Cercospora leaf spot is fast turning into a critically important disease in Zimbabwe.The disease is caused by Cercospora coffeicola which significantly reduces productivity and quality of coffee.Disturbingly,optimum s...Cercospora leaf spot is fast turning into a critically important disease in Zimbabwe.The disease is caused by Cercospora coffeicola which significantly reduces productivity and quality of coffee.Disturbingly,optimum sporulation of Cercospora coffeicola in culture remains a limiting factor for microbial analysis and quantitative studies of Cercospora leaf spot.Faced with this challenge,an in-vitro study was conducted at Coffee Research Institute,Manicaland,Zimbabwe to examine growth of Cercospora coffeicola in different nutrient media and to determine the best media for Cercospora coffeicola analysis.Six nutrient media were assessed(corn meal agar,oat meal agar,Czapek Dox agar,malt extract agar,yeast extract agar and potato dextrose agar)for the growth of Cercospora coffeicola.The laboratory-based experiment was duplicated,laid out in a Completely Randomized Design,replicated three times and based on Cercospora coffeicola nutrient inoculation.Data were collected on radial growth,colour and texture of mycelium at 3 and 6 days after inoculation.There were significant differences(p<0.05)in the growth of Cercospora coffeicola in media after 3 and 6 days.Malt extract agar had the greatest radial growth(34 mm and 32 mm)of Cercospora coffeicola for trials 1 and 2 respectively,whilst the least growth was in the oat meal agar(14.2 mm and 15.7 mm)for trials 1 and 2 respectively.There were variations in colour and texture of mycelium with malt extract agar,potato dextrose agar and oat meal agar associated with darker colours and rough texture while smooth white mycelia were found in corn meal agar.After considering all nutrient media,malt extract agar was found to be the best media for the growth of Cercospora coffeicola in-vitro.On the basis of our findings,the authors recommend the use of malt extract agar as the primary media for identification and characterisation of Cercospora coffeicola.展开更多
本文报告了东北地区Cereospora属及相近属72个种,寄生于29科植物上,其中有5个新组合:忍冬短胖孢(Cercosporidium diervillae(Ell.et Ev.) Bai et Cheng);紫穗槐菌绒孢(Mycovellosiella passaloroides(Winter) Bai et Cheng);杯槐假尾孢(...本文报告了东北地区Cereospora属及相近属72个种,寄生于29科植物上,其中有5个新组合:忍冬短胖孢(Cercosporidium diervillae(Ell.et Ev.) Bai et Cheng);紫穗槐菌绒孢(Mycovellosiella passaloroides(Winter) Bai et Cheng);杯槐假尾孢(Pseudocercospora cladrastidis(Jacz.)Bai et Cheng);白头翁假尾孢(Pseudocercospora filiformis(Davis)Bai et Cheng);荚蒾假尾孢(Pseudocercospora varia(Peck)Bai et Cheng),及10个国内新记录种:假酸浆尾孢(Cercospora nicandrae Chupp);美女樱尾孢(Cercospora papillo(?)a Atkinson);苏子尾孢(Cercospora perillae Sawada);车前尾孢(Cercospora p(?)antaginis Sacc.);金光菊尾孢(Cercospora tabacina Ell.et Ev.);毛蕊花生尾孢(Cercospora verbascicola Ell.et Ev.);扁蓄假尾孢(Pseudocercospora avicularis(Winter) Khan et Shamsi);杜鹃假尾孢(Pseudocercospora handelii(Bubak)Deighton);一叶楸假尾孢(Pseudocercospora securingae(Togashi et Kats(?)ki) Deighton);芝麻假尾孢(Pseudocercospora sesami (Hansford) Deighton)。国内新寄主植物科2个;世界新寄主植物属2个;国内新寄主植物属12个;世界新寄主植物种11个;国内新寄主植物种16个。展开更多
The gray leaf spot caused by Cercospora zeina has become a serious disease in maize in China.The isolates of C.zeina from Yunnan,Sichuan,Guizhou,Hubei,Chongqing,Gansu,and Shaanxi were collected.From those,127 samples ...The gray leaf spot caused by Cercospora zeina has become a serious disease in maize in China.The isolates of C.zeina from Yunnan,Sichuan,Guizhou,Hubei,Chongqing,Gansu,and Shaanxi were collected.From those,127 samples were used for genetic diversity analysis based on inter-simple sequence repeat(ISSR)and 108 samples were used for multi-gene sequence analysis based on five gene fragments.The results indicated that populations of C.zeina were differentiated with a relatively high genetic level and were classified into two major groups and seven subgroups.The intra-population genetic differentiation of C.zeina is the leading cause of population variation in China,and interpopulation genetic similarity is closely related to the colonization time and spread direction.The multi-gene sequence analysis of C.zeina isolates demonstrated that there were nine haplotypes.Genetic diversity and multi-gene sequence revealed that Yunnan population of C.zeina,the earliest colonizing in China,had the highest genetic and haplotype diversity and had experienced an expansion event.With the influence of the southwest monsoon in the Indian Ocean,C.zeina from Yunnan gradually moved to Sichuan,Guizhou,Shaanxi,Gansu,and Chongqing.Meanwhile,C.zeina was transferred directly from the Yunnan into the Hubei Province via seed and then came into Shaanxi,Henan,and Chongqing along with the wind from Hubei.展开更多
