TITLE:
Bioherbicidal Efficacy of a Myrothecium verrucaria-Sector on Several Plant Species
AUTHORS:
Robert E. Hoagland, Clyde D. Boyette, Kenneth C. Stetina, Robin H. Jordan
KEYWORDS:
Bioherbicide, Glyphosate-Resistance, Palmer Amaranth, Kudzu, Hemp Sesbania, Sicklepod, Myrothecium verrucaria, Fungal Sector
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.16,
November
29,
2016
ABSTRACT: Comparative studies were conducted on mycelial preparations of the bioherbicide, Myrothecium verrucaria (MV) strain IMI 361690 and a recently discovered sector
(MV-Sector BSH) of this fungus. The whitish sector was discovered, isolated, grown
in pure culture on PDA and found to be a stable, non-spore producing mutant when
cultured over several months under conditions that cause circadian sporulation during
growth of its MV parent. Application of MV and MV-Sector BSH mycelial preparations
to intact plants (hemp sesbania and sicklepod) and leaf discs (kudzu and
glyphosate-resistant Palmer amaranth) showed that the sector efficacy was generally
equal to, or slightly lower than MV. Bioassays of MV and this sector on seed germination
and early growth of sicklepod and hemp sesbania seeds demonstrated that
hemp sesbania seeds were slightly more sensitive to the fungus than sicklepod seeds
and that the sector bioherbicidal activity was slightly less than that of MV.
SDS-PAGE protein profiles of cellular extracts of MV and the sector and their respective
culture supernatants showed several differences with respect to quantity and
number of certain protein bands. Overall results showed that the isolate was a
non-spore producing mutant with phytotoxicity to several weeds (including weeds
tolerant or resistant to glyphosate), and that the phytotoxic effects were generally
equivalent to those caused by MV treatment. Results of this first report of a
non-sporulating MV mutant that suggest additional studies on protein analysis, and
an extended weed host range under greenhouse and field conditions are needed in
order to further evaluate its possible bioherbicidal potential.