Rhizosphere bacteria antagonistic to soybean cyst (Heterodera glycines) and root-knot (Meloidogyne incognita) nematodes: Identification by fatty acid analysis and frequency of biological control activity

1992 ◽  
Vol 139 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Joseph W. Kloepper ◽  
Rodrigo Rodr�guez-K�bana ◽  
John A. McInroy ◽  
Rebecca W. Young
Keyword(s):  
Biological Control ◽  
Fatty Acid ◽  
Meloidogyne Incognita ◽  
Heterodera Glycines ◽  
Fatty Acid Analysis ◽  
Rhizosphere Bacteria ◽  
Control Activity

Influence of disease-suppressive strains of Streptomyces on the native Streptomyces community in soil as determined by the analysis of cellular fatty acids

1996 ◽  
Vol 42 (1) ◽  
pp. 27-37 ◽  
Author(s):  
John H. Bowers ◽  
Linda L. Kinkel ◽  
Roger K. Jones
Keyword(s):  
Biological Control ◽  
Fatty Acid ◽  
Potato Scab ◽  
Cellular Fatty Acid ◽  
Fatty Acid Analysis ◽  
Community Diversity ◽  
Group Method ◽  
Fatty Acid Profiles ◽  
Field Plots ◽  
Related Population

Analysis of cellular fatty acid profiles was used to distinguish among introduced pathogen- suppressive strains and indigenous strains of Streptomyces spp. isolated from soil of field plots established to test the efficacy of Streptomyces strains PonSSII and PonR in the biological control of potato scab. Reference libraries of fatty acid profiles were developed for a collection of known pathogenic strains and the introduced suppressive strains. Population densities of pathogen-related, suppressive, and saprophytic Streptomyces strains were determined from the relationship of field isolates to mean library profiles using cluster analysis and the unweighted pair-group method using arithmetic averages. Community diversity was similarly determined. Streptomyces strains PonSSII and PonR were distinguished from each other and from the pathogen group (which clustered together) based on fatty acid profiles. The introduced, suppressive strains successfully colonized the soil and represented 2–19% of the isolates sampled over 2 years. The introduction of the suppressive strains inhibited the population of strains related to the pathogen library at each sample date; the pathogen population was substantially lower in soil from treatments where the suppressive strains were introduced compared with the nonamended control. At harvest, the pathogen-related population was suppressed 85–93 and 36–44% in 1991 and 1992, respectively, in treatments with the suppressive strains compared with the nonamended control. Diversity of the community was not affected by the introduced strains, and diversity and equitability indices were similar among treatments at any sample time. The inhibition of the pathogen-related population was correlated with a reduction of scab symptoms observed in the field plots into which the suppressive strains were introduced. Implications of a fundamental shift in the pathogen-related population in response to the introduction of the suppressive strains for long-term biological control of potato scab are encouraging.Key words: Streptomyces, fatty acid analysis, biological control, community ecology.

Chemical Constituents in Some Promising Genotypes of Indian Mustard [Brassica juncea (L.) Czern and Coss.]

2017 ◽  
Vol 4 (04) ◽  
Author(s):  
SUNITA SINGH ◽  
R. P. SINGH ◽  
H. K. SINGH ◽  
N. A. KHAN ◽  
M. K. MAURYA
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Erucic Acid ◽  
Brassica Juncea ◽  
Acid Composition ◽  
Chemical Constituents ◽  
Indian Mustard ◽  
Acid Value ◽  
Fatty Acid Analysis ◽  
Crude Fibre

Among the oilseed Brassica crops, Indian mustard [Brassica juncea (L.) Czern and Coss.] is an important source of oil from a nutritional point of view. The nutritional value of oil and cake quality is governed mainly by the composition of its fatty acids, iodine value, saponification, acid value, glucosinolates, crude fibre, protein and limiting amino acids, etc. Seventeen varieties/strains of Indian mustard were taken for saturated and unsaturated fatty acid analysis. The eicosenoic was absent in genotype (NUDBYJ-10) and erucic acid (NUDBYJ-10, LES-46 and Pusa mustard- 21). The fatty acid composition found a variable in different genotypes. Saturated fatty acid, Palmitic + Stearic ranged between 2.3 to 6.5%, Oleic 10.6 to 40.7%, Linoleic 16.1 to 37.7%, Linolenic 13.3 to 26.7%, Eicosenoic 0.00 to 10.30% and Erucic acid 0.00 to 47.50%, respectively. Alternaria blight severity also varied in different genotypes and ranged between 18.75 to 56.25%, maximum being in genotype Kranti and minimum in LES-47. No significant correlation was observed between the fatty acid composition and disease severity. The oil content range from 38.1 to 42.60% and protein content was found highest in variety RGN-73. The amino acid viz. methionine and tryptophan range between 0.41 to 1.81 g/16gN and 0.41 to 1.81 g /16g N, respectively.

EVLUETION OF DIETARY UTILIZATION OF BLOOM-FORMING CYANOBACTERIA BY SMALL-BODIED CRUSTACEAN ZOOPLANKTON USING FATTY ACID ANALYSIS

2019 ◽  
Vol 75 (7) ◽  
pp. III_367-III_374
Author(s):  
Souta AOMORI ◽  
Megumu FUJIABAYASHI ◽  
Kunihiro OKANO ◽  
Yoshihiro TAKADA ◽  
Naoyuki MIYATA
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Analysis ◽  
Crustacean Zooplankton

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

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