Influence of spore density and extracellular conidial matrix on spore germination in Colletotrichum capsici

The influence of extracellular conidial matrix on germinability was investigated using a tropical isolate of Colletotrichum capsici. Decreasing spore density and the amount of accompanying matrix increased germinability of freshly gathered spores, especially those from < 10-day-old cultures. Removing the matrix altogether by washing and then decreasing spore density significantly increased germinability. When subjected to drying, germinability of matrix-free (washed) spores was negligible, whilst that of unwashed spores remained the same as for freshly harvested spores, especially with increasing spore density and culture age. As there is no occasion for seasonal carry-over of inoculum in the tropics, it is suggested that with C. capsici the inhibitory or retardatory role of the matrix should be considered in the context of mass survival previous to splash-dispersal.