The Barley mlo-gene: an important powdery mildew resistance source

Lyngkjær, Michael Foged; Newton, A. C.; Atzema, Jannie L.; Baker, S.J.

doi:10.1051/agro:2000173

Cited by 117 publications

(105 citation statements)

References 46 publications

(89 reference statements)

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…In the 20 th century, about 36 genes for specific resistance have been used in Europe in more than 700 cultivars (Brown andJørgensen 1991, Czembor andCzembor 2001). However, resistance conferred by most of these genes has not been effective for more than a few (4 6) years with the exception of alleles mlo (Schwarzbach 1998, Hovmøller et al 2000, Lyngkjaer et al 2000. This was caused by high level of pathogenic variability encountered in natural populations of B. graminis f.sp.…”

Section: Discussionmentioning

confidence: 99%

“…Recessive alleles at the Mlo locus condition penetration resistance of barley of attacked epidermal cells by rapid deposition of large callose-containing appositions (papillae) in the epidermal cell wall, directly subtending the attacking fungal appressoria. This infection type is characteristic only for mlo alleles and is designed as 0(4) (Jørgensen 1992, Atzema 1998, Lyngkjaer et al 2000.…”

mentioning

confidence: 99%

“…However many factors e.g. temperature, water stress or light intensity may affect the expression of this gene (Atzema 1998, Schwarzbach 1998, Lyngkjaer et al 2000. Negative pleiotropic effects that were common when mlo was used in earlier crosses have been overcome by recent breeding and this type of resistance is presently utilised with increasing intensity in spring barley production.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei)

Czembor¹,

Czembor²

2002

PLANT SOIL ENVIRON

View full text Add to dashboard Cite

Powdery mildew on barley (Hordeum vulgare L.) caused by the pathogen Blumeria graminis f.sp. hordei occurs worldwide and can result in severe yield loss. Because agronomical methods to control the disease are not completely effective, cultivars with genetic resistance are needed. Therefore, there is a need to describe new sources of genes that confer resistance to barley powdery mildew. This study was conducted to determine the genetic basis of resistance to powdery mildew in three selections 995-1-1, 995-1-2, 995-1-3 from barley landrace 995 (ICB 112840) collected in Al Aziziyah district, Tripolitania, Libya. Landrace originated from International Center for Agricultural Research in the Dry Areas ICARDA, Aleppo, Syria. To determine the number of genes, the types of genes action and the gene loci in tested lines two types of crosses were made: (1) the lines were crossed to the susceptible cultivar Pallas, (2) the lines were crossed with Pallas isoline P22 carrying gene mlo5. The parents and progeny F 2 were evaluated with isolate R303.1 for the powdery mildew resistance. Based on segregation ratios we found that resistance in these three selections was determined by a single recessive gene allelic to the Mlo locus occurring in Pallas isoline P22. In addition tested lines showed resistance reaction type 0(4) characteristic only for genes mlo. The value of new identified sources of highly effective powdery mildew resistance to breeding programs and barley production is discussed.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei)

Czembor¹,

Czembor²

2002

PLANT SOIL ENVIRON

View full text Add to dashboard Cite

show abstract

“…Full resistance requires loss-of-function of all three co-orthologs, i.e., an Atmlo2 Atmlo6 Atmlo12 triple mutant (Consonni et al 2006). Barley mlo mutants have been known for more than 60 years (Freisleben and Lein 1942) and have been successfully employed in European barley agriculture for more than 25 years (Lyngkjaer et al 2000), emphasizing the principal durability of mlo-mediated disease resistance under agricultural conditions.…”

mentioning

confidence: 99%

Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function

Bai¹,

Pavan²,

Zheng³

et al. 2008

MPMI

274

307

View full text Add to dashboard Cite

The resistant cherry tomato (Solanum lycopersicum var. cerasiforme) line LC-95, derived from an accession collected in Ecuador, harbors a natural allele (ol-2) that confers broad-spectrum and recessively inherited resistance to powdery mildew (Oidium neolycopersici). As both the genetic and phytopathological characteristics of ol-2-mediated resistance are reminiscent of powdery mildew immunity conferred by loss-of-function mlo alleles in barley and Arabidopsis, we initiated a candidate-gene approach to clone Ol-2. A tomato Mlo gene (SlMlo1) with high sequence-relatedness to barley Mlo and Arabidopsis AtMLO2 mapped to the chromosomal region harboring the Ol-2 locus. Complementation experiments using transgenic tomato lines as well as virus-induced gene silencing assays suggested that loss of SlMlo1 function is responsible for powdery mildew resistance conferred by ol-2. In progeny of a cross between a resistant line bearing ol-2 and the susceptible tomato cultivar Moneymaker, a 19-bp deletion disrupting the SlMlo1 coding region cosegregated with resistance. This polymorphism results in a frameshift and, thus, a truncated nonfunctional SlMlo1 protein. Our findings reveal the second example of a natural mlo mutant that possibly arose postdomestication, suggesting that natural mlo alleles might be evolutionarily short-lived due to fitness costs related to loss of mlo function.

show abstract

“…For instance, loss-of-function mutations of barley MLO endow resistance to PM fungus Blumeria graminis f. sp. hordei, and was successfully applied in barley breeding nearly 40 years ago [ 17 ]. Similarly, knockdown through RNA interference of PhMLO1 in petunia increases resistance to PM [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

Genome-wide Identiﬁcation, Classiﬁcation and Expression Analysis of the Mildew Resistance Locus O ( MLO ) Gene Family in Sweet Orange ( Citrus sinensis )

Liu

JinWang

et al. 2017

Braz. arch. biol. technol.

View full text Add to dashboard Cite

show abstract

The Barley mlo-gene: an important powdery mildew resistance source

Cited by 117 publications

References 46 publications

Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei)

Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei)

Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function

Genome-wide Identiﬁcation, Classiﬁcation and Expression Analysis of the Mildew Resistance Locus O ( MLO ) Gene Family in Sweet Orange ( Citrus sinensis )

Contact Info

Product

Resources

About