A Streptomyces cameroonensis based bioformulation (SCaB) has been developed and shown to be stable and effective in controlling the early proliferation of P. megakarya and promoting the growth of cocoa seedlings in nu...A Streptomyces cameroonensis based bioformulation (SCaB) has been developed and shown to be stable and effective in controlling the early proliferation of P. megakarya and promoting the growth of cocoa seedlings in nursery. This study was carried out to explore the molecular mechanisms associated with the interaction of SCaB, cocoa seedlings, and the pathogen during the early stages of seedling growth in the nursery. For this purpose, seedling treatment with 10% W/W SCaB under greenhouse conditions evaluated SCaB’s capacity to stimulate the defense mechanisms in cocoa. Agronomic growth parameters and the level of induction of defense-associated compounds were analyzed. Real-time (rt) PCR was used to assess the level of expression of defense genes. Here, we showed that the application of SCaB as a seedling treatment enhanced the growth of cocoa seedlings in the nursery by an average of 15.6% after 30 days of growth and led to an average reduction in disease severity of 64% when challenged with P. megakarya. The latter led to an increased synthesis of total phenolic compounds, flavonoids, chitinases, peroxidases, and β-1,3-glucanases and an induced up-regulation of TcChiB, TcGlu-1, TcPer-1, and TcMYBPA genes. This research provides a basis for the optimization of beneficial microorganisms as a viable alternative to chemical fungicides used in disease suppression.展开更多
The aim of this study was to evaluate the ability of oyster shell powder soil amendment to enhance cocoa seedling growth and induce resistance against Phytophthora megakarya in nurseries. The results showed that heat-...The aim of this study was to evaluate the ability of oyster shell powder soil amendment to enhance cocoa seedling growth and induce resistance against Phytophthora megakarya in nurseries. The results showed that heat-treated oyster shells powder at 1% (w/w) soil amendment significantly increased plant height, leaf number, leaf area, dry shoot and root weight more than chemical fungicide and control treatment after twelve weeks of growth. The results showed that heat-treated oyster shell powder raised soil pH significantly and reduced P. megakarya load of the soil suspension by 82%. Assessment of resistance stimulation by leaf inoculation showed the highest level of resistance recorded in plants treated either with heat-treated or non-treated oyster shell powder. Furthermore, total phenolic compounds contents, total soluble proteins contents, polyphenoloxidase, chitinase, peroxidase and β-1,3-glucanases activities increased in both healthy or infected leaves from cacao plants treated with oyster shell powder more than those treated with chemical fungicide. These findings demonstrated that heat-treated oyster shell powder could be used as biofertilizer and biofungicide to improve the quality of cocoa seedling production and protect the plant against P. megakarya.展开更多
文摘A Streptomyces cameroonensis based bioformulation (SCaB) has been developed and shown to be stable and effective in controlling the early proliferation of P. megakarya and promoting the growth of cocoa seedlings in nursery. This study was carried out to explore the molecular mechanisms associated with the interaction of SCaB, cocoa seedlings, and the pathogen during the early stages of seedling growth in the nursery. For this purpose, seedling treatment with 10% W/W SCaB under greenhouse conditions evaluated SCaB’s capacity to stimulate the defense mechanisms in cocoa. Agronomic growth parameters and the level of induction of defense-associated compounds were analyzed. Real-time (rt) PCR was used to assess the level of expression of defense genes. Here, we showed that the application of SCaB as a seedling treatment enhanced the growth of cocoa seedlings in the nursery by an average of 15.6% after 30 days of growth and led to an average reduction in disease severity of 64% when challenged with P. megakarya. The latter led to an increased synthesis of total phenolic compounds, flavonoids, chitinases, peroxidases, and β-1,3-glucanases and an induced up-regulation of TcChiB, TcGlu-1, TcPer-1, and TcMYBPA genes. This research provides a basis for the optimization of beneficial microorganisms as a viable alternative to chemical fungicides used in disease suppression.
文摘The aim of this study was to evaluate the ability of oyster shell powder soil amendment to enhance cocoa seedling growth and induce resistance against Phytophthora megakarya in nurseries. The results showed that heat-treated oyster shells powder at 1% (w/w) soil amendment significantly increased plant height, leaf number, leaf area, dry shoot and root weight more than chemical fungicide and control treatment after twelve weeks of growth. The results showed that heat-treated oyster shell powder raised soil pH significantly and reduced P. megakarya load of the soil suspension by 82%. Assessment of resistance stimulation by leaf inoculation showed the highest level of resistance recorded in plants treated either with heat-treated or non-treated oyster shell powder. Furthermore, total phenolic compounds contents, total soluble proteins contents, polyphenoloxidase, chitinase, peroxidase and β-1,3-glucanases activities increased in both healthy or infected leaves from cacao plants treated with oyster shell powder more than those treated with chemical fungicide. These findings demonstrated that heat-treated oyster shell powder could be used as biofertilizer and biofungicide to improve the quality of cocoa seedling production and protect the plant against P. megakarya.
