Full Text Available Monitoring of Puccinia graminis subsp. graminicola and Puccinia coronata f. sp. lolii was carried out in Plant breeding station called Větrov. The pathogens were estimated on turf grass (Lolium perenne L., Deschampsia caespitosa (L. P. B. from 2009 to 2014. Puccinia graminis subsp. graminicola was detected in the increased level in 2009 and 2012. The highest amount of mixed infections was determined in 2014 because of the warmest winter from all monitored years and low precipitations. Significant differences were found out in the resistance of similar plant materials grown in different fields. Significant effect of weather conditions and supposed effect of different infectious pressure on various fields were reflected in these facts. At evaluated grasses, the highest (P < 0.05 occurence of Puccinia graminis subsp. graminicola. Lolium perenne L. was observed and the infection of Puccinia graminis subsp. graminicola (P < 0.05 was determined higher than in Deschampsia caespitosa (L. P. B.
A total of 12 collections of Puccinia graminis f. sp. tritici were obtained from Kenya during 2011. Collections were made around Mount Kenya and in wheat growing areas southwest towards Nakuru in the Rift Valley. Four collections were made from the international stem rust screening nursery in Njoro....
Berlin, Anna; Samils, Berit; Andersson, Björn
Cereal rust fungi ( Puccinia spp.) are among the most economically important plant pathogens. These fungi have a complex life cycle, including five spore stages and two hosts. They infect one grass host on which they reproduce clonally and cause the cereal rust diseases, while the alternate host is required for sexual reproduction. Although previous studies clearly demonstrate the importance of the alternate host in creating genetic diversity in cereal rust fungi, little is known about the amount of novel genotypes created in each successful completion of a sexual reproduction event. In this study, single sequence repeat markers were used to study the genotypic diversity within aecial clusters by genotyping individual aecial cups. Two common cereal rusts, Puccinia graminis causing stem rust and Puccinia coronata the causal agent of crown rust were investigated. We showed that under natural conditions, a single aecial cluster usually include several genotypes, either because a single pycnial cluster is fertilized by several different pycniospores, or because aecia within the cluster are derived from more than one fertilized adjoining pycnial cluster, or a combination of both. Our results imply that although sexual events in cereal rust fungi in most regions of the world are relatively rare, the events that occur may still significantly contribute to the genetic variation within the pathogen populations.
Stem rust, caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn.(Pgt), is a destructive disease of wheat that can be controlled by deploying effective stem rust resistance (Sr) genes. Highly virulent races of Pgt in Africa have been detected and characterized. These include race T...
Full Text Available Stem rust development on four species of grasses was studied in field experiments conducted at Radzików in 1997-2001. Population of Puccinia graminis ssp. graminicola from different hosts was characterised and their harmfulness for grass grown for seed was estimated. The materials for study were ecotypes and strains of Lolium perenne, Festuca rubra, Poa pratensis and Deschampsia caespitosa collected in breeding nursery and cultivars and strains of L.perenne, F.rubra, P.pratensis cultivated for seed. It was found that the changes in environmental conditions during last years influenced earlier occurrence of stem rust on grasses in Poland. All examined species were the host of P.graminis ssp. graminicola, however the period of infection of particular hosts were different. L.perenne and D.caespitosa were infected in early summer but F.rubra and P.pratensis in late summer or in the autumn. Morphological analysis of spores of P.graminis ssp. graminicola have shoved significant differences between populations obtained from L.perenne and D.caespitosa. Some differences were found between populations from F.rubra and P.pratensis also, but they need more study. Every year occurrence of stem rust on L.perenne and D.caespitosa and its relation with spring temperature in Radzików indicated that populations of patogen could overwinter in local turf. Incidental appearance of stem rust on F.rubra and P.pratensis in centre of Poland allowed to suppose that spores of these forms might be transfer by wind from other regions. The investigation revealed that stem rust can be dangerous for L.perenne grown for seed when infection occurs at flowering time. It has been established that infection of F.rubra and P.pratensis in autumn should not be disregarded. Damages of leaves by P.graminis ssp. graminicola substantially limited plant heading in the next year.
Full Text Available The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt poses a threat to food security. These concerns have catalyzed an extensive global effort towards controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize specific components of the pathogen, known as avirulence (Avr proteins. A significant drawback to deploying cultivars with single Sr genes is that they are often overcome by evolution of the pathogen to escape recognition through alterations in Avr genes. Thus, a key element in achieving durable rust control is the deployment of multiple effective Sr genes in combination, either through conventional breeding or transgenic approaches, to minimize the risk of resistance breakdown. In this situation, evolution of pathogen virulence would require simultaneous changes in multiple Avr genes in order to bypass recognition. However, choosing the optimal Sr gene combinations to deploy is a challenge that requires detailed knowledge of the pathogen Avr genes with which they interact and the virulence phenotypes of Pgt existing in nature. Identifying specific Avr genes from Pgt will provide screening tools to enhance pathogen virulence monitoring, assess heterozygosity and propensity for mutation in pathogen populations, and confirm individual Sr gene functions in crop varieties carrying multiple effective resistance genes. Towards this goal, much progress has been made in assembling a high quality reference genome sequence for Pgt, as well as a Pan-genome encompassing variation between multiple field isolates with diverse virulence spectra. In turn this has allowed prediction of Pgt effector gene candidates based on known features of Avr genes in other plant pathogens
Figueroa, Melania; Upadhyaya, Narayana M; Sperschneider, Jana; Park, Robert F; Szabo, Les J; Steffenson, Brian; Ellis, Jeff G; Dodds, Peter N
The recent resurgence of wheat stem rust caused by new virulent races of Puccinia graminis f. sp. tritici (Pgt) poses a threat to food security. These concerns have catalyzed an extensive global effort toward controlling this disease. Substantial research and breeding programs target the identification and introduction of new stem rust resistance (Sr) genes in cultivars for genetic protection against the disease. Such resistance genes typically encode immune receptor proteins that recognize specific components of the pathogen, known as avirulence (Avr) proteins. A significant drawback to deploying cultivars with single Sr genes is that they are often overcome by evolution of the pathogen to escape recognition through alterations in Avr genes. Thus, a key element in achieving durable rust control is the deployment of multiple effective Sr genes in combination, either through conventional breeding or transgenic approaches, to minimize the risk of resistance breakdown. In this situation, evolution of pathogen virulence would require changes in multiple Avr genes in order to bypass recognition. However, choosing the optimal Sr gene combinations to deploy is a challenge that requires detailed knowledge of the pathogen Avr genes with which they interact and the virulence phenotypes of Pgt existing in nature. Identifying specific Avr genes from Pgt will provide screening tools to enhance pathogen virulence monitoring, assess heterozygosity and propensity for mutation in pathogen populations, and confirm individual Sr gene functions in crop varieties carrying multiple effective resistance genes. Toward this goal, much progress has been made in assembling a high quality reference genome sequence for Pgt, as well as a Pan-genome encompassing variation between multiple field isolates with diverse virulence spectra. In turn this has allowed prediction of Pgt effector gene candidates based on known features of Avr genes in other plant pathogens, including the related flax rust
Duplessis, Sebastien; Cuomo, Christina A.; Lin, Yao-Cheng; Aerts, Andrea; Tisserant, Emilie; Veneault-Fourrey, Claire; Joly, David L.; Hacquard, Stephane; Amselem, Joelle; Cantarel, Brandi; Chiu, Readman; Couthinho, Pedro; Feau, Nicolas; Field, Matthew; Frey, Pascal; Gelhaye, Eric; Goldberg, Jonathan; Grabherr, Manfred; Kodira, Chinnappa; Kohler, Annegret; Kues, Ursula; Lindquist, Erika; Lucas, Susan; Mago, Rohit; Mauceli, Evan; Morin, Emmanuelle; Murat, Claude; Pangilinan, Jasmyn L.; Park, Robert; Pearson, Matthew; Quesneville, Hadi; Rouhier, Nicolas; Sakthikumar, Sharadha; Salamov, Asaf A.; Schmutz, Jeremy; Selles, Benjamin; Shapiro, Harris; Tangay, Philippe; Tuskan, Gerald A.; Peer, Yves Van de; Henrissat, Bernard; Rouze, Pierre; Ellis, Jeffrey G.; Dodds, Peter N.; Schein, Jacqueline E.; Zhong, Shaobin; Hamelin, Richard C.; Grigoriev, Igor V.; Szabo, Les J.; Martin1, Francis
Rust fungi are some of the most devastating pathogens of crop plants. They are obligate biotrophs, which extract nutrients only from living plant tissues and cannot grow apart from their hosts. Their lifestyle has slowed the dissection of molecular mechanisms underlying host invasion and avoidance or suppression of plant innate immunity. We sequenced the 101 mega base pair genome of Melampsora larici-populina, the causal agent of poplar leaf rust, and the 89 mega base pair genome of Puccinia graminis f. sp. tritici, the causal agent of wheat and barley stem rust. We then compared the 16,841 predicted proteins of M. larici-populina to the 18,241 predicted proteins of P. graminis f. sp tritici. Genomic features related to their obligate biotrophic life-style include expanded lineage-specific gene families, a large repertoire of effector-like small secreted proteins (SSPs), impaired nitrogen and sulfur assimilation pathways, and expanded families of amino-acid, oligopeptide and hexose membrane transporters. The dramatic upregulation of transcripts coding for SSPs, secreted hydrolytic enzymes, and transporters in planta suggests that they play a role in host infection and nutrient acquisition. Some of these genomic hallmarks are mirrored in the genomes of other microbial eukaryotes that have independently evolved to infect plants, indicating convergent adaptation to a biotrophic existence inside plant cells
Brachypodium distachyon is regarded as non-host to the causal agent of stem rust in wheat and barley, P. graminis f. sp. tritici (Pgt), and a near-host to the pathogens of forage grasses, P. graminis f. sp. lolii (Pgl) and P. graminis f. sp. phlei-pratensis (Pgp). Given the devastating effect of ste...
Patpour, M.; Hovmøller, M. S.; Justesen, A. F.
of wheat fields in Africa (Kenya, 9; Uganda, 28; Rwanda, 41; and Egypt, 6) were sent to the Global Rust Reference Center (GRRC, Denmark) for race analysis. Puccinia graminis f. sp. tritici (Pgt) samples were recovered on cv. Morocco, and resulting urediniospores of 53 single-pustule isolates were......Tmp) to confirm their virulence/avirulence combinations to Sr24, Sr31, Sr36, and SrTmp. Race TTKTK was also detected at two locations in Uganda (Rubaya and Muko in Kabale region) and at five locations in Rwanda (Kinigi, Rwerere, Rufungo, Gatebe, and Kamenyo). Three isolates derived from stem rust samples...
Rutter, William B; Salcedo, Andres; Akhunova, Alina; He, Fei; Wang, Shichen; Liang, Hanquan; Bowden, Robert L; Akhunov, Eduard
Two opposing evolutionary constraints exert pressure on plant pathogens: one to diversify virulence factors in order to evade plant defenses, and the other to retain virulence factors critical for maintaining a compatible interaction with the plant host. To better understand how the diversified arsenals of fungal genes promote interaction with the same compatible wheat line, we performed a comparative genomic analysis of two North American isolates of Puccinia graminis f. sp. tritici (Pgt). The patterns of inter-isolate divergence in the secreted candidate effector genes were compared with the levels of conservation and divergence of plant-pathogen gene co-expression networks (GCN) developed for each isolate. Comprative genomic analyses revealed substantial level of interisolate divergence in effector gene complement and sequence divergence. Gene Ontology (GO) analyses of the conserved and unique parts of the isolate-specific GCNs identified a number of conserved host pathways targeted by both isolates. Interestingly, the degree of inter-isolate sub-network conservation varied widely for the different host pathways and was positively associated with the proportion of conserved effector candidates associated with each sub-network. While different Pgt isolates tended to exploit similar wheat pathways for infection, the mode of plant-pathogen interaction varied for different pathways with some pathways being associated with the conserved set of effectors and others being linked with the diverged or isolate-specific effectors. Our data suggest that at the intra-species level pathogen populations likely maintain divergent sets of effectors capable of targeting the same plant host pathways. This functional redundancy may play an important role in the dynamic of the "arms-race" between host and pathogen serving as the basis for diverse virulence strategies and creating conditions where mutations in certain effector groups will not have a major effect on the pathogen
Localisation of genes for resistance against ¤Blumeria graminis¤ f.sp. ¤hordei¤ and ¤Puccinia graminis¤ in a cross between a barley cultivar and a wild barley (¤Hordeum vulgare¤ ssp. ¤spontaneum¤) line
Backes, G.; Madsen, L.H.; Jaiser, H.
The aims of this investigation have been to map new (quantitative) resistance genes against powdery mildew, caused by Blumeria graminis f.sp. hordei L., and leaf rust, caused by Puccinia hordei L., in a cross between the barley (Hordeum vulgare ssp. vulgare) cultivar "Vada" and the wild barley...... (Hordeum vulgare ssp. spontaneum) line "1B-87" originating from Israel. The population consisted of 121 recombinant inbred lines. Resistance against leaf rust and powdery mildew was tested on detached leaves. The leaf rust isolate "I-80" and the powdery mildew isolate "Va-4", respectively, were used...
Genome-wide association study for crown rust (Puccinia coronata f. sp. avenae) and powdery mildew (Blumeria graminis f. sp. avenae) resistance in an oat (Avena sativa) collection of commercial varieties and landraces.
Montilla-Bascón, Gracia; Rispail, Nicolas; Sánchez-Martín, Javier; Rubiales, Diego; Mur, Luis A J; Langdon, Tim; Howarth, Catherine J; Prats, Elena
Diseases caused by crown rust (Puccinia coronata f. sp. avenae) and powdery mildew (Blumeria graminis f. sp. avenae) are among the most important constraints for the oat crop. Breeding for resistance is one of the most effective, economical, and environmentally friendly means to control these diseases. The purpose of this work was to identify elite alleles for rust and powdery mildew resistance in oat by association mapping to aid selection of resistant plants. To this aim, 177 oat accessions including white and red oat cultivars and landraces were evaluated for disease resistance and further genotyped with 31 simple sequence repeat and 15,000 Diversity Arrays Technology (DArT) markers to reveal association with disease resistance traits. After data curation, 1712 polymorphic markers were considered for association analysis. Principal component analysis and a Bayesian clustering approach were applied to infer population structure. Five different general and mixed linear models accounting for population structure and/or kinship corrections and two different statistical tests were carried out to reduce false positive. Five markers, two of them highly significant in all models tested were associated with rust resistance. No strong association between any marker and powdery mildew resistance at the seedling stage was identified. However, one DArT sequence, oPt-5014, was strongly associated with powdery mildew resistance in adult plants. Overall, the markers showing the strongest association in this study provide ideal candidates for further studies and future inclusion in strategies of marker-assisted selection.
Tallo, Ivar, 1964-
Politoloog Ivar Tallo arvates võiks Riigikogu välja tulla initsiatiiviga luua ühiskonna esindajate osavõtul vigade ja pettuste paljastajate kaitse seadus. Küsimusele, kust läheb politseiametniku sõnavabaduse piir vastavad Ain Seppik, Tarmo Loodus ja Jaanus Rahumägi. Indrek Sirgi juhtum
Full Text Available Sphaerellopsis filum is a well-known parasite associated with many species of rust fungi. It is of frequent occurrence as parasite of cereal rusts: Puccinia recondita, P. coronata, P. graminis, P. hordei and P. striiformis. Uredial sori of Puccinia recondita f.sp. tritici infected with Sphaerellopsis filum were examined by light and scanning microscope to determine morphology of hyperparasite as well as the parasite-hyperparasite contact. The microscopical examination of infected uredinia clearly showed the intimate connection of S. filum with its rust host.
Keywords: AFLP, wheat, stem rust, genetic diversity, population differentiation ... the method described by Vos et al (1995), with little modification, i.e., 1 µl genomic ..... Agriculture, Veterinary Science, Nutrition and Natural Resources, 1, 1- 13.
The developed AFLP fingerprints for the Ethiopian Pgt isolates reported herein could support the breeding program to develop strategies for the deployment of resistance genes in its continued effort to minimize the impact of stem rust on wheat in Ethiopia. Keywords: AFLP, wheat, stem rust, genetic diversity, population ...
Tallo, Ivar, 1964-
e-Riigi Akadeemia Sihtasutuse direktor Ivar Tallo kõrgemate riigiametnike koolitamisest info- ja kommunikatsioonitehnoloogia kasutamiseks ja edendamiseks avalikus halduses. Kogemusi jagatakse Kesk-Aasias, Kaukaasias ja Balkanimaades
Martens, J.W.; Brown, P.D.; McKenzie, R.I.H.; Harder, D.E.
The evaluation of over seven million M 2 oat plants derived from irradiated and chemical mutagen treated seeds (about 50,000) or low-level chronically irradiated growing plants produced no new sources of useful resistance. However, preliminary results indicate that the gene Pg-16 has been transferred from the tetraploid Avena barbata L. to the hexaploid A. sativa L. by irradiation of disomic alien addition lines and monosomic alien substitution lines. This gene is highly effective and confers resistance to all but two of the known races of stem rust occurring in North America. (author)
Tallo, Ivar, 1964-
e-Riigi Akadeemia Sihtasutuse direktor räägib infoühiskonna arengust Eestis, koostööprojektidest välispartneritega, infoühiskonna keskkonnamõõtest ja e-Riigi Akadeemia tulevikuplaanidest. Lisa: Ivar Tallo CV
Luz Angela Peña O.
Full Text Available Del extracto etanólico del tallo de Piper chiadoense Junker (Piperaceae fueron aislados por métodos cromatográficos la aristolactama identificada como lactama del ácido 10-amino-3,4-dimetoxifenantreno-l carboxílico (cepharanone B; campesterol; estigmasterol y B-sitosterol. Sus estructuras fueron determinadas por métodos espectroscópicos y por comparación con datos reportados en la literatura.
Full Text Available La romboencefalitis por Listeria monocytogenes es una presentación poco común de la listeriosis del sistema nervioso central; sin embargo, es la presentación más común en personas inmunocompetentes. Aun más rara es la combinación de romboencefalitis con mielitis causada por L. monocytogenes; no obstante, en este artículo se reporta un caso de encefalitis del tallo y mielitis grave en un paciente sin compromiso del sistema inmunitario. Se presenta un paciente de 21 años de edad, sin deficiencias del sistema inmunitario, que consumió productos lácteos no pasteurizados y, posteriormente, presentó un cuadro de cefalea, vómito, deterioro de su estado general y, finalmente, alteración del estado de conciencia y muerte. Consultó al Instituto Neurológico de Colombia y se hizo diagnóstico de encefalitis del tallo y mielitis por L. monocytogenes. Se discuten las diferencias entre el caso presentado y los reportados en la literatura científica. Ante un paciente con signos de compromiso del tallo cerebral, de posible origen infeccioso, es prudente iniciar tratamiento antibiótico para L. monocytogenes y, en caso de poca respuesta, escalar rápidamente en dicho tratamiento. También lo es extender el estudio radiológico hacia la columna vertebral, con el fin de descartar compromiso de la médula espinal. doi: http://dx.doi.org/10.7705/biomedica.v33i3.1482
Wilman Delgado A.
Full Text Available Del extracto etanólico del tallo de P. augustum Rudge se aislaron: 3beta-hidroxi- 24-etil-delta5.22colestadieno (estigmasterol I ; l,2-metilendioxi-6-metil-4H-dibenzo(deg quinolina-4,5(6Hdiona (Cepharadione A II; lactama del ácido lO-amino-3,4- dimetoxifenantreno-1-carboxílico (Cepharanone B n i y el nuevo compuesto natural: lactama del ácido N-metil-lO-amino- 4-hidroxi-2,3-dimetoxifenantreno-1 –carboxílico IV, Todos los compuestos fueron identificados mediante técnicas espectroscópicas (EM, RMN 'H y "C, IR y UV y comparación con datos reportados en la literatura; adicionalmente I y II fueron identificados por comparación con muestras auténticas (CCF, pf, y pf, mixto. El extracto etanólico del tallo de Piper augustum Rudge presentó una moderada actividad biológica (DL50 = 350 ppm según el ensayo de mortalidad de Artemia salina Leach (Brine Shrimp Lethality.
Rodrigo Neves Graca; Amy Ross-Davis; Ned Klopfenstein; Mee Sook Kim; Tobin Peever; Phil Cannon; Janice Uchida; Acelino Couto Alfenas
Puccinia psidii causes rust disease on many host species in the Myrtaceae . First reported in 1884 on guava in Southern Brazil , the rust has since been detected on several myrtaceous in South America, Central America, Caribbean, Mexico, USA: in Florida, California, and Hawaii. More recently, P. psidii was reported in Japan infecting M. polymorpha. Of special...
Since the first appearance of wheat stripe rust in 1996 in South Africa, four Puccinia striiformis races have been described. The first detected race, 6E16A−, was proposed to be a foreign introduction from Central or Western Asia that subsequently gained additional virulence through step-wise mutations. Simple sequence ...
Cecília do Nascimento Peixoto
Full Text Available Several gramineous plants occurring in rice fields show symptoms of crown sheath rot of rice, caused by Gaeumannomyces graminis var. graminis (Ggg, under natural conditions of infection. The pathogenicity of the Ggg-a 01 isolate, collected from rice, was tested on seven grass species and eight cereals, under greenhouse conditions, in order to get information on host-range and resistance of rice genotypes to crown sheath rot. The inoculation tests showed that the rice isolate was pathogenic to weeds such as Echinochloa crusgalli, Pennisetum setosum, Brachiaria sp., Digitaria horizontalis, Brachiaria plantaginea, Eleusine indica and Cenchrus echinatus, and that these species are potential hosts to the pathogen. Winter cereals such as wheat, oat, rye, barley and triticale, as well as sorghum, maize and millet, presented different degrees of susceptibility to the Ggg-a isolate. Significant differences were observed in relation to lesion height and production of hyphopodia and perithecia on culms. Perithecia were not observed on millet, sorghum, southern sandbur and maize. The resistance of 58 upland rice genotypes was tested, and the SCIA16 and SCIA08 genotypes presented lesion height significantly smaller, being considered resistant, when compared to the highly susceptible CNAS10351 genotype.
Gupta, Om Prakash; Permar, Vipin; Koundal, Vikas; Singh, Uday Dhari; Praveen, Shelly
Plants have evolved diverse mechanism to recognize pathogen attack and triggers defense responses. These defense responses alter host cellular function regulated by endogenous, small, non-coding miRNAs. To understand the mechanism of miRNAs regulated cellular functions during stem rust infection in wheat, we investigated eight different miRNAs viz. miR159, miR164, miR167, miR171, miR444, miR408, miR1129 and miR1138, involved in three different independent cellular defense response to infection. The investigation reveals that at the initiation of disease, accumulation of miRNAs might be playing a key role in hypersensitive response (HR) from host, which diminishes at the maturation stage. This suggests a possible host-fungal synergistic relation leading to susceptibility. Differential expression of these miRNAs in presence and absence of R gene provides a probable explanation of miRNA regulated R gene mediated independent pathways.
1968-01-01After a short introductory chapter on the occurrence of Ophiobolus graminis (take-all disease) in the polders, in chapter 2 the course of the disease and the biology of the fungus are described. The third chapter deals with materials and methods. The following chapters deal with
Heshof, Ruud; van Schayck, J Paul; Tamayo-Ramos, Juan Antonio; de Graaff, Leo H
Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans.
Christiansen, S.K.; Knudsen, S.; Giese, H.
Particle gun acceleration appears to be a possible way to transform mycelium cells of obligate plant parasites growing on host surfaces, GUS expression was obtained in E. graminis f.sp. hordei cells after bombardment with the GUS gene under the control of the E. graminis f.sp. hordei beta...
Luz Angela Peña O.
Full Text Available Del extracto etanólico del tallo de Piper chiadoense Junker (Piperaceae fueron aislados por métodos cromatográficos la aristolactama identificada como lactama del ácido 10- mino-3,4-dimetoxifenantreno-l-carboxílico (cepharanone B; campesterol; estigmasterol y B-sitosterol. Sus estructuras fueron determinadas por métodos espectroscópicos y por comparación con datos reportados en la literatura.
Peña O., Luz Angela; P. de Díaz, Aura M.
Del extracto etanólico del tallo de Piper chiadoense Junker (Piperaceae) fueron aislados por métodos cromatográficos la aristolactama identificada como lactama del ácido 10- mino-3,4-dimetoxifenantreno-l-carboxílico (cepharanone B); campesterol; estigmasterol y B-sitosterol. Sus estructuras fueron determinadas por métodos espectroscópicos y por comparación con datos reportados en la literatura.
Ana M. Arambarri
Full Text Available Se estudió la anatomía de los tallos de 37 hierbas terrestres pertenecientes a 19 familias usadas en la medicina popular de la región rioplatense. El objetivo fue elaborar una clave dicotómica para la determinación de los taxones a partir de los caracteres morfo-histológicos de los tallos, ya sea que este material se encuentre al estado entero o fragmentado. Se estudiaron tallos frescos y de ejemplares de herbario, mediante técnicas histológicas convencionales. Se realizó análisis histoquímico para la identificación de almidón, mucílagos, sustancias lipídicas y fenólicas. Entre los caracteres diagnóstico hallados se destacan: contorno de la sección transversal del tallo; presencia y los tipos de tricomas; posición de los estomas con respecto al nivel de las restantes células epidérmicas; presencia de hipodermis, de anillos fibrosos en la corteza y de dos ciclos vasculares en la eustela; presencia de endodermis conspicua; diferentes tipos de cristales y estructuras secretoras internas, con sustancias lipófilas, mucílagos y la presencia de almidón. Los caracteres morfo-histológicos de los tallos permitieron elaborar una clave de diferenciación.
The biology and epidemiology of the rust fungus Puccinia punctiformis (Str.) Röhl was investigated to evaluate the potential of this rust as a biological agent against the clonal plant species Cirsium arvense (L) Scop., which is considered
Rafael F. Alfenas; Marcelo M. Coutinho; Camila S. Freitas; Rodrigo G. Freitas; Acelino C. Alfenas
Besides its high resistance to Chrysoporthe cubensis canker, Eucalyptus cloeziana F. Muell. is a highly valuable tree species for wood production. It can be used for furniture, electric poles, fence posts, and charcoal. Nevertheless, it is highly susceptible to the rust caused by Puccinia psidii, which...
Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming
With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.
Calzada-Sánchez, Erika Viridiana; Aguilar-Rodríguez, Silvia; López-Villafranco, Ma. Edith; Aguilar-Contreras, Abigail
Actualmente Aloysia triphylla, Lantana camara, Lippia dulcis, Verbena bipinnatifida, V. carolina y V. litoralis, se encuentran en lista de espera para su inclusión en la Farmacopea Herbolaria de los Estados Unidos Mexicanos. Con la finalidad de contribuir a dicha incorporación y a su identificación, en el presente estudio se compararon caracteres morfo-anatómicos de la hoja, tallo y ramas, de estas seis especies de Verbenaceae empleadas en la medicina tradicional mexicana. Se reconocen dos ti...
Full Text Available BACKGROUND: The wheat stripe rust fungus (Puccinia striiformis f. sp. tritici, PST is responsible for significant yield losses in wheat production worldwide. In spite of its economic importance, the PST genomic sequence is not currently available. Fortunately Next Generation Sequencing (NGS has radically improved sequencing speed and efficiency with a great reduction in costs compared to traditional sequencing technologies. We used Illumina sequencing to rapidly access the genomic sequence of the highly virulent PST race 130 (PST-130. METHODOLOGY/PRINCIPAL FINDINGS: We obtained nearly 80 million high quality paired-end reads (>50x coverage that were assembled into 29,178 contigs (64.8 Mb, which provide an estimated coverage of at least 88% of the PST genes and are available through GenBank. Extensive micro-synteny with the Puccinia graminis f. sp. tritici (PGTG genome and high sequence similarity with annotated PGTG genes support the quality of the PST-130 contigs. We characterized the transposable elements present in the PST-130 contigs and using an ab initio gene prediction program we identified and tentatively annotated 22,815 putative coding sequences. We provide examples on the use of comparative approaches to improve gene annotation for both PST and PGTG and to identify candidate effectors. Finally, the assembled contigs provided an inventory of PST repetitive elements, which were annotated and deposited in Repbase. CONCLUSIONS/SIGNIFICANCE: The assembly of the PST-130 genome and the predicted proteins provide useful resources to rapidly identify and clone PST genes and their regulatory regions. Although the automatic gene prediction has limitations, we show that a comparative genomics approach using multiple rust species can greatly improve the quality of gene annotation in these species. The PST-130 sequence will also be useful for comparative studies within PST as more races are sequenced. This study illustrates the power of NGS for
Delgado A., Wilman; Avella M., Eliseo; P. de Díaz, Aura M.
