Alternative methods are needed to assess the severity of charcoal rot disease [Macrophomina phaseolina (Tassi) Goid] in soybean [Glycine max (L.)] plant tissue. The objective of this study was to define the relationsh...Alternative methods are needed to assess the severity of charcoal rot disease [Macrophomina phaseolina (Tassi) Goid] in soybean [Glycine max (L.)] plant tissue. The objective of this study was to define the relationship between light reflectance properties and microsclerotia content of soybean stem and root tissue. Understanding that relationship could lead to using spectral reflectance data as a tool to assess the severity of charcoal rot disease in soybean plants, thus reducing human bias associated with qualitative analysis of soybean plant tissue and cost and time issues connected with quantitative analysis. Hyperspectral reflectance measurements (400-2490 nm) were obtained with a non-imaging spectroradiometer of non-diseased and charcoal rot diseased ground stem and root tissue samples of six soybean genotypes (“Clark”, “LD00-3309”, “LG03- 4561-14”, “LG03-4561-19”, “Saline”, and “Y227-1”). Relationships between the reflectance measurements and tissue microsclerotia content were evaluated with Spearman correlation (rs) analysis (p < 0.05). Moderate (rs = ±0.40 to ±0.59), strong (rs = ±0.60 to ±0.79), and very strong (rs = ±0.80 to ±1.00) negative and positive statistically significant (p < 0.05) monotonic relationships were observed between tissue spectral reflectance values and tissue microsclerotia content. Near-infrared and shortwave-infrared wavelengths had the best relationships with microsclerotia content in the ground tissue samples, with consistent results obtained with near-infrared wavelengths in that decreases in near-infrared spectral reflectance values were associated with increases in microsclerotia content in the stem and root tissue of the soybean plants. The findings of this study provided evidence that relationships exist between tissue spectral reflectance and tissue microsclerotia content of soybean plants, supporting spectral reflectance data as a means for assessing variation of microsclerotia content in soybean plants. Future research should focus on the modelling capabilities of the selected wavelengths and on the feasibility of using these wavelengths in machine learning algorithms to differentiate non-diseased from charcoal rot diseased tissue.展开更多
This study investigated the antifungal activity of leaf extracts of Prosopis africana and Anacardium occidentale against Macrophomina phaseolina, the causal agent of root rot of Sesamum indicum L. Phytochemical analys...This study investigated the antifungal activity of leaf extracts of Prosopis africana and Anacardium occidentale against Macrophomina phaseolina, the causal agent of root rot of Sesamum indicum L. Phytochemical analysis of the two plants showed the presence of alkaloids, saponins, tannins, flavonoids and anthraquinones in petroleum ether, ethyl acetate, methanol and water extracts. The effectiveness of the two medicinal plants viz: P. africana and A. occidentale was tested against the causative agent of root rot of Sesamum indicum L. The effect of plant leaf extracts on mycelia growth of the test organism shows that both P. africana and A. anacardium reduced the mycelia growth significantly as compared to the control (plate, 2, 3, 4). The antifungal property of P. africana and A. occidentale makes these plants of potential interest for the control of the fungi Macrophomina phaseolina.展开更多
An endophytic fungus MOD-1 was isolated from the roots of mulberry trees,and was identified as Macrophomina phaseolina by morphology and molecular biology.The 5.8 S rDNA/ITS region sequence of the strain has been regi...An endophytic fungus MOD-1 was isolated from the roots of mulberry trees,and was identified as Macrophomina phaseolina by morphology and molecular biology.The 5.8 S rDNA/ITS region sequence of the strain has been registered in GeneBank with the accession number of EU250575.展开更多
文摘Alternative methods are needed to assess the severity of charcoal rot disease [Macrophomina phaseolina (Tassi) Goid] in soybean [Glycine max (L.)] plant tissue. The objective of this study was to define the relationship between light reflectance properties and microsclerotia content of soybean stem and root tissue. Understanding that relationship could lead to using spectral reflectance data as a tool to assess the severity of charcoal rot disease in soybean plants, thus reducing human bias associated with qualitative analysis of soybean plant tissue and cost and time issues connected with quantitative analysis. Hyperspectral reflectance measurements (400-2490 nm) were obtained with a non-imaging spectroradiometer of non-diseased and charcoal rot diseased ground stem and root tissue samples of six soybean genotypes (“Clark”, “LD00-3309”, “LG03- 4561-14”, “LG03-4561-19”, “Saline”, and “Y227-1”). Relationships between the reflectance measurements and tissue microsclerotia content were evaluated with Spearman correlation (rs) analysis (p < 0.05). Moderate (rs = ±0.40 to ±0.59), strong (rs = ±0.60 to ±0.79), and very strong (rs = ±0.80 to ±1.00) negative and positive statistically significant (p < 0.05) monotonic relationships were observed between tissue spectral reflectance values and tissue microsclerotia content. Near-infrared and shortwave-infrared wavelengths had the best relationships with microsclerotia content in the ground tissue samples, with consistent results obtained with near-infrared wavelengths in that decreases in near-infrared spectral reflectance values were associated with increases in microsclerotia content in the stem and root tissue of the soybean plants. The findings of this study provided evidence that relationships exist between tissue spectral reflectance and tissue microsclerotia content of soybean plants, supporting spectral reflectance data as a means for assessing variation of microsclerotia content in soybean plants. Future research should focus on the modelling capabilities of the selected wavelengths and on the feasibility of using these wavelengths in machine learning algorithms to differentiate non-diseased from charcoal rot diseased tissue.
文摘This study investigated the antifungal activity of leaf extracts of Prosopis africana and Anacardium occidentale against Macrophomina phaseolina, the causal agent of root rot of Sesamum indicum L. Phytochemical analysis of the two plants showed the presence of alkaloids, saponins, tannins, flavonoids and anthraquinones in petroleum ether, ethyl acetate, methanol and water extracts. The effectiveness of the two medicinal plants viz: P. africana and A. occidentale was tested against the causative agent of root rot of Sesamum indicum L. The effect of plant leaf extracts on mycelia growth of the test organism shows that both P. africana and A. anacardium reduced the mycelia growth significantly as compared to the control (plate, 2, 3, 4). The antifungal property of P. africana and A. occidentale makes these plants of potential interest for the control of the fungi Macrophomina phaseolina.
基金Supported by National Cocoon and Silk Development Risk Fund(GJXBH 200732)Natural Science Foundation of Shandong Province(2007ZRB01872).
文摘An endophytic fungus MOD-1 was isolated from the roots of mulberry trees,and was identified as Macrophomina phaseolina by morphology and molecular biology.The 5.8 S rDNA/ITS region sequence of the strain has been registered in GeneBank with the accession number of EU250575.