Late-cycle diseases (LCD) cause a significant deterioration in quality and reduce yields in soybean crops. In Argentina, in particular, leaf blight and purple seed stain, caused by the agent Cercospora kikuchii, and f...Late-cycle diseases (LCD) cause a significant deterioration in quality and reduce yields in soybean crops. In Argentina, in particular, leaf blight and purple seed stain, caused by the agent Cercospora kikuchii, and frog eye spot, caused by C. sojina, are the prevailing sources of diseases. The early, rapid and accurate detection of these phytopathogens becomes essential, and would contribute to preserving both the environment and the health of humans and animals by preventing the wasteful or improper use of chemicals such as pesticides. In order to detect Cercospora species in soybean plants at an early stage, immunochemical and molecular techniques were developed in this work. Strains from the NITE Biological Resource Center collection (Japan): Cercospora kikuchii NBRC 6711 and Cercospora sojina NBRC 6715 and regional isolates of C. kikuchii were used. To develop Dot-Blot and PCR techniques, experiments with plants undergoing different treatments were carried out: those experimentally inoculated with these fungi, those treated with sterile water and healthy plants as well. Both techniques allowed the detection, at early stages, of Cercospora species involved in two of the most frequent LCD in the country, when the cercosporin concentration produced by the fungus was higher than 3.93 ± 0.39 nmol·cyl-1 ±SD. The sensitivity between both techniques was very different. While Dot-Blot allowed the detection of the disease 4 days after inoculation, PCR detected it after 4 hours, even without visible symptoms of the disease.展开更多
文摘Cercospora leaf spot is fast turning into a critically important disease in Zimbabwe.The disease is caused by Cercospora coffeicola which significantly reduces productivity and quality of coffee.Disturbingly,optimum sporulation of Cercospora coffeicola in culture remains a limiting factor for microbial analysis and quantitative studies of Cercospora leaf spot.Faced with this challenge,an in-vitro study was conducted at Coffee Research Institute,Manicaland,Zimbabwe to examine growth of Cercospora coffeicola in different nutrient media and to determine the best media for Cercospora coffeicola analysis.Six nutrient media were assessed(corn meal agar,oat meal agar,Czapek Dox agar,malt extract agar,yeast extract agar and potato dextrose agar)for the growth of Cercospora coffeicola.The laboratory-based experiment was duplicated,laid out in a Completely Randomized Design,replicated three times and based on Cercospora coffeicola nutrient inoculation.Data were collected on radial growth,colour and texture of mycelium at 3 and 6 days after inoculation.There were significant differences(p<0.05)in the growth of Cercospora coffeicola in media after 3 and 6 days.Malt extract agar had the greatest radial growth(34 mm and 32 mm)of Cercospora coffeicola for trials 1 and 2 respectively,whilst the least growth was in the oat meal agar(14.2 mm and 15.7 mm)for trials 1 and 2 respectively.There were variations in colour and texture of mycelium with malt extract agar,potato dextrose agar and oat meal agar associated with darker colours and rough texture while smooth white mycelia were found in corn meal agar.After considering all nutrient media,malt extract agar was found to be the best media for the growth of Cercospora coffeicola in-vitro.On the basis of our findings,the authors recommend the use of malt extract agar as the primary media for identification and characterisation of Cercospora coffeicola.