Del extracto etanólico del tallo de P. augustum Rudge se aislaron: 3beta-hidroxi- 24-etil-delta5.22colestadieno (estigmasterol) I ; l,2-metilendioxi-6-metil-4H-dibenzo(deg) quinolina-4,5(6H)diona (Cepharadione A) II; lactama del ácido lO-amino-3,4- dimetoxifenantreno-1-carboxílico (Cepharanone B) n i y el nuevo compuesto natural: lactama del ácido N-metil-lO-amino- 4-hidroxi-2,3-dimetoxifenantreno-1 –carboxílico IV, Todos los compuestos fueron identificados mediante técnicas espectroscópicas ...
Patpour, Mehran; Hovmøller, Mogens; Shahin, Atef
, Kenya, Ethiopia, Sudan, Tanzania, Eritrea, Rwanda, South Africa, Zimbabwe, Mozambique, Yemen, and Iran (Patpour et al. 2015). In the 2014 crop season, the presence of virulence to Sr31 in Egypt was suspected based on preliminary field observations of high infection on sources of Sr31 planted...
Pedersen, C.; Wu, B.; Giese, H.
A bacterial artificial chromosome (BAC) library of Blumeria graminis f.sp. hordei, containing 12,000 clones with an average insert size of 41 kb, was constructed. The library represents about three genome equivalents and BAC-end sequencing showed a high content of repetitive sequences, making...... contigs, at or close to avirulence loci, were constructed. Single nucleotide polymorphism (SNP) markers were developed from BAC-end sequences to link the contigs to the genetic maps. Two other BAC contigs were used to study microsynteny between B. graminis and two other ascomycetes, Neurospora crassa...
Torp, J.; Andersen, Brian
Conidial proteins from barley powdery mildew, Erysiphe graminis f. sp. hordei, were separated by 2-dimensional electrophoresis in polyacrylamide slab gels. Isoelectric focusing was used in the first dimension and separation according to molecular weight in a gel containing sodium dodecyl sulphate...
Trujillo, M.; Troeger, M.; Niks, R.E.; Kogel, K.H.; Huckelhoven, R.
Non-host resistance of barley to Blumeria graminis f.sp. tritici (Bgt), an inappropriate forma specialis of the grass powdery mildew fungus, is associated with formation of cell wall appositions (papillae) at sites of attempted fungal penetration and a hypersensitive cell death reaction (HR) of
In the barley-Blumeria interaction, resistance at penetration stage in association with papilla formation is a commonly occurring mechanism. This mechanism of defense reduces the infection severity by adapted powdery mildew pathogen (basal resistance to Blumeria graminis f.sp. hordei, Bgh) and fully
While wheat powdery mildew occurs throughout the south-central and eastern U.S.A, epidemics are especially damaging in the Mid-Atlantic states. The structure of the U.S. Blumeria graminis f. sp. tritici population was assessed based on a sample of 238 single-spored isolates. The isolates were coll...
Full Text Available Our research goal was to perform hygienic assessment of risks caused by Graminis KE and Rinkor VG herbicides for people working with them. We applied sanitary-hygienic and toxicological research techniques in our work in full conformity with valid technical regulatory documents and guidelines. We set the following research tasks: to analyze literature and information sources; to perform primary toxicological assessment of preparatory herbicides and study their acute toxicity together with sensitizing effects at intragastric introduction, cutaneous application, and inhalation exposure on laboratory animals; to examine herbicides cumulative effects and calculation their cumulation coefficient; to examine working conditions during a natural experiment when Graminis KE and Rinkor VG herbicides were applied and calculate risks for workers; to work out scientifically grounded recommendations on their safety application in agriculture. The examined herbicides, Graminis KE and Rinkor VG, are classified as substances with the 3rd hazard degree as per their toxicometric parameters (moderately hazardous substances. Calculated risks of complex (inhalant and dermal exposure to Gramins KE and Rinkor VG herbicides for workers (operators who refills them and those who spray plants with them when they are applied in agriculture don't exceed acceptable levels (are less than 1. Our work results allow to enrich a set of plant protectors which are applied in the country and to use such preparations in agriculture which are the least harmful for health and the environment. Application of Graminis KE and Rinkor VG herbicides will help to increase crops productivity.
Villaverde, J.J.; Vlist, van der V.; Santos, S.A.O.; Haarmann, T.; Langfelder, K.; Pirttimaa, M.; Nyyssola, A.; Jylhä, S.; Tamminen, T.; Kruus, K.; Graaff, de L.H.; Pascoal Neto, C.; Simoes, M.M.Q.; Domingues, M.R.M.; Silvestre, A.J.D.; Eidner, J.; Buchert, J.
Linoleic acid was converted into hydroperoxides by a Gaeumannomyces graminis tritici lipoxygenase produced recombinantly in Trichoderma reesei. Hydroperoxide production was optimized using a face-centred experimental design in order to study the effects of pH, temperature and time on the conversion
Background Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt), we have generated Expressed Sequence Tags (ESTs) by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores) and asexual (germinated urediniospores) stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum), 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs). Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt) and stripe rust, P. striiformis f. sp. tritici (Pst), and poplar
Full Text Available Abstract Background Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt, we have generated Expressed Sequence Tags (ESTs by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores and asexual (germinated urediniospores stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum, 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs. Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt and stripe rust, P. striiformis f. sp
Stefan Martyniuk; Marian Jurzysta
Different concentrations of medicagenic acid and five glycosides of this acid isolated from alfalfa (Medicago sativa) were added to agar medium (corn meal agar, CMA) inoculated with cultures of Gaeumannomyces graminis var. tritici (Ggt). After 7 days of incubation at 25oC colony radius was measured and % of inhibition calculated in relation to the control medium (CMA enriched with the solvent of the tested compounds). Within the tested concentrations, only 3-O-β -D -glucopiranoside medicagena...
Leon Sarmiento, Fidias E.
Full Text Available El reflejo mandibular o maseterino posee conexiones nerviosas únicas, diferentes de las exhibidas por otros reflejos monosinápticos humanos, y permite evaluar, de forma fácil y eficiente, el tallo cerebral por medio de la estimulación mecánica, eléctrica o magnética. Diversos estudios han demostrado la participación en este reflejo de las interneuronas del tallo cerebral y su modulación por estructuras supraespinales, que hacen parte fundamental de su integración motora. El reflejo mandibular es útil para evaluar la afectación trigémino-trigeminal en polineuropatías como la diabetes, neuromiopatías como la esclerosis múltiple y en pacientes con trastornos del movimiento, con o sin disfunción oromandibular. La evaluación neurofuncional de este reflejo craneofacial ayuda a identificar la integración sensorimotora del tallo cerebral y las posibles alteraciones de estas vías reflejas, debidas a anormalidades del sistema nervioso central o del periférico. Su apropiada ejecución e interpretación, clínica y neurológica, permite aplicar de manera más personalizada diversos protocolos de neurorrehabilitación, con el fin de ayudar a mejorar la calidad de vida de los individuos con afectación de estas vías neurales.
Tejeda-Sartorius, Olga; Escalante-Estrada, J. Alberto; Soto-Hernández, Marcos; Rodríguez-González, Ma. Teresa; Vibrans, Heike; Ramírez-Guzmán, Martha E.
Se evaluó el efecto del extracto acuoso del residuo seco del tallo del amaranto (Amaranthus hypochondriacus L. var. Azteca) a diferentes concentraciones, en la germinación y longitud de radícula y vástago de Amaranthus hybridus L. Dicho extracto, a 108 y 54 ppm inhibió la germinación de la especie en 100% y 68.42%, respectivamente, disminuyendo significativamente la longitud del vástago y la radícula, cuando la inhibición de la germinación no fue total. Se identificaron los ácidos ferúlico (A...
Li, Wei; Feng, Yanxia; Sun, Haiyan; Deng, Yuanyu; Yu, Hanshou; Chen, Huaigu
Understanding the genetic structure of Gaeumannomyces graminis var. tritici is essential for the establishment of efficient disease control strategies. It is becoming clear that microsatellites, or simple sequence repeats (SSRs), play an important role in genome organization and phenotypic diversity, and are a large source of genetic markers for population genetics and meiotic maps. In this study, we examined the G. graminis var. tritici genome (1) to analyze its pattern of SSRs, (2) to compare it with other plant pathogenic filamentous fungi, such as Magnaporthe oryzae and M. poae, and (3) to identify new polymorphic SSR markers for genetic diversity. The G. graminis var. tritici genome was rich in SSRs; a total 13,650 SSRs have been identified with mononucleotides being the most common motifs. In coding regions, the densities of tri- and hexanucleotides were significantly higher than in noncoding regions. The di-, tri-, tetra, penta, and hexanucleotide repeats in the G. graminis var. tritici genome were more abundant than the same repeats in M. oryzae and M. poae. From 115 devised primers, 39 SSRs are polymorphic with G. graminis var. tritici isolates, and 8 primers were randomly selected to analyze 116 isolates from China. The number of alleles varied from 2 to 7 and the expected heterozygosity (He) from 0.499 to 0.837. In conclusion, SSRs developed in this study were highly polymorphic, and our analysis indicated that G. graminis var. tritici is a species with high genetic diversity. The results provide a pioneering report for several applications, such as the assessment of population structure and genetic diversity of G. graminis var. tritici.
Rigoberto Castro Rivera
Full Text Available El objetivo del estudio fue determinar la elongación, crecimiento, senescencia, peso y dinámica de tallos de cinco asociaciones conformadas por dos gramíneas y una leguminosa sembradas en diferentes proporciones. Se evaluaron cinco tratamientos: 4:3:3; 4:6:0; 4:0:6; 4:4:2 y 4:2:4 de trébol blanco-ovillo-ballico perenne, los cuales se distribuyeron en 20 unidades experimentales de 104 m2 , en un diseño en bloques completos al azar. La mayor elongación y crecimiento neto de la hoja de las especies evaluadas fue en verano, con 7.1 y 6.53 cm tallo -1 d -1 , para el pasto ovillo, y 7 y 6.7 cm tallo -1 d -1 , para ballico perenne; en trébol blanco no existió diferencia en el recambio de tejido foliar y del peciolo en verano y primavera ( P>0.05. El mayor peso de tallos de ballico perenne y ovillo se registró en verano (0.38g -1 tallo - 1 y las mayores densidades en la época de invierno (9,961 y 10,423 tallos m-2 , respectivamente. El recambio de tejido de las especies evaluadas presentó marcada estacionalidad, siendo más dinámico en verano que en otoño. La asociación de tres especies permitió una mayor dinámica en comparación con la asociación de dos especies.
Chang Huerta, Lorenzo; Rosabal Carbonell, Yeisa; Morales León, José Ángel
Introducción: Solanum nigrum L. se emplea como antiséptico, expectorante, cardiotónico, digestivo diaforético y sedativo. Las hojas son usadas como emplastos para el reumatismo, enfermedades de la piel, y para el tratamiento de la tuberculosis. Se considera un potente antiinflamatorio. Objetivos: determinar la composición fitoquímica de los extractos etéreo, alcohólico y acuoso de tallos y hojas de la especie Solanum nigrum L. Métodos: se recolectaron tallos y hojas de Solanum nigrum L., se l...
Ramírez V Carlos Mario
Full Text Available Un prototipo para aplicar vibración circular al tallo del cafeto, desarrollado en el Centro Nacional de Investigaciones de Café CENICAFÉ, fue evaluado en campo para estudiar su factibilidad técnica en la cosecha mecanizada de café. La evaluación consistió en determinar el efecto de la frecuencia, excentricidad y punto de aplicación de la vibración circular en la selectividad y el rendimiento del desprendimiento de frutos de café. El análisis estadístico indicó que el mejor tratamiento para vibrar el tallo (chupón y tocón de la zoca del café corresponde a una frecuencia de excitación de 2000 c.p.m, con una excentricidad de 2,5 cm aplicada en el chupón, lográndose desprender hasta el 45% de los frutos maduros presentes en el árbol con un porcentaje de frutos verdes desprendidos de 27%. Se encontró como en otros trabajos previos que el desprendimiento de los frutos depende del incremento de la amplitud (mayor excentricidad y de la frecuencia de vibración. La selectividad de este desprendimiento depende también del porcentaje inicial de frutos maduros presentes en los árboles.
João Batista Vida
Full Text Available È registrada a primeira ocorrência de ferrugem em capim-limão (Cymbopogon citratus (DC. Stapf, causada por Puccinia cymbopogonis Mass., no Brasil, Estado do Paraná.It is reported the first occurrence of the lemongrass (Cymbopogon citratus (DC. Stapf rust fungi caused by Puccinia cymbopogonis Mass. in Brazil, State of Paraná.
Durham, D R
Rhodotorula graminis utilized DL-mandelate, L(+)-mandelate, and D(-)-mandelate as sole sources of carbon and energy. Growth on these aromatic substrates resulted in the induction of an NAD-dependent D(-)-mandelate dehydrogenase and a dye-linked L(+)-mandelate dehydrogenase, each catalyzing the stereospecific conversion of its respective enantiomer of mandelate to benzoylformate. Benzoylformate was oxidized to benzaldehyde, which was dehydrogenated to benzoate by an NAD-dependent benzaldehyde dehydrogenase. Benzoate was further metabolized through p-hydroxybenzoate and the protocatechuate branch of the beta-ketoadipate pathway. PMID:6389497
Line, R.F.; Allan, R.E.; Konzak, C.F.
Resistance to Puccinia striiformis in wheat cultivars, breeding lines, and induced mutants, was studied on plants exposed to natural rust inoculum at field sites and on plants inoculated with specific races and grown under controlled temperatures. Based on infection types and disease intensity at various stages of plant growth throughout the duration of rust establishment, the following resistance-types (R-types) were identified: R-type 1, plants resistant or susceptible at all stages of growth and at both low and high temperatures throughout duration of rust establishment; R-type 2, plants initially resistant in the seedling stage but eventually become susceptible, plants resistant at later stages in the field; R-type 3, variable resistance in the seedling stage, high resistance in later growth stages; R-type 4, plants resistant in the eedling stage, but susceptible in late stages of growth; R-type 5, plants susceptible, but the pathogen is slow to sporulate and consequently, rust increases slower in the field; R-type 6, plants susceptible at low temperatures and resistant at high temperatures at all stages of growth; R-type 7, plants very susceptible at both low and high temperatures in the seedling stage and at low temperatures in later stages; when temperatures are high, plants become more resistant in later stages; R-type 8, plants susceptible at all stages, when rust intensity is low and when not under stress, but become more resistant when intensity is high or under moderate stress in the field. Combinations of the above types were also observed. Techniques for identifying resistance to stripe rust, race specificity of the resistance-types, relationship of plant growth habit and head characteristics to disease intensity, historical significance of various types of resistance in the United States, and methods of using the resistance-types are also discussed. (author)
Hiddink, G.A.; Bruggen, van A.H.C.; Termorshuizen, A.J.; Raaijmakers, J.M.; Semenov, A.V.
Organic management of soils is generally considered to reduce the incidence and severity of plant diseases caused by soil-borne pathogens. In this study, take-all severity on roots of barley and wheat, caused by Gaeumannomyces graminis var. tritici, was significantly lower in organically-managed
Powdery mildew caused by Blumeria graminis (DC.) Speer f. sp. tritici (Em. Marchal) is a serious disease of wheat that can cause a severe reduction in yield. In Egypt, high powdery mildew severity has been observed in the past few years on many commercial cultivars of both bread and durum wheat. Lit...
Droce, Aida; Holm, Kirsten B.; Olsson, Stefan
The obligate ascomycete parasitic fungus Blumeria graminis f. sp. hordei (Bgh) has a unique lifestyle as it is completely dependent on living barley leaves as substrate for growth. Genes involved in inorganic nitrogen utilization are notably lacking, and the fungus relies on uptake of host...
Crovadore, Julien; Calmin, Gautier; Chablais, Romain; Cochard, Bastien; Schulz, Torsten; Lefort, François
We report here the whole-genome shotgun sequence of the strain UASWS1507 of the species Pseudomonas graminis, isolated in Switzerland from an apple tree. This is the first genome registered for this species, which is considered as a potential and valuable resource of biological control agents and biofertilizers for agriculture. Copyright © 2016 Crovadore et al.
Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion Bravo, Victor; Mora, María de la Luz; Pozo, María J.
Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne
Parlange, Z.; Oberhaensli, S.; Breen, J.; Platzer, M.; Taudien, S.; Šimková, Hana; Wicker, T.; Doležel, Jaroslav; Keller, B.
Roč. 11, č. 4 (2011), s. 671-677 ISSN 1438-793X R&D Projects: GA MŠk ED0007/01/01 Institutional research plan: CEZ:AV0Z50380511 Keywords : Blumeria graminis * BAC library * BAC-end sequences Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.842, year: 2011
Here we report the screening of 338 new accessions of 11 different wild oat species (Avena) from the USDA Small Grains Collection for resistance to crown rust (Puccinia coronata). Wild oat species were originally collected in Morocco by C. Al Faiz, INRAT Rabat: Avena agadiriana, A. atlantica, A. bar...
PUCCINIA HORIANA is a quarantine-significant fungal pathogen and causal agent of Chrysanthemum white rust, first discovered in the U.S. in 1977. The disease was eradicated and for many years successfully controlled by fungicides and strict regulatory measures. However, recently Chrysanthemum white r...
Puccinia striiformis f. sp. tritici (Pst) causes stripe rust, one of the most important diseases of wheat worldwide. To identify Pst genes involved in infection and sporulation, a custom oligonucleotide Genechip was made using sequences of 442 genes selected from Pst cDNA libraries. Microarray analy...
Lichtenberg, H; Prange, A; Hormes, J; Steiner, U; Oerke, E-C
In this study, wheat leaves infected with brown rust, a plant disease of serious economic concern caused by the fungus Puccinia triticina, were investigated using spatially resolved XANES (X-ray Absorption Near Edge Structure) spectroscopy at the sulfur K-absorption edge.
Lichtenberg, H; Prange, A; Hormes, J [CAMD, Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA 70806 (United States); Steiner, U; Oerke, E-C, E-mail: email@example.com [INRES-Phytomedicine, University of Bonn, Nussallee 9, 53115 Bonn (Germany)
In this study, wheat leaves infected with brown rust, a plant disease of serious economic concern caused by the fungus Puccinia triticina, were investigated using spatially resolved XANES (X-ray Absorption Near Edge Structure) spectroscopy at the sulfur K-absorption edge.
Sugarcane industry in Brazil suffers yield loss due to brown rust (Puccinia melanocephala) since 1986 and orange rust (P. kuehnii) as recent as 2009. The main control measure for both diseases has been cultivar resistance. Nevertheless, recent onsets of orange rust on previously resistant cultivars ...
Walter, Stephanie; Ali, Sajid; Justesen, Annemarie Fejer
The ever more frequent and severe large-scale epidemics of wheat yellow/stripe rust disease (caused by Puccinia striiformis) pose a severe threat to the world’s wheat production (Hovmøller et al. 2010). The onset of a new series of world-wide wheat yellow rust epidemics in 2000 has been linked...
Orange rust, Puccinia kuehnii (W. Krüger) E.J. Butler, is an important disease of sugarcane (complex hybrid of Saccharum L. species) that causes yield losses, and impacts breeding programs. Initially confined to the Asia-Oceania region (5), P. kuehnii was reported in Florida in June 2007 (2) and lat...
In de gerst (Hordeum vulgare) - dwergroest (Puccinia hordei) relatie zijn twee typen van resistentie te onderscheiden, namelijk overgevoeligheidsresistentie en partiële resistentie. Deze typen kunnen beschouwd worden als voorbeelden van Van der Plank's verticale en horizontale
R. N. Graca; A. C. Alfenas; A. L. Ross-Davis; Ned Klopfenstein; M. -S. Kim; T. L. Peever; P. G. Cannon; J. Y. Uchida; C. Y. Kadooka; R. D. Hauff
Puccinia psidii is the cause of rust disease of many host species in the Myrtaceae family, including guava (Psidium spp.), eucalypt (Eucalyptus spp.), rose apple (Syzygium jambos), and 'ohi'a (Metrosideros polymorpha). First reported in 1884 on guava in Brazil, the rust has since been detected in South America (Argentina, Brazil, Colombia, Paraguay, Uruguay,...
Carver, T.L.W.; Roberts, P.C.; Thomas, B.J.
Germination by Blumeria graminis. DC Speer ff. spp. avenae, hordei and tritici, was greatly suppressed when conidia fell within colonies of ff. spp. avenae or hordei established on susceptible oat or barley, respectively. On healthy oat or barley, and when distant from powdery mildew, colonies. all...... ff. spp. formed normal appressoria. This was also true When conidia germinated within established barley mildew colonies. Within barley mildew colonies, appressoria of f. sp. hordei penetrated epidermal cells formed haustoria more frequently than appressoria distant from colonies. Similarly, ff. spp....... avenae and tritici, normally unable to infect barley. frequently penetrated epidermal cells subtending established barley mildew colonies. Thus, colony, establishment induced barley epidermal cell accessibility, even to non-pathogenic ff. spp, In contrast. when all three ff. spp. germinated within...
Full Text Available Different concentrations of medicagenic acid and five glycosides of this acid isolated from alfalfa (Medicago sativa were added to agar medium (corn meal agar, CMA inoculated with cultures of Gaeumannomyces graminis var. tritici (Ggt. After 7 days of incubation at 25oC colony radius was measured and % of inhibition calculated in relation to the control medium (CMA enriched with the solvent of the tested compounds. Within the tested concentrations, only 3-O-β -D -glucopiranoside medicagenate (monoglucoside significantly reduced the growth of Ggt on CMA medium. This compound at 0.05 mM concentration completely inhibited the development of the fungus and the effect was shown to be fungi-toxic.
pigmentos. Este estudio tiene por objeto identificar los tejidos del tallo de los cactus en los cuales se acumulan las betacianinas. Esta acumulación se observó en tejidos tanto cultivados, como en la naturaleza. La localización de las betacianinas en los tallos de los cactus se observó en estudios de microscopía de luz en secciones transversales de tubérculos. Durante el trabajo de campo en la planicie mexicana en marzo, se observaron tallos rojizos en muchas especies de cactus de diferentes géneros. Los estudios en microscopía de luz mostraron que las betacianinas se acumulan en la hipodermis y en las capas más externas del clorénquima, donde pueden funcionar como pantalla, protegiendo los fotosistemas presentes en la capa subyacente, y posiblemente como antioxidante en la corteza.
Infante, Danay; Martínez, B; González, E; González, Noyma
La caña de azúcar es atacada por dos especies de Puccinia: la roya carmelita causada por P. melanocephala y la anaranjada por P. kuehnii. La primera ha prevalecido en el continente Americano, mientras que la segunda en Asia y Oceanía. Estas royas se diferencian respecto a las condiciones ambientales, la forma de presentarse el síntoma y el lugar de desarrollo del mismo. La mayor severidad causada por la roya carmelita se manifiesta durante los periodos fríos, en plantaciones de tres a seis me...
Full Text Available The effect of DL-β-aminobutyric acid (BABA, benzothiadiazole (BTH, indoleacetic acid (IAA and salicylic acid (SA on induced systemic resistance was investigated in moderately susceptible and susceptible wheat genotypes Tamuz-2 and AL-8/70 against Puccinia striiformis f. sp. tritici. Resistance was characterized by reduced infection of yellow rust disease (Yrd. Changes in peroxidase, phenylalanine ammonia-lyase activities and in total phenolic compound content demonstrated that the resistance to Puccinia striiformis can be induced by BABA, BTH, IAA and SA in these two wheat genotypes. Further studies are needed before a practical method using many analogue compounds, such as potassium phosphate and biotic agent for Yrd resistance in wheat is developed.
Frank M. Dugan; Michael J. Cashman; Richard C. Johnson; Meinan Wang; Chen Xianming
Differential resistance to stripe rust (Puccinia striiformis) in a planting of 111 wild collections of Basin wild rye (Leymus cinereus) was noted 2011-2013. In 2011, rust severity was rated on a scale of 1-9. Much lighter infection in 2012 and 2013 was rated as the number of symptomatic leaves per plant divided by plant circumference (to adjust for plant size). Effect...
Wang, Xiao-Yan; Wen-Feng, Li; Ying-Kun, Huang; Xin, Lu; Zhi-Ming, Luo; Jiong, Yin; Hong-Li, Shan; Rong-Yue, Zhang
Sugarcane brown rust disease caused by Puccinia melanocephala is one of the important fungal diseases affecting sugarcane yield around the world. Cultivar resistance is the most appropriate control method for this disease. In this study, 62 introgression lines chosen from the crossing Saccharum officinarum L. cv. Ludashi x Erianthus rockii Yunnan 95-19 were evaluated for brown rust resistance using artificial inoculation. More than 30% of the introgression lines were identified as resistant. ...
Li, Jie; Yang, Xiwen; Liu, Xinhao; Yu, Haibo; Du, Congyang; Li, Mengda; He, Dexian
Proteome characteristics of wheat leaves with the powdery mildew pathogen Blumeria graminis f. sp. tritici (Bgt) infection were investigated by two-dimensional electrophoresis and tandem MALDI-TOF/TOF-MS. We identified 46 unique proteins which were differentially expressed at 24, 48, and 72 h post-inoculation. The functional classification of these proteins showed that most of them were involved in photosynthesis, carbohydrate and nitrogen metabolism, defense responses, and signal transduction. Upregulated proteins included primary metabolism pathways and defense responses, while proteins related to photosynthesis and signal transduction were mostly downregulated. As expected, more antioxidative proteins were activated at the later infection stage than the earlier stage, suggesting that the antioxidative system of host plays a role in maintaining the compatible interaction between wheat and powdery mildew. A high accumulation of 6-phosphogluconate dehydrogenase and isocitrate dehydrogenase in infected leaves indicated the regulation of the TCA cycle and pentose phosphate pathway in parallel to the activation of host defenses. The downregulation of MAPK5 could be facilitated for the compatible interaction of wheat plants and Bgt. qRT-PCR analysis supported the data of protein expression profiles. Our results reveal the relevance of primary plant metabolism and defense responses during compatible interaction, and provide new insights into the biology of susceptible wheat in response to Bgt infection. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Kropp, B R; Hansen, D R; Wolf, P G; Flint, K M; Thomson, S V
ABSTRACT The identity of a Puccinia species occurring on the introduced weed dyer's woad (Isatis tinctoria) was studied using sequences from the internal transcribed spacer of the nuclear ribosomal DNA. The relationship of this fungus to other Puccinia species occurring on the family Brassicaceae in Europe and North America was examined, and we tested the hypothesis that P. thlaspeos and P. monoica are correlated species. The data suggest that the Puccinia species from dyer's woad is closely related to the North American species P. consimilis and may be derived from an indigenous strain of P. consimilis that switched hosts. Thus, the Puccinia species from dyer's woad is probably native to North America and is unlikely to cause disease epidemics on indigenous plants if used as a biological control agent against dyer's woad. P. thlaspeos appears to be polyphyletic and, therefore, P. thlaspeos and P. monoica do not appear to be correlated species. Additional DNA sequence data will be needed to clarify further the phylogeny of Puccinia species on the family Brassicaceae.
Manzano Santana, Patricia; Miranda Martínez, Migdalia; Montes de Oca Porto, Rodney; Orellana León, Tulio; Abreu Payrol, Juan; Peralta García, Esther L
Introducción: Vernonanthura patens (Kunth) H. Rob. es una especie que crece silvestre en el Ecuador, para la cual existen escasos antecedentes de estudios químicos y biológicos, y en ninguno de estos se aborda el estudio de fracciones lipídicas. Objetivos: estudiar las fracciones de compuestos lipídicos presentes en las hojas, tallos y flores de la especie. Métodos: la planta se recolectó en estado adulto, en época de floración, los órganos vegetales fueron secados en estufa por separado, se ...
Full Text Available Take-all, which is caused by the fungal pathogen, Gaeumannomyces graminis var. tritici (Ggt, is an important soil-borne root rot disease of wheat occurring worldwide. However, the genetic basis of Ggt pathogenicity remains unclear. In this study, transcriptome sequencing for Ggt in axenic culture and Ggt-infected wheat roots was performed using Illumina paired-end sequencing. Approximately 2.62 and 7.76 Gb of clean reads were obtained, and 87% and 63% of the total reads were mapped to the Ggt genome for RNA extracted from Ggt in culture and infected roots, respectively. A total of 3,258 differentially expressed genes (DEGs were identified with 2,107 (65% being 2-fold up-regulated and 1,151 (35% being 2-fold down-regulated between Ggt in culture and Ggt in infected wheat roots. Annotation of these DEGs revealed that many were associated with possible Ggt pathogenicity factors, such as genes for guanine nucleotide-binding protein alpha-2 subunit, cellulase, pectinase, xylanase, glucosidase, aspartic protease and gentisate 1, 2-dioxygenase. Twelve DEGs were analyzed for expression by qRT-PCR, and could be generally divided into those with high expression only early in infection, only late in infection and those that gradually increasing expression over time as root rot developed. This indicates that these possible pathogenicity factors may play roles during different stages of the interaction, such as signaling, plant cell wall degradation and responses to plant defense compounds. This is the first study to compare the transcriptomes of Ggt growing saprophytically in axenic cultures to it growing parasitically in infected wheat roots. As a result, new candidate pathogenicity factors have been identified, which can be further examined by gene knock-outs and other methods to assess their true role in the ability of Ggt to infect roots.
