Wheat stripe rust has become the most dangerous disease which threaten safe yield of wheat in Sichuan Province. It is meaningful to provide technique support for integrated disease control by exploring the effective c...Wheat stripe rust has become the most dangerous disease which threaten safe yield of wheat in Sichuan Province. It is meaningful to provide technique support for integrated disease control by exploring the effective control measures of wheat stripe rust. Wheat stripe rust dynamic developments of all-planting and mixed-planting have been systematically investigated in this study by taking different mixed-planting combinations among 6 wheat varieties with different resistance levels. The results of this experiment show that the mixed-plantings of 4 and 6 wheat varieties can delay the occurance of wheat stripe rust,slow the speed of disease and decline the damage of disease as well as stabilize yield of wheats.展开更多
[Objective] The aim of this study is to establish the model for forecasting wheat stripe rust occurrence condition using meteorological factors. [Method] Based on the data of wheat stripe rust occurrence degrees in it...[Objective] The aim of this study is to establish the model for forecasting wheat stripe rust occurrence condition using meteorological factors. [Method] Based on the data of wheat stripe rust occurrence degrees in its past prevalent years and the meteorological data at corresponding periods, the methods of grey correlation analysis and fuzzy mathematics were employed to establish the forecast model for four pathogenesis indices according to the time sequence before winter, Early March, Early April and Middle May. Thus, the criterion for forecasting the occurrence degree of wheat stripe rust was obtained based on the distribution method of arithmetic progression. [Result] The model corresponding to meteorological conditions for forecasting wheat stripe rust was successfully established. According to the verification, the forecasting results before winter and in Early Mar. were more severer than the real occurrence condition, while the forecasting results in Early Apr. and Middle May were basically consistent with real values. [Conclusion] The results of the present study may avail the control of wheat stripe rust in Henan Province.展开更多
Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental fa...Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental factor affecting the occurrence and epidemiology of wheat stripe rust. Investigating UV-B radiation effects on the epidemiology of stripe rust may be conducive to monitoring and predicting this disease. In this study, wheat seedlings were exposed to UV-B radiation during different periods under laboratory conditions and radiation effects on epidemiological components of wheat stripe rust were investigated. Results showed that incubation period was shortened, and the infection efficiency, sporulation quantity and disease index increased when UV-B radiation was performed only pre-inoculation. When the UV-B radiation was performed only postinoculation or both pre-and post-inoculation, the incubation period was prolonged, and the infection efficiency, sporulation quantity and disease index were reduced. When healthy wheat seedlings were inoculated using urediospores collected from wheat leaves irradiated by UV-B only post-inoculation or both pre-and post-inoculation, infection efficiency, sporulation quantity and disease index were also reduced. However, in the latter, the disease incubation period did not differ under varying UV-B radiation intensities compared to that when wheat leaves were not treated with UV-B radiation. Overall, the effects of direct exposure of wheat plants to UV-B radiation with different intensities in different periods on epidemiological components of wheat stripe rust were systematically explored, and the results suggest that the effects of UV-B radiation increased gradually with the increase of UV-B radiation intensity. This information provides a basis for monitoring and predicting this disease as well as for conducting further studies on pathogen virulence variation.展开更多
Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics ...Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen due mainly to the nature of obligate biotrophism and the lack of systems for studying its genetics and molecular manipulations. To overcome these limitations, a natural Pst population comprising 352 isolates representative of a diverse virulence spectrum was genotyped using 97 secreted protein-single nucleotide polymorphism (SP-SNP) markers to identify candidate avirulence genes using association analysis. Among avirulence genes corresponding to 19 resistance genes, significantly associated SP-SNP markers were detected for avirulence genes AvYr1, AvYr2, AvYr6, AvYr7, AvYr8, AvYr44, AvYrExp2, AvYrSP, and AvYrTye. These results indicate that association analysis can be used to identify markers for avirulence genes. This study has laid the foundation for developing more SP-SNPs for mapping avirulence genes using segregating populations that can be generated through sexual reproduction on alternate hosts of the pathogen.展开更多
