2117.2.4.1 Fusarium Seed Rot Life Cycle
The asexual life cycle of Fusarium begins with conidia (asexually produced spores;
Fig. 7.4a ). Two types of conidia, macroconidia and microconidia, are normally pro-
duced, although some of the strains from B. tectorum rarely if ever produce
ab
c
Fig. 7.4 ( a ) Macroconidia produced by a Fusarium strain from a die-off soil. ( b ) The development
of abundant mycelium on killed Bromus tectorum seeds that had been inoculated with Fusarium
macroconidia, incubated for 7 days at −1.5 MPa, and then transferred to free water (inset shows the
development of infection cushions or “white tufts” over the point of incipient radicle emergence
during incubation at low water potential). ( c ) Bromus tectorum seed mortality caused by 16 strains
of Fusarium when inoculated seeds were incubated for 7 days at −1.5 MPa prior to transfer to
water ( upper panel ) and when inoculated seeds were placed directly into free water ( lower panel )
at 25 °C (From Meyer et al. 2014a )
7 Community Ecology of Fungal Pathogens on Bromus tectorum