Factors associated with the distribution of some phylloplane microbes

Abstract

Using the spore-fall method, colonies of Sporobolomyces and Tilletiopsis were isolated, during autumn, from leaves of ferns, conifers, mono-and di-cotyledonous plants. Colonies on agar, which mirror-imaged leaf surface distributions, indicated that the above-mentioned fungi were, on some hosts, restricted to leaf margins while on others they occurred mainly along veins, were absent from veins or were randomly distributed. Colonies were commonly more numerous on parasitized than on undamaged leaves. Increased numbers of Sporobolomyces were associated with rust and powdery mildew attacks and damage by (a) the nematode Aphelenchoides ritzema-bosi and (13) the mite Eriophyes macrorrhynchus. Only powdery mildews increased significantly the incidence of Tilletiopsis.

Interaction between phyllosphere yeasts, aphid honeydew and fungicide effectiveness in wheat under field conditions

“…Neither prochloraz nor triadimenol had an effect on yeasts, in accordance with the findings of Magan & Lacey (1986) and Fokkema & De Nooij (1981). The maximum yeast population density was higher in the mildew-infected experiments at 'Droevendaal', as was found by Last (1970). The decrease in the yeast and bacterial populations during the last week of June 1989 coincided with a rapid decrease in aphid populations.…”

Role of Leaf Surface Sugars in Colonization of Plants by Bacterial Epiphytes

“…Possibly, the very waxy surface of those leaves prevents the nutrients from being available. Leaves have been shown to have very irregular surfaces, which in turn are unevenly colonized (3,23,25). We hypothesize that at the small scale at which bacterial colonization of plants occurs, leaves are not uniformly wetted and diffusion of nutrients is restricted on the leaf.…”

Der Einfluß von Venturia inaequalis und V. pirina auf die saprophytische Mikroflora von Apfel- und Birnblättern1)

“…STADELMANN und SCH'WINN saprophytisdien Bakterien (CROSSE 1971), ballistosporenbildenden Hefen (DERX 1930, NYLAND 1949, BRADY 1960, LAST 1970, PADY 1974 und saprophytisdien Fadenpilzen (SCOTT und RORER 1908, NICOLAS und AGGERY 1931, KEENER 1954 mit Blattparasiten wird gelegentlidi beriditet. Aufier bei LAST (1970) besdiranken sidi diese Arbeiten aber auf einzelne Saprophytenarten, ohne auf den quantitativen Effekt von Blattparasiten einzugehen.…”