Culturable bacterial and Trichoderma biofilms isolated from sweet potato as it relates to biological control of rhizopus soft rot.
C. Stevens, A. Fyffe, V.A. Khan, C. Wilson, J. Williams and M. Wisniewski.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino,Italy,. 507 pages.
2008
บทคัดย่อ
Culturable bacterial and Trichoderma biofilms isolated from sweet potato as it relates to biological control of rhizopus soft rot.
Culturable biofilms were isolated on nutrient yeast dextrose agar (NYDA) and potato dextrose agar (PDA) by direct impression (storage root impression culture plate method) and washings from (storage roots disk washate method) from ‘Jewel’ sweetpotato.Root impressions revealed the presence of amorphous biofilmlike particles, and culturable bacteria, andTrichodermabiofilms, within 24 h on PDA and NYDA; within 12 days different colony morphologies were identified using stereo microscope images digitized by a Kodak Microscopy Documentation System. The colony morphotypes termed culturable biofilm morphotypes, when streaked on NYDA contained a mixture of solitary and biofilm bacteria, and grew on both media. Bacteral biofilms from washings were identified mainly asBacillus cereus. Antagonists of the microflora present on the rootsurfaces,played an important role in suppression the growth ofRhizopus stolonifer. For example, simultaneous growth ofR. stoloniferand bacterial biofilms invitro,suppressed and deteriorated aerial hyphal growth ofR. stoloniferon NYDA. Suppression of aerial hyphal growth and disintegration ofR. stoloniferbyTrichodermaisolates were also apparent on PDA. Results revealed that suppression of aerial hyphal growth ofR. stoloniferoccurred as a result of mycoparasitism ofTrichodermabiofilm isolates. Antagonistic biological control microorganisms involved in reducing the inoculum potential ofR.stolonifer,appeared to achieve better control with a mixture of several antagonists or types of antagonist, than with a single one.