Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation me...Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680 bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples.展开更多
Septoria carvi belong to the fungi recently detected on caraway plants in the Polish climatic conditions. In many European countries, this fungus causes significant losses in caraway cultivation and decreases the qual...Septoria carvi belong to the fungi recently detected on caraway plants in the Polish climatic conditions. In many European countries, this fungus causes significant losses in caraway cultivation and decreases the quality and quantity of the herb material. The aim of the present work was to study the fungus harmfulness towards the sowing materials, stems, leaves and umbels of caraway. The pathogenicity tests according to Koch＇s postulates were carried out for isolates ofS. carvi using post-culture liquids and a water suspension of conidia to inoculate the plants＇ parts. The studies were conducted in the laboratory, the climatic chamber and in field conditions. S. carvi caused disease symptoms in the form of spots and necrosis on all tested plants organs. The infection was followed by natural openings what was shown by scanning electron microscope （SEM） microscopic observations. The efficiency of inoculation increased injuries and anatomical dipping of plant epidermal tissue. The study showed the ability for asymptomatic S. carvi colonization of inoculated plants＇ parts. The performed pathogenicity tests and microscopic observations SEM showed that the tested isolates of S. carvi were occasional pathogens of caraway.展开更多
Both grain yield and disease performance are important factors to consider for winter wheat （Triticum aestivum） cultivar selection. However, disease index and yield data are often presented separately, making it dif...Both grain yield and disease performance are important factors to consider for winter wheat （Triticum aestivum） cultivar selection. However, disease index and yield data are often presented separately, making it difficult to compare values across multiple environments. Two-year investigations （2009-2010）, in which eight common wheat lines/genotypes were included to test their susceptibility against wheat LR （leaf rust） Puccinia triticina f. sp. tritici Roberge ex Desm., and the SLB （SeptoriaJStagonospora leaf blotch） complex Septoria tritici Desm. and Stagonospora nodorum, were carried out in the experimental field of ATTC （Agriculture Technology Transfer Centre） of Lushnje （Albania）. The objective of this study was to use a rank-based method to compare cultivars based on yield and disease performance combined across multiple environments. Analysis of variance revealed the presence of an important and significant variability in the experimental materials used to evaluate the susceptibility and the resistance of common wheat lines against SLB and LR. There were high negative correlations between yieldS, tritici （0.6683） and yield--P, recondita f. sp. tritici （0.5261）. The negative effects of two pathogens have shown ＂the parallel＂/similar negative influences on yield trait and there was a high positive correlation （0.7631） between S. tritici and P. recondita f. sp. tritici. According to study results the lines Regina × L-776, IKB-P6 and Bullgar 3 × KB 703 have shown good results of resistance （R） level against S. tritici and P. recondita f. sp. tritici.展开更多
Reactions 13 wheat cultivars to 18 Mycosphaerella graminicola isolates, collected from three distinct localities, were in average different but differences among individual cultivars were small. All cultivars were sus...Reactions 13 wheat cultivars to 18 Mycosphaerella graminicola isolates, collected from three distinct localities, were in average different but differences among individual cultivars were small. All cultivars were susceptible to septoria tritici blotch. Reactions of wheat cultivars to M. graminicola isolates varied from 31% to 41%. Some cultivars had low differences but the other high in reactions to used isolates in average. Variance of individual cultivars to all isolates in reactions of maximal and minimal values fluctuated between 44-80%. More differences were in reactions between individual isolates to single cultivars. Aggressiveness individual isolates to all tested cultivars oscillated in average from 9% to 66% of necrotic leaf area covered by pycnidia. Three isolates had very low, whereas five isolates had high aggressiveness in average to all cultivars. Difference in maximal and minimal aggressiveness of individual isolates to all cultivars was between 13 and 60%. Avirulent reaction was ascertained in the cultivar Rexia to one isolate. Isolates showed wide differences in colored and morphological characteristics. Dissimilarity and similarity was in border shape, cultivation types, surface and coloration of isolate colony also.展开更多
Field studies were conducted at Hazara Agriculture Research Station, Abbottabad to evaluate thirteen AVRDC lines along with one commercial check (Roma) for potential of fruit yield against septoria leaf spot during su...Field studies were conducted at Hazara Agriculture Research Station, Abbottabad to evaluate thirteen AVRDC lines along with one commercial check (Roma) for potential of fruit yield against septoria leaf spot during summer season 2014. The disease established itself by natural infection and disease severity was estimated with the help of 0 - 5 disease rating scale after 15 days interval from the onset of symptoms. The lines showed significant difference in % septoria leaf spot infection. The disease severity % increased up to 100% in line AVTO1314 whereas the lowest % severity was recorded in AVTO1173 which showed the highest yield (468.1 g) with average fruit weight 122.22 g while the significantly lowest mean yield/plant (35.05 g) was calculated in line AVTO1314 with fruit weight 47.92 g. It was concluded that the line AVTO1173 could be useful in genetic programs for incorporating resistant genes in local tomato germplasm against septoria leaf spot disease.展开更多