The aim of this study is to clarify the application effect of pesticide decrement synergist ＇ Jijian＇ on wheal stripe lUSt. Sampling investigation, randomized block design and statistic analysis were carried out to ...The aim of this study is to clarify the application effect of pesticide decrement synergist ＇ Jijian＇ on wheal stripe lUSt. Sampling investigation, randomized block design and statistic analysis were carried out to find out the field efficacy of adding ＇ Jijian＇ to triadimefon WP and propiconazole EC on controlling wheat stripe rust. The results showed that during the epidemic period of stripe rust, the control effects on the 7^th and the 19^th d reached more than 93% and 100% , respectively, by the application of 15% triadimefon WP of 1 200 g/hm^2 and 25% propiconazole EC of 600 mlhm^2 , respectively for 2 times ; when 15% triadimefon WP of 840 g/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 or 25 % propiconazole EC of 420 mlhm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 were applied （ adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by 30% ） , the control effect on the 7^th d was 89.4% and 91.7% , respectively, while the control effect on the 19a＇ d was 99.8 - 100% ; when 15% triadimefon WP of 720 - 600 g/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 or 25% propiconazole EC 360 - 300 mlhm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 were applied （ adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by 40% - 50% ） , the control effect on the 7a＇ day reached more than 78.0% , while the control effect on the 19^th day was 97.7% - 99.8%. There was no significant difference on the control effect at the 7^th d between the treatments using the 2 pesticides alone and the treatments adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by 30%, but all had significant differences from the treatments adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by40% -50%. There was no significant difference on the control effect of the 19^th d among different treatments. Therefore, if the disease is not serious, the application of ＇ Jijian＇ can reduce the application amounts of pesticides by 40% -50%, that is, 15% triadimefon WP of 720 -600 g/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 or 25 % propiconazole EC of 360- 300 ml/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2, which is helpful to reduce the pesticide application amounts and pesticide residue pollution, and save the control costs.展开更多
Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.（ Pst）,is one of the most destructive diseases of wheat（ Triticum aestivum L.） worldwide. Sichuan province plays an important role in...Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.（ Pst）,is one of the most destructive diseases of wheat（ Triticum aestivum L.） worldwide. Sichuan province plays an important role in stripe rust epidemic in China. To identify and evaluate wheat stripe rust resistance in Sichuan Province,134 wheat cultivars（ lines） were inoculated with seven Pst races at seedling stage and adult stage. The results indicated that the resistance frequencies of wheat cultivars（ lines） against seven races CYR31,Su11-7,CYR29,Su11-4,CYR32,CYR33 and V26 were 92. 4%,92. 5%,89. 3%,89. 4%,87. 3%,85. 0% and 82. 8%,respectively. Among 134 materials,76（ 56. 0%） performed resistance against all tested races both in seedling and adult stages. The virulence of new pathogenic type V26 of Pst on wheat cultivars（ lines） was stronger than the dominant races CYR32 and CYR33. All wheat cultivars（ lines） were classified into three types according to analysis of resistance spectrum; 66. 4% of cultivars（ lines） showed all-stage resistance,17. 9% were adult-plant resistance,and 15. 7% were susceptible. This indicated that although the overall resistance level of wheat cultivars（ lines） in Sichuan Province was very high,the resistance type was simple. Therefore,it is important to identify new resistance genes and enhance resistance gene diversity. Meanwhile,pyramiding breeding of all-stage resistance gene and adult-plant resistance gene could be gradually developed,to achieve durable resistance of wheat cultivars（lines） against stripe rust in Sichuan Province.展开更多
In order to realize monitoring and early warning and comprehensive management of wheat stripe rust and to reduce its occurrence in Nanchong City, the occurrence and epidemic regularity of wheat stripe rust in Nanchong...In order to realize monitoring and early warning and comprehensive management of wheat stripe rust and to reduce its occurrence in Nanchong City, the occurrence and epidemic regularity of wheat stripe rust in Nanchong was studied by system monitoring and general survey, resistance identification, physiological race monitoring and meteorological data analysis. The initial occurrence location and spreading pathway of Puccinia striiformis f. sp. tritici （Pst） were first verified; there were two infection peaks of wheat stripe rust in Nanchong and one to three epidemic peaks in fields, in which the occurrence area of the first epidemic peak played a pivotal role in disease prevalence in that