文摘本文报告了东北地区Cereospora属及相近属72个种,寄生于29科植物上,其中有5个新组合:忍冬短胖孢(Cercosporidium diervillae(Ell.et Ev.) Bai et Cheng);紫穗槐菌绒孢(Mycovellosiella passaloroides(Winter) Bai et Cheng);杯槐假尾孢(Pseudocercospora cladrastidis(Jacz.)Bai et Cheng);白头翁假尾孢(Pseudocercospora filiformis(Davis)Bai et Cheng);荚蒾假尾孢(Pseudocercospora varia(Peck)Bai et Cheng),及10个国内新记录种:假酸浆尾孢(Cercospora nicandrae Chupp);美女樱尾孢(Cercospora papillo(?)a Atkinson);苏子尾孢(Cercospora perillae Sawada);车前尾孢(Cercospora p(?)antaginis Sacc.);金光菊尾孢(Cercospora tabacina Ell.et Ev.);毛蕊花生尾孢(Cercospora verbascicola Ell.et Ev.);扁蓄假尾孢(Pseudocercospora avicularis(Winter) Khan et Shamsi);杜鹃假尾孢(Pseudocercospora handelii(Bubak)Deighton);一叶楸假尾孢(Pseudocercospora securingae(Togashi et Kats(?)ki) Deighton);芝麻假尾孢(Pseudocercospora sesami (Hansford) Deighton)。国内新寄主植物科2个;世界新寄主植物属2个;国内新寄主植物属12个;世界新寄主植物种11个;国内新寄主植物种16个。
基金supported by the China Agriculture Research System from MOAR and MOF(CARS-02)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2017-ICS)。
文摘The gray leaf spot caused by Cercospora zeina has become a serious disease in maize in China.The isolates of C.zeina from Yunnan,Sichuan,Guizhou,Hubei,Chongqing,Gansu,and Shaanxi were collected.From those,127 samples were used for genetic diversity analysis based on inter-simple sequence repeat(ISSR)and 108 samples were used for multi-gene sequence analysis based on five gene fragments.The results indicated that populations of C.zeina were differentiated with a relatively high genetic level and were classified into two major groups and seven subgroups.The intra-population genetic differentiation of C.zeina is the leading cause of population variation in China,and interpopulation genetic similarity is closely related to the colonization time and spread direction.The multi-gene sequence analysis of C.zeina isolates demonstrated that there were nine haplotypes.Genetic diversity and multi-gene sequence revealed that Yunnan population of C.zeina,the earliest colonizing in China,had the highest genetic and haplotype diversity and had experienced an expansion event.With the influence of the southwest monsoon in the Indian Ocean,C.zeina from Yunnan gradually moved to Sichuan,Guizhou,Shaanxi,Gansu,and Chongqing.Meanwhile,C.zeina was transferred directly from the Yunnan into the Hubei Province via seed and then came into Shaanxi,Henan,and Chongqing along with the wind from Hubei.
文摘Late-cycle diseases (LCD) cause a significant deterioration in quality and reduce yields in soybean crops. In Argentina, in particular, leaf blight and purple seed stain, caused by the agent Cercospora kikuchii, and frog eye spot, caused by C. sojina, are the prevailing sources of diseases. The early, rapid and accurate detection of these phytopathogens becomes essential, and would contribute to preserving both the environment and the health of humans and animals by preventing the wasteful or improper use of chemicals such as pesticides. In order to detect Cercospora species in soybean plants at an early stage, immunochemical and molecular techniques were developed in this work. Strains from the NITE Biological Resource Center collection (Japan): Cercospora kikuchii NBRC 6711 and Cercospora sojina NBRC 6715 and regional isolates of C. kikuchii were used. To develop Dot-Blot and PCR techniques, experiments with plants undergoing different treatments were carried out: those experimentally inoculated with these fungi, those treated with sterile water and healthy plants as well. Both techniques allowed the detection, at early stages, of Cercospora species involved in two of the most frequent LCD in the country, when the cercosporin concentration produced by the fungus was higher than 3.93 ± 0.39 nmol·cyl-1 ±SD. The sensitivity between both techniques was very different. While Dot-Blot allowed the detection of the disease 4 days after inoculation, PCR detected it after 4 hours, even without visible symptoms of the disease.
