White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China.However,we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China durin...White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China.However,we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China during recent disease surveys.Thus,the objective of this study was to confirm the causal agents from diseased pea plants.The obtained isolates of white mold from Chongqing and Sichuan were identified by morphological characters and molecular characterization to determine the pathogen species,and their pathogenicity was confirmed on pea through completing Koch’s postulates.Fungal isolates of Sclerotinia-like were obtained from diseased plants or sclerotia.Based on morphological characteristics and molecular characterization,30 isolates were identified to three species,six isolates as S.minor,seven as S.sclerotiorum,and 17 as S.trifoliorum.In pathogenicity tests on pea cultivars Zhongwan 4 and Longwan 1,all 30 isolates caused typical symptoms of white mold on the inoculated plants,and the inoculated pathogens were re-isolated from the diseased plants.This study confirmed that white mold of pea was caused by three Sclerotinia species,S.sclerotiorum,S.minor and S.trifoliorum in Chongqing and Sichuan.It is the first report that S.minor and S.trifoliorum cause white mold of pea in Southwest China.展开更多
The potential use ofcomposted wood fibre waste （WFW） for the cultivation of bacterial antagonists of Sclerotinia minor was examined with the result that a mix of millet seed （20% w/w） and WFW, suitably amended wit...The potential use ofcomposted wood fibre waste （WFW） for the cultivation of bacterial antagonists of Sclerotinia minor was examined with the result that a mix of millet seed （20% w/w） and WFW, suitably amended with nutrients, proved to be an ideal matrix for the growth of some of these bacteria. Densities in terms ofcfu＇s ranged from 8.5 IOgl0 cfu/g dw to 10.5 logl0 cfu/g dw ullder sterile conditions after 14 days incubation. Lower population densities of the antagonists were achieved under non-sterile conditions in the compost： millet mix of between 7.9-9.3 logm cfu/g dw at the same period. However, when applied in a pot （glasshouse） trial to protect against S. minor, the millet seed appeared to stimulate the growth of this pathogen resulting in a high incidence of attack of lettuce plants after 2-3 weeks. Although the percentage of healthy seedlings increased following application of compost mix grown antagonists （at a rate of 5% v/v） when compared to the control treatment, these values were not statistically significant （p〉0.05） in most cases. Therefore, the use of millet seeds cannot be recommended as a nutrient supplement for the bacterial antagonist cultivation, if to be subsequently used to control fungal pathogens in the field.展开更多
The main objective of this research was to investigate the ability of a Trichoderma sp. （Td22）, inhibitory to Sclerotinia minor Jagger, to grow and survive in mature wood fibre waste （WFW） compost of paper mill or...The main objective of this research was to investigate the ability of a Trichoderma sp. （Td22）, inhibitory to Sclerotinia minor Jagger, to grow and survive in mature wood fibre waste （WFW） compost of paper mill origin following nutrient amendment. The growth and survival of the fungus in the WFW compost was assessed by serial dilution plate count method followed by confirmation of the fungal identity using pectic enzyme analysis as described in Cruickshank and Pitt [1]. It was found in this study that the population densities of TdE2 achieved under non-sterile conditions in the WFW compost following nutrient amendment was approximately in the range of 7.0 lOgl0 CFU/g dw - 8.5 log10 CFU/g dw after 28 days, depending on pre-treatment. The efficacy of this WFW compost-grown TdE2 for protection of lettuce from attack by S. minor was also demonstrated in glasshouse trials. This study indicates that cellulosic paper mill waste compost could provide an abundant low-cost growth medium for the large-scale cultivation of fungal antagonists, improving prospects for cost-competitiveness with chemical treatments.展开更多
基金supported by the China Agriculture Research System of MOF and MARA(CARS-08)the National Crop Germplasm Resources Center of China(NCGRC-2020-09)the Scientific Innovation Program of the Chinese Academy of Agricultural Sciences。
文摘White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China.However,we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China during recent disease surveys.Thus,the objective of this study was to confirm the causal agents from diseased pea plants.The obtained isolates of white mold from Chongqing and Sichuan were identified by morphological characters and molecular characterization to determine the pathogen species,and their pathogenicity was confirmed on pea through completing Koch’s postulates.Fungal isolates of Sclerotinia-like were obtained from diseased plants or sclerotia.Based on morphological characteristics and molecular characterization,30 isolates were identified to three species,six isolates as S.minor,seven as S.sclerotiorum,and 17 as S.trifoliorum.In pathogenicity tests on pea cultivars Zhongwan 4 and Longwan 1,all 30 isolates caused typical symptoms of white mold on the inoculated plants,and the inoculated pathogens were re-isolated from the diseased plants.This study confirmed that white mold of pea was caused by three Sclerotinia species,S.sclerotiorum,S.minor and S.trifoliorum in Chongqing and Sichuan.It is the first report that S.minor and S.trifoliorum cause white mold of pea in Southwest China.
文摘The potential use ofcomposted wood fibre waste （WFW） for the cultivation of bacterial antagonists of Sclerotinia minor was examined with the result that a mix of millet seed （20% w/w） and WFW, suitably amended with nutrients, proved to be an ideal matrix for the growth of some of these bacteria. Densities in terms ofcfu＇s ranged from 8.5 IOgl0 cfu/g dw to 10.5 logl0 cfu/g dw ullder sterile conditions after 14 days incubation. Lower population densities of the antagonists were achieved under non-sterile conditions in the compost： millet mix of between 7.9-9.3 logm cfu/g dw at the same period. However, when applied in a pot （glasshouse） trial to protect against S. minor, the millet seed appeared to stimulate the growth of this pathogen resulting in a high incidence of attack of lettuce plants after 2-3 weeks. Although the percentage of healthy seedlings increased following application of compost mix grown antagonists （at a rate of 5% v/v） when compared to the control treatment, these values were not statistically significant （p〉0.05） in most cases. Therefore, the use of millet seeds cannot be recommended as a nutrient supplement for the bacterial antagonist cultivation, if to be subsequently used to control fungal pathogens in the field.
文摘The main objective of this research was to investigate the ability of a Trichoderma sp. （Td22）, inhibitory to Sclerotinia minor Jagger, to grow and survive in mature wood fibre waste （WFW） compost of paper mill origin following nutrient amendment. The growth and survival of the fungus in the WFW compost was assessed by serial dilution plate count method followed by confirmation of the fungal identity using pectic enzyme analysis as described in Cruickshank and Pitt [1]. It was found in this study that the population densities of TdE2 achieved under non-sterile conditions in the WFW compost following nutrient amendment was approximately in the range of 7.0 lOgl0 CFU/g dw - 8.5 log10 CFU/g dw after 28 days, depending on pre-treatment. The efficacy of this WFW compost-grown TdE2 for protection of lettuce from attack by S. minor was also demonstrated in glasshouse trials. This study indicates that cellulosic paper mill waste compost could provide an abundant low-cost growth medium for the large-scale cultivation of fungal antagonists, improving prospects for cost-competitiveness with chemical treatments.