Background:Septoria tritici blotch(STB)(Zymoseptoria tritici)is a major disease of durum wheat,an economic crop grown in the highlands of Wollo in Ethiopia.Methods:To determine the status of this disease,we conducted ...Background:Septoria tritici blotch(STB)(Zymoseptoria tritici)is a major disease of durum wheat,an economic crop grown in the highlands of Wollo in Ethiopia.Methods:To determine the status of this disease,we conducted surveys in five districts of Wollo(Meket,Woreilu,Wadila,Jama,and Dessie Zuria)during the 2015 cropping season.We visited 75 farm plots to determine the prevalence,incidence,and severity of STB.Results:STB prevalence varied among locations,genotypes,planting dates,growth stages,previous crops,plant population,weed population,and soil types.Similarly,disease intensity also varied along all independent variables.The level of incidence was high in all the visited districts,and the level severity ranged from 9.9 to 59.3%while the incidence varied from 50 to 100%.The mean differences in incidence and severity within the districts’variable classes,altitude,varieties,growth stage,plant population,planting date,previous crop,weed population,and soil type were high.The independent variables,districts,altitude,varieties,growth stage,plant population,planting date,previous crops,weed population,and soil type,were significantly associated with high incidence and severity of STB as single predictor in the logistic regression model.A reduced multiple variable model was fitted using districts,altitude,varieties,growth stage,plant population,planting date,previous crop,weed population,and soil type as independent variables.High incidence(>50%)and severity(>25%)had a high probability of association to all independent variables,except previous crop.Low disease incidence(≤50%)and low disease severity(≤25%)had high probability of association to the previous crop.Conclusion:Environmental variables,cultivation practice,and responses were important for the development of STB.Therefore,these factors must be considered in designing strategies for the effective management of STB.展开更多
首次较系统地研究白芷斑枯病菌的生物学特性,结果表明：菌丝生长和产孢的温度范围为10~35℃,最适温度为25℃;最适pH5~7;病菌在PDA培养基上能够很好的生长和产孢;对碳源的利用以双糖最佳,对氮源的利用以无机氨态氮最好;光照对病菌的生长...首次较系统地研究白芷斑枯病菌的生物学特性,结果表明：菌丝生长和产孢的温度范围为10~35℃,最适温度为25℃;最适pH5~7;病菌在PDA培养基上能够很好的生长和产孢;对碳源的利用以双糖最佳,对氮源的利用以无机氨态氮最好;光照对病菌的生长和产孢无显著影响。分生孢子在无菌水中的萌发率极低,加入糖分或寄主汁液可显著提高孢子的萌发率;分生孢子萌发的温度范围为10~35℃,最适温度为25~28℃;相对湿度93%以上孢子才能萌发,以RH100%＋水中孢子萌发率最高;pH5~7最有利于孢子萌发。在最适条件下,病菌孢子8 h开始萌发,24 h萌发率达到90%以上。光照对分生孢子的萌发无显著影响。分生孢子的致死温度为50℃（10 m in）。展开更多
基金financially supported by Tarbiat Modares University
文摘Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680 bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples.
文摘Septoria carvi belong to the fungi recently detected on caraway plants in the Polish climatic conditions. In many European countries, this fungus causes significant losses in caraway cultivation and decreases the quality and quantity of the herb material. The aim of the present work was to study the fungus harmfulness towards the sowing materials, stems, leaves and umbels of caraway. The pathogenicity tests according to Koch＇s postulates were carried out for isolates ofS. carvi using post-culture liquids and a water suspension of conidia to inoculate the plants＇ parts. The studies were conducted in the laboratory, the climatic chamber and in field conditions. S. carvi caused disease symptoms in the form of spots and necrosis on all tested plants organs. The infection was followed by natural openings what was shown by scanning electron microscope （SEM） microscopic observations. The efficiency of inoculation increased injuries and anatomical dipping of plant epidermal tissue. The study showed the ability for asymptomatic S. carvi colonization of inoculated plants＇ parts. The performed pathogenicity tests and microscopic observations SEM showed that the tested isolates of S. carvi were occasional pathogens of caraway.
文摘Both grain yield and disease performance are important factors to consider for winter wheat （Triticum aestivum） cultivar selection. However, disease index and yield data are often presented separately, making it difficult to compare values across multiple environments. Two-year investigations （2009-2010）, in which eight common wheat lines/genotypes were included to test their susceptibility against wheat LR （leaf rust） Puccinia triticina f. sp. tritici Roberge ex Desm., and the SLB （SeptoriaJStagonospora leaf blotch） complex Septoria tritici Desm. and Stagonospora nodorum, were carried out in the experimental field of ATTC （Agriculture Technology Transfer Centre） of Lushnje （Albania）. The objective of this study was to use a rank-based method to compare cultivars based on yield and disease performance combined across multiple environments. Analysis of variance revealed the presence of an important and significant variability in the experimental materials used to evaluate the susceptibility and the resistance of common wheat lines against SLB and LR. There were high negative correlations between yieldS, tritici （0.6683） and yield--P, recondita f. sp. tritici （0.5261）. The negative effects of two pathogens have shown ＂the parallel＂/similar negative influences on yield trait and there was a high positive correlation （0.7631） between S. tritici and P. recondita f. sp. tritici. According to study results the lines Regina × L-776, IKB-P6 and Bullgar 3 × KB 703 have shown good results of resistance （R） level against S. tritici and P. recondita f. sp. tritici.
