Partial resistance to Erysiphe graminis hordei in old European barley varieties

Euphytica ◽  
1985 ◽  
Vol 34 (2) ◽  
pp. 499-507 ◽  
Author(s):  
I. T. Jones ◽  
I. J. E. R. Davies
Keyword(s):  
Partial Resistance ◽  
Erysiphe Graminis ◽  
Erysiphe Graminis Hordei

Cytological studies of early stages of powdery mildew in barley and wheat. V. Effects of calcium on the infection of coleoptiles of barley by Erysiphe graminis hordei

1978 ◽  
Vol 56 (20) ◽  
pp. 2544-2549 ◽  
Author(s):  
Susumu Takamatsu ◽  
Hiroshi Ishizaki ◽  
Hitoshi Kunoh
Keyword(s):  
Powdery Mildew ◽  
Calcium Chloride ◽  
Calcium Nitrate ◽  
Infection Process ◽  
Erysiphe Graminis ◽  
Calcium Salts ◽  
Early Stages ◽  
Erysiphe Graminis Hordei ◽  
The Times ◽  
Chloride Treatment

Some effects of calcium salts on the infection process of Erysiphe graminis hordei in coleoptiles of barley were investigated. Calcium chloride enhanced the incidence of haustoria but depressed that of papillae. Calcium bromide and calcium nitrate likewise enhanced the incidence of haustoria. Calcium chloride treatment at varied times and with varied durations during incubation after inoculation showed that events occurring in coleoptiles between 9 and 13 h after inoculation were most affected by the treatment. This period included the times that appressoria matured, cytoplasm aggregated, papillae were produced, and haustoria were formed, and the effect of calcium might be associated with one or more of these events.

Cytological studies of early stages of powdery mildew in barley and wheat. VI. Antagonistic effects of calcium and lithium on the infection of coleoptiles of barley by Erysiphe graminis hordei

1979 ◽  
Vol 57 (4) ◽  
pp. 408-412 ◽  
Author(s):  
S. Takamatsu ◽  
H. Ishizaki ◽  
H. Kunoh
Keyword(s):  
Powdery Mildew ◽  
Binding Site ◽  
Calcium Chloride ◽  
Lithium Chloride ◽  
Calcium Ions ◽  
Infection Process ◽  
Erysiphe Graminis ◽  
Antagonistic Effects ◽  
Early Stages ◽  
Erysiphe Graminis Hordei

Earlier researchers have shown that the susceptibility of barley to infection by Erysiphe graminis hordei is enhanced by calcium ions but inhibited by lithium. Some effects of these ions on the infection process of E. graminis hordei in coleoptiles of barley were investigated in this study. Whereas 1 mM lithium chloride inhibited appressorial formation considerably and haustorial formation completely, these effects were totally offset by 10 mM calcium chloride. Moreover, whereas 5 and 10 mM lithium chloride inhibited both appressorial and haustorial formation completely, the former was offset considerably by 10 mM calcium chloride, but the latter was not.Sequential calcium chloride − lithium chloride or lithium chloride − calcium chloride treatments carried out at different times and for various durations showed that events occurring in coleoptiles 11 to 13 h after inoculation were most vulnerable to the treatments. These events correspond to infection stages involving the development of cytoplasmic aggregates, papillae, and haustoria. The data suggest that the two ions in question might compete for a common binding site in a reaction(s) associated with certain stages of appressorial and haustorial development.

Lipid in Erysiphe graminis hordei and its possible role during germination

1970 ◽  
Vol 16 (11) ◽  
pp. 1041-1044 ◽  
Author(s):  
W. E. McKeen
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Erysiphe Graminis ◽  
Glutaraldehyde Fixation ◽  
Sudan Black B ◽  
Erysiphe Graminis Hordei ◽  
Sudan Iv ◽  
Mother Cells ◽  
Hyphal Tip

Osmiophilic bodies appear in parts of the colonial growth of Erysiphe graminis DC. f. sp. hordei Em Marchal culture CR3 growing on the susceptible commercial Keystone variety of barley. They are readily observed by the light and electron microscope after osmium tetroxide staining and are abundant in conidiophores, conidia, and mycelium except in haustorial mother cells, in which they are usually absent. The metabolism of haustorial mother cells is distinct and the fine structure of adjoining cells is frequently different. Osmiophilic bodies are absent from the growing hyphal tip, but gradually increase in number and size further back in the terminal cell. Electron micrographs show that they are intracytoplasmic, intravacuolar, and up to 1 μ in diameter. When the colony is washed with acetone or alcohol rather than with aqueous buffer, after glutaraldehyde fixation, before osmium tetroxide fixation, the osmiophilic bodies are removed, indicating that they are lipids. Fat stains, Sudan black B, and Sudan IV stain these bodies. Perhaps the water needs of the germinating conidium are met in part by the oxidation of fats.

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