A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and fo...A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.展开更多
The present PCR assay was conducted to develop rapid and sensitive detection of Phytophthora colocasiae,in order to provide a robust and reliable tool for healthy seedling production of taro and limiting the transmiss...The present PCR assay was conducted to develop rapid and sensitive detection of Phytophthora colocasiae,in order to provide a robust and reliable tool for healthy seedling production of taro and limiting the transmission and spread of the causal organism of taro leaf blight in taro planting regions.The samples were used to extract total DNA and to be detected by PCR with P.colocasiae specific primer pairs PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.Distinct fragments of about 200 bp and 240 bp were amplified by PCR using primers PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.The analysis of the nucleotide sequence of the PCR products were found to be 99% identical to sequence of RAS-related protein (Ypt1) and phospho-ribosylanthranilate isomerase (TRP1) in P.colocasiae,respectively.It is concluded that rapid and sensitive developed PCR assay for detection of P.colocasiae could be used in routine diagnosis and aid in management practices to mitigate taro leaf blight.展开更多
从150条RAPD随机引物中筛选出多态性引物12条,对分离自福建省10个不同市(县)的番茄或马铃薯晚疫病标样中的63个致病疫霉菌株进行遗传多样性分析,共产生92条RAPD条带,其中85条为多态性条带,多态检测率为92.4%。利用NTSYSpc Version 2.1...从150条RAPD随机引物中筛选出多态性引物12条,对分离自福建省10个不同市(县)的番茄或马铃薯晚疫病标样中的63个致病疫霉菌株进行遗传多样性分析,共产生92条RAPD条带,其中85条为多态性条带,多态检测率为92.4%。利用NTSYSpc Version 2.1软件对供试菌株间的遗传距离进行聚类分析并构建系统树状图,供试63个菌株被划分为6个遗传聚类组,RAPD分组与菌株的地理来源、寄主均无明显相关性。聚类分析结果表明,福建省不同地区的致病疫霉菌株整体亲缘关系相近,但各菌株间存在遗传差异,病原菌随病果运输迁移及A2交配型的存在可能是导致这种现象的原因。展开更多
Late blight caused by Phytophthora infestans is the most serious disease of tomato production in China. Studies on the genetics of resistance and identification of molecular markers are very useful for breeding late b...Late blight caused by Phytophthora infestans is the most serious disease of tomato production in China. Studies on the genetics of resistance and identification of molecular markers are very useful for breeding late blight resistant varieties. The objective of this paper was to study the inheritance of late blight resistance and identify simple sequence repeat （SSR） markers associated with resistance allele in tomato （Lycopersicon esculentum Mill）. The results came from an F2 progeny of 241 plants derived from a cross between 5~ inbred line that is susceptible to late blight and a resistant accession CLN2037E. The late blight responses of F2 plants were tested by artificially inoculation of detached-leaflets in plate and natural infection assayed under greenhouse conditions. Both methods showed that the resistance is dominant and inherited as monogenic trait. Genetic mapping and linkage analysis showed that the late blight resistance gene Ph-ROL was located on chromosome 9 with a genetic distance of 5.7 cM to the SSR marker TOM236.展开更多
Potato late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases in the agricultural sector around the world. Many genes (R genes) conferring resistance to late blight have be...Potato late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases in the agricultural sector around the world. Many genes (R genes) conferring resistance to late blight have been identified in various potato species and most of these R genes have been used in potato breeding. The aim of this study was to develop and validate PCR-based assays for the R genes Rpi-blb1, Rpi-blb2, Rpi-blb3 and Rpi-bt1, to distinguish between late blight resistant and late blight susceptible potato progeny in the given breeding background. A total of 100 breeding progeny were screened for the presence of these R genes and tested for resistance against P. infestans mating type A2, genotype US-8 strain, using detached leaf and tuber rot assays. PCR products for the Rpi-blb1 and Rpi-bt1 resistance genes were identified in the resistant progeny but were absent in the susceptible ones;therefore these PCR assays could differentiate between late blight resistant and susceptible plants. Genotypic data from the DNA markers derived from the Rpi-blb1 and Rpi-bt1 genes was found to correlate with the phenotypic data for foliar late blight but not with data for tuber rot. Our results demonstrate that markers derived from these two R genes could be useful for marker-assisted selection (MAS) for foliar late blight resistance in potato breeding programs.展开更多