Alegre, Isabel; Viñas, Inmaculada; Usall, Josep; Teixidó, Neus; Figge, Marian J; Abadias, Maribel
The consumption of fresh-cut fruit has substantially risen over the last few years, leading to an increase in the number of outbreaks associated with fruit. Moreover, consumers are currently demanding wholesome, fresh-like, safe foods without added chemicals. As a response, the aim of this study was to determine if the naturally occurring microorganisms on fruit are "competitive with" or "antagonistic to" potentially encountered pathogens. Of the 97 and 107 isolates tested by co-inoculation with Escherichia coli O157:H7, Salmonella and Listeria innocua on fresh-cut apple and peach, respectively, and stored at 20 °C, seven showed a strong antagonistic capacity (more than 1-log unit reduction). One of the isolates, CPA-7, achieved the best reduction values (from 2.8 to 5.9-log units) and was the only isolate able to inhibit E. coli O157:H7 at refrigeration temperatures on both fruits. Therefore, CPA-7 was selected for further assays. Dose-response assays showed that CPA-7 should be present in at least the same amount as the pathogen to adequately reduce the numbers of the pathogen. From the results obtained in in vitro assays, competition seemed to be CPA-7's mode of action against E. coli O157:H7. The CPA-7 strain was identified as Pseudomonas graminis. Thus, the results support the potential use of CPA-7 as a bioprotective agent against foodborne pathogens in minimally processed fruit. Copyright © 2013 Elsevier Ltd. All rights reserved.
Vatter, Thomas; Maurer, Andreas; Perovic, Dragan; Kopahnke, Doris; Pillen, Klaus; Ordon, Frank
The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM) was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars.
Vatter, Thomas; Maurer, Andreas; Perovic, Dragan; Kopahnke, Doris; Pillen, Klaus
The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM) was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars. PMID:29370232
Full Text Available The biotrophic rust fungi Puccinia hordei and Puccinia striiformis are important barley pathogens with the potential to cause high yield losses through an epidemic spread. The identification of QTL conferring resistance to these pathogens is the basis for targeted breeding approaches aiming to improve stripe rust and leaf rust resistance of modern cultivars. Exploiting the allelic richness of wild barley accessions proved to be a valuable tool to broaden the genetic base of resistance of barley cultivars. In this study, SNP-based nested association mapping (NAM was performed to map stripe rust and leaf rust resistance QTL in the barley NAM population HEB-25, comprising 1,420 lines derived from BC1S3 generation. By scoring the percentage of infected leaf area, followed by calculation of the area under the disease progress curve and the average ordinate during a two-year field trial, a large variability of resistance across and within HEB-25 families was observed. NAM based on 5,715 informative SNPs resulted in the identification of twelve and eleven robust QTL for resistance against stripe rust and leaf rust, respectively. Out of these, eight QTL for stripe rust and two QTL for leaf rust are considered novel showing no overlap with previously reported resistance QTL. Overall, resistance to both pathogens in HEB-25 is most likely due to the accumulation of numerous small effect loci. In addition, the NAM results indicate that the 25 wild donor QTL alleles present in HEB-25 strongly differ in regard to their individual effect on rust resistance. In future, the NAM concept will allow to select and combine individual wild barley alleles from different HEB parents to increase rust resistance in barley. The HEB-25 results will support to unravel the genetic basis of rust resistance in barley, and to improve resistance against stripe rust and leaf rust of modern barley cultivars.
Wichmann, Fabienne; Asp, Torben; Widmer, Franko
Xanthomonas translucens pv. graminis (Xtg) causes bacterial wilt, a severe disease of forage grasses such as Italian ryegrass (Lolium multiflorum Lam.). In order to gain a more detailed understanding of the genetic control of resistance mechanisms and to provide prerequisites for marker assisted...... selection, the partial transcriptomes of two Italian ryegrass genotypes, one resistant and one susceptible to bacterial wilt were compared at four time points after Xtg infection. A cDNA microarray developed from a perennial ryegrass (Lolium perenne) expressed sequence tag set consisting of 9,990 unique...
Full Text Available Durante el crecimiento y desarro- llo de las flores, la nutrición fosforada es un factor que puede influir en la vida en flore- ro. El objetivo de este trabajo fue evaluar el efecto de cinco niveles de fósforo (P: 0, 0.5, 1.0, 1.5 y 2.0 me·L-1 de P aplicados en precosecha, mediante un sistema hidropóni- co abierto, en el comportamiento fisiológico postcosecha de tallos florales de rosa (Rosa hybrida L. ‘Classy’ y ‘Vega’. Las variables evaluadas durante la vida de florero de los tallos florales fueron: transpiración foliar y floral, potencial de turgencia foliar y de pétalos. Además, se evaluó la concentración de antocianinas en pétalos al momento de la cosecha. Las aplicaciones de P en precose- cha tuvieron efecto significativo únicamente en la transpiración foliar; sin embargo, se demostró que la mayor vida en florero (15.8 días de ‘Classy’ en comparación con ‘Vega’ (11.7 días estuvo directamente asociada con mayores potenciales de turgencia foliar y de pétalos, mayor tasa transpiratoria floral y menor tasa transpiratoria foliar en ‘Classy’.
Tallo, Ivar, 1964-
Autori arvates vähendavad meedias levitatavad süüdistused president Toomas Hendrik Ilvese Ärma talu ümber toimuva suhtes presidendi väga olulist võimet eetika teemadel sõna võtta. Riigile oleks vajalik eetikakoja loomine, kuhu saaksid pöörduda need, kelle tegevusele hinnangu andmine on põhjustanud kriisi avalikus arvamuses
Rodrigo N. Graca; Amy L. Ross-Davis; Ned B. Klopfenstein; Mee-Sook Kim; Tobin L. Peever; Phil G. Cannon; Cristina P. Aun; Eduardo G. Mizubuti; Acelino C. Alfenas
The rust fungus, Puccinia psidii, is a devastating pathogen of introduced eucalypts (Eucalyptus spp.) in Brazil where it was first observed in 1912. This pathogen is hypothesized to be endemic to South and Central America and to have first infected eucalypts via a host jump from native guava (Psidium guajava). Ten microsatellite markers were used to genotype 148 P....
Niks, R.E.; Heyzen, van S.; Szabo, L.J.; Alemu, S.K.
The pathogenicity and identity was studied of a field sample (PcE) of crown rust fungus Puccinia coronata collected in Hungary on wild couch grass (Elymus repens) and of a field sample (Psb) of stripe rust (P. striiformis) collected in the Netherlands on California brome (Bromus carinatus). We
Barbieri, M.; Marcel, T.C.; Niks, R.E.; Francia, E.; Pasquariello, M.; Mazzamurro, V.; Garvin, D.F.; Pecchioni, N.
The potential of the model grass Brachypodium distachyon L. (Brachypodium) for studying grass–pathogen interactions is still underexploited. We aimed to identify genomic regions in Brachypodium associated with quantitative resistance to the false brome rust fungus Puccinia brachypodii. The inbred
The pathogenicity and identity of a field sample (PcE) of crown rust fungus Puccinia coronata collected in Hungary on wild couch grass (Elytrigia repens) and of a field sample (Psb) of stripe rust (P. striiformis) collected in the Netherlands on California brome (Bromus carinatus) was studied. We fo...
Puccinia striiformis causes stripe rust on wheat, barley, and grasses. Natural population studies have indicated that somatic recombination plays a possible role in the pathogen variation. To determine if somatic recombination can occur, susceptible wheat or barley plants were inoculated with mixe...
Amy L. Ross-Davis; Rodrigo N. Graca; Acelino C. Alfenas; Tobin L. Peever; Jack W. Hanna; Janice Y. Uchida; Rob D. Hauff; Chris Y. Kadooka; Mee-Sook Kim; Phil G. Cannon; Shigetou Namba; Nami Minato; Sofia Simeto; Carlos A. Perez; Min B. Rayamajhi; Mauricio Moran; D. Jean Lodge; Marcela Arguedas; Rosario Medel-Ortiz; M. Armando Lopez-Ramirez; Paula Tennant; Morag Glen; Ned B. Klopfenstein
Puccinia psidii Winter (Basidiomycota, Uredinales) is a biotrophic rust fungus that was first reported in Brazil from guava in 1884 (Psidium guajava; Winter 1884) and later from eucalypt in 1912 (Joffily 1944). Considered to be of neotropical origin, the rust has also been reported to infect diverse myrtaceous hosts elsewhere in South America, Central America, the...
N. B. Klopfenstein; J. W. Hanna; R. N. Graca; A. L. Ross-Davis; P. G. Cannon; A. C. Alfenas; M. -S. Kim
Puccinia psidii is the cause of Eucalyptus/guava/myrtle rust disease of many host species in the Myrtaceae family, including guava (Psidium spp.), eucalypt (Eucalyptus spp.), rose apple (Syzygium jambos), and ohia (Metrosideros polymorpha) (Farr and Rossman 2010). First reported in 1884 on guava in Brazil (Maclachlan 1938), the rust has since been detected in other...
Sørensen, Chris Khadgi; Justesen, Annemarie Fejer; Hovmøller, Mogens Støvring
Differentiation of haustoria on primary infection hyphae of the fungal pathogen Puccinia striiformis was studied in wheat seedlings with two-photon microscopy in combination with a classical staining technique. Our results showed a significant increase in the average haustorium size 22, 44, 68, 92...
Sugarcane is susceptible to infection by two rust pathogens, Puccinia melanocephala and P. kuehnii, causing brown and orange rust, respectively. Orange rust of sugarcane was first reported in the Western hemisphere in Florida in July 2007. The pathogen was found to be distributed widely throughout t...
Collections of Puccinia triticina, the wheat leaf rust pathogen, were obtained from Pakistan in 2008, 2010, 2011, 2013, and 2014. Collections were also obtained from Bhutan in 2013. Single uredinial isolates were derived and tested for virulence phenotype to 20 lines of Thatcher wheat that differ fo...
The Portuguese durum landraces, Aus26582 and Aus26579, showed resistance against two very different durum-specific Puccinia triticina (Pt) races CA 1.2 and ETH 12.5-2 collected from California and Ethiopia, respectively. Aus26582 and Aus26579 were crossed with a susceptible landrace Bansi to develop...
Tartu linnapeakandidaadid Ivar Tallo, Teet Jagomägi, Jüri Kumar, Malle Salupere, Tõni Kauba, Tõnis Lukas ja Andrus Ansip vastavad küsimustele : Tartu Ülikooli arenguvõimalustest ja -vajadustest, konkurentsivõime suurendamisest / vahendasid Sander Silm, Priit Rajalo, Ivi Drikkit
Laar, van de J.H.J.
Due to the increasing importance of the wheat disease 'tarwehalmdoder' in the Netherlands, research was started on its occurrence and cause. An extensive literature review proved the identity of 'tarwehalmdoder' with take-all or whiteheads, which were caused by 0. graminis. The symptoms of the
Haugaard, H.; Collinge, D.B.; Lyngkjær, Michael Foged
associated with papilla formation was detected. However, a post-penetration effect was observed, as B. graminis colonies on mycelial extract-treated leaves produced 50% fewer hyphae than on controls. Northern blot analyses showed earlier accumulation of defence-related gene transcripts following treatment...
Damgaard, C.; Giese, Nanna Henriette
Genetic variation of the barley powdery mildew fungus (Erysiphe graminis f.sp. hordei) was estimated in three Danish local populations. Genetic variation was estimated from the variation amongst clones of Egh, and was therefore an estimate of the maximum genetic variation in the local populations...
Roberta M.N. Peil
Full Text Available El cultivo de tomate en primavera con baja densidad inicial de plantas y luego aumentar-se la densidad efectiva mediante el desarrollo de tallos laterales, cuando las integrales diarias de radiación son altas, parece ser una manera prometedora de incrementar el número de frutos m-2 y uniformizar el tamaño del fruto; y presenta la ventaja adicional de requerir-se un menor número de plantas para la superficie de cultivo. Por lo tanto, se ha llevado a cabo un ensayo cuyo objetivo ha sido evaluar los efectos de la densidad de tallos sobre el rendimiento y la uniformidad de los frutos de un cultivo de tomate injertado y no injertado. El cultivo se realizó de marzo a julio de 1998, en las condiciones de invernadero en Almería (sudeste español. La densidad inicial de plantación fue de 2,4 y 3,0 plantas m-2, en el caso de las plantas no injertadas, que presentaban un único tallo en el transplante; y 1,2 plantas m-2 en las plantas injertadas, que tenían dos tallos (2,4 tallos m-2. A partir del mes de abril, mediante el desarrollo de tallos laterales (cuando el tratamiento así lo exigía se pasó a tener las siguientes densidades: 2,4; 3,0 y 3,5 tallos m-2 (plantas injertadas y no injertadas; y 3,0 plantas no injertadas m-2 a un tallo durante todo el ciclo. Los resultados muestran que plantas de tomate injertadas y transplantadas a dos tallos tuvieron igual producción total, pero frutos de tamaño más uniforme, que plantas no injertadas transplantadas a un tallo y con doble densidad de plantas. Dentro del rango de 2,4 a 3,5 tallos m-2, una mayor densidad de tallos aumentó la producción precoz y dio un tamaño más uniforme de frutos, no afectando su peso promedio y la producción total. La adición de tallos laterales (3,0 tallos m-2 supuso una reducción de un 20% en el rendimiento total, pero vino acompañada por un ahorro de un 21% y de un 39% en el número de plantas no injertadas e injertadas, respectivamente, necesarias para la misma
Full Text Available Conidia of the obligate biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt play a vital role in its survival and rapid dispersal. However, little is known about the genetic basis for its asexual reproduction. To uncover the primary metabolic and regulatory events during conidiation, we sequenced the transcriptome of Bgt epiphytic structures at 3 (vegetative hyphae growth, 4 (foot cells initiation, and 5 (conidiophore erection days post-inoculation (dpi. RNA-seq analyses identified 556 and 404 (combined 685 differentially expressed genes (DEGs at 4 and 5 dpi compared with their expression levels at 3 dpi, respectively. We found that several genes involved in the conversion from a variety of sugars to glucose, glycolysis, the tricarboxylic acid cycle (TAC, the electron transport chain (ETC, and unsaturated fatty acid oxidation were activated during conidiation, suggesting that more energy supply is required during this process. Moreover, we found that glucose was converted into glycogen, which was accumulated in developing conidiophores, indicating that it could be the primary energy storage molecule in Bgt conidia. Clustering for the expression profiles of 91 regulatory genes showed that calcium (Ca2+, H2O2, and phosphoinositide (PIP signaling were involved in Bgt conidiation. Furthermore, a strong accumulation of H2O2 in developing conidiophores was detected. Application of EGTA, a Ca2+ chelator, and trifluoperazine dihydrochloride (TFP, a calmodulin (CaM antagonist, markedly suppressed the generation of H2O2, affected foot cell and conidiophore development and reduced conidia production significantly. These results suggest that Ca2+ and H2O2 signaling play important roles in conidiogenesis and a crosslink between them is present. In addition to some conidiation-related orthologs known in other fungi, such as the velvet complex components, we identified several other novel B. graminis-specific genes that have not been previously
Milus, Eugene A; Kristensen, Kristian; Hovmøller, Mogens S
Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based on vir...... that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments......Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based...... regimes for latent period, lesion length, lesion width, lesion area, and spore production on adult plants of a susceptible wheat cultivar with no known genes for resistance to stripe rust. "New" isolates (since 2000) were significantly more aggressive than "old" isolates (before 2000) for all variables...
María I. Oloriz; Luis Rojas; Víctor Gil; Orelvis Portal; Elio Jiménez
Induction of mutations is an alternative for genetic improvement of sugarcane (Saccharum spp. hybrid). It has been used to obtain mutants with resistance to rust (Puccinia melanocephala). Characteristics of pathogen infection process were identified through histopathological studies in a mutant (IBP 8518) of the B4362 variety, with resistance to this disease. Fragments of leaves were inoculated with P. melanocephala . Then, these were stained with lactophenol tripan blue to observe, in the op...
Full Text Available Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76% and T. longibrachiatum (52.38% respectively.
Rust diseases caused by Puccinia spp. pose a major threat to global wheat production. Puccinia triticina (Pt), an obligate basidiomycete biotroph, causes leaf rust disease which incurs yield losses of up to 50% in wheat. Historically, resistant wheat cultivars have been used to control leaf rust, bu...
Stem rust caused by Puccinia graminis f.sp tritici Erik. & E. Henn. is a highly destructive disease of wheat (Triticum aestivum L.). The effects of fungicide application on stem rust (Puccinia graminis tritici) epidemics and yield of three bread wheat varieties varying in reaction to the disease were studied in two major wheat ...
Full Text Available Two novel endophytic yeast strains, WP1 and PTD3, isolated from within the stems of poplar (Populus trees, were genetically characterized with respect to their xylose metabolism genes. These two strains, belonging to the species Rhodotorula graminis and R. mucilaginosa, respectively, utilize both hexose and pentose sugars, including the common plant pentose sugar, D-xylose. The xylose reductase (XYL1 and xylitol dehydrogenase (XYL2 genes were cloned and characterized. The derived amino acid sequences of xylose reductase (XR and xylose dehydrogenase (XDH were 32%~41% homologous to those of Pichia stipitis and Candida. spp., two species known to utilize xylose. The derived XR and XDH sequences of WP1 and PTD3 had higher homology (73% and 69% identity with each other. WP1 and PTD3 were grown in single sugar and mixed sugar media to analyze the XYL1 and XYL2 gene regulation mechanisms. Our results revealed that for both strains, the gene expression is induced by D-xylose, and that in PTD3 the expression was not repressed by glucose in the presence of xylose.
Full Text Available Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt. In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous “Mapuche” communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.
Mandal, Md Siddikun Nabi; Fu, Ying; Zhang, Sheng; Ji, Wanquan
Powdery mildew of wheat is caused by Blumeria graminis f. sp. tritici (Bgt). Although many wheat cultivars resistant to this disease have been developed, little is known about their resistance mechanisms. The aim of this study was to identify proteins showing changes in abundance during the resistance response of the wheat line N0308 infected by Bgt. In two-dimensional electrophoresis analyses, 45 spots on the gels showed significant changes in abundance at 24, 48, and 72 h after inoculation, as compared to non-inoculated plants. Of these 45 proteins, 44 were identified by mass spectrometry analysis using the NCBInr database of Triticum aestivum (26 spots) and closely related species in the Triticum genus (18 spots). These proteins were associated with the defense response, photosynthesis, metabolism, and other cellular processes in wheat. Most of the up-regulated proteins were identified as stress- and defense-related proteins. In particular, the product of a specific powdery mildew resistance gene (Pm3b and its homolog) and some other defense- and pathogenesis-related proteins were overexpressed. The resistance gene product mediates the immune response and coordinates other cellular processes during the resistance response to Bgt.
Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion, Victor J; Mora, María de la Luz; Pozo, María J
Wheat production around the world is severely compromised by the occurrence of "take-all" disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous "Mapuche" communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.
Full Text Available Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst is an important disease on wheat. In this study, quantitative determination of germinability of Pst urediospores was investigated by using near infrared reflectance spectroscopy (NIRS combined with quantitative partial least squares (QPLS and support vector regression (SVR. The near infrared spectra of the urediospore samples were acquired using FT-NIR MPA spectrometer and the germination rate of each sample was measured using traditional spore germination method. The best QPLS model was obtained with vector correction as the preprocessing method of the original spectra and 4000–12000 cm−1 as the modeling spectral region while the modeling ratio of the training set to the testing set was 4 : 1. The best SVR model was built when vector normalization was used as the preprocessing method, the modeling ratio was 5 : 1 and the modeling spectral region was 8000–11000 cm−1. The results showed that the effect of the best model built using QPLS or SVR was satisfactory. This indicated that quantitative determination of germinability of Pst urediospores using near infrared spectroscopy technology is feasible. A new method based on NIRS was provided for rapid, automatic, and nondestructive determination of germinability of Pst urediospores.
On testing mutant lines in M 12 , M 13 and M 14 generations derived from cultivar San Pastore, after treatment by gamma rays for the resistance to Puccinia recondita tritici, certain resistance was found which was expressed in lower severity, type of infection and modification of tolerance between and within the lines. The mutant lines of the resistance type 0/1, 0/4T and type 4 lines of moderate tolerance, were selected. The tolerance expressed as the kernel weight per spike on rusted/non-rusted plot, was about 1 for groups 0/1 and 0/4T compared with control which had a tolerance of 0.95. Group 4 had the same tolerance as control. The tolerance expressed by weight of 1000 kernels was 0.94 for group 0/1, 0.96 for group 0/4T, and 0.90 for control. For group 4, it was 0.87, the same as the control. On considering these results, it seems much easier and more efficient to select for type of resistance and low severity than for tolerance. (author)
Peixoto-Junior, R F; Creste, S; Landell, M G A; Nunes, D S; Sanguino, A; Campos, M F; Vencovsky, R; Tambarussi, E V; Figueira, A
Brown rust (causal agent Puccinia melanocephala) is an important sugarcane disease that is responsible for large losses in yield worldwide. Despite its importance, little is known regarding the genetic diversity of this pathogen in the main Brazilian sugarcane cultivation areas. In this study, we characterized the genetic diversity of 34 P. melanocephala isolates from 4 Brazilian states using loci identified from an enriched simple sequence repeat (SSR) library. The aggressiveness of 3 isolates from major sugarcane cultivation areas was evaluated by inoculating an intermediately resistant and a susceptible cultivar. From the enriched library, 16 SSR-specific primers were developed, which produced scorable alleles. Of these, 4 loci were polymorphic and 12 were monomorphic for all isolates evaluated. The molecular characterization of the 34 isolates of P. melanocephala conducted using 16 SSR loci revealed the existence of low genetic variability among the isolates. The average estimated genetic distance was 0.12. Phenetic analysis based on Nei's genetic distance clustered the isolates into 2 major groups. Groups I and II included 18 and 14 isolates, respectively, and both groups contained isolates from all 4 geographic regions studied. Two isolates did not cluster with these groups. It was not possible to obtain clusters according to location or state of origin. Analysis of disease severity data revealed that the isolates did not show significant differences in aggressiveness between regions.
Crude extracts of Drimys winteri bark to inhibit growth of Gaeumannomyces graminis var. tritici Inhibición del crecimiento de Gaeumannomyces graminis var. tritici empleando extractos obtenidos de corteza de Drimys winteri
Full Text Available The aim of this study was to assess the effect of Drimys winteri J.R. Forst. & G. Forst. bark and its extracts, obtained sequentially with n-hexane, acetone, and methanol, against Gaeumannomyces graminis var. tritici (Ggt. Ground bark of D. winteri was mixed with potato dextrose agar growth media at concentrations of 250, 500, 1000, 2000, and 4000 mg L-1 in Petri plates. Each extract was mixed at concentrations of 100, 200, 400, and 800 mg L-1. Petri plates were inoculated in the center with a 5-mm mycelium disk and were incubated at 24 ± 1 ºC. Daily measurements of mycelium radial growth were taken to determine growth rate and growth inhibition (%. A ground bark concentration of 978 mg L-1 was needed to inhibit Ggt growth by 50%, while extracts obtained with n-hexane and acetone only required 198 and 234 mg L-1, respectively. The methanol extract only inhibited Ggt growth by 33% when tested at the highest concentration. In conclusion, ground bark and crude extracts, obtained sequentially with n-hexane, acetone, and methanol, from D. winteri bark inhibit Ggt growth when applied in vitro. The n-hexane extract showed the highest inhibitory growth activity.El objetivo de esta investigación fue evaluar la actividad de la corteza de Drimys winteri J.R Forst. & G. Forst. y sus extractos obtenidos secuencialmente con n-hexano, acetona y metanol sobre el crecimiento in vitro de Gaeumannomyces graminis var. tritici (Ggt. Con este propósito se mezclaron en placas Petri, corteza molida de D. winteri con medio de crecimiento agar papa dextrosa a concentraciones de 250, 500, 1000, 2000 y 4000 mg L-1. Cada extracto fue mezclado a concentraciones de 100, 200, 400 y 800 mg L-1. Las placas se inocularon en su centro con un disco de 5 mm de micelio de Ggt y se incubaron a 24 ± 1 ºC. Diariamente se midió el crecimiento radial del micelio, se determinó velocidad de crecimiento e índice de inhibición del crecimiento (%. Para inhibir el crecimiento de Ggt
Full Text Available Se propone un criterio metodológico para estudiar el desarrollo de tallos permineralizados, aplicado en el análisis de los patrones evolutivos-del desarrollo de los ejes caulinares de las Corystospermaceae, familia de "pteridospermas" dominante en las paleofloras triásicas gondwánicas. Este grupo representa un excelente caso de estudio dado que sus tallos se preservan permineralizados, por lo que exhiben detalles celulares e histológicos, y, asimismo, su ontogenia entera puede ser examinada en un solo ejemplar debido a que las células del xilema y floema secundario son producidas en capas sucesivas que retienen su posición de manera permanente. En los estudios ontogenéticos de pteridospermas los mecanismos reguladores del desarrollo deben ser discernidos por medio de la comparación con ontogenias de plantas vivientes comparables. Esta extrapolación es posible ya que se sabe que los procesos reguladores del crecimiento secundario son homólogos en todas las lignofitas. Los troncos de las corystospermas presentan un cilindro vascular secundario disecto y tejidos vasculares de desarrollo y posición inusuales, lo que es causado por cuatro clases de desviación de la actividad cambial típica: 1- actividad diferencial; 2- actividad remanente; 3- cámbium inverso o centrípeto; y 4- cámbiumes sucesivos inversos y/o normales (polixilia. El origen de estas variantes del cámbium está intimamente vinculado con eventos heterotópicos, incluyendo la homeosis. Al comparar con estudios de plantas vivientes, se teoriza que los genes homéoticos implicados en estos eventos podrían ser aquellos relacionados con el inicio de la actividad cambial, la diferenciación de las células vasculares y la organización de los haces vasculares.A methodological critera to study the development of permineralized stems is proposed, which is applied in the analysis of the evo-devo patterns of Corystospermaceae axes, the most important Mesozoic seed fern family
Zhang, R; Ma, Z H; Wu, B M
Biotrophic fungi, such as Puccinia striiformis f. sp. tritici, because they cannot be cultured on nutrient media, to obtain adequate quantity of DNA for molecular genetic analysis, are usually propagated on living hosts, wheat plants in case of P. striiformis f. sp. tritici. The propagation process is time-, space- and labor-consuming and has been a bottleneck to molecular genetic analysis of this pathogen. In this study we evaluated multiple displacement amplification (MDA) of pathogen genomic DNA from urediospores as an alternative approach to traditional propagation of urediospores followed by DNA extraction. The quantities of pathogen genomic DNA in the products were further determined via real-time PCR with a pair of primers specific for the β-tubulin gene of P. striiformis f. sp. tritici. The amplified fragment length polymorphism (AFLP) fingerprints were also compared between the DNA products. The results demonstrated that adequate genomic DNA at fragment size larger than 23 Kb could be amplified from 20 to 30 urediospores via MDA method. The real-time PCR results suggested that although fresh urediospores collected from diseased leaves were the best, spores picked from diseased leaves stored for a prolonged period could also be used for amplification. AFLP fingerprints exhibited no significant differences between amplified DNA and DNA extracted with CTAB method, suggesting amplified DNA can represent the pathogen's genomic DNA very well. Therefore, MDA could be used to obtain genomic DNA from small precious samples (dozens of spores) for molecular genetic analysis of wheat stripe rust pathogen, and other fungi that are difficult to propagate.
Oloriz, María I; Gil, Víctor; Rojas, Luis; Portal, Orelvis; Izquierdo, Yovanny; Jiménez, Elio; Höfte, Monica
Brown rust caused by the fungus Puccinia melanocephala is a major disease of sugarcane (Saccharum spp.). A sugarcane mutant, obtained by chemical mutagenesis of the susceptible variety B4362, showed a post-haustorial hypersensitive response (HR)-mediated resistance to the pathogen and was used to identify genes differentially expressed in response to P. melanocephala via suppression subtractive hybridization (SSH). Tester cDNA was derived from the brown rust-resistant mutant after inoculation with P. melanocephala, while driver cDNAs were obtained from the non-inoculated resistant mutant and the inoculated susceptible donor variety B4362. Database comparisons of the sequences of the SSH recombinant clones revealed that, of a subset of 89 non-redundant sequences, 88% had similarity to known functional genes, while 12% were of unknown function. Thirteen genes were selected for transcript profiling in the resistant mutant and the susceptible donor variety. Genes involved in glycolysis and C4 carbon fixation were up-regulated in both interactions probably due to disturbance of sugarcane carbon metabolism by the pathogen. Genes related with the nascent polypeptide associated complex, post-translational proteome modulation and autophagy were transcribed at higher levels in the compatible interaction. Up-regulation of a putative L-isoaspartyl O-methyltransferase S-adenosylmethionine gene in the compatible interaction may point to fungal manipulation of the cytoplasmatic methionine cycle. Genes coding for a putative no apical meristem protein, S-adenosylmethionine decarboxylase, non-specific lipid transfer protein, and GDP-L-galactose phosphorylase involved in ascorbic acid biosynthesis were up-regulated in the incompatible interaction at the onset of haustorium formation, and may contribute to the HR-mediated defense response in the rust-resistant mutant.
