CELL-POPULATION DYNAMICS IN COPRINUS-CINEREUS - NARROW AND INFLATED HYPHAE IN THE BASIDIOME STIPE

The stipes of post-meiotic basidiomes of Coprinus cinereus always contained a significant numerical proportion (23-54%) of narrow (cross-sectional area < 20 mum2) as well as inflated hyphae, although the former only contributed 1-4% to the overall cross-sectional area of the stipe. At the extreme bases and apices of elongating stipes, the central region was occupied exclusively by narrow hyphae, which were also concentrated on the outside of the stipe and fringing the central lumen. Elsewhere, narrow hyphae were interspersed between the inflated hyphae. Nearest-neighbour analysis showed that inflated hyphae were evenly rather than randomly distributed regardless of the age of the basidiome (27-70 mm tall) and position within the stipe. The spatial distribution of narrow hyphae differed significantly from randomness only in the upper middle and upper apical regions of 27 mm and 70 mm tall basidiomes, respectively, where their distribution was more even. The proportion of narrow hyphae decreased with time, possibly due to some becoming inflated. The even distribution of inflated hyphae could be due to some sort of organizational control over their pattern of differentiation from narrow hyphae. During normal stipe extension the greatest cell expansion was seen in the inflated cells situated between the mid-cortex and the lumen, and not at the periphery of the stipe, Narrow hyphae tended to stain differentially and to have varied spatial arrangements, suggesting that although morphologically alike, they serve distinct functions.