year; the cumulative occurrence area in late January was positively correlated with annual occurrence area, with the correlation coefficient of 0.769 ; the prediction model for infected field rate, diseased plant rate and annual occurrence area was established. The internal reason for heavy occurrence and prevalence of wheat stripe rust in Nanchong was the decline or loss of wheat resistance against stripe rust, as well as the appearance of physiological races of Pst, which later became dominant races. Large fluctuation of temperature in warm winter and spring and more fog and dew days were external reasons responsible for prevalence of stripe rust. From 2002 to 2014 ,the accuracy rate of short-term prediction of wheat stripe rust reached 100%, while that of me- dium-term and long-term prediction reached over 98% and 95%, respectively, 5% -15% higher than that of the years before 1998.展开更多
To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image pro...To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image processing was developed using MATLAB GUIDE platform in combination with Local C Compiler(LCC).The system is independent of the MATLAB environment and can be run on a computer without the MATLAB software.Using this system,automatic counting of Pst urediospores in a microscopic image can be implemented via image processing technologies including image scaling,clustering segmentation,morphological modification,watershed transformation,connected region labeling,etc.Structure design of the automatic counting system,the key algorithms used in the system and realization of the main functions of the system were described in detail.Spore counting tests were conducted using microscopic digital images of Pst urediospores and the high accuracies more than 95%were obtained.The results indicated that it is feasible to count Pst urediospores automatically using the developed system based on image processing.展开更多
[Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth ...[Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth area were identified by wheat stripe rust under high temperature; then the wheat cultivars showing stripe rust at seedling stage were further used to identify the same resistance in field. [Results] 13 cultivars were proved to be stripe rust resistant under high temperature, and the expression stages of stripe rust in the 13 cultivars were revealed. The field identification results confirmed the identification results at seedling stage via inoculation of mixed stripe rust of physiological races. The stripe resistances of wheat cultivars were also proved to be non-race-specific. [Conclusion] Wheat resources in Huanghuai growth area are abundant in wheat cultivars with high temperature resistance to stripe rust.展开更多
The wheat canopy reflectance spectrum is affected by many internal and external factors such as diseases and growth stage. Separating the effects of disease stress on the crop from the observed mixed signals is crucia...The wheat canopy reflectance spectrum is affected by many internal and external factors such as diseases and growth stage. Separating the effects of disease stress on the crop from the observed mixed signals is crucial for increasing the precision of remote sensing monitoring of wheat stripe rust. The canopy spectrum of winter wheat infected by stripe rust was processed with the difference-in-differences(DID) algorithm used in econometrics. The monitoring accuracies of wheat stripe rust before and after processing with the DID algorithm were compared in the presence of various external factors, disease severity, and several simulated satellite sensors. The correlation between the normalized difference vegetation index processed by the DID algorithm(NDVI-DID) and the disease severity level(SL) increased in comparison with the NDVI before processing. The increase in precision in the natural disease area in the field in the presence of large differences in growth stage, growth, planting, and management of the crop was greater than that in the controlled experiment. For low disease levels(SL < 20%), the R2 of the regression of NDVI-DIDon SL was 38.8% higher than that of the NDVI and the root mean square error(RMSE) was reduced by 11.1%. The increase in precision was greater than that for the severe level(SL > 40%).According to the measured hyperspectral data, the spectral reflectance of three satellite sensor levels was simulated. The wide-band NDVI was calculated. Compared with the wide-band NDVI and vegetation indexes(VI) before DID processing, there were increases in the correlation between SL and the various types of VIS-DID, as well as in the correlation between SL and NDVI-DID. It is feasible to apply the DID algorithm to multispectral satellite data and diverse types of VISfor monitoring wheat stripe rust. Our results improve the quantification of independent effects of stripe rust infection on canopy reflectance spectrum,increase the precision of remote sensing monitoring of wheat stripe rust, and provide a reference for remote sensing monitoring of other crop diseases.展开更多
Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the major diseases of wheat in China. In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars （lines） from the Pac...Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the major diseases of wheat in China. In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars （lines） from the Pacific Northwest （PNW） of the United States, to provide resistance resources for genetic improvement of wheat stripe rust resistance in China, 59 wheat cultivars （lines） from PNW of the United States were infected by 3 mixed races of predominant Chinese stripe rust races CRY31, CRY32, and CRY33 to evaluate their resistance at seedling and adult plant stages, and screened with molecular markers tightly linked to currently effective all-stage resistance genes YrlO, Yrl5 and adult plant resistance genes Yrl8, Yr39. Of 59 American cultivars （lines）, five cultivars （lines）, Expresso, 02W50076, ACS52610, WA008012, and WA00801833, had all-stage resistance, showing resistance to mixed races of CRY31, CRY32, and CRY33 at both seedling and adult plant stages. 33 cultivars （lines） had adult plant resistance, only showing resistance to stripe rust at adult stage. Based on the molecular screening, none of the 59 PNW cultivars （lines） had the polymorphic bands of linked markers to YrlO. There were 12, 33 and 29 cultivars （lines） which bad polymorphic bands of linked markers to Yr15, Yr18 and Yr39, accounting for 20, 55 and 49% of the 59 PNW cultivars （lines）, respectively. All these results suggested that Yr15, Yr18 and Yr39 were widespread among PNW cultivars （cultivars） and could be utilized in Chinese wheat stripe rust resistance breeding.展开更多
Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted ...Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted 70% on wheat variety Mexipak in Syria, and recurrent infection in 2010, caused by a virulent race called Yr27, caused a considerable loss in the production of bread wheat cultivars （Cham 8, Cham 6 particularly） amounted 90%. Recently, 15 races of yellow rust had been addressed in Syria for seasons 2010-2014; 159E256, 166E254, 166E256, 255 E112, 0 E0, 64 E 6, 230 El50, 0 E 18, 198 El30, 166 El50, 102 El60, 128 E0, 126 El50, 214E150, and 6E16. The race 6E16 was the most frequent during the two seasons, while the race 255El12 was the most virulent, followed by the race 230E222 and the race 0E0 was the weakest one. This study revealed the presence of fourteen newly observed races in Syria. Molecular Variance Analysis of Molecular Variance （AMOVA） of 55 yellow rust Puccinia striiformis f.sp tritici isolates examined by Amplify Fragment Length Polymorphism （AFLP） revealed high genetic variation within population, and the dimensional scale analysis （MSD） and tree diagram showed that the Syrian yellow rust isolates were clustered in three groups： the first group contained isolates derived from durum wheat, the second one contained bread wheat isolates, but the third was made of isolates derived from both durum and bread wheat species.展开更多
The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in f...The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.展开更多
Loss of variety resistance to stripe rust （Puccinia striiformis Westend f. sp.tritici） is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of...Loss of variety resistance to stripe rust （Puccinia striiformis Westend f. sp.tritici） is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of rust pathogen have led to serious crisis of resistance loss in widely planted varieties. This has quickened the search for new resistance resources. Molecular marker could facilitate the identification of the location of novel genes. A line A-3 with high resistance （immune） to currently epidemic yellow rust races （CY29, 31, 32） was screened out in offspring of Triticum aestivura x Thinopyrum ponticum. Segregation in F2 and BC1 populations indicated that the resistance was controlled by two independent genes： one dominant and one recessive. SSR markers were employed to map the two resistant genes in the F2 and BC1 populations. A marker WMC477-167bp located on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-2os bp located on 7BS was linked to the recessive-resistant gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistant genes, which were temporarily designated as YrTpl and YrTp2, respectively. The tightly linking markers facilitate transfer of the two resistant genes into the new varieties to control epidemic of yellow rust.展开更多
文摘Wheat stripe rust has become the most dangerous disease which threaten safe yield of wheat in Sichuan Province. It is meaningful to provide technique support for integrated disease control by exploring the effective control measures of wheat stripe rust. Wheat stripe rust dynamic developments of all-planting and mixed-planting have been systematically investigated in this study by taking different mixed-planting combinations among 6 wheat varieties with different resistance levels. The results of this experiment show that the mixed-plantings of 4 and 6 wheat varieties can delay the occurance of wheat stripe rust,slow the speed of disease and decline the damage of disease as well as stabilize yield of wheats.