Gill, Upinder S; Uppalapati, Srinivasa R; Nakashima, Jin; Mysore, Kirankumar S
Switchgrass rust, caused by Puccinia emaculata, is an important disease of switchgrass, a potential biofuel crop in the United States. In severe cases, switchgrass rust has the potential to significantly affect biomass yield. In an effort to identify novel sources of resistance against switchgrass rust, we explored nonhost resistance against P. emaculata by characterizing its interactions with six monocot nonhost plant species. We also studied the genetic variations for resistance among Brachypodium inbred accessions and the involvement of various defense pathways in nonhost resistance of Brachypodium. We characterized P. emaculata interactions with six monocot nonhost species and identified Brachypodium distachyon (Bd21) as a suitable nonhost model to study switchgrass rust. Interestingly, screening of Brachypodium accessions identified natural variations in resistance to switchgrass rust. Brachypodium inbred accessions Bd3-1 and Bd30-1 were identified as most and least resistant to switchgrass rust, respectively, when compared to tested accessions. Transcript profiling of defense-related genes indicated that the genes which were induced in Bd21after P. emaculata inoculation also had higher basal transcript abundance in Bd3-1 when compared to Bd30-1 and Bd21 indicating their potential involvement in nonhost resistance against switchgrass rust. In the present study, we identified Brachypodium as a suitable nonhost model to study switchgrass rust which exhibit type I nonhost resistance. Variations in resistance response were also observed among tested Brachypodium accessions. Brachypodium nonhost resistance against P. emaculata may involve various defense pathways as indicated by transcript profiling of defense related genes. Overall, this study provides a new avenue to utilize novel sources of nonhost resistance in Brachypodium against switchgrass rust.
Full Text Available Wheat leaf rust, caused by the basidiomycete Puccinia triticina, can cause yield losses of up to 20% in wheat producing regions. During infection, the fungus forms haustoria that secrete proteins into the plant cell and effect changes in plant transcription, metabolism and defense. It is hypothesized that new races emerge as a result of overcoming plant resistance via changes in the secreted effector proteins. To understand gene expression during infection and find genetic differences associated with races, RNA from wheat leaves infected with six different rust races, at six days post inoculation, was sequenced using Illumina. As P. triticina is an obligate biotroph, RNA from both the host and fungi were present and separated by alignment to the P. triticina genome and a wheat EST reference. A total of 222,571 rust contigs were assembled from 165 million reads. An examination of the resulting contigs revealed 532 predicted secreted proteins among the transcripts. Of these, 456 were found in all races. Fifteen genes were found with amino acid changes, corresponding to putative avirulence effectors potentially recognized by 11 different leaf rust resistance (Lr genes. Thirteen of the potential avirulence effectors have no homology to known genes. One gene had significant similarity to cerato-platanin, a known fungal elicitor, and another showed similarity to fungal tyrosinase, an enzyme involved in melanin synthesis. Temporal expression profiles were developed for these genes by qRT-PCR and show that the 15 genes share similar expression patterns from infection initiation to just prior to spore eruption.
Carver, T.L.W.; Lyngkjær, M.F.; Neyron, L.
graminis DC.). Successful penetration and haustorium formation by the inducer rendered living epidermal cells highly accessible to later challenge attack as judged by increased frequency of challenge penetration success compared to controls. Conversely, where failure of inducer attack on living epidermal......First-formed (seedling) and later-formed leaves of oat cvs Selma (susceptible) and Maldwyn (adult plant resistance under complex genetic control) were subjected to a double inoculation procedure ('inducer' followed by 'challenger') with conidia of Blumeria graminis (DC.) Speer (Syn. Erysiphe......, suggesting that induced changes in (in)accessibility may be a common consequence of B. graminis attack in cereals. As expected, in Maldwyn, cell death was a consistent but infrequent response to attack (5-20%, of attacks caused cell death in controls). Here, the successful formation of an inducer haustorium...
Full Text Available Se determinaron las variaciones patogÃ©nica e isoenzimÃ¡tica de aislamientos de Fusarium spp. asociadas con la pudriciÃ³n de tallo y raÃz de un cultivar de vainilla en la regiÃ³n del Totonacapan, Veracruz, MÃ©xico. Los patrones de patogenicidad y los perfiles de bandas esterasas de los aislamientos evaluados demostraron que no sÃ³lo existe variabilidad morfolÃ³gica y patogÃ©nica, sino tambiÃ©n un alto grado de variabilidad bioquÃmica dentro de los hongos causantes de la pudriciÃ³n de tallo de Vanilla planifolia Jacks. ex Andrews. La producciÃ³n de algunas esterasas (banda Rf = 0.75 al parecer estÃ¡ asociada con el grado de patogenicidad de los hongos, ya que no se detectÃ³ su presencia en los aislamientos que resultaron no patogÃ©nicos para este cultivo. Este marcador bioquÃmico podrÃa ser una alternativa rÃ¡pida, confiable y econÃ³mica, con relaciÃ³n a otras tecnologÃas moleculares ya establecidas para evaluar el grado de patogenicidad de Fusarium spp. en V. planifolia, asÃ como de otras especies o razas de este gÃ©nero, causantes de la pudriciÃ³n de tallo y raÃz en el cultivo.
Costa,Sara Macías de; Montenegro,Mariana A.; Arregui,Teresa; Pinto,M. Inés Sánchez de; Nazareno,Mónica A.; Mishima,Beatriz López de
Se realizaron estudios de caracterización integral de acelga (Beta vulgaris, var. cycla) cultivada en la Provincia de Santiago del Estero, Argentina. Por tratarse de un vegetal de importante consumo regional, se realizó la determinación de sus constituyentes básicos, minerales y pigmentos para conocer los valores nutricionales que aporta este alimento en nuestra región. Se analizaron comparando hoja y tallo: humedad, cenizas, proteínas, grasas, hidratos de carbono utilizables, fibra dietaria ...
Quecine, Maria Carolina; Leite, Thiago Falda; Bini, Andressa Peres; Regiani, Thais; Franceschini, Lívia Maria; Budzinski, Ilara Gabriela Frasson; Marques, Felipe Garbelini; Labate, Mônica Teresa Veneziano; Guidetti-Gonzalez, Simone; Moon, David Henry; Labate, Carlos Alberto
Puccinia psidii sensu lato (s.l.) is the causal agent of eucalyptus and guava rust, but it also attacks a wide range of plant species from the myrtle family, resulting in a significant genetic and physiological variability among populations accessed from different hosts. The uredospores are crucial to P. psidii dissemination in the field. Although they are important for the fungal pathogenesis, their molecular characterization has been poorly studied. In this work, we report the first in-depth proteomic analysis of P. psidii s.l. uredospores from two contrasting populations: guava fruits (PpGuava) and eucalyptus leaves (PpEucalyptus). NanoUPLC-MSE was used to generate peptide spectra that were matched to the UniProt Puccinia genera sequences (UniProt database) resulting in the first proteomic analysis of the phytopathogenic fungus P. psidii. Three hundred and fourty proteins were detected and quantified using Label free proteomics. A significant number of unique proteins were found for each sample, others were significantly more or less abundant, according to the fungal populations. In PpGuava population, many proteins correlated with fungal virulence, such as malate dehydrogenase, proteossomes subunits, enolases and others were increased. On the other hand, PpEucalyptus proteins involved in biogenesis, protein folding and translocation were increased, supporting the physiological variability of the fungal populations according to their protein reservoirs and specific host interaction strategies.
Maria Carolina Quecine
Full Text Available Puccinia psidii sensu lato (s.l. is the causal agent of eucalyptus and guava rust, but it also attacks a wide range of plant species from the myrtle family, resulting in a significant genetic and physiological variability among populations accessed from different hosts. The uredospores are crucial to P. psidii dissemination in the field. Although they are important for the fungal pathogenesis, their molecular characterization has been poorly studied. In this work, we report the first in-depth proteomic analysis of P. psidii s.l. uredospores from two contrasting populations: guava fruits (PpGuava and eucalyptus leaves (PpEucalyptus. NanoUPLC-MSE was used to generate peptide spectra that were matched to the UniProt Puccinia genera sequences (UniProt database resulting in the first proteomic analysis of the phytopathogenic fungus P. psidii. Three hundred and fourty proteins were detected and quantified using Label free proteomics. A significant number of unique proteins were found for each sample, others were significantly more or less abundant, according to the fungal populations. In PpGuava population, many proteins correlated with fungal virulence, such as malate dehydrogenase, proteossomes subunits, enolases and others were increased. On the other hand, PpEucalyptus proteins involved in biogenesis, protein folding and translocation were increased, supporting the physiological variability of the fungal populations according to their protein reservoirs and specific host interaction strategies.
Chandra, Amaresh; Keizerweerd, Amber T; Grisham, Michael P
Puccinia kuehnii is a fungal pathogen that causes orange rust in sugarcane, which is now prevalent in many countries. At the early stage of disease, it is almost indistinguishable from brown rust, which is caused by Puccinia melanocephala. Although several PCR assays are available to detect these diseases, the loop-mediated isothermal amplification (LAMP)-based assay has been reported to be more economical and easier to perform. Under isothermal conditions, DNA is amplified with high specificity and rapidity. Moreover, visual judgment of color change without further post-amplification processing makes the method convenient. The present study was undertaken to detect P. kuehnii genomic DNA using four primers corresponding to a unique DNA sequence of P. kuehnii. The LAMP assay was found to be optimal when 8 mM MgSO4 was used and the reaction was incubated at 63 °C for 90 min. Positive samples showed a color change from orange to green upon SYBR Green I dye addition. Specificity of the LAMP test was checked with DNA of P. melanocephala, which showed no reaction. Sensitivity of the LAMP method was observed to be the same as real-time PCR at 0.1 ng, thus providing a rapid and more affordable option for early disease detection.
Sørensen, Chris Khadgi; Justesen, Annemarie Fejer; Hovmøller, Mogens Støvring
Fitness costs associated with the emergence of virulence (loss of avirulence) have been a subject of much debate in plant pathology. Here, differences in fitness between two pairs of wild types and spontaneous virulence mutants in Puccinia striiformis were studied. The mutants differed from...
Leaf rust, caused by Puccinia triticina is the most prevalent and widespread disease of wheat in South America. The objective of this study was to determine the number of genetically differentiated groups of P. triticina that are currently present in South America, and to compare the South American ...
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat (Triticum aestivum) worldwide. Wheat high-temperature seedling-plant (HTSP) resistance to Pst is non-race-specific and durable. WRKY transcription factors have proven to play important roles in ...
Oat crown rust, caused by the fungus Puccinia coronata f. sp. avenae (Pca), is a devastating disease that impacts worldwide oat production. For much of its life cycle Pca is dikaryotic with two separate haploid nuclei that may vary in virulence genotypes, which highlights the importance of understan...
Walter, Stephanie; Kemen, Eric; Brown, James K. M.
New genomic and transcriptomic methods greatly facilitate the study of the biology and evolution of fungal plant pathogens. The obligate biotrophic and asexually reproducing rust fungus Puccinia striiformis f.sp. tritici (Pst) forms haustoria during plant infection and delivers proteins and other...
Thach, T.; Ali, S.; Justesen, A. F.
A unique collection of spore samples of Puccinia striiformis, often referred to as the ‘Stubbs collection’, has been stored in liquid nitrogen from 18 to 45 years. A subset of samples representing 35 countries and 28 years was investigated to assess recovery rate, race identity and previously...
Puccinia triticina, Puccinia graminis and Puccinia striiformis cause leaf, stem and yellow rust, respectively. Wheat rusts can cause losses as high as 70%. The rusts ability to evolve fungicide resistance has resulted in the use of resistant cultivars as the primary method of control. Breeding resistant cultivars is a long process ...
Full Text Available Abstract Background Puccinia striiformis f. sp. tritici is an obligate biotrophic pathogen that causes leaf stripe rust on wheat. Although it is critical to understand molecular mechanisms of pathogenesis in the wheat stripe rust fungus for developing novel disease management strategies, little is known about its genome and gene functions due to difficulties in molecular studies with this important pathogen. To identify genes expressed during early infection stages, in this study we constructed a cDNA library with RNA isolated from urediniospores of P. striiformis f. sp. tritici germinated for 10 h. Results A total of 4798 ESTs were sequenced from the germinated urediniospore library and assembled into 315 contigs and 803 singletons. About 23.9% and 13.3% of the resulting 1118 unisequences were homologous to functionally characterized proteins and hypothetical proteins, respectively. The rest 62.8% unisequences had no significant homologs in GenBank. Several of these ESTs shared significant homology with known fungal pathogenicity or virulence factors, such as HESP767 of the flax rust and PMK1, GAS1, and GAS2 of the rice blast fungus. We selected six ESTs (Ps28, Ps85, Ps87, Ps259, Ps261, and Ps159 for assaying their expression patterns during urediniospore germination and wheat infection by quantitative real-time PCR. All of them had the highest transcript level in germinated urediniospores and a much less transcript level in un-germinated urediniospores and infected wheat tissues (1–7 dpi. The transcript level of Ps159 increased at later infection stages (6–7 dpi. Our data indicated that these genes were highly expressed in germinated urediniospores and may play important roles in fungal-plant interactions during early infection stages in the wheat stripe rust fungus. Conclusion Genes expressed in germinated urediniospores of P. striiformis f. sp. tritici were identified by EST analysis. Six of them were confirmed by quantitative real
Full Text Available Este estudio reporta un sistema de regeneración simple y eficiente a partir de explantes de hoja de Diacol Capira (DC y Parda Pastusa (PP, dos variedades comerciales de papa cultivadas en Colombia. Un medio único de cultivo es usado tanto para la inducción de callos como para la regeneración de tallos. Se comparó el efecto de diferentes relaciones entre auxinas y citoquininas adicionadas a un medio selectivo para regenerar tallos (4.3 g/L de Sales de Murashige and Skoog (1962, 30 g/L sacarosa, 0.5g/L tiamina, 1 mg/L ácido giberélico, 40mg/L ácido ascórbico y 1.7 g/L fitagel pH 5.7 a partir de explantes de hoja. El análisis de los resultados demostró que todos los explantes de hojas de DC, tratados con zeatina ribósida- ZR (3mg/L, ácido indol -3- acético - AIA (1mg/L y todos los explantes de hojas de PP tratados con ZR (3 mg/L, regeneraron plántulas fuertes y morfológicamente normales. El medio fue utilizado en posteriores experimentos de transformación genética.
Tallo, Ivar, 1964-
Siiani on lahendamata erakondade rahastamise küsimus, samuti on reguleerimata, kes ja missuguses vormis tohib lobby teha ja kuidas peavad avaliku võimu esindajad sellisesse huvide esindamisse suhtuma. Autor: Rahvaerakond Mõõdukad
Tallo, Ivar, 1964-
Ametnike politiseerimisest ja selle põhjusest. Autor on arvamusel, et sotsiaalminister Maret Maripuu valis endale 2007. a. kantsleriks inimese, kellel puudus ametnikuelu kogemus. See, et sotsiaalministeeriumi kantsler vabastatakse ja minister jätkab ametis, meenutab autori sõnul pigem monarhiat, kus monarh ei saanud eksida ja keegi alamatest pidi süü endale võtma
Tallo, Ivar, 1964-
Ilmunud ka: Põhjarannik ; Severnoje Poberezhje 2. oktoober lk. 2. Riigikogu liikmete palgast ja ametihüvedest. Autor: Rahvaerakond Mõõdukad. Vt. samas küsitlus Kuidas suhtute Riigikogu liikmete peaaegu kontrollimatutesse hüvitistesse? Vastavad: Eri Klas, Jaak Mae, Kuno Pajula, Mati Unt
Tallo, Ivar, 1964-
Valitsuse korruptsioonivastase asjatundjate komisjoni juht aastatel 2002-2003 on seisukohal, et ajakirjandus on ainult üks võimalikest vahenditest tõe tuvastamisel ning lõpliku tõe Edgar Savisaare ja Ain Hanschmidti jt seotud skandaalide kohta peavad selgitama võimuinstitutsioonid
Tallo, Ivar, 1964-
Riigikogus lugemisel olevast avaliku teabe seaduse eelnõust, milles nähakse ette võimalus, et internetis veebilehtedel olevaid andmeid riigiasutuste kohta võib riigi julgeoleku huvides hakata varjama
Tallo, Ivar, 1964-
Autori arvates on riiklike registrite poolt jagatava teabe eest tasu võtmine avaliku teabe seadusega vastuolus ega vasta kaasaegsetele infotehnoloogilistele lahendustele. Vastuseks vt.Viljar Peep. Registritest 6.aug. Postimees lk. 10
Full Text Available Phytopathogenic fungi interrupt the macromorphogenesis of wheat (Triticum aestivum but biotic elicitors stimulate the nonspecific tolerance, growth and development of plant stems. It is shown that oxalic acid as a biotic elicitor and donor of nitric oxide signal molecule (sodium nitroprusside stimulate stem growth in height and last leaves length, as well as grain quantity and productivity both in cv. ‘Poliska 90’ and cv. ‘Stolychna’ under Septoria tritici and Puccinia recondita infection in field trials. It is detected that the degree of infected leaf area decreased in both treated cultivars under Saari-Prescott scale. Cv. ‘Poliska 90’ is more sensitive to both fungal pathogens than cv. ‘Stolychna’, but elicitor influence on its architectonics was no less than on cv. ‘Stolychna’.
Rochi, Lucia; Diéguez, María José; Burguener, Germán; Darino, Martín Alejandro; Pergolesi, María Fernanda; Ingala, Lorena Romina; Cuyeu, Alba Romina; Turjanski, Adrián; Kreff, Enrique Domingo; Sacco, Francisco
Rust fungi are one of the most devastating pathogens of crop plants. The biotrophic fungus Puccinia sorghi Schwein (Ps) is responsible for maize common rust, an endemic disease of maize (Zea mays L.) in Argentina that causes significant yield losses in corn production. In spite of this, the Ps genomic sequence was not available. We used Illumina sequencing to rapidly produce the 99.6Mbdraft genome sequence of Ps race RO10H11247, derived from a single-uredinial isolate from infected maize leaves collected in the Argentine Corn Belt Region during 2010. High quality reads were obtained from 200bppaired-end and 5000bpmate-paired libraries and assembled in 15,722 scaffolds. A pipeline which combined an ab initio program with homology-based models and homology to in planta enriched ESTs from four cereal pathogenic fungus (the three sequenced wheat rusts and Ustilago maydis) was used to identify 21,087 putative coding sequences, of which 1599 might be part of the Ps RO10H11247 secretome. Among the 458 highly conserved protein families from the euKaryotic Orthologous Groups (KOG) that occur in a wide range of eukaryotic organisms, 97.5% have at least one member with high homology in the Ps assembly (TBlastN, E-value⩽e-10) covering more than 50% of the length of the KOG protein. Comparative studies with the three sequenced wheat rust fungus, and microsynteny analysis involving Puccinia striiformis f. sp. tritici (Pst, wheat stripe rust fungus), support the quality achieved. The results presented here show the effectiveness of the Illumina strategy for sequencing dikaryotic genomes of non-model organisms and provides reliable DNA sequence information for genomic studies, including pathogenic mechanisms of this maize fungus and molecular marker design. Copyright © 2016 Elsevier Inc. All rights reserved.
Ana Patricia Martinez Gonzalez
Full Text Available En el presente estudio se describe un flujo de trabajo que puede ser aplicado a diferentes especies vegetales, con el fin de obtener extractos apoplásticos que puedan ser usados para análisis proteómicos. Para ello, usando tallos y raíces de clavel, se evaluaron parámetros claves para la extracción de estas proteínas. Se determinó que para esta especie (Dianthus caryophyllus L se debe usar la solución amortiguadora fosfato de sodio 0,1 M pH 6,5, cloruro de sodio 50 mM y 0,1% β-mercaptoetanol para la infiltración; con tres tiempos de vacío de 20 s a 70 kPa y centrifugación a 1000 x g durante 20 min a 4 ºC, seguido de precipitación y concentración de proteínas con el método (TCA-Ácido tricloroacético/acetona. Bajo estas condiciones, se obtienen extractos que permiten análisis electroforéticos en 2D de proteínas de apoplasto, usando para el isolectroenfoque tiras con gradientes de pH 5-8 para raíz y pH 3-10 para tallo. Las condiciones descritas permitirán profundizar sobre el papel de las proteínas apoplásticas en diversidad de fenómenos biológicos que involucren esta especie vegetal.
Full Text Available Glycerol-3-phosphate (G3P is a proposed regulator of plant defense signaling in basal resistance and systemic acquired resistance (SAR. The GLY1-encoded glycerol-3-phosphate dehydrogenase (G3PDH and GLI1-encoded glycerol kinase (GK are two key enzymes involved in the G3P biosynthesis in plants. However, their physiological importance in wheat defense against pathogens remains unclear. In this study, quantification analysis revealed that G3P levels were significantly induced in wheat leaves challenged by the avirulent Puccinia striiformis f. sp. tritici (Pst race CYR23. The transcriptional levels of TaGLY1 and TaGLI1 were likewise significantly induced by avirulent Pst infection. Furthermore, knocking down TaGLY1 and TaGLI1 individually or simultaneously with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS inhibited G3P accumulation and compromised the resistance in the wheat cultivar Suwon 11, whereas the accumulation of salicylic acid (SA and the expression of the SA-induced marker gene TaPR1 in plant leaves were altered significantly after gene silencing. These results suggested that G3P contributes to wheat systemic acquired resistance (SAR against stripe rust, and provided evidence that the G3P function as a signaling molecule is conserved in dicots and monocots. Meanwhile, the simultaneous co-silencing of multiple genes by the VIGS system proved to be a powerful tool for multi-gene functional analysis in plants.
Ki Woo Kim
Full Text Available Interaction of the the rust fungus Puccinia miscanthi with the biofuel plant Miscanthus sinensis during the teliospore phase was investigated by light and electron microscopy. P. miscanthi telia were oval-shaped and present on both the adaxial and abaxial leaf surfaces. Teliospores were brown, one-septate (two-celled, and had pedicels attached to one end. Transmission electron microscopy revealed numerous electron-translucent lipid globules in the cytoplasm of teliospores. Extensive cell wall dissolution around hyphae was not observed in the host tissues beneath the telia. Hyphae were found between mesophyll cells in the leaf tissues as well as in host cells. Intracellular hyphae, possibly haustoria, possessed electron-dense fungal cell walls encased by an electron-transparent fibrillar extrahaustorial sheath that had an electron-dense extrahaustorial membrane. The infected host cells appeared to maintain their membrane-bound structures such as nuclei and chloroplasts. These results suggest that the rust fungus maintains its biotrophic phase with most mesophyll cells of M. sinensis. Such a nutritional mode would permit the rust fungus to obtain food reserves for transient growth in the course of host alteration.
Full Text Available Mixed inheritance analysis using joint segregation analysis (JSA for stripe rust (Puccinia striiformis f. sp. tritici resistance was carried out in six basic populations (P1, F1, P2, BC1, BC2 and F2 of four wheat crosses (Hashim-08 × LU-26, Farid-06 × Shafaq, Parula × Blue Silver, TD-1 × D-97603 during crop season 2009 to 2012. Genes controlling stripe rust resistance were assessed by using area under disease progress curve (AUDPC. The AUDPC was controlled by mixed two additive-dominant-epistatic major genes plus additive-dominant-epistasis of polygenes in cross Hashim-08 × LU-26 (model E, while in Farid-06 × Shafaq, it was controlled by mixed two major additive-dominant genes plus additive-dominant polygenes (model E-2. In cross Parula × Blue Silver, the AUDPC was managed by additive, dominance and epistasis of two major genes (model B-1, however, it was controlled by mixed one major gene and additive dominant polygenes in cross TD-1 × D-97603 (model D-1. Genetic variation and heritability was higher in major genes than polygene for all the crosses showing that AUDPC was mainly controlled by major genes. The genetic behavior of the AUDPC revealed that stripe rust resistance was controlled by mixed interaction of one to two major genes plus polygenes.
MOHAMAD TAUFIK FAUZI
Full Text Available A research was conducted to investigate the biological control ability of Puccinia abrupta var. partheniicola infected to parthenium weed (Parthenium hysterophorus L. at different stages of growth in a glasshouse. The study also investigated the combined effect of the infection and the competitor plant, i.e. buffel grass (Cenchrus ciliaris L., a pasture species usually found in the weed habitat in Central Queensland. The 2 × 3 factorial experiment was arranged in a completely randomized design with six replicates in each treatment. The parthenium weeds were planted with or without buffel grass. The plants were inoculated with P. abrupta var. partheniicola urediniospores either at the rosette, flowering or mature growth stage of development. As controls, an additional six non inoculated plants with and without buffel grass were planted. The results showed that P. abrupta var. partheniicola affected more on the younger plants than on the older ones. Its infection decreased the plant height. A higher reduction in plant above ground biomass was recorded because of the rust when the plants were inoculated at the rosette growth stage of development in the presence of competition. The impact of the rust was greatest on the ability of parthenium to produce seeds.
Joelma dos Santos Garcia
Full Text Available This study characterizes and compares the stem and root anatomy of Echinopsis calochlora and E. rhodotricha (Cactaceae occurring in the Central-Western Region of Brazil, in Mato Grosso do Sul State. Three individuals of each species were collected, fixed, stored and prepared following usual anatomy techniques, for subsequent observation in light and scanning electronic microscopy. Echinopsis calochlora revealed uniseriated epidermis, while E. rhodotricha had patches of bisseriated epidermis; all species showed thick cuticle, parallelocytic stomata at the epidermis level, and a well-developed hypodermis. Cortical and medullary bundles are present in the studied species, as well as mucilage cells in the cortex region. The secondary phloem is composed by sieve tube elements, companion cells, axial and radial parenchyma. Sclereids were found at the outer regions of phloem in the roots. The secondary xylem is non fibrous in the stems of E. calochlora, and fibrous in the stems of E. rhodotricha and in the roots of both species. Many of these characteristics are commonly found in Cactaceae, and represent important adaptations for survival in xeric environments.Este estudio está enfocado a caracterizar y comparar la anatomía de tallos y raíces de Echinopsis calochlora y E. rhodotricha (Cactaceae que habitan en la región centro-oeste de Brasil, en el Estado de Mato Grosso do Sul. Se recolectaron 3 individuos de cada especie, los cuales fueron fijados, almacenados y preparados siguiendo las técnicas comunes de anatomía, para observarlos en microscopía de luz y electrónica de barrido. Echinopsis calochlora mostró epidermis uniseriada, mientras que la de E. rhodotricha fue biseriada; todas las especies presentaron cutícula gruesa, estomas paralelocíticos a nivel de la epidermis y una hipodermis bien desarrollada. Se presentaron haces vasculares corticales y medulares en las especies estudiadas, así como células mucilaginosas en la regi
Rong, Wei; Qi, Lin; Wang, Jingfen; Du, Lipu; Xu, Huijun; Wang, Aiyun; Zhang, Zengyan
Take-all, caused by soil-borne fungus Gaeumannomyces graminis var. tritici (Ggt), is a devastating root disease of wheat (Triticum aestivum) worldwide. Breeding resistant wheat cultivars is the most promising and reliable approach to protect wheat from take-all. Currently, no resistant wheat germplasm is available to breed cultivars using traditional methods. In this study, gene transformation was carried out using Snakin-1 (SN1) gene isolated from potato (Solanum tuberosum) because the peptide shows broad-spectrum antimicrobial activity in vitro. Purified SN1 peptide also inhibits in vitro the growth of Ggt mycelia. By bombardment-mediated method, the gene SN1 was transformed into Chinese wheat cultivar Yangmai 18 to generate SN1 transgenic wheat lines, which were used to assess the effectiveness of the SN1 peptide in protecting wheat from Ggt. Genomic PCR and Southern blot analyses indicated that the alien gene SN1 was integrated into the genomes of five transgenic wheat lines and heritable from T₀ to T₄ progeny. Reverse transcription-PCR and Western blot analyses showed that the introduced SN1 gene was transcribed and highly expressed in the five transgenic wheat lines. Following challenging with Ggt, disease test results showed that compared to segregants lacking the transgene and untransformed wheat plants, these five transgenic wheat lines expressing SN1 displayed significantly enhanced resistance to take-all. These results suggest that SN1 may be a potentially transgenic tool for improving the take-all resistance of wheat.
