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
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
The direct impact of seed-borne fungi on seed is considerable. Many fungi are serious parasites of seed primordial and maturing seeds and reduce yield of seed both quantitatively and qualitatively. Other fungi, includ...The direct impact of seed-borne fungi on seed is considerable. Many fungi are serious parasites of seed primordial and maturing seeds and reduce yield of seed both quantitatively and qualitatively. Other fungi, including saprophytes and very weak parasites, may lower the quality of seeds by causing discoloration which may seriously depreciate the commercial value of seeds, particularly of grain when graded for consumption. Studies by using scanning electron microscopy （SEM） confirmed the importance of the seed coat, and seed cells as infection sites as well as location of the mycelium of the investigated fungus. Macrophominaphaseolina The present investigation is undertaken to study the colonization, infection and fungal establishment on different sesame seed parts by （SEM）. A successful colonization of M. phaseolina to seed tissues was also detected. Different forms of pycnidial shapes were also observed.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.
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.
文摘The direct impact of seed-borne fungi on seed is considerable. Many fungi are serious parasites of seed primordial and maturing seeds and reduce yield of seed both quantitatively and qualitatively. Other fungi, including saprophytes and very weak parasites, may lower the quality of seeds by causing discoloration which may seriously depreciate the commercial value of seeds, particularly of grain when graded for consumption. Studies by using scanning electron microscopy （SEM） confirmed the importance of the seed coat, and seed cells as infection sites as well as location of the mycelium of the investigated fungus. Macrophominaphaseolina The present investigation is undertaken to study the colonization, infection and fungal establishment on different sesame seed parts by （SEM）. A successful colonization of M. phaseolina to seed tissues was also detected. Different forms of pycnidial shapes were also observed.
