Abstract
Fungal colonies reproduce via asexual spores which
differentiate on selected hyphae. At low magnification,
the spores appear as a point set distribution.
A practical method to empirically evaluate these
spatial point sets is developed which is premised on
finding the Minimal Spanning Tree (MST). This is a
graph theoretic approach to solving the generalized
‘Travelling Salesman Problem’ - that is, how to
connect a set of isolated points in the most efficient
way. This paper applies a computerised method
using the S-Plus object oriented programming language
for cluster analysis of these spatial patterns.
The MST returns a unique branching, continuously
connected pattern which summarises the shortest
distance path which connects all the spores. We
can hypothesise that this pathway is one geometric
representation of the minimum physiological connectedness
needed for the coordinated structural
development of the asexual reproduction mechanism
in fungi. Sporulation is generally considered to
be an adaptive response which allows epigenic control
of growth in hostile conditions. The MST therefore
provides empirical measurement of the spatial
cluster-correlation of the pattern.