文摘[Objective] The aim of this study is to establish the model for forecasting wheat stripe rust occurrence condition using meteorological factors. [Method] Based on the data of wheat stripe rust occurrence degrees in its past prevalent years and the meteorological data at corresponding periods, the methods of grey correlation analysis and fuzzy mathematics were employed to establish the forecast model for four pathogenesis indices according to the time sequence before winter, Early March, Early April and Middle May. Thus, the criterion for forecasting the occurrence degree of wheat stripe rust was obtained based on the distribution method of arithmetic progression. [Result] The model corresponding to meteorological conditions for forecasting wheat stripe rust was successfully established. According to the verification, the forecasting results before winter and in Early Mar. were more severer than the real occurrence condition, while the forecasting results in Early Apr. and Middle May were basically consistent with real values. [Conclusion] The results of the present study may avail the control of wheat stripe rust in Henan Province.
基金supported by the National Key Basic Research Program of China(2013CB127700)the National Natural Science Foundation of China(31101393)
文摘Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental factor affecting the occurrence and epidemiology of wheat stripe rust. Investigating UV-B radiation effects on the epidemiology of stripe rust may be conducive to monitoring and predicting this disease. In this study, wheat seedlings were exposed to UV-B radiation during different periods under laboratory conditions and radiation effects on epidemiological components of wheat stripe rust were investigated. Results showed that incubation period was shortened, and the infection efficiency, sporulation quantity and disease index increased when UV-B radiation was performed only pre-inoculation. When the UV-B radiation was performed only postinoculation or both pre-and post-inoculation, the incubation period was prolonged, and the infection efficiency, sporulation quantity and disease index were reduced. When healthy wheat seedlings were inoculated using urediospores collected from wheat leaves irradiated by UV-B only post-inoculation or both pre-and post-inoculation, infection efficiency, sporulation quantity and disease index were also reduced. However, in the latter, the disease incubation period did not differ under varying UV-B radiation intensities compared to that when wheat leaves were not treated with UV-B radiation. Overall, the effects of direct exposure of wheat plants to UV-B radiation with different intensities in different periods on epidemiological components of wheat stripe rust were systematically explored, and the results suggest that the effects of UV-B radiation increased gradually with the increase of UV-B radiation intensity. This information provides a basis for monitoring and predicting this disease as well as for conducting further studies on pathogen virulence variation.
文摘Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust that is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen due mainly to the nature of obligate biotrophism and the lack of systems for studying its genetics and molecular manipulations. To overcome these limitations, a natural Pst population comprising 352 isolates representative of a diverse virulence spectrum was genotyped using 97 secreted protein-single nucleotide polymorphism (SP-SNP) markers to identify candidate avirulence genes using association analysis. Among avirulence genes corresponding to 19 resistance genes, significantly associated SP-SNP markers were detected for avirulence genes AvYr1, AvYr2, AvYr6, AvYr7, AvYr8, AvYr44, AvYrExp2, AvYrSP, and AvYrTye. These results indicate that association analysis can be used to identify markers for avirulence genes. This study has laid the foundation for developing more SP-SNPs for mapping avirulence genes using segregating populations that can be generated through sexual reproduction on alternate hosts of the pathogen.
基金Supported by the Notice of the Ministry of Agriculture on Approving the First National Modern Agricultural Demonstration Zones in China(Nongjifa[2010]No.22)the Notice of the General Office of the Ministry of Science and Technology on the Construction of the Sixth National Agricultural Science and Technology Parks(National Science and Technology Office for Agriculture[2015]No.9)the Chongqing Research Program of Basic Research and Frontier Technology(cstc2016jcyjA 0316)
文摘The aim of this study is to clarify the application effect of pesticide decrement synergist ＇ Jijian＇ on wheal stripe lUSt. Sampling investigation, randomized block design and statistic analysis were carried out to find out the field efficacy of adding ＇ Jijian＇ to triadimefon WP and propiconazole EC on controlling wheat stripe rust. The results showed that during the epidemic period of stripe rust, the control effects on the 7^th and the 19^th d reached more than 93% and 100% , respectively, by the application of 15% triadimefon WP of 1 200 g/hm^2 and 25% propiconazole EC of 600 mlhm^2 , respectively for 2 times ; when 15% triadimefon WP of 840 g/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 or 25 % propiconazole EC of 420 mlhm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 were applied （ adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by 30% ） , the control effect on the 7^th d was 89.4% and 91.7% , respectively, while the control effect on the 19a＇ d was 99.8 - 100% ; when 15% triadimefon WP of 720 - 600 g/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 or 25% propiconazole EC 360 - 300 mlhm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 were applied （ adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by 40% - 50% ） , the control effect on the 7a＇ day reached more than 78.0% , while the control effect on the 19^th day was 97.7% - 99.8%. There was no significant difference on the control effect at the 7^th d between the treatments using the 2 pesticides alone and the treatments adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by 30%, but all had significant differences from the treatments adding ＇ Jijian＇ and reducing the dosage of the 2 pesticides by40% -50%. There was no significant difference on the control effect of the 19^th d among different treatments. Therefore, if the disease is not serious, the application of ＇ Jijian＇ can reduce the application amounts of pesticides by 40% -50%, that is, 15% triadimefon WP of 720 -600 g/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2 or 25 % propiconazole EC of 360- 300 ml/hm^2 ＋ ＇ Jijian＇ of 225 g/hm^2, which is helpful to reduce the pesticide application amounts and pesticide residue pollution, and save the control costs.