Ali, Sajid; Gladieux, Pierre; Leconte, Marc; Gautier, Angélique; Justesen, Annemarie F.; Hovmøller, Mogens S.; Enjalbert, Jérôme; de Vallavieille-Pope, Claude
Analyses of large-scale population structure of pathogens enable the identification of migration patterns, diversity reservoirs or longevity of populations, the understanding of current evolutionary trajectories and the anticipation of future ones. This is particularly important for long-distance migrating fungal pathogens such as Puccinia striiformis f.sp. tritici (PST), capable of rapid spread to new regions and crop varieties. Although a range of recent PST invasions at continental scales are well documented, the worldwide population structure and the center of origin of the pathogen were still unknown. In this study, we used multilocus microsatellite genotyping to infer worldwide population structure of PST and the origin of new invasions based on 409 isolates representative of distribution of the fungus on six continents. Bayesian and multivariate clustering methods partitioned the set of multilocus genotypes into six distinct genetic groups associated with their geographical origin. Analyses of linkage disequilibrium and genotypic diversity indicated a strong regional heterogeneity in levels of recombination, with clear signatures of recombination in the Himalayan (Nepal and Pakistan) and near-Himalayan regions (China) and a predominant clonal population structure in other regions. The higher genotypic diversity, recombinant population structure and high sexual reproduction ability in the Himalayan and neighboring regions suggests this area as the putative center of origin of PST. We used clustering methods and approximate Bayesian computation (ABC) to compare different competing scenarios describing ancestral relationship among ancestral populations and more recently founded populations. Our analyses confirmed the Middle East-East Africa as the most likely source of newly spreading, high-temperature-adapted strains; Europe as the source of South American, North American and Australian populations; and Mediterranean-Central Asian populations as the origin of
Full Text Available Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst, is one of the most important diseases of wheat worldwide. Understanding the survival of Pst during the overwintering period is critical for predicting Pst epidemics in the spring. Real-time quantitative PCR (qPCR methods quantifying Pst DNA and RNA (cDNA were developed and compared for the ability to quantify viable Pst in leaf tissues. Both qPCR of DNA and RNA can provide reliable measurement of viable Pst in plant tissues prior to the late sporulation stage for which qPCR of DNA gave a much higher estimate of fungal biomass than qPCR of RNA. The percentage of Pst biomass that was viable in detached and attached leaves under low temperatures decreased over time. Pst survived longer on attached leaves than on detached leaves. The survival of Pst in cultivars with strong winter-hardiness at 0°C and -5°C was greater than those with weak winter-hardiness. However, such differences in Pst survival among cultivars were negligible at -10, -15 and -20°C. Results indicated that Pst mycelia inside green leaves can also be killed by low temperatures rather than through death of green leaves under low temperatures. The relationship of Pst survival in attached leaves with temperature and winter-hardiness was well described by logistic models. Further field evaluation is necessary to assess whether inclusion of other factors such as moisture and snow cover could improve the model performance in predicting Pst overwintering potential, and hence the epidemic in spring.
Full Text Available N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs are involved in plant resistance; however, the role of SYP71 in the regulation of plant–pathogen interactions is not well known. In this study, we characterized a plant-specific SNARE in wheat, TaSYP71, which contains a Qc-SNARE domain. Three homologues are localized on chromosome 1AL, 1BL and 1DL. Using Agrobacterium-mediated transient expression, TaSYP71 was localized to the plasma membrane in Nicotiana benthamiana. Quantitative real-time PCR assays revealed that TaSYP71 homologues was induced by NaCl, H2O2 stress and infection by virulent and avirulent Puccinia striiformis f. sp. tritici (Pst isolates. Heterologous expression of TaSYP71 in Schizosaccharomyces pombe elevated tolerance to H2O2. Meanwhile, H2O2 scavenging gene (TaCAT was downregulated in TaSYP71 silenced plants treated by H2O2 compared to that in control, which indicated that TaSYP71 enhanced tolerance to H2O2 stress possibly by influencing the expression of TaCAT to remove the excessive H2O2 accumulation. When TaSYP71 homologues were all silenced in wheat by the virus-induced gene silencing system, wheat plants were more susceptible to Pst, with larger infection area and more haustoria number, but the necrotic area of wheat mesophyll cells were larger, one possible explanation that minor contribution of resistance to Pst was insufficient to hinder pathogen extension when TaSYP71were silenced, and the necrotic area was enlarged accompanied with the pathogen growth. Of course, later cell death could not be excluded. In addition, the expression of pathogenesis-related genes were down-regulated in TaSYP71 silenced wheat plants. These results together suggest that TaSYP71 play a positive role in wheat defence against Pst.
De Backer, M; Bonants, P; Pedley, K F; Maes, M; Roldan-Ruiz, I; Van Bockstaele, E; Heungens, K; van der Lee, T
The obligate biotrophic pathogen Puccinia horiana is the causal agent of chrysanthemum white rust. Although P. horiana is a quarantine organism, it has been able to spread to most chrysanthemum-producing regions in the world since the 1960s; however, the transfer routes are largely obscure. An extremely low level of allelic diversity was observed in a geographically diverse set of eight isolates using complexity reduction of polymorphic sequences (CRoPS) technology. Only 184 of the 16,196 contigs (1.1%) showed one or more single-nucleotide polymorphisms (SNPs). Thirty-two SNPs and one simple-sequence repeat were translated into molecular markers and used to genotype 45 isolates originating from North and South America, Asia, and Europe. In most cases, phylogenetic clustering was related to geographic origin, indicating local establishment. The European isolates mostly grouped in two major populations that may relate to the two historic introductions previously reported. However, evidence of recent geographic transfer was also observed, including transfer events between Europe and South America and between Southeast Asia and Europe. In contrast with the presumed clonal propagation of this microcyclic rust, strong indications of marker recombination were observed, presumably as a result of anastomosis, karyogamy, and somatic meiosis. Recombination and transfer also explain the geographic dispersal of specific markers. A near-to-significant correlation between the genotypic data and previously obtained pathotype data was observed and one marker was associated with the most virulent pathotype group. In combination with a fast SNP detection method, the markers presented here will be helpful tools to further elucidate the transfer pathways and local survival of this pathogen.
David Eduardo Torres
Full Text Available Puccinia horiana Hennings, the causal agent of chrysanthemum white rust, is a worldwide quarantine organism and one of the most important fungal pathogens of Chrysanthemum × morifolium cultivars, which are used for cut flowers and as potted plants in commercial production regions of the world. It was previously reported to be controlled by Lecanicillium lecanii, Cladosporium sphaerospermum, C. uredinicola and Aphanocladium album, due to their antagonistic and hyperparasitic effects. We report novel antagonist species on Puccinia horiana. Fungi isolated from rust pustules in a commercial greenhouse from Villa Guerrero, México, were identified as Cladosporium cladosporioides and Cladosporium pseudocladosporioides based upon molecular analysis and morphological characters. The antagonism of C. cladosporioides and C. pseudocladosporioides on chrysanthemum white rust was studied using light and electron microscopy in vitro at the host/parasite interface. Cladosporium cladosporioides and C. pseudocladosporioides grew towards the white rust teliospores and colonized the sporogenous cells, but no direct penetration of teliospores was observed; however, the structure and cytoplasm of teliospores were altered. The two Cladosporium spp. were able to grow on media containing laminarin, but not when chitin was used as the sole carbon source; these results suggest that they are able to produce glucanases. Results from the study indicate that both Cladosporium species had potential as biological control agents of chrysanthemum white rust.
Consecutive monitoring of lifelong production of conidia by individual conidiophores of Blumeria graminis f. sp. hordei on barley leaves by digital microscopic techniques with electrostatic micromanipulation.
Moriura, Nobuyuki; Matsuda, Yoshinori; Oichi, Wataru; Nakashima, Shinya; Hirai, Tatsuo; Sameshima, Takeshi; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Higashi, Katsuhide; Toyoda, Hideyoshi
Conidial formation and secession by living conidiophores of Blumeria graminis f. sp. hordei on barley leaves were consecutively monitored using a high-fidelity digital microscopic technique combined with electrostatic micromanipulation to trap the released conidia. Conidial chains formed on conidiophores through a series of septum-mediated division and growth of generative cells. Apical conidial cells on the conidiophores were abstricted after the conidial chains developed ten conidial cells. The conidia were electrically conductive, and a positive charge was induced in the cells by a negatively polarized insulator probe (ebonite). The electrostatic force between the conidia and the insulator was used to attract the abstricted conidia from the conidiophores on leaves. This conidium movement from the targeted conidiophore to the rod was directly viewed under the digital microscope, and the length of the interval between conidial septation and secession, the total number of the conidia produced by a single conidiophore, and the modes of conidiogenesis were clarified. During the stage of conidial secession, the generative cells pushed new conidial cells upwards by repeated division and growth. The successive release of two apical conidia was synchronized with the successive septation and growth of a generative cell. The release ceased after 4-5 conidia were released without division and growth of the generative cell. Thus, the life of an individual conidiophore (from the erection of the conidiophore to the release of the final conidium) was shown to be 107 h and to produce an average of 33 conidia. To our knowledge, this is the first report on the direct estimation of life-long conidial production by a powdery mildew on host leaves.
Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. The most effective and widely uti...
Life Table Parameters and Consumption Rate of Cydnodromus picanus Ragusa, Amblyseius graminis Chant, and Galendromus occidentalis (Nesbitt on Avocado Red Mite Oligonychus yothersi (McGregor (Acari: Phytoseiidae, Tetranychidae Parámetros de Tabla de Vida y Tasa de Consumo de Cydnodromus picanus Ragusa, Amblyseius graminis Chant y Galendromus occidentalis (Nesbitt, sobre la Arañita Roja del Palto Oligonychus yothersi (McGregor (Acari: Phytoseiidae, Tetranychidae
Tommy Rioja S
Full Text Available The avocado red mite Oligonychus yothersi (McGregor is the major leaf pest in Chile’s avocado orchards. Itaffects leaf physiology and makes it necessary to seek new natural enemies to interact with low population densities of O. yothersi. The potentiality of three predator mites: Cydnodromus picanus Ragusa, Amblyseius graminis Chant, and Galendromus occidentalis (Nesbitt was evaluated under laboratory conditions (27 ± 1.93ºC, 87 ± 3.61% H.R. and 16:8 (L:D photoperiod on avocado leaf disks Persea americana Mill. var. Hass (Ø = 5 cm by separately feeding eggs, immature, and adult females of O. yothersi, and registering postembryonic development, consumption, as well as life table parameters. The postembryonic development of C. picanus was significantly lower (5.46 days compared to both A. graminis (7.33 days and G. occidentalis (8.69 days which were fed with immature O. yothersi. The life table parameters of C. picanus were net reproductive rate R0 = 25.41, finite rate of increase λ = 1.29, and Mean Generation Time T = 12.46. The Net Intrinsic Rate of Increase (r m was significantly higher for C. picanus (r m = 0.25 in contrast with G. occidentalis (r m = 0.19, while A. graminis showed r m = -0.06 indicating that its population didn’t have descendants. Under laboratory conditions, r m registered by C. picanus is an indicator of its predatory potential to control O. Yothersi. It can be assumed that the pest population reduction pattern could be maintained under field conditions.En Chile la arañita roja del palto Oligonychus yothersi (McGregor es la plaga más importante a nivel foliar en huertos comerciales afectando la fisiología de la hoja, siendo necesario la búsqueda de nuevos enemigos naturales que interactúen a bajas densidades poblacionales de O. yothersi. Se evaluó en condiciones de laboratorio (27±1,93ºC, 87±3,61 % H.R. y un fotoperíodo de 16:8 (L:O sobre discos de hojas de palto Persea americana Mill. var. Hass (Ø = 5
Manjunatha, C; Sharma, Sapna; Kulshreshtha, Deepika; Gupta, Sangeeta; Singh, Kartar; Bhardwaj, Subhash C; Aggarwal, Rashmi
Leaf rust of wheat caused by Puccinia triticina has significant impact on wheat production worldwide. Effective and quick detection methodologies are required to mitigate yield loss and time constraints associated with monitoring and management of leaf rust of wheat. In the present study, detection of P. triticina has been simplified by developing a rapid, reliable, efficient and visual colorimetric method i.e., loop mediated isothermal amplification of DNA (LAMP). Based on in silico analysis of P. triticina genome, PTS68, a simple sequence repeat was found highly specific to leaf rust fungus. A marker (PtRA68) was developed and its specificity was validated through PCR technique which gave a unique and sharp band of 919 bp in P. triticina pathotypes only. A novel gene amplification method LAMP which enables visual detection of pathogen by naked eye was developed for leaf rust pathogen. A set of six primers was designed from specific region of P. triticina and conditions were optimised to complete the observation process in 60 minutes at 65o C. The assay developed in the study could detect presence of P. triticina on wheat at 24 hpi (pre-symptomatic stage) which was much earlier than PCR without requiring thermal cycler. Sensitivity of LAMP assay developed in the study was 100 fg which was more sensitive than conventional PCR (50 pg) and equivalent to qPCR (100 fg). The protocol developed in the study was utilized for detection of leaf rust infected samples collected from different wheat fields. LAMP based colorimetric detection assay showed sky blue color in positive reaction and violet color in negative reaction after addition of 120 μM hydroxyl napthol blue (HNB) solution to reaction mixture. Similarly, 0.6 mg Ethidium bromide/ml was added to LAMP products, placed on transilluminator to witness full brightness in positive reaction and no such brightness could be seen in negative reaction mixture. Further, LAMP products spread in a ladder like banding pattern in
Leaf rust, caused by Puccinia triticina (Pt) and stem rust caused by Puccinia graminis f. sp. tritici (Pgt) are important diseases of durum wheat. This study determined the inheritance and genomic locations of leaf rust resistance (Lr) genes to Pt-race BBBQJ and stem rust resistance (Sr) genes to Pg...
Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important fungal diseases on wheat worldwide and a serious threat to wheat production. Understanding the plant-microbe interaction mechanism is the basic step to assist future plant breeding aiming at increasing...... factor. By using the yeast two-hybrid system, the adenosine kinase (ADK) was identified as a host target of PEC6. Virus-induced gene silencing (VIGS) of ADK enhanced wheat susceptibility to stripe rust indicates that ADK is a positive regulator in plant defense. Based on EtHAn-mediated effector delivery......, seventy-two wheat landraces were screened to search for the presence of potential resistance (R) genes. Three landraces showed strong hypersensitive response (HR) when PEC6 was expressed in the cells, suggesting the presence of certain R gene(s) recognizing PEC6. However, these landraces did not show...
Rafael Fávero Peixoto Júnior
Entre as doenças que trazem preocupações e podem causar prejuízos no setor canavieiro em todo o Brasil, destaca-se a ferrugem marrom, causada pelo fungo Puccinia melanocephala H. & P. Sydow. Essa doença ocorre em todas as regiões canavieiras do mundo, desde a Ásia e a África, de onde o complexo \\"Sacharum spp.\\" é originário, até as Américas e Oceania. No Brasil, a ferrugem foi detectada, pela primeira vez em 1986, no município de Capivari-SP e logo em seguida em Pernambuco e Alagoas. Desde ...
Full Text Available A long-standing biological question is how evolution has shaped the genomic architecture of dikaryotic fungi. To answer this, high-quality genomic resources that enable haplotype comparisons are essential. Short-read genome assemblies for dikaryotic fungi are highly fragmented and lack haplotype-specific information due to the high heterozygosity and repeat content of these genomes. Here, we present a diploid-aware assembly of the wheat stripe rust fungus Puccinia striiformis f. sp. tritici based on long reads using the FALCON-Unzip assembler. Transcriptome sequencing data sets were used to infer high-quality gene models and identify virulence genes involved in plant infection referred to as effectors. This represents the most complete Puccinia striiformis f. sp. tritici genome assembly to date (83 Mb, 156 contigs, N50 of 1.5 Mb and provides phased haplotype information for over 92% of the genome. Comparisons of the phase blocks revealed high interhaplotype diversity of over 6%. More than 25% of all genes lack a clear allelic counterpart. When we investigated genome features that potentially promote the rapid evolution of virulence, we found that candidate effector genes are spatially associated with conserved genes commonly found in basidiomycetes. Yet, candidate effectors that lack an allelic counterpart are more distant from conserved genes than allelic candidate effectors and are less likely to be evolutionarily conserved within the P. striiformis species complex and Pucciniales. In summary, this haplotype-phased assembly enabled us to discover novel genome features of a dikaryotic plant-pathogenic fungus previously hidden in collapsed and fragmented genome assemblies.
Peng, Fred Y; Yang, Rong-Cai
The resistance to leaf rust (Lr) caused by Puccinia triticina in wheat (Triticum aestivum L.) has been well studied over the past decades with over 70 Lr genes being mapped on different chromosomes and numerous QTLs (quantitative trait loci) being detected or mapped using DNA markers. Such resistance is often divided into race-specific and race-nonspecific resistance. The race-nonspecific resistance can be further divided into resistance to most or all races of the same pathogen and resistance to multiple pathogens. At the molecular level, these three types of resistance may cover across the whole spectrum of pathogen specificities that are controlled by genes encoding different protein families in wheat. The objective of this study is to predict and analyze genes in three such families: NBS-LRR (nucleotide-binding sites and leucine-rich repeats or NLR), START (Steroidogenic Acute Regulatory protein [STaR] related lipid-transfer) and ABC (ATP-Binding Cassette) transporter. The focus of the analysis is on the patterns of relationships between these protein-coding genes within the gene families and QTLs detected for leaf rust resistance. We predicted 526 ABC, 1117 NLR and 144 START genes in the hexaploid wheat genome through a domain analysis of wheat proteome. Of the 1809 SNPs from leaf rust resistance QTLs in seedling and adult stages of wheat, 126 SNPs were found within coding regions of these genes or their neighborhood (5 Kb upstream from transcription start site [TSS] or downstream from transcription termination site [TTS] of the genes). Forty-three of these SNPs for adult resistance and 18 SNPs for seedling resistance reside within coding or neighboring regions of the ABC genes whereas 14 SNPs for adult resistance and 29 SNPs for seedling resistance reside within coding or neighboring regions of the NLR gene. Moreover, we found 17 nonsynonymous SNPs for adult resistance and five SNPs for seedling resistance in the ABC genes, and five nonsynonymous SNPs for
Full Text Available Com o objetivo de avaliar métodos de preservação de urediniósporos de Puccinia kuehnii, conduziram-se dois bioensaios sendo o primeiro (B1 com diferentes métodos de desidratação e o segundo (B2, com diferentes métodos de reidratação. Em B1 foi adicionado um grânulo de sílica gel para preservação dos urediniósporos nos tubos de microcentrífuga. Foram coletadas folhas com sintomas de ferrugem alaranjada, P. kuehnii, da cultivar de cana-de-açúcar SP89 1115. Os urediniósporos do agente causal de ferugem foram extraídos das folhas com o auxílio de bomba a vácuo. Posteriormente, estes foram acondicionados em tubos de microcentrífuga. Os tratamentos para B1 foram: l- desidratação em sílica gel, liofilização e sem desidratação; ll- temperatura ambiente (20ºC, geladeira (5ºC, congelador (-20ºC e deep-freezer (-80ºC. Para B2 os tratamentos foram: l- desidratação em sílica gel e sem desidratação; ll- temperatura ambiente (20ºC, geladeira (5ºC, congelador (-20ºC e deep-freezer (-80ºC; lll- com reidratação e sem reidratação nas avaliações. Para ambos os bioensaios foi realizada a germinação inicial, outras aos 15 e 30 dias de armazenamento e posteriormente a cada 30 dias, até 180 dias. Prepararam-se suspensões de urediniósporos em água e uma alíquota de 0,1 mL foi transferida para placas de Petri contendo meio ágar-água (15g L-1. Essas permaneceram a 20ºC, no escuro. Para a avaliação da viabilidade, procedeu-se a contagem de 200 urediniósporos por placa. Os dados foram submetidos à análise de variância não paramétrica de Kruskal-Wallis e complementadas com o teste de Dunn. Os resultados demonstraram que a viabilidade decresceu em função do tempo, sendo que os melhores tratamentos atingiram 27,6% e 6,6% aos 30 dias, e 12,0% e 1,9% aos 60 dias, para B1 e B2, respectivamente. O método da desidratação em sílica gel seguido do armazenamento a -80ºC foi o único que apresentou uredini
Anderson, Robert C.
Puccinia psidii was first described by Winter (1884) on guava (Psidium guajava L.) in Brazil. The rust is still a major pest of native guava in Brazil and is often referred to as “guava rust” internationally. It is unusual among rust fungi because of its broad and ever-expanding host-range within the Myrtaceae plant family (Simpson et al. 2006). The pathogen is regarded as a major threat to Eucalyptus plantations and other Myrtaceae worldwide (Coutinho et al. 1998, Grgurinovic et al. 2006, Glen et al. 2007). Infections of leaves and meristems are particularly severe on susceptible seedlings, cuttings, young trees, and coppice, causing plants to be stunted and multi-branched, inhibiting normal growth and development, and sometimes causing death to young seedlings (Booth et al. 2000, Rayachhetry et al. 2001). The fungus has expanded its host-range in Brazil, affecting both native and introduced Myrtaceae (Coutinho et al. 1998). Since its discovery in 1884, P. psidii has continually been discovered to have an expanding host-range within the Myrtaceae, affecting hosts throughout much of South and Central America and the Caribbean. Spreading out originally from Brazil in 1884, the fungus has been reported on hosts in the following countries (first record in parentheses): Paraguay (1884), Uruguay (1889), Ecuador (1891), Colombia (1913), Puerto Rico (1913), Cuba (1926), Dominican Republic (1933), Venezuela (1934), Jamaica (1936), Argentina (1946), Dominica (1948), Trinidad and Tobago (1951), Guatemala (1968), United States (Florida; 1977), Mexico (1981), El Salvador (1987), and Costa Rica (1998) (Simpson et al. 2006). It is possible that P. psidii was present in El Salvador and Costa Rica prior to 1980, but was not reported until 1987 and 1998, respectively. Until recently, Puccinia psidii was restricted to the Neotropics, Mexico, and the state of Florida in the United States. While the rust has been present in Florida for over 30 years, only recently has it spread
Tallo, Ivar, 1964-
Vt. ka Postimees : na russkom jazõke 27. juuni lk. 7. Autor leiab, et andmekaitse kohta käivad otsused peavad olema põhjalikult läbi mõeldud ning samas peaksid ka kodanikud andmete avalikustamisest rohkem teadma
Tallo, Ivar, 1964-
Kõrgemate riigiteenijate palgakorraldusest ja vastavast seaduseelnõust. Lisatud: riigiteenijate palga muutus. Tabelis on toodud andmed ka presidendi palga kohta. Vt. ka juhtkiri lk. 2: Palgad jälle tõusevad
Tallo, Ivar, 1964-
Autor viitab kohalike valimiste tulemustele järgnenud valulikule reaktsioonile avalikus meediaruumis. Järgmist, valimistevahelist aastat tuleb kasutada ühiskonna lepitamiseks ja ratsionaalse poliitikakäitumise edendamiseks
Tallo, Ivar, 1964-
Autori arvates valitseb Eestis olukord, kus tegelikke otsuseid langetatakse väljaspool otsustamise mehhanisme ning otsuste formaalsed tegijad ja nende eest vastutajad on erinevad inimesed. Erakondlik poliitika ja poliitikud
Full Text Available Niña de 12 años de edad con padecimiento de un mes de evolución caracterizado por cefalea, mareo, vómito y marcha atáxica. Días antes de su internamiento fue operada por presentar cuadro de abdomen agudo secundario a una apendicitis aguda. Después de recuperarse de esa cirugía la paciente tuvo somnolencia, bradipsiquia, bradilalia, diplopia y nistagmo, motivo por el cual acudió a nuestra institución.
Kong, Lingyao; Chang, Cheng
Wheat TaCDK8 interacts with TaWIN1 to regulate very-long-chain aldehyde biosynthesis required for efficient germination of Blumeria graminis f.sp. tritici. Powdery mildew caused by Blumeria graminis f.sp. tritici (Bgt) is a devastating disease of common wheat (Triticum aestivum L.). Bgt infection initiates with its conidia germination on the aerial surface of wheat. In this study, we isolated the cyclin-dependent kinase 8 (TaCDK8) from wheat cultivar Jing411 and found that silencing of TaCDK8 impeded Bgt germination. The biochemical and molecular-biological assays revealed that TaCDK8 interacts with and phosphorylates the wheat transcription factor wax inducer 1 (TaWIN1) to stimulate the TaWIN1-dependent transcription. Bgt conidia on the leaves of TaWIN1-silenced plants also showed reduced germination. Gas chromatographic analysis revealed that knockdown of TaCDK8 or TaWIN1 resulted in decreases of wax components and cutin monomers in wheat leaves. Moreover, Bgt germination on leaves of TaCDK8 or TaWIN1 silenced plants could be fully restored by application of wild-type cuticular wax. In vitro studies demonstrated that very-long-chain aldehydes absent from the cuticular wax of the TaCDK8 or TaWIN1 silenced plants were capable of chemically stimulating Bgt germination. These results implicated that the suppression of TaCDK8/TaWIN1 interaction negatively affects Bgt germination by interfering with very-long-chain aldehyde biosynthesis required for efficient fungal germination.
Schwessinger, Benjamin; Sperschneider, Jana; Cuddy, William S; Garnica, Diana P; Miller, Marisa E; Taylor, Jennifer M; Dodds, Peter N; Figueroa, Melania; Park, Robert F; Rathjen, John P
A long-standing biological question is how evolution has shaped the genomic architecture of dikaryotic fungi. To answer this, high-quality genomic resources that enable haplotype comparisons are essential. Short-read genome assemblies for dikaryotic fungi are highly fragmented and lack haplotype-specific information due to the high heterozygosity and repeat content of these genomes. Here, we present a diploid-aware assembly of the wheat stripe rust fungus Puccinia striiformis f. sp. tritici based on long reads using the FALCON-Unzip assembler. Transcriptome sequencing data sets were used to infer high-quality gene models and identify virulence genes involved in plant infection referred to as effectors. This represents the most complete Puccinia striiformis f. sp. tritici genome assembly to date (83 Mb, 156 contigs, N 50 of 1.5 Mb) and provides phased haplotype information for over 92% of the genome. Comparisons of the phase blocks revealed high interhaplotype diversity of over 6%. More than 25% of all genes lack a clear allelic counterpart. When we investigated genome features that potentially promote the rapid evolution of virulence, we found that candidate effector genes are spatially associated with conserved genes commonly found in basidiomycetes. Yet, candidate effectors that lack an allelic counterpart are more distant from conserved genes than allelic candidate effectors and are less likely to be evolutionarily conserved within the P. striiformis species complex and Pucciniales In summary, this haplotype-phased assembly enabled us to discover novel genome features of a dikaryotic plant-pathogenic fungus previously hidden in collapsed and fragmented genome assemblies. IMPORTANCE Current representations of eukaryotic microbial genomes are haploid, hiding the genomic diversity intrinsic to diploid and polyploid life forms. This hidden diversity contributes to the organism's evolutionary potential and ability to adapt to stress conditions. Yet, it is
Full Text Available ResumenEl complejo Diaporthe/Phomopsis es un importante grupo de hongos patógenos de la soja. Dentro del mismo, Diaporthe phaseolorum var. caulivora es uno de los agentes causales del cancro del tallo. Veintitrés aislamientos de este hongo, provenientes de diferentes zonas geográficas de la provincia de Buenos Aires, fueron caracterizados morfológica y genéticamente. Los criterios morfológicos fueron tipo y color de micelio; formación del teleomorfo y/o del anamorfo. La identificación molecular fue llevada a cabo utilizando una técnica de restricción de fragmentos de amplificación (PCR-RFLP de la región ITS de ADN ribosomal. Adicionalmente, los productos de amplificación fueron secuenciados y comparados con la información de bancos de datos. Los aislamientos presentaron características morfológicas y patogénicas propias de la variedad, y los patrones de restricción con la enzima Alu I fueron concordantes con la identificación morfológica y con la información de secuencias disponibles. Las reconstrucciones filogenéticas apoyan la idea de que D. meridionalis y D. caulivora son entidades biológicamente aisladas. Los resultados obtenidos confirmaron la utilidad del uso del método de PCR-RFLP para la identificación precisa y rápida de D. caulivora. Por sus características, este método puede ser implementado para análisis de rutina en laboratorios de pequeña y mediana escala.AbstractDiaporthe/Phomopsis is an important group of soybean pathogens. Diaporthe phaseolorum var. caulivora is one of the causal agents of stem canker. Twenty three isolates from different regions from the Province of Buenos Aires were morphologically and genetically characterized and assigned to different taxa within the Diaporthe/Phomopsis complex; diagnostic morphological traits were: mycelium type and color, teleomorph/anamorph occurrence. Molecular characterization was carried out using RFLP analyses of PCR-amplified DNA (PCRRFLP for the
Caracterización de acelga fresca de Santiago del Estero (Argentina. Comparación del contenido de nutrientes en hoja y tallo. Evaluación de los carotenoides presentes Characterization of fresh Beta vulgaris from Santiago del Estero (Argentina. Nutrient and caroteniod content of stem and leaves
Sara Macías de Costa
Full Text Available Se realizaron estudios de caracterización integral de acelga (Beta vulgaris, var. cycla cultivada en la Provincia de Santiago del Estero, Argentina. Por tratarse de un vegetal de importante consumo regional, se realizó la determinación de sus constituyentes básicos, minerales y pigmentos para conocer los valores nutricionales que aporta este alimento en nuestra región. Se analizaron comparando hoja y tallo: humedad, cenizas, proteínas, grasas, hidratos de carbono utilizables, fibra dietaria total, contenido de clorofila y carotenoides. En cuanto a minerales, se determinaron calcio, magnesio, sodio, potasio, manganeso, zinc, hierro, fósforo y boro. Se encontraron diferencias en los aportes de minerales, proteínas, grasas y fibra entre hoja y tallo, así como también el contenido de carotenoides exclusivamente en las hojas. Los resultados marcan importantes diferencias en el contenido energético y en su valor provitamínico A entre la hoja y el tallo de este vegetal, mostrando que este último es una parte aprovechable de la planta, recomendable en dietas hipocalóricas.An integrated characterization study of Swiss chard grown in Santiago del Estero, Argentina, was carried out. As Swiss chard is a vegetable of important regional consumption, the determination of its basic constituents, minerals and pigments was done to appraise the nutritional value offered by this food in our area. Moisture, ash content, proteins, fats, available carbohydrates, total dietary fiber, chlorophylls and carotenoids were analysed, comparing the leaves and the stems. As to minerals, calcium, magnesium, sodium, manganese, zinc, iron, phosphorous, potassium, and boron were determined. Differences in the concentration of minerals, proteins, fats and fiber between the leaves and the stems were found, as well as the carotenoid content mainly in the leaves. These findings revealed important differences in energy content and provitamin A value, showing that the stem
M. Kathryn Turner
Full Text Available New crops with greater capacity for delivering ecosystem services are needed to increase agricultural sustainability. However, even in these crops, seed yield is usually the main criteria for grain domestication. This focus on yield can cause unintended structural and functional changes. Leaves of selected plants tend to be more vulnerable to infection, which can reduce performance, assimilates, and ultimately yield. Our objectives were to determine the impact of rust (caused by Puccinia silphii on yield and leaf function in selected Silphium integrifolium (Asteraceae plants. We tested the effect of a fungicide treatment on rust severity and yield, compared the rust infection of individuals in a population selected for yield, and related this to chemical changes at the leaf level. We also estimated heritability for rust resistance. We found that productivity indicators (head number and weight, leaf weight and leaf processes (photosynthetic capacity, water use efficiency were reduced when silphium leaves and stems were more heavily infected by P. silphii. Leaf resin content increased when susceptible plants were infected. Fungicide treatments were effective at reducing rust infection severity, but were ineffective at preventing yield losses. We propose that disease resistance should be included early in the selection process of new perennial crops.