Late blight (LB), caused by the oomycete Phytophthora infestans, is one of the most devastating diseases of tomato. Three major genes Ph-1, Ph-2 and Ph-3 conferring resistance to LB have been identified and mapped to ...Late blight (LB), caused by the oomycete Phytophthora infestans, is one of the most devastating diseases of tomato. Three major genes Ph-1, Ph-2 and Ph-3 conferring resistance to LB have been identified and mapped to the chromosomes 7, 10 and 9, respectively. However, PCR-based molecular markers associated with these genes are limited. Molecular markers are extremely useful in the screening and selection of tomato lines for the development of LB resistant genotypes. The objective of this study was to identify molecular markers associated with Ph-3 gene conferring LB resistance in tomato. Four co-dominant markers were found to be associated with Ph-3, all of which were sequence characterized amplified region (SCAR) type. Breeding lines and cultivars were inoculated with a field isolate of Phytophthora infestans to collect phenotypic data on disease resistance. Genotypic data from molecular markers associated with Ph-3 were in close agreement with the phenotypic data for the lines tested. With the verification of genotypic data from novel molecular markers in known genotypes supported by phenotypic data, the novel molecular markers may be useful in screening tomato populations aiming to develop LB resistant genotypes or cloning the LB resistant genes.展开更多
Greenhouse studies were performed to determine the reactions of 10 “California Wonder” (Capsicum annuum) accessions to the three forms of Phytophthora blight (root rot, stem blight and foliar blight) caused by Phyto...Greenhouse studies were performed to determine the reactions of 10 “California Wonder” (Capsicum annuum) accessions to the three forms of Phytophthora blight (root rot, stem blight and foliar blight) caused by Phytophthora capsici. Differences in root rot, stem blight and foliar blight severities among accessions were significant. The accessions consistently differentiated into two groups across the three disease syndromes. Simple sequence repeat (SSR) markers showed variability both within and between accessions of California Wonder. The variability in the responses to the three forms of Phytophthora blight does not warrant its usefulness as a standard susceptible control in studies involving the Capsicum-P. capsici patho-system.展开更多
Late blight caused by <i>Phytophthora</i> <i>infestans</i> (Mont.) De Bary is the most devastating disease of potato. This study was carried out to evaluate the efficacy of ten botanical extrac...Late blight caused by <i>Phytophthora</i> <i>infestans</i> (Mont.) De Bary is the most devastating disease of potato. This study was carried out to evaluate the efficacy of ten botanical extracts against the late blight disease incidence and severity in experimental potato field at University of Rajshahi, Bangladesh during 2019-2020. Crude aqueous extract of leaves of <i>Syzygium</i> <i>cumini</i>, <i>Psidium</i> <i>guajava</i>, <i>Eucalyptus</i> <i>globusus</i>, <i>Carica</i> <i>papaya</i> and <i>Lawsonia</i> <i>inermis</i>;fruits of <i>Terminalia</i> <i>bellirica</i>, <i>T.</i> <i>chebula</i> and <i>Piper</i> <i>nigrum</i>;flower buds of <i>Syzygium</i> <i>aromaticum</i> and cloves of <i>Allium</i> <i>sativum</i> were used at 5% (w/v) concentration for evaluation. Out of ten botanicals, <i>Syzygium</i> <i>cumini</i> leaves extract was found most effective in controlling the late blight disease incidence and severity up to 66 DAS (days after sowing) and increased the potato yield by 71.29% compare to untreated control. The efficacy of <i>Lawsonia</i> <i>inermis</i> extract against late blight disease was found promising and increased the potato yield by 48.51%. Other four botanical extracts (<i>Terminalia</i> <i>chebula</i>, <i>Piper</i> <i>nigrum</i>, <i>Syzygium</i> <i>aromaticum</i> and <i>Carica</i> <i>papaya</i>) showed moderate efficacy <span>against the incidence and severity of late blight disease, and increased 30% </span>more potato yield compare to control. These results suggest that botanical extract of <i>Syzygium</i> <i>cumini</i> ha<span style="font-family:;" "="">s</span><span style="font-family:;" "=""> a great potential as an alternative </span><span style="font-family:;" "="">of</span><span style="font-family:;" "=""> chemical fungicides to control the late blight disease of potato in</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">eco-friendly way.</span>展开更多
文摘A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.