基金Supported by China Agriculture Research System(CARS-03)International Joint Research Project of Sichuan Province(2014HH0052)+1 种基金Key Research Project of Wheat Breeding in Sichuan ProvinceInnovation Team Project of Wheat in Sichuan Province
文摘Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.（ Pst）,is one of the most destructive diseases of wheat（ Triticum aestivum L.） worldwide. Sichuan province plays an important role in stripe rust epidemic in China. To identify and evaluate wheat stripe rust resistance in Sichuan Province,134 wheat cultivars（ lines） were inoculated with seven Pst races at seedling stage and adult stage. The results indicated that the resistance frequencies of wheat cultivars（ lines） against seven races CYR31,Su11-7,CYR29,Su11-4,CYR32,CYR33 and V26 were 92. 4%,92. 5%,89. 3%,89. 4%,87. 3%,85. 0% and 82. 8%,respectively. Among 134 materials,76（ 56. 0%） performed resistance against all tested races both in seedling and adult stages. The virulence of new pathogenic type V26 of Pst on wheat cultivars（ lines） was stronger than the dominant races CYR32 and CYR33. All wheat cultivars（ lines） were classified into three types according to analysis of resistance spectrum; 66. 4% of cultivars（ lines） showed all-stage resistance,17. 9% were adult-plant resistance,and 15. 7% were susceptible. This indicated that although the overall resistance level of wheat cultivars（ lines） in Sichuan Province was very high,the resistance type was simple. Therefore,it is important to identify new resistance genes and enhance resistance gene diversity. Meanwhile,pyramiding breeding of all-stage resistance gene and adult-plant resistance gene could be gradually developed,to achieve durable resistance of wheat cultivars（lines） against stripe rust in Sichuan Province.
基金Supported by Comprehensive Prevention and Treatment Monitoring Station of Inoculum Source of Wheat Stripe Rust in Nanchong City(NYBNJH[2003]104)Notice of the Ministry of Agriculture on Identification of the First Batch of National Modern Agricultural Demonstration Zone(NJF[2010]22)+2 种基金Occurrence and Epidemic Regularity of Wheat Stripe Rust and Its Integrated Control Technology in Nanchong City(N1998-ZC018)Fundamental Research Funds for the Central Universities(XDJK2015C060,SWU114046,2362015xk04)Open Project Program of State Key Laboratory of Crop Stress Biology for Arid Areas(CSBAA2015009)
文摘In order to realize monitoring and early warning and comprehensive management of wheat stripe rust and to reduce its occurrence in Nanchong City, the occurrence and epidemic regularity of wheat stripe rust in Nanchong was studied by system monitoring and general survey, resistance identification, physiological race monitoring and meteorological data analysis. The initial occurrence location and spreading pathway of Puccinia striiformis f. sp. tritici （Pst） were first verified; there were two infection peaks of wheat stripe rust in Nanchong and one to three epidemic peaks in fields, in which the occurrence area of the first epidemic peak played a pivotal role in disease prevalence in that year; the cumulative occurrence area in late January was positively correlated with annual occurrence area, with the correlation coefficient of 0.769 ; the prediction model for infected field rate, diseased plant rate and annual occurrence area was established. The internal reason for heavy occurrence and prevalence of wheat stripe rust in Nanchong was the decline or loss of wheat resistance against stripe rust, as well as the appearance of physiological races of Pst, which later became dominant races. Large fluctuation of temperature in warm winter and spring and more fog and dew days were external reasons responsible for prevalence of stripe rust. From 2002 to 2014 ,the accuracy rate of short-term prediction of wheat stripe rust reached 100%, while that of me- dium-term and long-term prediction reached over 98% and 95%, respectively, 5% -15% higher than that of the years before 1998.
