacy cultivars of lettuce

Šimko, Ivan; Atallah, A.; Ochoa, O.; Antonise, Rudie; Galeano, Carlos H.; Truco, María José; Michelmore, Richard W.

doi:10.1038/srep02875

Cited by 42 publications

(31 citation statements)

References 48 publications

(82 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some lettuce cultivars such as Iceberg and Grand Rapids exhibit resistance at the adult plant stage in the field that cannot be attributed to Dm genes (Milbrath 1923;Verhoeff 1960;Crute and Norwood 1981). This quantitative resistance phenotype (Norwood and Crute 1985;Grube and Ochoa 2005) has so far been shown to be inherited polygenically (Simko et al 2013); transgressive segregation resulting in elevated resistance has been observed in progeny from cvs. Grand Rapids 9 Iceberg (Grube and Ochoa 2005;Simko et al 2013).…”

Section: Genetics Of Resistance and Nomenclature Of Resistance Genesmentioning

confidence: 99%

“…This quantitative resistance phenotype (Norwood and Crute 1985;Grube and Ochoa 2005) has so far been shown to be inherited polygenically (Simko et al 2013); transgressive segregation resulting in elevated resistance has been observed in progeny from cvs. Grand Rapids 9 Iceberg (Grube and Ochoa 2005;Simko et al 2013). Some cultivars such as Green towers and Cobham Green have no known Dm genes and are used as susceptible lines to grow B. lactucae isolates; however, the European isolate Serr84/99 is avirulent on Cobham Green and there is some evidence suggesting polygenic resistance in this cultivar (Maisonneuve 2011b).…”

Section: Genetics Of Resistance and Nomenclature Of Resistance Genesmentioning

confidence: 99%

See 1 more Smart Citation

Rationalization of genes for resistance to Bremia lactucae in lettuce

Parra¹,

Maisonneuve²,

Lebeda³

et al. 2016

Euphytica

View full text Add to dashboard Cite

Lettuce downy mildew caused by Bremia lactucae is the most important disease of lettuce worldwide. Breeding for resistance to this disease is a major priority for most lettuce breeding programs. Many genes and factors for resistance to B. lactucae have been reported by multiple researchers over the past *50 years. Their nomenclature has not been coordinated, resulting in duplications and gaps in nominations. We have reviewed the available information and rationalized it into 51 resistance genes and factors and 15 quantitative trait loci along with supporting documentation as well as genetic and molecular information. This involved multiple rounds of consultation with many of the original authors. This paper provides the foundation for naming additional genes for resistance to B. lactucae in the future as well as for deploying genes to provide more durable resistance. Keywords

show abstract

Section: Genetics Of Resistance and Nomenclature Of Resistance Genesmentioning

confidence: 99%

Section: Genetics Of Resistance and Nomenclature Of Resistance Genesmentioning

confidence: 99%

Rationalization of genes for resistance to Bremia lactucae in lettuce

Parra¹,

Maisonneuve²,

Lebeda³

et al. 2016

Euphytica

View full text Add to dashboard Cite

show abstract

“…Lettuce is a diploid, self-pollination species with 2n = 2x = 18 chromosomes. Based on plant morphology, lettuce can be classified into four types including iceberg lettuce, romaine lettuce, butterhead lettuce and non-heading leaf-type lettuces (Simko et al, 2013). Unlike most other flowering plants, transition from vegetative to reproductive phase in lettuce is induced by high temperatures, and followed by rapid stem elongation (bolting) and flowering (Fukuda et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativa L.)

Han

Chen

et al. 2016

Front. Plant Sci.

View full text Add to dashboard Cite

Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs. S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA) treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines.

show abstract

“…In each experiment, seeds were planted in two or three complete blocks to produce approximately 30 plants of each RIL and parent per plot. Disease assessment was done by scoring disease severity on a scale ranging from 0 (no disease) to 5 (severe disease) for each plot (Simko et al, 2013). Disease assessments were performed at market maturity.…”

Section: Methodsmentioning

confidence: 99%

Comparing the Predictive Abilities of Phenotypic and Marker‐Assisted Selection Methods in a Biparental Lettuce Population

et al. 2016

Self Cite

View full text Add to dashboard Cite

Breeding for traits with polygenic inheritance is a challenging task that can be done by phenotypic selection, marker-assisted selection (MAS) or genome-wide selection. We comparatively evaluated the predictive abilities of four selection models on a biparental lettuce (Lactuca sativa L.) population genotyped with 95 single nucleotide polymorphisms and 205 amplified fragment length polymorphism markers. These models were based on (i) phenotypic selection, (ii) MAS (with quantitative trait locus (QTL)-linked markers), (iii) genomic prediction using all the available molecular markers, and (iv) genomic prediction using molecular markers plus QTL-linked markers as fixed covariates. Each model's performance was assessed using data on the field resistance to downy mildew (DMR, mean heritability ~0.71) and the quality of shelf life (SL, mean heritability ~0.91) of lettuce in multiple environments. The predictive ability of each selection model was computed under three cross-validation (CV) schemes based on sampling genotypes, environments, or both. For the DMR dataset, the predictive ability of the MAS model was significantly lower than that of the genomic prediction model. For the SL dataset, the predictive ability of the genomic prediction model was significantly lower than that for the model using QTL-linked markers under two of the three CV schemes. Our results show that the predictive ability of the selection models depends strongly on the CV scheme used for prediction and the heritability of the target trait. Our study also shows that molecular markers can be used to predict DMR and SL for individuals from this cross that were genotyped but not phenotyped.

show abstract

Identification of QTLs conferring resistance to downy mildew in legacy cultivars of lettuce

Cited by 42 publications

References 48 publications

Rationalization of genes for resistance to Bremia lactucae in lettuce

Rationalization of genes for resistance to Bremia lactucae in lettuce

MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativa L.)

Comparing the Predictive Abilities of Phenotypic and Marker‐Assisted Selection Methods in a Biparental Lettuce Population

Contact Info

Product

Resources

About