基金Sponsored by Science and Technology Major Project of Guangxi(AA17204026)Basic Research Special Fund,and Scientific and Technological Fund of Guangxi Academy of Agricultural Sciences(2016YM20,2018JZ37)Guangxi Natural Science Fund(2016GXNSFAA380195)
文摘The present PCR assay was conducted to develop rapid and sensitive detection of Phytophthora colocasiae,in order to provide a robust and reliable tool for healthy seedling production of taro and limiting the transmission and spread of the causal organism of taro leaf blight in taro planting regions.The samples were used to extract total DNA and to be detected by PCR with P.colocasiae specific primer pairs PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.Distinct fragments of about 200 bp and 240 bp were amplified by PCR using primers PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.The analysis of the nucleotide sequence of the PCR products were found to be 99% identical to sequence of RAS-related protein (Ypt1) and phospho-ribosylanthranilate isomerase (TRP1) in P.colocasiae,respectively.It is concluded that rapid and sensitive developed PCR assay for detection of P.colocasiae could be used in routine diagnosis and aid in management practices to mitigate taro leaf blight.
文摘从150条RAPD随机引物中筛选出多态性引物12条,对分离自福建省10个不同市(县)的番茄或马铃薯晚疫病标样中的63个致病疫霉菌株进行遗传多样性分析,共产生92条RAPD条带,其中85条为多态性条带,多态检测率为92.4%。利用NTSYSpc Version 2.1软件对供试菌株间的遗传距离进行聚类分析并构建系统树状图,供试63个菌株被划分为6个遗传聚类组,RAPD分组与菌株的地理来源、寄主均无明显相关性。聚类分析结果表明,福建省不同地区的致病疫霉菌株整体亲缘关系相近,但各菌株间存在遗传差异,病原菌随病果运输迁移及A2交配型的存在可能是导致这种现象的原因。
文摘Late blight caused by Phytophthora infestans is the most serious disease of tomato production in China. Studies on the genetics of resistance and identification of molecular markers are very useful for breeding late blight resistant varieties. The objective of this paper was to study the inheritance of late blight resistance and identify simple sequence repeat （SSR） markers associated with resistance allele in tomato （Lycopersicon esculentum Mill）. The results came from an F2 progeny of 241 plants derived from a cross between 5~ inbred line that is susceptible to late blight and a resistant accession CLN2037E. The late blight responses of F2 plants were tested by artificially inoculation of detached-leaflets in plate and natural infection assayed under greenhouse conditions. Both methods showed that the resistance is dominant and inherited as monogenic trait. Genetic mapping and linkage analysis showed that the late blight resistance gene Ph-ROL was located on chromosome 9 with a genetic distance of 5.7 cM to the SSR marker TOM236.
文摘Potato late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases in the agricultural sector around the world. Many genes (R genes) conferring resistance to late blight have been identified in various potato species and most of these R genes have been used in potato breeding. The aim of this study was to develop and validate PCR-based assays for the R genes Rpi-blb1, Rpi-blb2, Rpi-blb3 and Rpi-bt1, to distinguish between late blight resistant and late blight susceptible potato progeny in the given breeding background. A total of 100 breeding progeny were screened for the presence of these R genes and tested for resistance against P. infestans mating type A2, genotype US-8 strain, using detached leaf and tuber rot assays. PCR products for the Rpi-blb1 and Rpi-bt1 resistance genes were identified in the resistant progeny but were absent in the susceptible ones;therefore these PCR assays could differentiate between late blight resistant and susceptible plants. Genotypic data from the DNA markers derived from the Rpi-blb1 and Rpi-bt1 genes was found to correlate with the phenotypic data for foliar late blight but not with data for tuber rot. Our results demonstrate that markers derived from these two R genes could be useful for marker-assisted selection (MAS) for foliar late blight resistance in potato breeding programs.
