PMID- 12166677
OWN - NLM
STAT- MEDLINE
DCOM- 20030129
LR  - 20190720
IS  - 0008-4166 (Print)
IS  - 0008-4166 (Linking)
VI  - 48
IP  - 6
DP  - 2002 Jun
TI  - Population biology of Aureobasidium pullulans on apple leaf surfaces.
PG  - 500-13
AB  - Colonization of apple leaves by the yeast-like fungus Aureobasidium pullulans was 
      studied in the field on eight dates over 2 years. Population densities from 
      adaxial leaf surfaces were approximately log10 0.5-2.6 U higher when enumerated 
      directly along line transects as microscopic counts of A. pullulans cells 
      specifically identified by fluorescence in situ hybridization (FISH) than 
      indirectly as CFU obtained by plating leaf washings from comparable surfaces onto 
      nutrient media. Site-specific mapping of the leaf landscape colonized by A. 
      pullulans was facilitated by use of geographic information system (GIS) software. 
      Colonization was plotted and analyzed both qualitatively (as occupancy) and 
      quantitatively (as density). Overall, when expressed as mean occupancy per date, 
      22-42% of the microscope fields (each 0.196 mm2) contained > or = 1 A. pullulans 
      cell. Occupancy on a microscope field basis was greater over the midvein (47-89%) 
      or smaller veins (49-65%) than over interveinal regions (11-21%). Intensity of 
      colonization, whether expressed as percentage of total A. pullulans cells 
      associated with a particular leaf feature or as cell density per unit area, was 
      also significantly greater (P < 0.05) over the veinal areas compared with the 
      interveinal areas. The primary fungal morphotypes involved in colonization were 
      blastospores, swollen cells, and chlamydospores; only infrequently were hyphae or 
      pseudohyphae seen. Numbers of microcolonies (> or = 10 clustered cells) and 
      percentage of total A. pullulans cells that occurred as microcolonies increased 
      over the growing season and were significantly greater (P < 0.05) over veinal 
      regions compared with interveinal regions. Locally high concentrations of A. 
      pullulans were associated with naturally occurring micro-wounds in interveinal 
      areas. We conclude that A. pullulans colonizes the phylloplane predominantly as 
      single cells and groups thereof in a highly heterogeneous fashion and that sites 
      exist that are relatively conducive (veins; wounds) or nonconducive (unwounded 
      interveinal areas) for epiphytic fungal growth.
FAU - Andrews, John H
AU  - Andrews JH
AD  - Department of Plant Pathology, University of Wisconsin, Madison 53706, USA. 
      jha@plantpath.wisc.edu
FAU - Spear, Russell N
AU  - Spear RN
FAU - Nordheim, Erik V
AU  - Nordheim EV
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - Canada
TA  - Can J Microbiol
JT  - Canadian journal of microbiology
JID - 0372707
RN  - 0 (Oligonucleotides)
SB  - IM
MH  - Ascomycota/*physiology
MH  - In Situ Hybridization, Fluorescence
MH  - Malus/*microbiology
MH  - Oligonucleotides/genetics/isolation & purification
MH  - Plant Leaves/*microbiology
EDAT- 2002/08/09 10:00
MHDA- 2003/01/30 04:00
CRDT- 2002/08/09 10:00
PHST- 2002/08/09 10:00 [pubmed]
PHST- 2003/01/30 04:00 [medline]
PHST- 2002/08/09 10:00 [entrez]
AID - 10.1139/w02-044 [doi]
PST - ppublish
SO  - Can J Microbiol. 2002 Jun;48(6):500-13. doi: 10.1139/w02-044.