基金supported by International Research Exchange Scheme of the Marie Curie Program of the 7th Framework Program(Ref.PIRSES-GA-2013-612659)National Key Basic Research Program of China(2013CB127700)National Key Technologies Research and Development Program of China(2012BAD19BA04).
文摘To realize automatic counting of urediospores of Puccinia striiformis f.sp.tritici(Pst)(causal agent of wheat stripe rust),an automatic counting system for urediospores of wheat stripe rust pathogen based on image processing was developed using MATLAB GUIDE platform in combination with Local C Compiler(LCC).The system is independent of the MATLAB environment and can be run on a computer without the MATLAB software.Using this system,automatic counting of Pst urediospores in a microscopic image can be implemented via image processing technologies including image scaling,clustering segmentation,morphological modification,watershed transformation,connected region labeling,etc.Structure design of the automatic counting system,the key algorithms used in the system and realization of the main functions of the system were described in detail.Spore counting tests were conducted using microscopic digital images of Pst urediospores and the high accuracies more than 95%were obtained.The results indicated that it is feasible to count Pst urediospores automatically using the developed system based on image processing.
文摘[Objective] The study aimed to screen wheat cultivars with high temperature resistance to stripe rust from the wheat resources in Huanghuai growth area. [Method] Seedlings of 165 wheat cultivars from Huanghuai growth area were identified by wheat stripe rust under high temperature; then the wheat cultivars showing stripe rust at seedling stage were further used to identify the same resistance in field. [Results] 13 cultivars were proved to be stripe rust resistant under high temperature, and the expression stages of stripe rust in the 13 cultivars were revealed. The field identification results confirmed the identification results at seedling stage via inoculation of mixed stripe rust of physiological races. The stripe resistances of wheat cultivars were also proved to be non-race-specific. [Conclusion] Wheat resources in Huanghuai growth area are abundant in wheat cultivars with high temperature resistance to stripe rust.
基金supported by the National Natural Science Foundation of China (42171394, 41601467)。
文摘The wheat canopy reflectance spectrum is affected by many internal and external factors such as diseases and growth stage. Separating the effects of disease stress on the crop from the observed mixed signals is crucial for increasing the precision of remote sensing monitoring of wheat stripe rust. The canopy spectrum of winter wheat infected by stripe rust was processed with the difference-in-differences(DID) algorithm used in econometrics. The monitoring accuracies of wheat stripe rust before and after processing with the DID algorithm were compared in the presence of various external factors, disease severity, and several simulated satellite sensors. The correlation between the normalized difference vegetation index processed by the DID algorithm(NDVI-DID) and the disease severity level(SL) increased in comparison with the NDVI before processing. The increase in precision in the natural disease area in the field in the presence of large differences in growth stage, growth, planting, and management of the crop was greater than that in the controlled experiment. For low disease levels(SL < 20%), the R2 of the regression of NDVI-DIDon SL was 38.8% higher than that of the NDVI and the root mean square error(RMSE) was reduced by 11.1%. The increase in precision was greater than that for the severe level(SL > 40%).According to the measured hyperspectral data, the spectral reflectance of three satellite sensor levels was simulated. The wide-band NDVI was calculated. Compared with the wide-band NDVI and vegetation indexes(VI) before DID processing, there were increases in the correlation between SL and the various types of VIS-DID, as well as in the correlation between SL and NDVI-DID. It is feasible to apply the DID algorithm to multispectral satellite data and diverse types of VISfor monitoring wheat stripe rust. Our results improve the quantification of independent effects of stripe rust infection on canopy reflectance spectrum,increase the precision of remote sensing monitoring of wheat stripe rust, and provide a reference for remote sensing monitoring of other crop diseases.