Xiaojing WANG,Zhanhong MA,Yuying JIANG,Shouding SHI,Wancai LIU,Juan ZENG,Zhiwei ZHAO,Haiguang WANG
Full Text Available Wheat stripe rust caused by Puccinia striiformis f. sp. tritici occurs widely in China and seriously affects wheat production. Global warming could profoundly impact the incidence and prevalence of low-temperature diseases such as stripe rust. Studies on the effects of temperature on the distribution of overwintering stripe rust could help us understand the incidence and prevalence of the disease and could also provide support for monitoring, forecasting and developing control strategies. An exponential model and a spherical model of the ordinary Kriging method in the ArcGIS platform were used to predict the overwintering regions of stripe rust based on the probability that the average temperature of the coldest month from December to February was higher than -6 or -7ºC from 2001 to 2012. The results showed that the areas with a probability between 70% and 90% were transition regions for the overwintering of stripe rust. Based on annual mean temperature of the coldest month from December to February for 2001 to 2012, overwintering distribution of stripe rust was likewise evaluated. The boundary for overwintering of stripe rust was consistent with the areas where the probability was predicted to be 70% to 90% for the overwintering distribution of stripe rust, but the boundary was shifted northward toward Beijing in North China. Some areas in Xinjiang, including Akto, Pishan, Hotan and Yutian, were also predicted to be suitable for the overwintering of stripe rust.
Full Text Available Calcineurin plays a key role in morphogenesis, pathogenesis and drug resistance in most fungi. However, the function of calcineurin genes in Puccinia striiformis f. sp. tritici (Pst is unclear. We identified and characterized the calcineurin genes PsCNA1 and PsCNB1 in Pst. Phylogenetic analyses indicate that PsCNA1 and PsCNB1 form a calcium/calmodulin regulated protein phosphatase belonging to the calcineurin heterodimers composed of subunits A and B. Quantitative RT-PCR analyses revealed that both PsCNA1 and PsCNB1 expression reached their maximum in the stage of haustorium formation, which is one day after inoculation. Using barely stripe mosaic virus (BSMV as a transient expression vector in wheat, the expression of PsCNA1 and PsCNB1 in Pst was suppressed, leading to slower extension of fungal hyphae and reduced production of urediospores. The immune-suppressive drugs cyclosporin A and FK506 markedly reduced the germination rates of urediospores, and when germination did occur, more than two germtubes were produced. These results suggest that the calcineurin signaling pathway participates in stripe rust morphogenetic differentiation, especially the formation of haustoria during the early stage of infection and during the production of urediospores. Therefore PsCNA1 and PsCNB1 can be considered important pathogenicity genes involved in the wheat-Pst interaction.
Full Text Available Abstract Background Puccinia striiformis is a plant pathogenic fungus causing stripe rust, one of the most important diseases on cereal crops and grasses worldwide. However, little is know about its genome and genes involved in the biology and pathogenicity of the pathogen. We initiated the functional genomic research of the fungus by constructing a full-length cDNA and determined functions of the first group of genes by sequence comparison of cDNA clones to genes reported in other fungi. Results A full-length cDNA library, consisting of 42,240 clones with an average cDNA insert of 1.9 kb, was constructed using urediniospores of race PST-78 of P. striiformis f. sp. tritici. From 196 sequenced cDNA clones, we determined functions of 73 clones (37.2%. In addition, 36 clones (18.4% had significant homology to hypothetical proteins, 37 clones (18.9% had some homology to genes in other fungi, and the remaining 50 clones (25.5% did not produce any hits. From the 73 clones with functions, we identified 51 different genes encoding protein products that are involved in amino acid metabolism, cell defense, cell cycle, cell signaling, cell structure and growth, energy cycle, lipid and nucleotide metabolism, protein modification, ribosomal protein complex, sugar metabolism, transcription factor, transport metabolism, and virulence/infection. Conclusion The full-length cDNA library is useful in identifying functional genes of P. striiformis.
Bulli, Peter; Rynearson, Sheri; Chen, Xianming; Pumphrey, Michael
Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst) remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the United States Department of Agriculture-Agricultural Research Service National Small Grains Collection, representing major global production environments. The panel was characterized for field resistance in multi-environment field trials and seedling resistance under greenhouse conditions. A genome-wide set of 5,619 informative SNP markers were used to examine the population structure, linkage disequilibrium and marker-trait associations in the germplasm panel. Based on model-based analysis of population structure and hierarchical Ward clustering algorithm, the accessions were clustered into two major subgroups. These subgroups were largely separated according to geographic origin and improvement status of the accessions. A significant correlation was observed between the population sub-clusters and response to stripe rust infection. We identified 11 and 7 genomic regions with significant associations with stripe rust resistance at adult plant and seedling stages, respectively, based on a false discovery rate multiple correction method. The regions harboring all, except three, of the QTL identified from the field and greenhouse studies overlap with positions of previously reported QTL. Further work should aim at validating the identified QTL using proper germplasm and populations to enhance their utility in marker assisted breeding. PMID:28591221
Full Text Available Abstract Background Puccinia striiformis f.sp. tritici (PST, an obligate fungal pathogen causing wheat yellow/stripe rust, a serious disease, has been used to understand the evolution of crop pathogen using molecular markers. However, numerous questions regarding its evolutionary history and recent migration routes still remains to be addressed, which need the genotyping of a large number of isolates, a process that is limited by both DNA extraction and genotyping methods. To address the two issues, we developed here a method for direct DNA extraction from infected leaves combined with optimized SSR multiplexing. Findings We report here an efficient protocol for direct fungal DNA extraction from infected leaves, avoiding the costly and time consuming step of spore multiplication. The genotyping strategy we propose, amplified a total of 20 SSRs in three Multiplex PCR reactions, which were highly polymorphic and were able to differentiate different PST populations with high efficiency and accuracy. Conclusion These two developments enabled a genotyping strategy that could contribute to the development of molecular epidemiology of yellow rust disease, both at a regional or worldwide scale.
Full Text Available Abstract. In the Republic of Macedonia, wheat is a very important crop and it is grown on an area of around 250.000 ha. The most important regions for wheat growing are: Bitola, Kumanovo, Sveti Nikole, Skopje, Probistip, Kocani, Veles and Stip. The most important deseases on wheat are: Tapesia yallundae Wallwork and Spooner with its anamorphic stage Pseudocercosporella herpotrichoides (Fron Deighton causer of the desease „eyespot“ on barley and wheat; Puccinia graminis f. spp. tritici; Puccinia racondita f. spp. tritici; Gaeumannomyces graminis var. tritici; Bipolaris sorokiniana (Sacc. Shoemaker; Blumeria graminis var. tritici and Zymoseptoria tritici (Mycospharella graminicola (Fuckel Schroter. Many new diseases on wheat causing significant economic damage to producers are observed in Macedonia. The main aim of this article is to present the symptoms, morphology and protective measures of Zymoseptoria tritici (Mycospharella graminicola, the most widely spread fungal pathogens on wheat in the Republic of Macedonia. In the period between 2014 and 2016, the pathogen fungi on wheat with the highest intensity were: Zymoseptoria tritici, Tapesia yallundae, Puccinia graminis, Puccinia recondita, Gaeumannomyces graminis, Bipolaris sorokiniana, Blumeria graminis. The intensity of the diseases and the damages – yield losses of wheat, differed from year to year and between regions, depended on the sensitivity of the wheat varieties. The smallest yield loss was identified in wheat producers who treated the wheat with pesticides at least twice for vegetation season.
Full Text Available The exotic rust fungus Puccinia psidii sensu lato was first detected in Australia in April 2010. This study aimed to determine the host-range potential of this accession of the rust by testing its pathogenicity on plants of 122 taxa, representative of the 15 tribes of the subfamily Myrtoideae in the family Myrtaceae. Each taxon was tested in two separate trials (unless indicated otherwise that comprised up to five replicates per taxon and six replicates of a positive control (Syzygium jambos. No visible symptoms were observed on the following four taxa in either trial: Eucalyptus grandis×camaldulensis, E. moluccana, Lophostemon confertus and Sannantha angusta. Only small chlorotic or necrotic flecks without any uredinia (rust fruiting bodies were observed on inoculated leaves of seven other taxa (Acca sellowiana, Corymbia calophylla 'Rosea', Lophostemon suaveolens, Psidium cattleyanum, P. guajava 'Hawaiian' and 'Indian', Syzygium unipunctatum. Fully-developed uredinia were observed on all replicates across both trials of 28 taxa from 8 tribes belonging to the following 17 genera: Agonis, Austromyrtus, Beaufortia, Callistemon, Calothamnus, Chamelaucium, Darwinia, Eucalyptus, Gossia, Kunzea, Leptospermum, Melaleuca, Metrosideros, Syzygium, Thryptomene, Tristania, Verticordia. In contrast, the remaining 83 taxa inoculated, including the majority of Corymbia and Eucalyptus species, developed a broad range of symptoms, often across the full spectrum, from fully-developed uredinia to no visible symptoms. These results were encouraging as they indicate that some levels of genetic resistance to the rust possibly exist in these taxa. Overall, our results indicated no apparent association between the presence or absence of disease symptoms and the phylogenetic relatedness of taxa. It is most likely that the majority of the thousands of Myrtaceae species found in Australia have the potential to become infected to some degree by the rust, although this
Morin, Louise; Aveyard, Ruth; Lidbetter, Jonathan R.; Wilson, Peter G.
The exotic rust fungus Puccinia psidii sensu lato was first detected in Australia in April 2010. This study aimed to determine the host-range potential of this accession of the rust by testing its pathogenicity on plants of 122 taxa, representative of the 15 tribes of the subfamily Myrtoideae in the family Myrtaceae. Each taxon was tested in two separate trials (unless indicated otherwise) that comprised up to five replicates per taxon and six replicates of a positive control (Syzygium jambos). No visible symptoms were observed on the following four taxa in either trial: Eucalyptus grandis×camaldulensis, E. moluccana, Lophostemon confertus and Sannantha angusta. Only small chlorotic or necrotic flecks without any uredinia (rust fruiting bodies) were observed on inoculated leaves of seven other taxa (Acca sellowiana, Corymbia calophylla ‘Rosea’, Lophostemon suaveolens, Psidium cattleyanum, P. guajava ‘Hawaiian’ and ‘Indian’, Syzygium unipunctatum). Fully-developed uredinia were observed on all replicates across both trials of 28 taxa from 8 tribes belonging to the following 17 genera: Agonis, Austromyrtus, Beaufortia, Callistemon, Calothamnus, Chamelaucium, Darwinia, Eucalyptus, Gossia, Kunzea, Leptospermum, Melaleuca, Metrosideros, Syzygium, Thryptomene, Tristania, Verticordia. In contrast, the remaining 83 taxa inoculated, including the majority of Corymbia and Eucalyptus species, developed a broad range of symptoms, often across the full spectrum, from fully-developed uredinia to no visible symptoms. These results were encouraging as they indicate that some levels of genetic resistance to the rust possibly exist in these taxa. Overall, our results indicated no apparent association between the presence or absence of disease symptoms and the phylogenetic relatedness of taxa. It is most likely that the majority of the thousands of Myrtaceae species found in Australia have the potential to become infected to some degree by the rust, although this wide
Ventura Gonzalez, Morella Fuchs; Castroni, Sonia; Diaz, Ezequiel
With the purpose to generate sugar cane variability in vitro, in order the obtain genotypes resistant to the mosaic viruses and to the rusts (Puccinia melanocephala), callus coming from cultivars susceptible to the mosaic viruses (B 6749, B 7987 and PR 62258) and to the rusts (B 4362 and PR 641791) were irradiated with different gamma radiation dose. The IVIC cobalt source was used, being applied two, four, eight and twelve krads. The effect of irradiation on the percentage of regeneration of plants for each dose and variety was evaluated. The regenerated plants were taken to shelter, where they were inoculated with the mosaic viruses B (SCMB-B). The asymptomatic subclons were transplanted to field in August of 1992, to evaluate the presence of symptoms of mosaic and rusts. A high proportion of the plants didn't show symptoms of illnesses, being obtained 2,35% of sick plants coming from cultivar B 6749 and 0,72 from cultivar PR 62258. This low incidence of infection remained stable up to the following year of evaluation. The genetic variation was studied through isoenzymatics pattern, peroxidase specifically. This analysis allowed to detect variation in the number and intensity of the bands among the subclons and in the original variety. 229 subclons were selected from cultivar B 6749 and they were incorporated to the program of cultivation improvement. Among them 60 subclons, with good agronomic and productivity characteristics, were chosen and continue being evaluated to be incorporated to the regional essays, last phase of the selection process [es
Dracatos, Peter M; Khatkar, Mehar S; Singh, Davinder; Park, Robert F
Barley is an important cereal crop cultivated for malt and ruminant feed and in certain regions it is used for human consumption. It is vulnerable to numerous foliar diseases including barley leaf rust caused by the pathogen Puccinia hordei. A temporarily designated resistance locus RphCantala (RphC) identified in the Australian Hordeum vulgare L. cultivar 'Cantala' displayed an intermediate to low infection type (";12 = N") against the P. hordei pathotype 253P- (virulent on Rph1, Rph2, Rph4, Rph6, Rph8 and RphQ). Phenotypic assessment of a 'CI 9214' (susceptible) x 'Stirling' (RphC) (CI 9214/Stirling) doubled haploid (DH) population at the seedling stage using P. hordei pathotype 253P-, confirmed that RphC was monogenically inherited. Marker-trait association analysis of RphC in the CI 9214/Stirling DH population using 4,500 DArT-seq markers identified a highly significant (-log10Pvalue > 17) single peak on the long arm of chromosome 5H (5HL). Further tests of allelism determined that RphC was genetically independent of Rph3, Rph7, Rph11, Rph13 and Rph14, and was an allele of Rph12 (Rph9.z), which also maps to 5HL. Multipathotype tests and subsequent pedigree analysis determined that 14 related Australian barley varieties (including 'Stirling' and 'Cantala') carry RphC and that the likely source of this resistance is via a Czechoslovakian landrace LV-Kvasice-NA-Morave transferred through common ancestral cultivars 'Hanna' and 'Abed Binder'. RphC is an allele of Rph12 (Rph9.z) and is therefore designated Rph9.am. Bioinformatic analysis using sequence arrays from DArT-seq markers in linkage disequilibrium with Rph9.am identified possible candidates for further gene cloning efforts and marker development at the Rph9/Rph12/Rph9.am locus.
The neotropical rust fungus Puccinia psidii(P. psidii) was originally described from the host common guava in its native Brazil but has been found since on hosts throughout the myrtle family (Myrtaceae), including a dramatic host jump to nonnative Eucalyptus plantations. Most rust fungi are able to live only on a very narrow range of host species. P. psidii is unusual both for having a broad host range and for the intensity of its damage to susceptible young growth. This rust first got a foothold in the United States in Florida more than three decades ago. The U.S. Department of Agriculture (USDA) has since considered it a nonactionable, nonreportable pest. Hawaii and Florida are the only two states with native species in the myrtle family. Over a period of 30 years, this rust has done little damage to any of the scattered native Myrtaceae in Florida, although the host range of the rust has gradually grown to about 30 mostly nonnative species in the family, apparently because of increasing genetic variety of the rust by repeated introductions. However, Florida’s native Myrtaceae are among the roughly 1,100 neotropical species that are largely resistant to P. psidii. The 3,000 species of non-neotropical Myrtaceae of the Pacific, Australia, Asia, and Africa are expected to prove much more vulnerable to P. psidii. Little is known about the genetics or genetic strains of P. psidii, although existing literature shows that there are numerous strains that have differential ability to infect suites of host plants.
Ali, M.; Ji, W.G.; Hu, Y.G; Zhong, H.; Wang, C.Y.; Baloch, G.M.
Stripe rust caused by Puccinia striiformis f. sp. tritici is one of the most devastating diseases of wheat in China as well as in Pakistan. In the present studies F2 population was established by crossing N95175 resistant to stripe rust race CYR32 with two susceptible lines Huixianhong and Abbondanza to molecularly tag resistance gene existing in wheat line N95175. The segregation of phenotype was accorded with an expected 3:1 ratio in both combinations studied and fit the model of a single dominant gene controlling stripe rust resistance in N95175. Thirty five SSR primer pairs were screened on the parents and bulks and also on individuals since resistance gene to be located in chromosome 1B. The result indicated that most of resistant plants amplified same band as resistant parent while susceptible plants amplified same as susceptible parents studied and considered that markers co-segregated with resistant loci in N95175. This yellow rust resistance gene was considered to be Yr26 originally thought to be also located in chromosome arm 1BS linked to marker loci Xgwm273 and Xgwm11 with genetic distances ranging from 1.075cM to 2.74cM in both combinations studied. However, the closest loci were observed 2.67cM for Xgwm273 and 1.075cM for Xgwm11 in Huixianhong XN95175 and Abbondanza XN95175 crosses respectively. Hence, it has been concluded that the PCR-based micro satellite markers Xgwm273 and Xgwm11 located in chromosome 1B were shown to be very effective for the detection of Yr26 gene in segregating population and can be applied in future wheat breeding strategies. (author)
Secretome Characterization and Correlation Analysis Reveal Putative Pathogenicity Mechanisms and Identify Candidate Avirulence Genes in the Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici.
Xia, Chongjing; Wang, Meinan; Cornejo, Omar E; Jiwan, Derick A; See, Deven R; Chen, Xianming
Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is one of the most destructive diseases of wheat worldwide. Planting resistant cultivars is an effective way to control this disease, but race-specific resistance can be overcome quickly due to the rapid evolving Pst population. Studying the pathogenicity mechanisms is critical for understanding how Pst virulence changes and how to develop wheat cultivars with durable resistance to stripe rust. We re-sequenced 7 Pst isolates and included additional 7 previously sequenced isolates to represent balanced virulence/avirulence profiles for several avirulence loci in seretome analyses. We observed an uneven distribution of heterozygosity among the isolates. Secretome comparison of Pst with other rust fungi identified a large portion of species-specific secreted proteins, suggesting that they may have specific roles when interacting with the wheat host. Thirty-two effectors of Pst were identified from its secretome. We identified candidates for Avr genes corresponding to six Yr genes by correlating polymorphisms for effector genes to the virulence/avirulence profiles of the 14 Pst isolates. The putative AvYr76 was present in the avirulent isolates, but absent in the virulent isolates, suggesting that deleting the coding region of the candidate avirulence gene has produced races virulent to resistance gene Yr76 . We conclude that incorporating avirulence/virulence phenotypes into correlation analysis with variations in genomic structure and secretome, particularly presence/absence polymorphisms of effectors, is an efficient way to identify candidate Avr genes in Pst . The candidate effector genes provide a rich resource for further studies to determine the evolutionary history of Pst populations and the co-evolutionary arms race between Pst and wheat. The Avr candidates identified in this study will lead to cloning avirulence genes in Pst , which will enable us to understand molecular mechanisms
Naruoka, Y; Garland-Campbell, K A; Carter, A H
Potential novel and known QTL for race-specific all-stage and adult plant resistance to stripe rust were identified by genome-wide association mapping in the US PNW winter wheat accessions. Stripe rust (Puccinia striiformis F. sp. tritici; also known as yellow rust) is a globally devastating disease of wheat (Triticum aestivum L.) and a major threat to wheat production in the US Pacific Northwest (PNW), therefore both adult plant and all-stage resistance have been introduced into the winter wheat breeding programs in the PNW. The goal of this study was to identify quantitative trait loci (QTL) and molecular markers for these resistances through genome-wide association (GWAS) mapping in winter wheat accessions adapted to the PNW. Stripe rust response for adult plants was evaluated in naturally occurring epidemics in a total of nine environments in Washington State, USA. Seedling response was evaluated with three races under artificial inoculation in the greenhouse. The panel was genotyped with the 9K Illumina Wheat single nucleotide polymorphism (SNP) array and additional markers linked to previously reported genes and QTL for stripe rust resistance. The population was grouped into three sub-populations. Markers linked to Yr17 and previously reported QTL for stripe rust resistance were identified on chromosomes 1B, 2A, and 2B. Potentially novel QTL associated with race-specific seedling response were identified on chromosomes 1B and 1D. Potentially novel QTL associated with adult plant response were located on chromosomes 2A, 2B, 3B, 4A, and 4B. Stripe rust was reduced when multiple alleles for resistance were present. The resistant allele frequencies were different among sub-populations in the panel. This information provides breeders with germplasm and closely linked markers for stripe rust resistance to facilitate the transfer of multiple loci for durable stripe rust resistance into wheat breeding lines and cultivars.
Panwar, Vinay; Jordan, Mark; McCallum, Brent; Bakkeren, Guus
Leaf rust, caused by the pathogenic fungus Puccinia triticina (Pt), is one of the most serious biotic threats to sustainable wheat production worldwide. This obligate biotrophic pathogen is prevalent worldwide and is known for rapid adaptive evolution to overcome resistant wheat varieties. Novel disease control approaches are therefore required to minimize the yield losses caused by Pt. Having shown previously the potential of host-delivered RNA interference (HD-RNAi) in functional screening of Pt genes involved in pathogenesis, we here evaluated the use of this technology in transgenic wheat plants as a method to achieve protection against wheat leaf rust (WLR) infection. Stable expression of hairpin RNAi constructs with sequence homology to Pt MAP-kinase (PtMAPK1) or a cyclophilin (PtCYC1) encoding gene in susceptible wheat plants showed efficient silencing of the corresponding genes in the interacting fungus resulting in disease resistance throughout the T 2 generation. Inhibition of Pt proliferation in transgenic lines by in planta-induced RNAi was associated with significant reduction in target fungal transcript abundance and reduced fungal biomass accumulation in highly resistant plants. Disease protection was correlated with the presence of siRNA molecules specific to targeted fungal genes in the transgenic lines harbouring the complementary HD-RNAi construct. This work demonstrates that generating transgenic wheat plants expressing RNAi-inducing transgenes to silence essential genes in rust fungi can provide effective disease resistance, thus opening an alternative way for developing rust-resistant crops. © 2017 Her Majesty the Queen in Right of Canada. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.
Full Text Available In this research, the wheat cultivar 'Lovrin 10' and Puccinia triticina races 165 and 260 were used to constitute compatible and incompatible combinations to investigate the relationship between NO and H2O2 and between NO and calcium (Ca(2+ signaling in the cell defense process by pharmacological means. The specific fluorescent probe DAF-FM DA was coupled with confocal laser scanning microscopy and used to label intracellular nitric oxide (NO and monitoring the real-time NO dynamics during the processes of wheat defense response triggered by P. triticina infection. The results showed that at 4 h after inoculation, weak green fluorescence was observed in the stomatal guard cells at the P. triticina infection site in the incompatible combination, which indicates a small amount of NO production. Twelve hours after inoculation, the fluorescence of NO in- cell adjacent to the stomata gradually intensified, and the NO fluorescent area also expanded continuously; the green fluorescence primarily occurred in the cells undergoing a hypersensitive response (HR at 24-72 h after inoculation. For the compatible combination, however, a small amount of green fluorescence was observed in stomata where the pathogenic contact occurred at 4 h after inoculation, and fluorescence was not observed thereafter. Injections of the NO scavenger c-PTIO prior to inoculation postponed the onset of NO production to 48 h after inoculation and suppressed HR advancement. The injection of imidazole, a NADPH oxidase inhibitor, or EGTA, an extracellular calcium chelator, in the leaves prior to inoculation, delayed the onset of NO production in the incompatible combination and suppressed HR advancement. Combined with our previous results, it could be concluded that, Ca(2+ and hydrogen peroxide (H2O2 are involved in upstream of NO production to induce the HR cell death during P. triticina infection, and Ca(2+, NO and H2O2 are jointly involved in the signal transduction process of HR
Tallo, Ivar, 1964-
Autor analüüsib ebaõnnestumisi avaliku sektori IT-projektides ning ütleb, et kõige suurem kaotus on olnud usalduse kaotus uute e-lahenduste vastu. Riigis peaks olema üks inimene, kes vastutaks kogu avaliku sektori IT eest
Direct Effects of Physcion, Chrysophanol, Emodin, and Pachybasin on Germination and Appressorium Formation of the Barley ( Hordeum vulgare L.) Powdery Mildew Fungus Blumeria graminis f. sp. hordei (DC.) Speer.
Hildebrandt, Ulrich; Marsell, Alexander; Riederer, Markus
Several anthraquinone derivatives are active components of fungicidal formulations particularly effective against powdery mildew fungi. The antimildew effect of compounds such as physcion and chrysophanol is largely attributed to host plant defense induction. However, so far a direct fungistatic/fungicidal effect of anthraquinone derivatives on powdery mildew fungi has not been unequivocally demonstrated. By applying a Formvar-based in vitro system we demonstrate a direct, dose-dependent effect of physcion, chrysophanol, emodin, and pachybasin on conidial germination and appressorium formation of Blumeria graminis f. sp. hordei (DC.) Speer, the causative agent of barley ( Hordeum vulgare L.) powdery mildew. Physcion was the most effective among the tested compounds. At higher doses, physcion mainly inhibited conidial germination. At lower rates, however, a distinct interference with appressorium formation became discernible. Physcion and others may act by modulating both the infection capacity of the powdery mildew pathogen and host plant defense. Our results suggest a specific arrangement of substituents at the anthraquinone backbone structure being crucial for the direct antimildew effect.