文摘Reactions 13 wheat cultivars to 18 Mycosphaerella graminicola isolates, collected from three distinct localities, were in average different but differences among individual cultivars were small. All cultivars were susceptible to septoria tritici blotch. Reactions of wheat cultivars to M. graminicola isolates varied from 31% to 41%. Some cultivars had low differences but the other high in reactions to used isolates in average. Variance of individual cultivars to all isolates in reactions of maximal and minimal values fluctuated between 44-80%. More differences were in reactions between individual isolates to single cultivars. Aggressiveness individual isolates to all tested cultivars oscillated in average from 9% to 66% of necrotic leaf area covered by pycnidia. Three isolates had very low, whereas five isolates had high aggressiveness in average to all cultivars. Difference in maximal and minimal aggressiveness of individual isolates to all cultivars was between 13 and 60%. Avirulent reaction was ascertained in the cultivar Rexia to one isolate. Isolates showed wide differences in colored and morphological characteristics. Dissimilarity and similarity was in border shape, cultivation types, surface and coloration of isolate colony also.
文摘Field studies were conducted at Hazara Agriculture Research Station, Abbottabad to evaluate thirteen AVRDC lines along with one commercial check (Roma) for potential of fruit yield against septoria leaf spot during summer season 2014. The disease established itself by natural infection and disease severity was estimated with the help of 0 - 5 disease rating scale after 15 days interval from the onset of symptoms. The lines showed significant difference in % septoria leaf spot infection. The disease severity % increased up to 100% in line AVTO1314 whereas the lowest % severity was recorded in AVTO1173 which showed the highest yield (468.1 g) with average fruit weight 122.22 g while the significantly lowest mean yield/plant (35.05 g) was calculated in line AVTO1314 with fruit weight 47.92 g. It was concluded that the line AVTO1173 could be useful in genetic programs for incorporating resistant genes in local tomato germplasm against septoria leaf spot disease.
文摘Background:Septoria tritici blotch(STB)(Zymoseptoria tritici)is a major disease of durum wheat,an economic crop grown in the highlands of Wollo in Ethiopia.Methods:To determine the status of this disease,we conducted surveys in five districts of Wollo(Meket,Woreilu,Wadila,Jama,and Dessie Zuria)during the 2015 cropping season.We visited 75 farm plots to determine the prevalence,incidence,and severity of STB.Results:STB prevalence varied among locations,genotypes,planting dates,growth stages,previous crops,plant population,weed population,and soil types.Similarly,disease intensity also varied along all independent variables.The level of incidence was high in all the visited districts,and the level severity ranged from 9.9 to 59.3%while the incidence varied from 50 to 100%.The mean differences in incidence and severity within the districts’variable classes,altitude,varieties,growth stage,plant population,planting date,previous crop,weed population,and soil type were high.The independent variables,districts,altitude,varieties,growth stage,plant population,planting date,previous crops,weed population,and soil type,were significantly associated with high incidence and severity of STB as single predictor in the logistic regression model.A reduced multiple variable model was fitted using districts,altitude,varieties,growth stage,plant population,planting date,previous crop,weed population,and soil type as independent variables.High incidence(>50%)and severity(>25%)had a high probability of association to all independent variables,except previous crop.Low disease incidence(≤50%)and low disease severity(≤25%)had high probability of association to the previous crop.Conclusion:Environmental variables,cultivation practice,and responses were important for the development of STB.Therefore,these factors must be considered in designing strategies for the effective management of STB.
文摘首次较系统地研究白芷斑枯病菌的生物学特性,结果表明：菌丝生长和产孢的温度范围为10~35℃,最适温度为25℃;最适pH5~7;病菌在PDA培养基上能够很好的生长和产孢;对碳源的利用以双糖最佳,对氮源的利用以无机氨态氮最好;光照对病菌的生长和产孢无显著影响。分生孢子在无菌水中的萌发率极低,加入糖分或寄主汁液可显著提高孢子的萌发率;分生孢子萌发的温度范围为10~35℃,最适温度为25~28℃;相对湿度93%以上孢子才能萌发,以RH100%＋水中孢子萌发率最高;pH5~7最有利于孢子萌发。在最适条件下,病菌孢子8 h开始萌发,24 h萌发率达到90%以上。光照对分生孢子的萌发无显著影响。分生孢子的致死温度为50℃（10 m in）。