基金funded by the National Natural Science Foundation of China(30971778)Open Fund Project of State Key Laboratory for Biology of Plant Diseases and Insect Pests,China(2008.1-2008.12)China Postdoctoral Science Foundation(200902552)
文摘Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the major diseases of wheat in China. In order to asses the resistance levels and existing Yr genes among 59 wheat cultivars （lines） from the Pacific Northwest （PNW） of the United States, to provide resistance resources for genetic improvement of wheat stripe rust resistance in China, 59 wheat cultivars （lines） from PNW of the United States were infected by 3 mixed races of predominant Chinese stripe rust races CRY31, CRY32, and CRY33 to evaluate their resistance at seedling and adult plant stages, and screened with molecular markers tightly linked to currently effective all-stage resistance genes YrlO, Yrl5 and adult plant resistance genes Yrl8, Yr39. Of 59 American cultivars （lines）, five cultivars （lines）, Expresso, 02W50076, ACS52610, WA008012, and WA00801833, had all-stage resistance, showing resistance to mixed races of CRY31, CRY32, and CRY33 at both seedling and adult plant stages. 33 cultivars （lines） had adult plant resistance, only showing resistance to stripe rust at adult stage. Based on the molecular screening, none of the 59 PNW cultivars （lines） had the polymorphic bands of linked markers to YrlO. There were 12, 33 and 29 cultivars （lines） which bad polymorphic bands of linked markers to Yr15, Yr18 and Yr39, accounting for 20, 55 and 49% of the 59 PNW cultivars （lines）, respectively. All these results suggested that Yr15, Yr18 and Yr39 were widespread among PNW cultivars （cultivars） and could be utilized in Chinese wheat stripe rust resistance breeding.
文摘Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted 70% on wheat variety Mexipak in Syria, and recurrent infection in 2010, caused by a virulent race called Yr27, caused a considerable loss in the production of bread wheat cultivars （Cham 8, Cham 6 particularly） amounted 90%. Recently, 15 races of yellow rust had been addressed in Syria for seasons 2010-2014; 159E256, 166E254, 166E256, 255 E112, 0 E0, 64 E 6, 230 El50, 0 E 18, 198 El30, 166 El50, 102 El60, 128 E0, 126 El50, 214E150, and 6E16. The race 6E16 was the most frequent during the two seasons, while the race 255El12 was the most virulent, followed by the race 230E222 and the race 0E0 was the weakest one. This study revealed the presence of fourteen newly observed races in Syria. Molecular Variance Analysis of Molecular Variance （AMOVA） of 55 yellow rust Puccinia striiformis f.sp tritici isolates examined by Amplify Fragment Length Polymorphism （AFLP） revealed high genetic variation within population, and the dimensional scale analysis （MSD） and tree diagram showed that the Syrian yellow rust isolates were clustered in three groups： the first group contained isolates derived from durum wheat, the second one contained bread wheat isolates, but the third was made of isolates derived from both durum and bread wheat species.
基金support by the Ministry of Science and Technology,China (2011CB100403)the Ministry of Agriculture,China (200903035)the Special Project from State Key Laboratory for Biology of Plant Diseases and Insect Pests,Chinese Academy of Agricltural Sciences (SKL2009OP09)
文摘The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.
文摘Loss of variety resistance to stripe rust （Puccinia striiformis Westend f. sp.tritici） is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of rust pathogen have led to serious crisis of resistance loss in widely planted varieties. This has quickened the search for new resistance resources. Molecular marker could facilitate the identification of the location of novel genes. A line A-3 with high resistance （immune） to currently epidemic yellow rust races （CY29, 31, 32） was screened out in offspring of Triticum aestivura x Thinopyrum ponticum. Segregation in F2 and BC1 populations indicated that the resistance was controlled by two independent genes： one dominant and one recessive. SSR markers were employed to map the two resistant genes in the F2 and BC1 populations. A marker WMC477-167bp located on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-2os bp located on 7BS was linked to the recessive-resistant gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistant genes, which were temporarily designated as YrTpl and YrTp2, respectively. The tightly linking markers facilitate transfer of the two resistant genes into the new varieties to control epidemic of yellow rust.
