Fig. 4: Changes in temperature did not alter the rate of aeciospore release.

a The distance traveled by aeciospores following ejection was determined. B. vulgaris leaf fragments containing a single Pg aecium were attached to the wall of a 100 mm square petri dish and aeciospore discharge distances measured by analysis of spore quantity across a series of adjacent microscope slides with a thin (2%) water agar layer. Aecial cups were incubated at 18 °C and assessments made after 18 h. b Representative micrographs of aeciospores identified at different distances from the aecium (1.9, 2.6, 3, and 3.8 cm) illustrate that aeciospores found more than 2 cm from the aecium were commonly found in clusters. c–e Alterations in temperature did not influence the distance aeciospores traveled. Aeciospore release was evaluated under 5, 10, 18, 25, 30, 33, and 37 °C, with no significant difference found (n = 6, Tukey’s HSD; p < 0.01). f The number of aeciospores released was much lower than the predicted full potential. Aeciospore content (“predicted”) per aecium were estimated by measuring the fungal mass and compared to those recorded as released (“released”). n  = 3; For all box plots, bars represent median values, boxes signify the upper (Q3) and lower (Q1) quartiles, whiskers are located at 1.5 the inter-quartile range.