Miller, Marisa E; Zhang, Ying; Omidvar, Vahid; Sperschneider, Jana; Schwessinger, Benjamin; Raley, Castle; Palmer, Jonathan M; Garnica, Diana; Upadhyaya, Narayana; Rathjen, John; Taylor, Jennifer M; Park, Robert F; Dodds, Peter N; Hirsch, Cory D; Kianian, Shahryar F; Figueroa, Melania
Oat crown rust, caused by the fungus Pucinnia coronata f. sp. avenae , is a devastating disease that impacts worldwide oat production. For much of its life cycle, P. coronata f. sp. avenae is dikaryotic, with two separate haploid nuclei that may vary in virulence genotype, highlighting the importance of understanding haplotype diversity in this species. We generated highly contiguous de novo genome assemblies of two P. coronata f. sp. avenae isolates, 12SD80 and 12NC29, from long-read sequences. In total, we assembled 603 primary contigs for 12SD80, for a total assembly length of 99.16 Mbp, and 777 primary contigs for 12NC29, for a total length of 105.25 Mbp; approximately 52% of each genome was assembled into alternate haplotypes. This revealed structural variation between haplotypes in each isolate equivalent to more than 2% of the genome size, in addition to about 260,000 and 380,000 heterozygous single-nucleotide polymorphisms in 12SD80 and 12NC29, respectively. Transcript-based annotation identified 26,796 and 28,801 coding sequences for isolates 12SD80 and 12NC29, respectively, including about 7,000 allele pairs in haplotype-phased regions. Furthermore, expression profiling revealed clusters of coexpressed secreted effector candidates, and the majority of orthologous effectors between isolates showed conservation of expression patterns. However, a small subset of orthologs showed divergence in expression, which may contribute to differences in virulence between 12SD80 and 12NC29. This study provides the first haplotype-phased reference genome for a dikaryotic rust fungus as a foundation for future studies into virulence mechanisms in P. coronata f. sp. avenae IMPORTANCE Disease management strategies for oat crown rust are challenged by the rapid evolution of Puccinia coronata f. sp. avenae , which renders resistance genes in oat varieties ineffective. Despite the economic importance of understanding P. coronata f. sp. avenae , resources to study the
Loope, Lloyd; La Rosa, Anne Marie
In April 2005, the rust fungus Puccinia psidii (most widely known as guava rust or eucalyptus rust) was found in Hawai'i. This was the first time this rust had been found outside the Neotropics (broadly-defined, including subtropical Florida, where the rust first established in the 1970s). First detected on a nursery-grown 'ohi'a plant, it became known as ''ohi'a rust'in Hawai'i. The rust spread rapidly and by August 2005 had been found throughout the main Hawaiian Islands. The rust probably reached Hawai'i via the live plant trade or via the foliage trade. In Hawai'i, the rust has infected three native plant species and at least eight non-native species. Effects have been substantial on the endangered endemic plant Eugenia koolauensis and the introduced rose apple, Syzygium jambos. Billions of yellow, asexual urediniospores are produced on rose apple, but a complete life cycle (involving sexual reproduction) has not yet been observed. The rust is autoecious (no alternate host known) on Myrtaceae. The strain introduced into Hawai'i is found sparingly on 'ohi'a (Metrosideros polymorpha), the dominant tree of Hawai'i's forests, with sporadic damage detected to date. The introduction of a rust strain that causes widespread damage to 'ohi'a would be catastrophic for Hawai'i's native biodiversity. Most imports of material potentially contaminated with rust are shipped to Hawai'i from Florida and California (from which P. psidii was reported in late 2005 by Mellano, 2006). Florida is known to have multiple strains. The identity of the strain or strains in California is unclear, but one of them is known to infect myrtle, Myrtus communis, a species commonly imported into Hawai'i. It is important to ecosystem conservation and commercial forestry that additional rust strains or genotypes be prevented from establishing in Hawai'i. The purpose of this analysis of risk is to evaluate the need for an interim rule by the Hawai'i Department of Agriculture to regulate plant
Full Text Available Abstract Background Puccinia striiformis f. sp. tritici is a fungal pathogen causing stripe rust, one of the most important wheat diseases worldwide. The fungus is strictly biotrophic and thus, completely dependent on living host cells for its reproduction, which makes it difficult to study genes of the pathogen. In spite of its economic importance, little is known about the molecular basis of compatible interaction between the pathogen and wheat host. In this study, we identified wheat and P. striiformis genes associated with the infection process by conducting a large-scale transcriptomic analysis using cDNA-AFLP. Results Of the total 54,912 transcript derived fragments (TDFs obtained using cDNA-AFLP with 64 primer pairs, 2,306 (4.2% displayed altered expression patterns after inoculation, of which 966 showed up-regulated and 1,340 down-regulated. 186 TDFs produced reliable sequences after sequencing of 208 TDFs selected, of which 74 (40% had known functions through BLAST searching the GenBank database. Majority of the latter group had predicted gene products involved in energy (13%, signal transduction (5.4%, disease/defence (5.9% and metabolism (5% of the sequenced TDFs. BLAST searching of the wheat stem rust fungus genome database identified 18 TDFs possibly from the stripe rust pathogen, of which 9 were validated of the pathogen origin using PCR-based assays followed by sequencing confirmation. Of the 186 reliable TDFs, 29 homologous to genes known to play a role in disease/defense, signal transduction or uncharacterized genes were further selected for validation of cDNA-AFLP expression patterns using qRT-PCR analyses. Results confirmed the altered expression patterns of 28 (96.5% genes revealed by the cDNA-AFLP technique. Conclusion The results show that cDNA-AFLP is a reliable technique for studying expression patterns of genes involved in the wheat-stripe rust interactions. Genes involved in compatible interactions between wheat and the
Fungicidas, doses e volumes de calda no controle químico da ferrugem da folha da aveia (Puccinia coronata f. sp. avenae Fungicides, rates and spray volumes in the chemical control of oats crown rust (Puccinia coronata f. sp. avenae
Ana R. de Oliveira
Full Text Available A ferrugem da folha (Puccinia coronata f. sp. avenae é a doença mais destrutiva da aveia, e aplicações de fungicidas com volumes baixos de calda podem reduzir a eficácia do controle químico. O objetivo do trabalho foi avaliar a eficiência técnica e econômica de fungicidas, doses e volumes de calda no controle da ferrugem da folha da aveia. O experimento foi conduzido no ano de 2003, na área experimental da FAMV/UPF, com a cultivar de aveia UPFA-20. Os tratamentos foram compostos pelas combinações entre dois fungicidas (tebuconazole, Folicur, 0,75 L ha-1 e epoxiconazole + piraclostrobim, Opera, 0,5 L ha-1, quatro doses (40; 60; 80 e 100% da dose recomendada e dois volumes de calda (100 e 200 L ha-1. O delineamento experimental foi o de blocos casualizados, com esquema fatorial (2x4x2 e quatro repetições. Avaliaram-se a severidade, o controle da ferrugem, a massa do hectolitro, a massa de mil grãos e o rendimento de grãos, realizando-se análise econômica. O volume de calda de 200 L ha-1 proporcionou maiores níveis de controle da doença. As aplicações dos fungicidas com volume de 200 L ha-1 e meia dose ou com 100 L ha-1 e dose cheia proporcionam níveis de controle da ferrugem equivalentes. O resultado econômico difere entre fungicidas e independe do volume de calda. Os efeitos de doses dependem do fungicida.Crown rust (Puccinia coronata f. sp. avenae is the most important disease of oats in Brazil. In susceptible oat cultivars, fungicides are needed to control the disease efficiently. However, spray at low volumes may reduce fungicide performance significantly. A field experiment with the oat cultivar UPFA-20 was carried out at the FAMV/UPF to evaluate the influence of fungicides, rates, and spray volumes on the efficacy of the chemical control for crown rust. The tested treatments combined two fungicides (tebuconazole, Folicur, 0,75 L ha-1; epoxiconazole + pyraclostrobin, Opera, 0,5 L ha-1, four rates (40; 60; 80 and 100
Ramachandran, Sowmya R; Yin, Chuntao; Kud, Joanna; Tanaka, Kiwamu; Mahoney, Aaron K; Xiao, Fangming; Hulbert, Scot H
Fungi that cause cereal rust diseases (genus Puccinia) are important pathogens of wheat globally. Upon infection, the fungus secretes a number of effector proteins. Although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. In this study, we mined the available transcriptomes of Puccinia graminis and P. striiformis to look for potential effectors that suppress host hypersensitive response (HR). Twenty small (wheat, confirming its activity in a homologous system. Overall, this study provides the first evidence for the presence of effectors in Puccinia species suppressing multiple plant defense responses.
Bread wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is one of the most important food crops world-wide, but is attacked by many diseases and pests that cause significant yield losses. Globally, stem rust (Sr) (Puccinia graminis f. sp. tritici Erikss & E. Henning), stripe rust (Yr) (Puccinia striiformis Westend. f. sp. tritici Eriks) and leaf rust (Lr) (Puccinia triticina Eriks) are a great threat to wheat production. The majority of the Sr, Yr and Lr resistance genes are already defeated...
MACHADO ASSEFH, C.R; COLLAVINO, N.G; DAZ, M; POCOVÍ, M; MARIOTTI, J.
La roya marrón de la caña de azúcar, causada por Puccinia melanocephala, es una enfermedad foliar de preocupación en casi todos los países donde se cultiva la caña de azúcar. Los programas de mejoramiento del cultivo se encuentran en la búsqueda de fuentes de resistencia de la planta al patógeno.
MACHADO ASSEFH, C.R
Full Text Available La roya marrón de la caña de azúcar, causada por Puccinia melanocephala, es una enfermedad foliar de preocupación en casi todos los países donde se cultiva la caña de azúcar. Los programas de mejoramiento del cultivo se encuentran en la búsqueda de fuentes de resistencia de la planta al patógeno.
Cassandra M. Kurtz; Mark H. Hansen
Japanese barberry (Berberis thunbergii), a member of the barberry family (Berberidaceae), is a low-growing perennial shrub. This ornamental shrub was sent to Boston from Russia in 1875 as a substitute for common barberry, a nuisance plant that harbors black stem rust (Puccinia graminis), which affects several cereal crops (...
Over the last decade a number of different molecular methods have been used to characterize genetic diversity in Puccinia graminis. Multilocus DNA fingerprinting methods (AFLPs, RAPDs, SAMs and S-SAPs) have proven to be useful, but limited to phenotypic analysis due to the dikaryotic nature of rust ...
Race-specific resistance genes protect much of the global wheat crop from stem rust disease caused by Puccinia graminis f. sp. tritici (Pgt), but often break down due to evolution of new virulent pathogen races. To understand the molecular mechanisms of virulence evolution in Pgt we identified the p...
Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat (Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of...
Wheat (Triticum aestivum) rust outbreak is the primary production constraint in Eastern Africa. Ethiopia, Kenya and Uganda are hot spots for the epidemic of rusts, due to higher rates of evolution of new pathogen races, especially of the virulent stem rust (Puccinia graminis) race, Ug99. The objective of this study was to ...
Wheat (Triticum aestivum) rust outbreak is the primary production constraint in Eastern Africa. Ethiopia, Kenya and Uganda are hot spots for the epidemic of rusts, due to higher rates of evolution of new pathogen races, especially of the virulent stem rust (Puccinia graminis) race, Ug99. The objective of this study was to ...
Stem rust, caused by Puccinia graminis f. sp. tritici, is one of the most devastating diseases of wheat and the novel highly virulent race of TTKSK and its lineage are threatening wheat production worldwide. The objective of the study was to identify new sources of resistance in wheat-alien introgre...
Research to identify and characterize stem rust resistance genes in common wheat, Triticum aestivum, has been stimulated by the emergence of Ug99-lineage races of the wheat stem rust pathogen, Puccinia graminis f. sp. tritici (Pgt), in Eastern Africa. The Montenegrin spring wheat landrace PI 362698 ...
Wheat stem rust, caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn, can incur yield losses on susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf.) Husnot. Though several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effec...
This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust
Wheat stem rust (Puccinia graminis f. sp. tritici Eriks. and E. Henn.) is one of the most destructive diseases world-wide. Races belonging to Ug99 (or TTKSK) continue to cause crop losses in East Africa and threaten global wheat production. Developing and deploying wheat varieties with multiple race...
The Puccinia graminis f. sp. tritici (Pgt) Ug99 race group is virulent to most stem rust resistance genes currently deployed in wheat and poses a serious threat to global wheat production. The durum wheat (Triticum turgidum ssp. durum) gene Sr13 confers resistance to Ug99 in addition to virulent rac...
Stem or black rust of wheat caused by the fungus Puccinia graminis f. sp. tritici Ericks and Henn (Pgt) is an important disease on wheat worldwide. Pgt is an obligate biotroph, heteroceous in its life cycle and heterothallic in mating type. Seedlings of 41 emmer (Triticum dicoccum), 56 durum (T. durum) wheat accessions were ...
The emergence and spread of new virulent races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici; Pgt), including the TTKSK (Ug99) race group, is a serious threat to global wheat production. In this study, we mapped and characterized two stem rust resistance genes from diploid wheat ...
Wheat stem rust caused by the fungus Puccinia graminis f.sp. tritici (Pgt) is a devastating disease that has largely been controlled for decades by the deployment of resistance genes. However, new races of this pathogen have emerged that overcome many important wheat stem rust resistance genes used ...
In 2016, wheat stripe rust caused by Puccinia striiformis f. sp. graminis was widespread throughout the United States. Cool temperatures and abundant rainfall in the southern Great Plains allowed stripe rust to become widely established and spread throughout the Great Plains and eastern United State...
This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust (P. recondita).
Stem rust, caused by Puccinia graminis Pers.:Pers. f.sp. tritici Eriks. and Henn., poses a serious threat to global wheat production because of the emergence of Pgt-TTKSK (Ug99). The TTKSK resistant gene Sr39 was derived from Aegilops speltoides through chromosome translocation. In this study, we ch...
. In South Africa, stem rust caused by Puccinia graminis Pers. f. sp. tritici. Eriks. & E. Henn. (Pgt) is an important disease of wheat. Records of stem rust occurrence in South Africa date back to the late 1720's, when it was first discovered in the ...
Prof. Adipala Ekwamu
Stem rust caused by Puccinia graminis f. sp. tritici is one of the major biotic limiting factors for wheat production in Ethiopia. Host plant resistance is the best option to manage stem rust from its economic and environmental points of view. Wheat cultivars are released for production without carrying race specific tests against ...
Stem rust of wheat caused by the fungal pathogen Puccinia graminis f. sp. tritici historically caused major yield losses of wheat worldwide. To understand the genetic basis of stem rust resistance in conventional North American spring wheat, genome-wide association analysis (GWAS) was conducted on a...
Wheat production is threatened by the disease stem rust, which is caused by the biotrophic fungal pathogen Puccinia graminis Pers.:Pers. f. sp. tritici (Pgt). Among all known Pgt races, TTKSK (Ug99) and TRTTF are significant threats to North American wheat production due to their virulence against f...
Claire L Anderson; Thomas L Kubisiak; C Dana Nelson; Jason A Smith; John M Davis
The genome size of the pine fusiform rust pathogen Cronartium quercuum f.sp. fusiforme (Cqf) was determined by flow cytometric analysis of propidium iodide-stained, intact haploid pycniospores with haploid spores of two genetically well characterized fungal species, Sclerotinia sclerotiorum and Puccinia graminis f.sp. tritici, as size standards. The Cqf haploid genome...
Stem or black rust caused by Puccinia graminis f. sp. tritici (Pgt) Erikss. & Henning causes severe losses to wheat (Triticum aestivum L.), historically threatening global wheat production. Characterizing prevalent isolates of Pgt would enhance the knowledge of population dynamics and evolution of t...
Herança da resistência à ferrugem da folha da aveia (Puccinia coronata f. sp. avenae Fraser & Led. em genótipos brasileiros de aveia branca Inheritance of oat leaf rust (Puccinia coronata f. sp. avenae Fraser & Led. resistance in white oat brazilian genotypes
Eduardo Alano Vieira
Full Text Available A ferrugem da folha da aveia é a moléstia mais importante que ataca a cultura da aveia, ocorrendo em praticamente todas as áreas em que a aveia é cultivada. A forma mais indicada para o seu controle é a utilização de cultivares resistentes. Contudo, para que seja alcançada a resistência durável ao patógeno, é necessário que se conheça a genética da resistência à ferrugem da folha em aveia. O objetivo foi determinar a forma de herança da resistência a três isolados de Puccinia coronata f. sp. avenae Fraser & Led., (coletados no sul do Brasil em genótipos brasileiros de aveia branca. Para a determinação da herança da resistência a cada um dos três isolados, foram utilizadas populações F2 geradas por meio de cruzamentos artificiais, entre genótipos resistentes (R e suscetíveis (S e entre genótipos resistentes (R. Desta forma, foram utilizadas populações F2 dos cruzamentos artificiais entre: i URPEL 15 (R x UFRGS 7 (S, UPF 16 (R x UFRGS 7 (S e URPEL 15 (R x UPF 16 (R, para a determinação da herança da resistência ao isolado um (1; ii URPEL 15 (R x UFRGS 7 (S, UPF 18 (R x UFRGS 7 (S e URPEL 15 (R x UPF 18 (R, para a determinação da herança da resistência ao isolado dois (2; iii URPEL 15 (R x UFRGS 7 (S e URPEL 15 (R x UPF 18 (S, para a determinação da herança da resistência ao isolado três (3. Os resultados obtidos evidenciaram que o genótipo URPEL 15 apresenta genes dominantes de resistência aos três isolados de ferrugem da folha da aveia avaliados, que o cultivar UPF 16 apresenta um gene recessivo de resistência ao isolado 1 e o cultivar UPF 18 apresenta um gene recessivo de resistência ao isolado 2. E que os genes de resistência apresentados pelos genótipos URPEL 15, UPF 16 e UPF 18, segregam de forma independente.Oat crown rust is the most important disease for the oat crop, occurring in practically all the areas where oat is cultivated. The most indicated form of control for this disease is
Jan 4, 2017 ... 2007; Zhang et al., 2008; Li et al., 2011; Alam et al.,. 2013; Quijano et al., 2015; ..... structure of the eastern US w heat pow dery mildew population. Plant. Dis. ... Collinearity-based marker mining for the fine mapping of Pm6, a ...
Evaluation of the phenotype variability and early selection to rust of the sugar cane (Puccinia melanocephala H. & P. Syd in plants generated from irradiated callus from the variaty of sugar cane ´SP 70-1284´.
Apolonio Valdez Balero
Full Text Available It was evaluated the variability fenotípic in early phases of selection from plants regenerated of the mutagenic treatment with dose of 30 Gy of radiations Gamma (source 60Co applicated to calluses in growth of the donating ´SP 70-1284´ tolerant to the rust disease of the sugarcane Puccinia melanocephala. The main changes the plants obtained in vitro, consinted in the height, the color, habit of growth, length and width of the leaf, as well as in the affectation for the rust disease. 14.28% of the changes all fenotipic was observed in plantín, and in the shoot the plants presented 10.99% of changes all fenotipic. In the vegetative multiplication one (MV1 three possible mutants were selected with smaller affectation in front rust disease of the sugarcan, resistance character to the rust disease efficiency of the tissue culture and the mutations induction with the dose of 30 Gy were of a mutant for each 1 525 plants evaluated in early phase of selection. Key words: variation fenotipic, selection early, mutagenesis
Tallo, Ivar, 1964-
Autor küsib, kas koalitsioonileppe näol on tegemist ühiste väärtuste deklaratsiooni, järgmiste aastate riigivalitsemise tegevuskava või kohtade jaotusega riigi juhtimiseks. Riigieelarve teadliku vähendamise probleemist
Tallo, Ivar, 1964-
Autor näeb vastuolu seoses vaidlusega kaitseväelaste õiguse üle määrata enda hukkumishüvitise saaja: konservatiivse IRL-i minister Jaak Aaviksoo kaitseb sõdurite valikuvabadust ning liberaalist Reformierakonna minister Jürgen Ligi tahaks sõdurite eest otsustada
Tallo, Ivar, 1964-
Autori hinnangul on riigi uuendamise teema jäänud viimase kolme valitsuse tähelepanu alt täiesti kõrvale - nagu oleks Eesti riik valmis saanud. Tema sõnul oleks e-riigi arendamisega võimalik Eesti murenevat positiivset mainet püsti hoida
Tallo, Ivar, 1964-
Tallinna linnavolikogus puhkenud lindiskandaalist. Autori arvates näitab järjekordne skandaal, et poliitikutel puudub elementaarne vastutustunne oma tegevuse tulemuste suhtes ning poliitika puhastumisprotsess Eestis alles kestab
Aday Díaz, Osmany; Barroso Medina, Francisco J; Díaz Mujica, Félix; Martín Tríada, Esther Lilia; Pérez Vicente, Luis; Alfonso Terry, Isabel; Pérez Milián, José; Barroso Melillo, Javier
Se identificaron síntomas de roya naranja (Puccinia kuehnii (Krüger) Butler) en áreas experimentales de la Estación Territorial de Investigaciones de la Caña de Azúcar de Villa Clara, región central de Cuba, y se confirmó su presencia mediante diagnóstico del Laboratorio Central de Cuarentena Vegetal. Se examinaron 562 variedades, de ellas 31 comerciales, 424 progenitores, seis patrones de resistencia a roya marrón y otras en estudios de selección. La infección por P. kuehnii se detectó en 58...
Reacción de 100 variedades de caña de azúcar (saccharum officinarum) del banco de germoplasma del cincae, al carbón (ustilago scitaminea sydow), roya (puccinia melanocephala sydow) y mosaico (sugarcane mosaic virus) en la zona del cantón el triunfo
Fiallos Encalada, Freddy Fabian; Quilambaqui Jara, Miguel
El presente trabajo tuvo como objetivo determinar la reacción de 100 variedades de Caña de Azúcar del Banco de Germoplasma del CINCAE inoculadas, al Carbón (Ustilago scitaminea Sydow), Roya (Puccinia melanocephala Sydow) y Mosaico (Sugarcane Mosaic Virus), las cuales son enfermedades que han causado enormes pérdidas en la producción del cultivo. El ensayo se realizó en el Centro de Investigación de la Caña de Azúcar del Ecuador (CINCAE), ubicado en el cantón El Triunfo, provincia del Guayas. ...
Tallo, Ivar, 1964-
Noortepeod Kadrioru presidendilossis. Avaliku halduse spetsialist vastab küsimustele, kuidas jaguneb Kadrioru lossis era- ja avalik ruum, kas on õigustatud presidendi kantselei taotlus registreerida kõik, ka erakülalised ning kas juhtunu võib kahjustada presidendi mainet. Kaart, skeem: sissepääsud. Vt. samas. Presidendipaar palus vabandust ; Politsei kogub Kadrioru lastepidude kohta infot. Tallinna Vanalinna hariduskolleegiumi põhikooli juhataja Alar Saare kommentaar ; Garel Püüa. Kärmas: tegu ei ole poliitilise vandenõuga
Tallo, Ivar, 1964-
Avaliku halduse spetsialist vastab küsimustele, kuidas jaguneb Kadrioru lossis era- ja avalik ruum, kas on õigustatud presidendi kantselei taotlus registreerida kõik, ka erakülalised ning kas juhtunu võib kahjustada presidendi mainet. Kaart, skeem: Sissepääsud. Kommenteerivad Andrus Ansip, Villu Reiljan, Andrus Saar. Vt. samas: Presidendipaar palus vabandust; Garel Püüa. Kärmas: tegu ei ole vandenõuga
Full Text Available WRKY transcription factors (TFs play crucial roles in plant resistance responses to pathogens. Wheat stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst, is a destructive disease of wheat (Triticum aestivum worldwide. In this study, the two WRKY genes TaWRKY49 and TaWRKY62 were originally identified in association with high-temperature seedling-plant resistance to Pst (HTSP resistance in wheat cultivar Xiaoyan 6 by RNA-seq. Interestingly, the expression levels of TaWRKY49 and TaWRKY62 were down- and up-regulated, respectively, during HTSP resistance in response to Pst. Silencing of TaWRKY49 enhanced whereas silencing TaWRKY62 reduced HTSP resistance. The enhanced resistance observed on leaves following the silencing of TaWRKY49 was coupled with increased expression of salicylic acid (SA- and jasmonic acid (JA-responsive genes TaPR1.1 and TaAOS, as well as reactive oxygen species (ROS-associated genes TaCAT and TaPOD; whereas the ethylene (ET-responsive gene TaPIE1 was suppressed. The decreased resistance observed on leaves following TaWRKY62 silencing was associated with increased expression of TaPR1.1 and TaPOD, and suppression of TaAOS and TaPIE1. Furthermore, SA, ET, MeJA (methyl jasmonate, hydrogen peroxide (H2O2 and abscisic acid (ABA treatments increased TaWRKY62 expression. On the other hand, MeJA did not affect the expression of TaWRKY49, and H2O2 reduced TaWRKY49 expression. In conclusion, TaWRKY49 negatively regulates while TaWRKY62 positively regulates wheat HTSP resistance to Pst by differential regulation of SA-, JA-, ET and ROS-mediated signaling.
Kaur, Jagdeep; Fellers, John; Adholeya, Alok; Velivelli, Siva L S; El-Mounadi, Kaoutar; Nersesian, Natalya; Clemente, Thomas; Shah, Dilip
Rust fungi of the order Pucciniales are destructive pathogens of wheat worldwide. Leaf rust caused by the obligate, biotrophic basidiomycete fungus Puccinia triticina (Pt) is an economically important disease capable of causing up to 50 % yield losses. Historically, resistant wheat cultivars have been used to control leaf rust, but genetic resistance is ephemeral and breaks down with the emergence of new virulent Pt races. There is a need to develop alternative measures for control of leaf rust in wheat. Development of transgenic wheat expressing an antifungal defensin offers a promising approach to complement the endogenous resistance genes within the wheat germplasm for durable resistance to Pt. To that end, two different wheat genotypes, Bobwhite and Xin Chun 9 were transformed with a chimeric gene encoding an apoplast-targeted antifungal plant defensin MtDEF4.2 from Medicago truncatula. Transgenic lines from four independent events were further characterized. Homozygous transgenic wheat lines expressing MtDEF4.2 displayed resistance to Pt race MCPSS relative to the non-transgenic controls in growth chamber bioassays. Histopathological analysis suggested the presence of both pre- and posthaustorial resistance to leaf rust in these transgenic lines. MtDEF4.2 did not, however, affect the root colonization of a beneficial arbuscular mycorrhizal fungus Rhizophagus irregularis. This study demonstrates that the expression of apoplast-targeted plant defensin MtDEF4.2 can provide substantial resistance to an economically important leaf rust disease in transgenic wheat without negatively impacting its symbiotic relationship with the beneficial mycorrhizal fungus.
Wheat is the staple food and the main source of caloric intake in most developing countries, and thereby an important source in order to maintain food security for the growing populations in those countries. Stem rust Puccinia graminis f. sp. tritici, and yellow rust P. striiformis f. sp. tritici of wheat continues to cause severe damage locally and globally, thereby contributing to food insecurity. In this paper biology and taxonomy of stem rust and yellow rust, breeding for resistance, util...
Justesen, Annemarie Fejer; Hansen, Jens Grønbech; Hovmøller, Mogens Støvring
Barberry (Berberis spp.) may serve as alternate host of several Puccinia species including Puccinia graminis and P. striiformis causing stem and yellow rust on cereals and grasses, respectively. In order to study the importance of barberry in the epidemiology of Puccinia species in the CWANA regi...... a rust survey was initiated. The aim was to 1) develop a surveillance protocol 2) develop molecular diagnostic tools for identifying Puccinia spp. from aecial samples, and 3) develop a data management and display system of results as part of the Wheat Rust ToolBox (http....... Due to variable quality of aecial samples DNA extraction was not successful for 40% of the samples. Sequences of EF1α, β-tubulin or ITS were analysed and compared to reference sequences of rust fungi infecting cereals and grasses. The analysis supported the presence of P. graminis s.l., P....... arrhenatheri and P. striiformoides on barberry species. Survey and DNA sample maps with species designation were displayed in the Wheat Rust ToolBox. The future aim is to integrate barberry rust survey data based on molecular diagnostics and infection assays from research groups world-wide in order to gain...
Assessing a sustainable sugar cane production system in Tucumán, Argentina: Part 2: Soil water and thermal regime, stalk population dynamics and sugarcane production Evaluación de un sistema sustentable de producción de caña de azúcar en Tucumán, R. Argentina: Parte II: Contenido de humedad y temperatura del suelo, dinámica de la población de tallos y producción de caña de azúcar
Patricia A. Digonzelli
("mulching" y b sin cobertura de residuos de cosecha (residuo quemado. Se establecieron macroparcelas en un lote comercial implantado con el cultivar LCP 85-384, en Albarracín, Cruz Alta, Tucumán, R. Argentina. El diseño experimental fue de parcelas divididas con tres repeticiones, estando cada parcela formada por cinco surcos de 30 m. Se evaluaron dos ciclos agrícolas: 2006/2007 y 2007/2008. A partir de la cosecha, se determinaron periódicamente la humedad del suelo a 20 cm y 40 cm de profundidad, la temperatura de suelo a 15 cm de profundidad, la infiltración básica y el número de tallos. Al momento de cosecha, se determinaron número y peso de tallos, a partir de los cuales se estimaron las toneladas de caña por surco y por hectárea. La humedad del suelo resultó mayor en el tratamiento con cobertura de residuos para el ciclo 2007/2008, no así para el ciclo 2006/2007, donde no hubo diferencias entre tratamientos. Este comportamiento dependió de la cantidad y distribución de las lluvias. La temperatura del suelo fue mayor en el tratamiento sin cobertura, situación que se mantuvo hasta el cierre del cañaveral. La dinámica de la población de tallos mostró un número de tallos mayor para el tratamiento con cobertura en el pico del macollaje. A cosecha se mantuvo esta tendencia, pero la diferencia solo fue significativa en 2007/2008. La producción de caña por hectárea fue un 12% y un 55% mayor en el tratamiento con cobertura en 2006/2007 y 2007/2008, respectivamente.
Heshof, R.; Schayck, van J.P.; Tamayo Ramos, J.A.; Graaff, de L.H.
Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain
Parodi, P.C.; Nebreda, I.M.
