| |
| Web URL(s): | http://archive.lib.msu.edu/tic/rpr/1996/Turfgrass/46981,%20Rutgers, Kobayashi.PDF
Last checked: 11/06/2013
Requires: PDF Reader |
|---|
| Publication Type:
| Report |
|---|
| Material Type: | Manuscript |
|---|
| Monographic Author(s): | Kobayashi, Donald Y.; Clarke, Bruce |
|---|
| Monograph Title: | Identification of Parasitic Bacteria as Biological Control Agents Against Summer Patch Disease: [1996 Annual Research Report], 1996. |
|---|
| Publishing Information: | New Brunswick, New Jersey: Department of Plant Pathology, Rutgers University |
|---|
| # of Pages: | 8 |
|---|
| Collation: | [8] pp. |
|---|
| Abstract/Contents: | "Stenotrophomonas (Xanthomonas) maltophilia 34S1 (Sm34S1) was previously identified as a biological control agent capable of controlling summer patch disease, caused by Magnaporthe poae. Greenhouse/growth chamber studies indicated that Sm34S1 reduced foliar symptoms on Kentucky bluegrass by as much as 70% compared to untreated disease controls. When Sm34S1 was applied to plants on a repeated basis, summer patch was suppressed at high, sustained levels. Colonization studies suggested that Sm34S1 populations should be established within the turfgrass rhizosphere at levels above 107 cfu/g sample during a two week period, and should remain above 105 cfu/g sample to achieve effective control. Sm34s1 was applied to pathogen-inoculated field plots located in a three year old Kentucky bluegrass stand that received minimal maintenance during the summer of 1995. Summer patch symptom development was not suppressed by Sm34S1 during that year. Population studies indicated that Sm34S1 was maintained at levels between 104 and 107 cfu/g sample. Sm34S1 was applied to pathogen-inoculated field plots in 1996 consisting of annual bluegrass/bentgrass green. Summer patch symptoms did not develop in field plots during 1996. Studies indicated that Sm34S1 populations fluctuated in the turfgrass rhizosphere over a range greater than that observed in 1995; however, on occasion, populations were established above the critically determined level of 107 cfu/g sample. A single chitinase gene was cloned from Sm34S1 and the nucleotide sequence was determined. The gene encoded a single polypeptide of ca. 1.6 kb, and was associated with a protein of 51.1 kdal in size. Site directed mutagenesis of the gene in 34S1 resulted in loss of chitinase activity, and a significant reduction in biocontrol of summer patch by this organism. Chitinase activity and biocontrol of summer patch was restored when the cloned gene was reintroduced into the mutant. Studies indicated that chitinase was expressed under conditions of nutrient stress and in the presence of chitin. These studies provide strong evidence for the role of chitinase in biocontrol activity by 34S1, and information towards understanding the conditions in which the gene is expressed. Previously isolated biocontrol strains that appeared similar to S. maltophilia 34S1 were compared on a taxonomic basis. Fatty acid analysis (MIDI) and nutritional utilization (Biolog) suggested that two isolates, N4-7 and N4-15, previously recovered from the turfgrass rhizosphere and demonstrated to have summer patch suppressive abilities, were closely related to Stenotrophomonas, Xanthomonas and Xylella species. Serological tests using polyclonal antibodies made against N4-7 indicated relatedness to Xylella and N4-15, but not to Stenotrophomonas. Comparisons of 16s rDNA sequences confirmed the relatedness of both N4-7 and N4-15 to Xylella and Stenotrophomonas. However, N4-7 appeared most closely related to an unidentified, hydrothermal vent eubacterium. These observations provide further information towards understanding the composition and diversity within the turfgrass microbial ecosystem." |
|---|
| Language: | English |
|---|
| References: | 0 |
|---|
| See Also: | See also related summary article "Identification of parasitic bacteria as biological control agents against summer patch disease" 1996 Turfgrass and Environmental Research Summary, 1996, pp. 44-45, R=46981. R=46981 |
|---|
| Note: | "1996 USGA Annual Report"
Graphs |
|---|
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
No defined citation format for TGIF #: 232183 |
| Fastlink to access this record outside TGIF: https://tic.lib.msu.edu/tgif/flink?recno=232183 |
| If there are problems with this record, send us feedback about record 232183. |
| Choices for finding the above item: |
|---|
| Web URL(s):
http://archive.lib.msu.edu/tic/rpr/1996/Turfgrass/46981,%20Rutgers, Kobayashi.PDF
Last checked: 11/06/2013
Requires: PDF Reader |
| Find from within TIC:
Digitally in TIC by record number. |
| Request through your local library's inter-library loan service (bring or send a copy of this TGIF record) |