文摘Late blight (LB), caused by the oomycete Phytophthora infestans, is one of the most devastating diseases of tomato. Three major genes Ph-1, Ph-2 and Ph-3 conferring resistance to LB have been identified and mapped to the chromosomes 7, 10 and 9, respectively. However, PCR-based molecular markers associated with these genes are limited. Molecular markers are extremely useful in the screening and selection of tomato lines for the development of LB resistant genotypes. The objective of this study was to identify molecular markers associated with Ph-3 gene conferring LB resistance in tomato. Four co-dominant markers were found to be associated with Ph-3, all of which were sequence characterized amplified region (SCAR) type. Breeding lines and cultivars were inoculated with a field isolate of Phytophthora infestans to collect phenotypic data on disease resistance. Genotypic data from molecular markers associated with Ph-3 were in close agreement with the phenotypic data for the lines tested. With the verification of genotypic data from novel molecular markers in known genotypes supported by phenotypic data, the novel molecular markers may be useful in screening tomato populations aiming to develop LB resistant genotypes or cloning the LB resistant genes.
文摘Greenhouse studies were performed to determine the reactions of 10 “California Wonder” (Capsicum annuum) accessions to the three forms of Phytophthora blight (root rot, stem blight and foliar blight) caused by Phytophthora capsici. Differences in root rot, stem blight and foliar blight severities among accessions were significant. The accessions consistently differentiated into two groups across the three disease syndromes. Simple sequence repeat (SSR) markers showed variability both within and between accessions of California Wonder. The variability in the responses to the three forms of Phytophthora blight does not warrant its usefulness as a standard susceptible control in studies involving the Capsicum-P. capsici patho-system.
文摘Late blight caused by <i>Phytophthora</i> <i>infestans</i> (Mont.) De Bary is the most devastating disease of potato. This study was carried out to evaluate the efficacy of ten botanical extracts against the late blight disease incidence and severity in experimental potato field at University of Rajshahi, Bangladesh during 2019-2020. Crude aqueous extract of leaves of <i>Syzygium</i> <i>cumini</i>, <i>Psidium</i> <i>guajava</i>, <i>Eucalyptus</i> <i>globusus</i>, <i>Carica</i> <i>papaya</i> and <i>Lawsonia</i> <i>inermis</i>;fruits of <i>Terminalia</i> <i>bellirica</i>, <i>T.</i> <i>chebula</i> and <i>Piper</i> <i>nigrum</i>;flower buds of <i>Syzygium</i> <i>aromaticum</i> and cloves of <i>Allium</i> <i>sativum</i> were used at 5% (w/v) concentration for evaluation. Out of ten botanicals, <i>Syzygium</i> <i>cumini</i> leaves extract was found most effective in controlling the late blight disease incidence and severity up to 66 DAS (days after sowing) and increased the potato yield by 71.29% compare to untreated control. The efficacy of <i>Lawsonia</i> <i>inermis</i> extract against late blight disease was found promising and increased the potato yield by 48.51%. Other four botanical extracts (<i>Terminalia</i> <i>chebula</i>, <i>Piper</i> <i>nigrum</i>, <i>Syzygium</i> <i>aromaticum</i> and <i>Carica</i> <i>papaya</i>) showed moderate efficacy <span>against the incidence and severity of late blight disease, and increased 30% </span>more potato yield compare to control. These results suggest that botanical extract of <i>Syzygium</i> <i>cumini</i> ha<span style="font-family:;" "="">s</span><span style="font-family:;" "=""> a great potential as an alternative </span><span style="font-family:;" "="">of</span><span style="font-family:;" "=""> chemical fungicides to control the late blight disease of potato in</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">eco-friendly way.</span>
