Colocation of downy mildew (Plasmopara halstedii) resistance genes in sunflower (Helianthus annuus L.)

Resistance in sunflower (Helianthus annuus L.) to downy mildew (Plasmopara halstedii (Farl.) Berl. et de Toni) is conditioned by a series of Pl. genes. Races 1 (European race), 2 (Red River race), and 3 (a new North American race encountered in the Red River valley in 1980) formed similar infection structures on inoculated seedlings whether susceptible or resistant to races 1 and 2; all cultivars tested were susceptible to race 3. The zoospores encysted and produced germ tubes and appressoria on the roots and hypocotyls. Penetration occurred and mycelium and haustoria developed in both compatible and incompatible host–pathogen combinations. Resistance did not appear to involve a hypersensitive reaction occurring prior to penetration.

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Lack of genetic variability in French identified races of Plasmopara halstedii, the cause of downy mildew in sunflower Helianthus annuus

Canadian Journal of Microbiology ◽

10.1139/m97-036 ◽

1997 ◽

Vol 43 (3) ◽

pp. 260-263 ◽

Cited By ~ 22

Author(s):

Patricia Roeckel-Drevet ◽

Véronique Coelho ◽

Paul Nicolas ◽

Jeanne Tourvieille ◽

Denis Tourvieille de Labrouhe

Keyword(s):

Genetic Variation ◽

Genetic Variability ◽

Helianthus Annuus ◽

Downy Mildew ◽

Random Amplified Polymorphic Dna ◽

Initial Screening ◽

Plasmopara Halstedii ◽

Helianthus Annuus L ◽

New Races

Downy mildew of sunflower (Helianthus annuus L.) incitated by Plasmopara halstedii is a potentially devastating disease. We report here the finding of two new races of P. halstedii and also two Apron35S fungicide-resistant isolates of race A. Using the random amplified polymorphic DNA (RAPD) technique as an initial screening for genetic variation within P. halstedii French races, genetic variation was not found between isolates within races 1, A, or B, and very few polymorphisms were distinguished between all French races known today.Key words: Plasmopara halstedii, race, genetic variability, RAPD.

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Identification of a second linkage group carrying genes controlling resistance to downy mildew (Plasmopara halstedii) in sunflower (Helianthus annuus L.)

Theoretical and Applied Genetics ◽

10.1007/s001220100660 ◽

2001 ◽

Vol 103 (6-7) ◽

pp. 992-997 ◽

Cited By ~ 48

Author(s):

P. F. Bert ◽

D. Tourvieille de Labrouhe ◽

J. Philippon ◽

S. Mouzeyar ◽

I. Jouan ◽

...

Keyword(s):

Linkage Group ◽

Helianthus Annuus ◽

Downy Mildew ◽

Plasmopara Halstedii ◽

Helianthus Annuus L

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Development and dissection of diagnostic SNP markers for the downy mildew resistance genes Pl Arg and Pl 8 and maker-assisted gene pyramiding in sunflower (Helianthus annuus L.)

Molecular Genetics and Genomics ◽

10.1007/s00438-017-1290-8 ◽

2017 ◽

Vol 292 (3) ◽

pp. 551-563 ◽

Cited By ~ 14

Author(s):

L. L. Qi ◽

Z. I. Talukder ◽

B. S. Hulke ◽

M. E. Foley

Keyword(s):

Helianthus Annuus ◽

Downy Mildew ◽

Resistance Genes ◽

Gene Pyramiding ◽

Snp Markers ◽

Downy Mildew Resistance ◽

Mildew Resistance ◽

Helianthus Annuus L

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BIOCHEMICAL AND HISTOLOGICAL CHANGES ASSOCIATED WITH DOWNY MILDEW (Plasmopara halstedii (Farl.) Berl. and de Toni) INFECTION IN SUNFLOWER (Helianthus annuus L.) / MODIFICACIONES BIOQUIMICAS E HISTOLOGICAS RELACIONADAS CON LA INFECCION DEL GIRASOL (Helianthus annuus L.) POR EL AGENTE DE MILDIU (Plasmopara halstedii (Farl.) Berl. y de Toni) / CHANGEMENTS BIOCHIMIQUES ET HISTOLOGIQUES ASSOCIÉS À L’INFECTION DU TOURNESOL (Helianthus annuus L.) PAR LE MILDIOU (Plasmopara halstedii (Farl.) Berl. et de Toni)

Helia ◽

10.1515/helia.2000.23.33.1 ◽

2000 ◽

Vol 23 (33) ◽

pp. 1-18

Author(s):

B.R. Prashanth Kumar ◽

Mahesh J. Kulkarni ◽

B.N. Veena Rao ◽

K. Chandrika ◽

V.R. Balakrishna Gowda ◽

...

Keyword(s):

Molecular Weight ◽

Helianthus Annuus ◽

High Molecular Weight ◽

Downy Mildew ◽

Soluble Sugars ◽

Molecular Weight Protein ◽

High Molecular Weight Protein ◽

Plasmopara Halstedii ◽

Helianthus Annuus L ◽

Weight Protein

SUMMARY Biochemical changes associated with downy mildew infection in sunflower revealed an increase in the total soluble proteins, 0-40% ammonium sulfate fractionated proteins and total soluble sugars. Molecular sieve chromatography of 0-40% ammonium sulphate fraction revealed for presence of a high molecular weight protein and polysaccharide in the downy mildew infected sunflower leaves. Antibodies raised against the high molecular weight protein and polysaccharide were used in the western blot/dot blot analysis. It has been shown that the downy mildew disease also induces PR proteins, which have antigenic homology with PR-S protein, a member of the PR-5 class of proteins. An increase in iPA (isopentenyl adenosine) content in the infected sample was observed. A positive correlation exists between iPA level, 0-40% protein and total sugar content. Histological studies revealed that the downy mildew fungal mycelium extensively proliferates, ramifies extensively the leaf tissue and forms a nutritional link with the host cell by producing the intracellular haustorium.

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