A non-destructive immunoblotting technique for visualisation and analysis of the growth dynamics of Rhizoctonia solani

Immunoblotting combined with computer imaging and a simple, non-linear math ematical model were used to demonstrate the potential of a technique for no n-destructive visualisation and analysis of fungal growth of Rhizoctonia so lani over the surface of nonsterile sand. Immunoblotting detected actively growing regions of mycelium enabling visualisation of individual hyphae at the colony edge, A zone of active growth was detected expanding radially ov er time, Active growth did not continue in the centre of the fungal colony leading to the development of a ring of mycelium surrounding the inoculum. Change in the density of actively growing mycelium with distance from the i noculum unit was summarised for each colony at each time by a Gaussian func tion, describing a wave of actively growing mycelium, symmetrical in densit y about its centre but differing amongst replicate colonies. The effectiven ess of the immunoblotting technique to detect differences in colony growth was tested by comparing the growth of replicate colonies for two contrastin g isolates of R. solani, When both isolates of R. solani were grown at 23 d egreesC the amplitude of the wave increased to a maximum and then decayed o ver time, the location of the centre of the wave moved outwards at a consta nt rate, whilst the width of the wave increased. Increasing the temperature to 28 degrees, accelerated this intrinsic growth process for one isolate, but retarded growth of the other.