Quantification of a novel biotrophic mycoparasitic fungus using genus specific real-time PCR for biocontrol of phytopathogenic Fusarium graminearum in wheat root under controlled conditions
Non-Peer ReviewedFusarium species are well-known causal agents of Fusarium root-rot, Fusarium head blight
(FHB), and Fusarium damaged kernels (FDK) diseases in Saskatchewan and other provinces
of Canada. Our goal is to develop quantitative real-time PCR techniques to determine and
evaluate interactions between Fusarium-associated biotrophic mycoparasitic fungus SMCD
2220 and 3-acetyldeoxynivalenol (3-ADON) producing Fusarium graminearum Schwabe –
in and surrounding wheat roots. ITS1F/ITS4 (internal transcribed spacer) sequences from
SMCD 2220 biotrophic mycoparasitic fungal isolate and 20 different Fusarium strains were
aligned, and consensus sequences were verified. Four candidate primer sets from ITS regions
were designed based on the non-conserved regions of the consensus sequences. Using the
primer set SmyITSF/R, the biotrophic mycoparasite genomic DNAs were amplified from
SMCD 2220. This primer set was developed for assessing and quantifying the interactions
between SMCD 2220 biotrophic mycoparasite and F. graminearum. Well-known
necrotrophic T. harzianum T-22, was used as the positive control. During in vitro studies,
only SMCD 2220 was observed to improve wheat seed germination, whereas T-22 induced
post-emergence damping-off symptoms. Under controlled phytotron conditions, both SMCD
2220 and T. harzianum strains were able to reduce the quantity of F. graminearum in spring
wheat root, as well as improving the survival and growth of the spring wheat seedlings.
However, amount of SMCD 2220 DNA detected was no significantly difference between
wheat inoculated with F. graminearum and without Fusarium. In contrary, the amount of T.
harzianum DNA monitored in the treatment inoculated with F. graminearum was observed to
reduce significantly, as compared to non-Fusarium treatment