DEPARTMENT OF MATHEMATICAL AND STATISTICAL SCIENCES
UNIVERSITY OF ALBERTA

PIMS-MITACS MATHEMATICAL BIOLOGY SEMINAR


 

MONDAY, November 15, 2004
3:00 - 4:00 p.m.
CAB 657

 

Dr. Karl Hadeler

Lehrstuhl fur Biomathematik
University of Tubingen

 

Persistence of fungal endophytes in grass populations

Certain fungal endophytes of the genus Neotypodium live on wild fescue populations. The fungus is not mutualistic (uninfected plants are always better off),  transmission seems to be entirely vertical (by grass seeds) but not perfect. Hence, this parasite should die out in evolutionary time. In fact the endophyte persists. Field observations and laboratory experiments have been performed to explain the discrepancy. Here a scenario is proposed in terms of a mathematical model for the dynamics of patches of infected and uninfected plants and inter-patch as well as intra-patch transmission. The analysis is based on an apparently novel result on the behavior of the spectral bound of quasi-monotone matrices under rank two perturbations.

(work in progress with H.R. Thieme and S. Faeth)