Seed from six genotypes of spring wheat: Huelquen, Collafen, Yafen, PLA771 and Bluebird No.3 (Triticum aestivum L.), and also Quilafen (Triticum durum Desf.) was exposed to gamma radiation in doses of 10 and 25 krad. The aim of the research is to produce cultivars resistant to the main diseases, with a high protein content and grain yield, for the north-central region of Chile (29-35 0 latitude south). The selection process up to the generation M 5 has made it possible to identify mutants with a higher level of resistance to Puccinia graminis, Puccinia recondita and Puccinia striiformis than the original genotypes. Progress made in improving resistance to a fungal complex attacking the spikelets of the mutant cultivars Huelquen and Yafen, to Erysiphe graminis, and to the yellow dwarf virus in barley (BYDV), has been slighter. The yield of grain and protein per unit surface of the mutants studied during repeated experiments has been greater than for the controls. If this trend continues, there should be a number of mutants that could be used for commercial cultivation. (author)
Tallo, Ivar, 1964-
Avaliku halduse ekspert analüüsib president Arnold Rüütli tegevust. Võrdlus president Lennart Meriga. Presidendi kantseleist. Vt. samas: Eesti Vabariigi president on meie põhiseaduse järgi Eesti riigipea, kellel on 20 konkreetset ametiülesannet. Lisa: President Rüütli tähtsamad abilised esimesel ametiajal
Full text: Seeds of variety ''Lalbahadur'' were treated with 0.04% NMH. M 2 plants were inoculated with a mixture of pathotypes of each of the 3 Puccinia species (P. graminis, P. recondita, P. striiformis). Plants with simultaneous resistance to all 3 rusts were selected. Repeated testing in subsequent generations confirmed the resistance. The mutant lines are morphologically similar to the parent cultivar and therefore could be used as components of a multiline variety. Comparison of variety pattern against the Indian pathotypes of rusts suggests that the mutant genes are different from the ones known already in bread wheat. (author)
According to the International Code of Botanical Nomenclature, Art. 23, the nomenclature of the Uredinales, Ustilaginales and Gasteromycetes begins with Persoon’s “Synopsis Methodica Fungorum”, published in 1801. His descriptions, however, are partly not very explicit and as, according to the Code,
Skottrup, Peter; Frøkiær, Hanne; Hearty, Stephen
The fungal pathogen Pst causes yellow rust disease in wheat plants leading to crop losses. The organism spreads by releasing wind-dispersed urediniospores from infected plants. In this study a library of novel monoclonal antibodies (mAbs) was developed against Pst urediniospores. Nine mAb-produci...
Shang Hongsheng; Jing Jinxue; Li Zhenqi
Uredospores of parent culture, cy 29-1, were treated by ultraviolet radiation and mutations to virulent were tested on resistant wheat cultivars inoculated with treated spores. 7 mutant cultures virulent to the test cultivars were developed with estimated mutation rate 10~6~10~4. The virulence of mutant cultures was different from the all known races of stripe rust. Resistance segregation to mutant cultures was detected in two test cultivars. The results suggested that mutation was important mechanism of virulence variation operative in asexual population of rust fungi
the wheat production in Asia, North America, Europe and other wheat growing areas. China is the largest ..... A history of wheat breeding. ... and Yr65 for stripe rust resistance in hexaploid derivatives of durum wheat accessions PI 331260.
Full Text Available The paper presents a rust species new for Poland, that affects the ornamental plant Scilla siberica Haw. The distribution of the fungus and its host plants, both introduced and native in Europe, have been investigated. The data from neighbouring countries indicate that the parasite has been probably overlooked in Poland till now. There is a possibility, however, that the species is currently spreading in central and north-eastern Europe.
Apr 18, 2011 ... Generation means and variance analyses were performed for the estimation of ... population falls into clearly defined and easily recogni- zable categories by ... additive x dominance and dominance x dominance gene effects.
Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng
Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.
Aoun, Meriem; Kolmer, James A; Rouse, Matthew N; Chao, Shiaoman; Bulbula, Worku Denbel; Elias, Elias M; Acevedo, Maricelis
Leaf rust, caused by Puccinia triticina, and stem rust, caused by P. graminis f. sp. tritici, are important diseases of durum wheat. This study determined the inheritance and genomic locations of leaf rust resistance (Lr) genes to P. triticina race BBBQJ and stem rust resistance (Sr) genes to P. graminis f. sp. tritici race TTKSK in durum accessions. Eight leaf-rust-resistant genotypes were used to develop biparental populations. Accessions PI 192051 and PI 534304 were also resistant to P. graminis f. sp. tritici race TTKSK. The resulting progenies were phenotyped for leaf rust and stem rust response at seedling stage. The Lr and Sr genes were mapped in five populations using single-nucleotide polymorphisms and bulked segregant analysis. Five leaf-rust-resistant genotypes carried single dominant Lr genes whereas, in the remaining accessions, there was deviation from the expected segregation ratio of a single dominant Lr gene. Seven genotypes carried Lr genes different from those previously characterized in durum. The single dominant Lr genes in PI 209274, PI 244061, PI387263, and PI 313096 were mapped to chromosome arms 6BS, 2BS, 6BL, and 6BS, respectively. The Sr gene in PI 534304 mapped to 6AL and is most likely Sr13, while the Sr gene in PI 192051 could be uncharacterized in durum.
Aktar-Uz-Zaman, Md; Tuhina-Khatun, Mst; Hanafi, Mohamed Musa; Sahebi, Mahbod
Rust is the most devastating fungal disease in wheat. Three rust diseases, namely, leaf or brown rust caused by Puccinia triticina Eriks, stem or black rust caused by Puccinia graminis f. sp. tritici West, and stripe or yellow rust caused by Puccinia striiformis f. Tritici Eriks, are the most economically significant and common diseases among global wheat cultivars. Growing cultivars resistant to rust is the most sustainable, cost-effective and environmentally friendly approach for controlling rust diseases. To date, more than 187 rust resistance genes (80 leaf rust, 58 stem rust and 49 stripe rust) have been derived from diverse wheat or durum wheat cultivars and the related wild species using different molecular methods. This review provides a detailed discussion of the different aspects of rust resistance genes, their primitive sources, their distribution in global wheat cultivars and the importance of durable resistant varieties for controlling rust diseases. This information will serve as a foundation for plant breeders and geneticists to develop durable rust-resistant wheat varieties through marker-assisted breeding or gene pyramiding
Tallo, Toomas, 1940-
Rein Tedrekulli koolitustsükkel (loengud Väike-Patarei 3, töötoad Liivalaia 19a): vanade uste restaureerimine - 1. III loeng, 5. III töötuba; vanade akende restaureerimine - 8. III loeng, 12. III töötuba; vana mööbli restaureerimine - 15. III loeng, 19. III töötuba. Siidimaali sissejuhatav kursus: 18. III Väike-Patarei 3 töötuba, mida juhendab kunstnik Evi Vares
The background of this research is the phenomenon of easyness of community to communicate since of ICT development, this article deals with phenomenon of the internet use, and access enabler, and mediating messages. This research uses the concept of activity within the concepts of Uses introduced by Levy in theoretical models of Uses and Gratifitcation. Data Collection is by survey. Based on the findings about the second dimension of activity phenomenon (communication sequence), especially in...
Battaglia-Brunet , Fabienne
Many metals and metalloïds are necessary for the devopment of human societies who exploited sub-soil ressources in strategic elements for centuries. However, living higher organisms affected by the toxicity of metals, that can induce important damages to health of impacted populations, and to polluted ecosystems. Environments which present high concentrations in metals and metalloïds present ecological conditions favorable for the development of some micro-organisms. Those environments contai...
Sallam, Ahmad H; Tyagi, Priyanka; Brown-Guedira, Gina; Muehlbauer, Gary J; Hulse, Alex; Steffenson, Brian J
Stem rust was one of the most devastating diseases of barley in North America. Through the deployment of cultivars with the resistance gene Rpg1 , losses to stem rust have been minimal over the past 70 yr. However, there exist both domestic (QCCJB) and foreign (TTKSK aka isolate Ug99) pathotypes with virulence for this important gene. To identify new sources of stem rust resistance for barley, we evaluated the Wild Barley Diversity Collection (WBDC) (314 ecogeographically diverse accessions of Hordeum vulgare subsp. spontaneum ) for seedling resistance to four pathotypes (TTKSK, QCCJB, MCCFC, and HKHJC) of the wheat stem rust pathogen ( Puccinia graminis f. sp. tritici , Pgt ) and one isolate (92-MN-90) of the rye stem rust pathogen ( P. graminis f. sp. secalis , Pgs ). Based on a coefficient of infection, the frequency of resistance in the WBDC was low ranging from 0.6% with HKHJC to 19.4% with 92-MN-90. None of the accessions was resistant to all five cultures of P. graminis A genome-wide association study (GWAS) was conducted to map stem rust resistance loci using 50,842 single-nucleotide polymorphic markers generated by genotype-by-sequencing and ordered using the new barley reference genome assembly. After proper accounting for genetic relatedness and structure among accessions, 45 quantitative trait loci were identified for resistance to P. graminis across all seven barley chromosomes. Three novel loci associated with resistance to TTKSK, QCCJB, MCCFC, and 92-MN-90 were identified on chromosomes 5H and 7H, and two novel loci associated with resistance to HKHJC were identified on chromosomes 1H and 3H. These novel alleles will enhance the diversity of resistance available for cultivated barley. Copyright © 2017 Sallam et al.
Věchet, L.; Vrchotová, Naděžda; Hanazalová, J.
Roč. 15, SI (2012), s. 61-62 ISSN 1335-258X Institutional support: RVO:67179843 Keywords : wheat * powdery mildew * inducers of plant origin * inducers of chemical origin Subject RIV: EH - Ecology, Behaviour
Castroagudín, V.L.; Moreira, S.I.; Pereira, D.A.S.; Moreira, S.S.; Brunner, P.C.; Maciel, J.L.N.; Crous, P.W.; McDonald, B.A.; Alves, E.; Ceresini, P.C.
Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses
Christiansen, S.K.; Justesen, A.F.; Giese, H.
to be similar for all four genes. The results of the codon-usage analysis suggest that Egh is more flexible than other fungi in the choice of nucleotides at the wobble position. Codon-usage preferences in Egh and barley genes indicate a level of difference which may be exploited to discriminate between fungal...
Torp, J.; Jensen, H.P.
Full text: Seedlings of 4 barley lines possessing resistance genes M1-a6, M1-a12 or M1-g were inoculated with powdery mildew culture CR3, which is a-virulent to the 4 host lines. In total, 50 million conidia were screened for the occurrence of virulent mutants, 43 putative virulent mutants were found. They could be grouped into 5 genotypes according to the virulence spectrum. They might have originated by one of the following events: 1. admixture, 2. physiological events that allow a few conidia to establish colonies in spite of the presence of a functional gene for resistance, 3. mutation in a gene for specificity, 4. deletion or mutation in some kind of suppressing element in which case more than one virulence may be affected. Based upon the virulence spectra, mating type, biochemical tests and analysis of test crosses, 3 of the genotypes were clearly classified as not being of mutational origin. Of the two remaining genotypes one differed in 4 virulences, the other by two virulences and one avirulence. Based upon expectations from the gene-for-gene concept, it is concluded that both were not of mutational origin. If in fact there are derived from a mutation, the concept of gene-for-gene interactions would have to be revised. Assuming that no mutations for virulence were found in this experiment, the spontaneous mutation frequency from avirulence to virulence would be below 2x10 -8 . (author)
In the last three decades, plant disease control has become heavily dependent on fungicides. This practice increased yield significantly but had also negative side-effects on the environment. In many countries, integrated control programs have been initiated in order to reduce pesticide use
Haugaard, H.; Jørgensen, H.J.L.; Lyngkjær, M.F.
, Trichoderma harzianum, Pythium ultimum and Rhizopus stolonifer). Three mycelial extracts from the taxonomically different fungi B. oryzae, A ultimum and R. stolonifer were selected for detailed study. In general the number of colonies formed was reduced by 70-98% compared with controls. Furthermore, the few...
Franco, Sulamita de Freitas; Baroni, Renata Moro; Carazzolle, Marcelo Falsarella; Teixeira, Paulo José Pereira Lima; Reis, Osvaldo; Pereira, Gonçalo Amarante Guimarães; Mondego, Jorge Maurício Costa
Thaumatin-like proteins (TLPs) are found in diverse eukaryotes. Plant TLPs, known as Pathogenicity Related Protein (PR-5), are considered fungal inhibitors. However, genes encoding TLPs are frequently found in fungal genomes. In this work, we have identified that Moniliophthora perniciosa, a basidiomycete pathogen that causes the Witches' Broom Disease (WBD) of cacao, presents thirteen putative TLPs from which four are expressed during WBD progression. One of them is similar to small TLPs, which are present in phytopathogenic basidiomycete, such as wheat stem rust fungus Puccinia graminis. Fungi genomes annotation and phylogenetic data revealed a larger number of TLPs in basidiomycetes when comparing with ascomycetes, suggesting that these proteins could be involved in specific traits of mushroom-forming species. Based on the present data, we discuss the contribution of TLPs in the combat against fungal competitors and hypothesize a role of these proteins in M. perniciosa pathogenicity. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available The present work points out to the interdisciplinary experimental results, obtained in the experimental fields of the Plant Protection and Soil Science Department, as well as at data which stress upon the interdependency between the satisfaction of the trophically needs of the wheat plants and the aggressiveness of the pathogens which cause the disease. The experimental results underline the fact that the attack level expressed through intensity and attack degree is different, both with the “out of root” fertilized variants and with the soil fertilization variants. The conclusions which come off the study of the obtained data point out at the fact that the fertilizer application, no matter the method, determines the growth or the regress of the attack degree. They also have an influence upon the Puccinia striformis f.sp. tritici, Blumeria graminis and, Septoria spp. fungus manifestation.
Full Text Available The powdery mildew and leaf rust caused by Blumeria graminis and Puccinia recondita (respectively are common diseases of wheat throughout the world. These fungal diseases greatly affect crop productivity. Incorporation of effective and durable disease resistance is an important breeding objective for wheat improvement. We have evaluated resistance of four bread wheat (Triticum aestivum and four spelt wheat (Triticum spelta cultivars. Chitinases occurrence as well as their activity was determined in leaf tissues. There was no correlation between resistance rating and activity of chitinase. The pattern of chitinases reveals four isoforms with different size in eight wheat cultivars. A detailed understanding of the molecular events that take place during a plant–pathogen interaction is an essential goal for disease control in the future.
Weinstein, L. H.; Osmeloski, J. F.; Wettlaufer, S. H.; Galston, A. W.
In higher plants, polyamines arise from arginine by one of two pathways: via ornithine and ornithine decarboxylase or via agmatine and arginine decarboxylase but in fungi, only the ornithine decarboxylase pathway is present. Since polyamines are required for normal growth of microorganisms and plants and since the ornithine pathway can be irreversibly blocked by alpha-difluoromethylornithine (DFMO) which has no effect on arginine decarboxylase, fungal infection of green plants might be controlled by the site-directed use of such a specific metabolic inhibitor. DFMO at relatively low concentrations provided effective control of the three biotrophic fungal pathogens studied, Puccinia recondita (leaf rust), P. graminis f. sp. tritici (stem rust), and Erysiphe graminis (powdery mildew) on wheat (Triticum aestivum L.) Effective control of infection by leaf or stem rust fungi was obtained with sprays of DFMO that ranged from about 0.01 to 0.20 mM in experiments where the inhibitor was applied after spore inoculation. The powdery mildew fungus was somewhat more tolerant of DFMO, but good control of the pathogen was obtained at less than 1.0 mM. In general, application of DFMO after spore inoculation was more effective than application before inoculation. Less control was obtained following treatment with alpha-difluoromethylarginine (DFMA) but the relatively high degree of control obtained raises the possibility of a DFMA to DFMO conversion by arginase.
Karavaev, V A; Solntsev, M K; Iurina, T P; Iurina, E V; Poliakova, I B; Kuznetsov, A M
We found that extracts from the leaves of medicinal comfrey and cowparsnip strongly inhibit the germination of Erysiphe graminis conidia and uredospores of Puccinia graminis. Spraying wheat seedlings with these extracts, in contrast to the irrigation of soil, markedly diminished infection in plants with powdery mildew. Antifungal activity in vitro and protective activity (when plants were sprayed) correlated with the level of phenolic compounds in these extracts. Experiments with healthy plants have demonstrated that the photosynthetic apparatus of wheat plants is stimulated by extracts. Spraying seedlings with the extracts resulted in an increased rate of O2 evolution calculated per unit of chlorophyll, an increase in the ratio (FM-FT)/FT in the experiments that recorded slow fluorescence induction, an increase in the relative light intensity of band A, and a decrease of relative intensity of band C in experiments with thermoluminescence of wheat leaves. These results provide evidence that the protective activity of comfrey and cowparsnip extracts is associated with their action on the pathogenic fungus and with the activation of natural defense reactions of the host plant.
Kuzdraliński, Adam; Kot, Anna; Szczerba, Hubert; Nowak, Michał; Muszyńska, Marta
Infection of phyllosphere (stems, leaves, husks, and grains) by pathogenic fungi reduces the wheat yield and grain quality. Detection of the main wheat pathogenic fungi provides information about species composition and allows effective and targeted plant treatment. Since conventional procedures for the detection of these organisms are unreliable and time consuming, diagnostic DNA-based methods are required. Nucleic acid amplification technologies are independent of the morphological and biochemical characteristics of fungi. Microorganisms do not need to be cultured. Therefore, a number of PCR-based methodologies have been developed for the identification of key pathogenic fungi, such as Fusarium spp., Puccinia spp., Zymoseptoria tritici, Parastagonospora nodorum, Blumeria graminis f. sp. tritici, and Pyrenophora tritici-repentis. This article reviews frequently used DNA regions for fungus identification and discusses already known PCR assays for detection of the aforementioned wheat pathogens. We demonstrate that PCR-based wheat pathogen identification assays require further research. In particular, the number of diagnostic tests for Fusarium graminearum, Puccinia spp., and P. tritici-repentis are insufficient. © 2017 S. Karger AG, Basel.
Njau, P.N.; Kinyua, M.G.; Karanja, L.; Maling'a, J.
Yellow rust caused by Puccinia striformis and stem rust caused by Puccinia graminis tritici are most destructive diseases in Kenya. In wheat improvement, development of varieties of wheat with resistance to these diseases has been among the foremost contributions in wheat breeding. In breeding programs each disease is considered as a separate problem. Attention has been given to varieties resistant to stem rust, yellow rust and leaf rust among other diseases. In the year 2001 program stem rust and yellow rust were recorded in all the sites where NPT was performed. Breeding for resistance for the two diseases is approached through the Introductions and Hybridisation. The Doubled Haploid Technique is used to quicken the time of homozygous lines production. The introduction and the homozygous lines are then evaluated for yield and disease resistance in the field under preliminary yield trials and the National Performance Trials (NPT) in 2001, 18 lines and 2 check varieties were included in the NPT. The results show that there were some differences in reaction to the three diseases where lines R946, K7972-1 and R899 had the lowest score of the diseases in all sites. In the commercial variety trial the results show that all the varietieshave become susceptible to stem rust and so the need to develop new cultivars which will be resistance to the rusts. Yombi a newly developed variety showed a substantially high level resistance. (author)
Christina A. Cuomo
Full Text Available Three members of the Puccinia genus, Puccinia triticina (Pt, P. striiformis f.sp. tritici (Pst, and P. graminis f.sp. tritici (Pgt, cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of Pt and Pst were sequenced and compared to that of Pgt to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi, and basidiomycetes, and to identify genes of significance for infection. Pt had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; in comparison, repeats occupy 31.5% for Pst and 36.5% for Pgt. We find all three genomes are highly heterozygous, with Pst [5.97 single nucleotide polymorphisms (SNPs/kb] nearly twice the level detected in Pt (2.57 SNPs/kb and that previously reported for Pgt. Of 1358 predicted effectors in Pt, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate degradation enzymes. Two allelic homeodomain pairs, HD1 and HD2, were identified in each dikaryotic Puccinia species along with three pheromone receptor (STE3 mating-type genes, two of which are likely representing allelic specificities. The HD proteins were active in a heterologous Ustilago maydis mating assay and host-induced gene silencing (HIGS of the HD and STE3 alleles reduced wheat host infection.
Vaz Patto, M.C.; Niks, R.E.
The directional growth of urediospores germ tubes along the transverse axis of a cereal's leaf is considered to be a response to stimuli from the plant surface. In order to find out if the germ tube growth is directed towards stomata, and if the cuticular wax layer plays a role in this orientated
In July 2010, Allium sativum, cultivar German Extra Hardy Porcelain plants showing foliar symptoms typical of rust infection were brought to the Plant Disease Clinic at the University of Minnesota by a commercial grower from Fillmore county Minnesota. Infected leaves showed circular to oblong lesio...
Voženílková, B.; Marková, J.; Klimeš, F.; Květ, Jan; Mašková, Z.
Roč. 115, č. 4 (2008), s. 167-171 ISSN 1861-3829 R&D Projects: GA ČR(CZ) GA206/99/1410 Institutional research plan: CEZ:AV0Z60870520 Keywords : Alopecurus pratensis * fallow stand * mown stand * mulched stand * rust fungi Subject RIV: EF - Botanics Impact factor: 0.566, year: 2008
Liliana M Cano
Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.
Rodriguez Algaba, Julian; Walter, Stephanie; Sørensen, Chris Khadgi
An effort to develop an experimental genetic system for the stripe (yellow) rust fungus using Berberis vulgaris as an alternate host has been made by INRA Grignon (F) and GRRC (DK). The first attempts to achieve infection using European isolates and B. vulgaris plants from France were unsuccessful...... and to study genotypic diversity. The markers confirmed the parental origin and markers that were heterozygous in the parent generally segregated in the S1 progenies. A largest number of multilocus genotypes observed among the progeny isolates confirmed successful sexual recombination. Segregation...... for avirulence and virulence was investigated using 15 single R-gene wheat lines. The sexual structures and spore forms were documented by microscopic and macroscopic imaging at crucial time points during the life cycle of Pst on the alternate host....
Garcia, Ely Oliveira; Casagrande, Marcos Virgílio; Rago, Alejandro Mário; Massola Junior, Nelson Sidnei
A sazonalidade na manifestação da ferrugem da cana dificulta a obtenção de esporos em quantidades adequadas para inoculações em qualquer época do ano, restringindo os trabalhos envolvendo o patógeno aos meses nos quais a doença esta presente no campo. O trabalho visou desenvolver uma metodologia para preservar os esporos por períodos prolongados, mantendo sua viabilidade e infectividade. Esporos foram coletados a partir de folhas naturalmente infectadas, com bomba de vácuo. Parte dos esporos ...
Sørensen, Chris Khadgi; Thach, Tine; Hovmøller, Mogens Støvring
flexible application procedure for spray inoculation and it gave highly reproducible results for virulence phenotyping. Six point inoculation methods were compared to find the most suitable for assessment of pathogen aggressiveness. The use of Novec 7100 and dry dilution with Lycopodium spores gave...... for the assessment of quantitative epidemiological parameters. New protocols for spray and point inoculation of P. striiformis on wheat are presented, along with the prospect for applying these in rust research and resistance breeding activities....
Full Text Available Leaf spot and rust are two important diseases on groundnut. Both diseases are frequently found at the same time that influence the growth and reduce the yield of groundnut. This study was conducted to evaluate thirteen groundnut genotypes resistance to leaf spot and rust disease. The experiment was conducted using a split plot design and three replications, with inoculated and uninoculated treatment as main plot, and groundnut genotypes as the sub plot. Disease assessment was conducted by counting number of pustules per leaf, the number of spots per leaf, rust disease intensity, the intensity of leaf spot disease, and leaf area index. Yield components including stover weight, number of pods per plant, number of empty pods, number of chipo pods, and weight of pods per plant were recorded for both inoculated and uninoculated plants. The result showed that leaf spot disease developed earlier than rust disease. Only one genotype was susceptible to rust and the other 12 genotypes were very susceptible, whereas all genotypes tested were very susceptible to leaf spot. The intensity of rust and leaf spot diseases was negatively correlated with yield (r = - 0.1 – (0.4. Rust and leaf spot diseases reduced the yield components including stover weight (73.2%, number of pods (68%, and weight of pods (72.5%. The number of empty pods and chipo pods were increase to 81% and 56.4% respectively.
The results revealed that stripe rust resistance genes Yr3, Yr5, Yr10, Yr15, Yr26, YrSP and YrCV were resistant, while Yr18 showed moderate susceptibility at all locations. Genes YrA-, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr27 and gene combinations Opata (Yr27+Yr18) and Super Kauz (Yr9, Yr27, Yr18) were found susceptible.
Věchet, L.; Martínková, J.; Šindelářová, Milada; Burketová, Lenka
Roč. 51, č. 10 (2005), s. 469-475 ISSN 1214-1178 R&D Projects: GA ČR GA522/03/0353 Institutional research plan: CEZ:AV0Z50380511 Keywords : winter wheat * inducer of resistence * powdery mildew Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.170, year: 2004
Komínková, Eva; Dreiseitl, A.; Malečková, Eva; Doležel, Jaroslav; Valárik, Miroslav
Roč. 11, č. 11 (2016), č. článku e0167099. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LO1204; GA MŠk(CZ) LD14105 Institutional support: RVO:61389030 Keywords : barley powdery mildew * f.sp hordei * isozyme variation * ssr markers * virulence * pathogen * complexity * france * frequencies * resistance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.806, year: 2016
Full Text Available 1. Engelbrecht E, Heinert K. Klassifikation und Behandlungsrichtlinien von Knochensubsanzverlusten bei Revisionsoperationen am Huftgelenk mittelfrsige Ergebnisse. Primare und Revisionsalloarthroplastik Hrsg-Endo-Klinik, Hamburg: Springer-Verlag, Berlin; 1987:189. 2. Merle d’Aubigné R, Postel M. Functional results of hip arthroplasty with acrylic prosthesis. J Bone Joint Surg Am 1954;36:451. 3. Hood RW, Wright TM, Burstein AH. Retrieval analysis of total knee prostheses: a method and its application to 48 total condylar prostheses. J Biomed Mat Res 1983;17:829. 4. Carlsson AS, Gentz CF, Stenport J. Fracture of the femoral prosthesis in total hip replacement according to Charnley. Acta Orthop Scand 1977;48:650-5. 5. Chao EYS, Coventry MB. Fracture of the femoral component after total hip replacement. An analysis of fifty-eight cases. J Bone Joint Surg Am 1981;63:1078-94. 6. Charnley J. Fracture of femoral prostheses in total hip replacement. A clinical study. Clin Orthop 1975;111:105. 7. Buttaro M, Mayor M, Van Citters D, Piccaluga F. Fracture of a proximally modular, distally fluted uncemented implant with diaphyseal fixation. J Arthroplasty 2007;22(5:780-3. 8. Bohm P, Bischel O. Femoral revision with the Wagner SL revision stem: evaluation of one hundred and twenty-nine revisions followed for a mean of 4.8 years. J Bone Joint Surg Am 2001;83(7:1023. 9. Woolson ST, Milbauer JP, Bobyn JD, Yue S, Maloney WJ. Fatigue fracture of a forged cobalt-chromium-molybdenum femoral component inserted with cement. A report of ten cases. J Bone Joint Surg Am 1997;79(12:1842.
Juárez Cruz, Aída
Entre las especies con potencial productivo, sobresalen la cruceta o jacube (Acanthocereus tetragonus), el nopal de cruz (Acanthocereus subinermis) y la pitahaya (Hylocereus undatus.) porque tienen uso como cerco vivo, ornamento, medicina y alimento en diferentes regiones de México. Sin embargo, existe poca información sobre el valor nutritivo y características anatómicas de éstos materiales, principalmente del género Acanthocereus; por lo anterior, la presente investigación tuvo como objetiv...
Full Text Available A chemical and biological preliminary study of the species Vismia cayennensis, collected in the Amazonas state, Venezuela. The antibacterial test of plant bark extract showed significant inhibition in Escherichia coli, Shigella sp and Staphylococcus aureus. In addition, three of the five soluble fractions of different polarity solvents, specifically those of chloroform, acetone and water, maintained moderately active against Shigella sp strain. The hydroalcoholic extract of the plant and the fraction soluble in chloroform, exhibited a significant antiinflammatory effect. Cytotoxicity tests performed by the methods of (3-(4,5-dimetiltiazol-2-yl-5-(3-carboximetoxifenil-2-(4-sulfophenyl-2H-tetrazolium/phenazine methosulfate of (MTS/PMS and sulforhodamine B , revealed that only has water soluble cytotoxic effect. Additionally, a study phytochemical obtained information on the presence of some families of secondary metabolites such as flavonoids, saponins, tannins, polyphenols, anthraquinones, triterpenes and sterols. It can be inferred that the stem bark of the plant V. cayennensis, is a promising source of bioactive secondary metabolites
la enfermedad se evaluó de acuerdo a una escala 0-6 a los 15 días después de la inoculación. Los resultados indicaron que las seis variedades evaluadas mostraron ser susceptibles a la infección. ‘Polar’, ‘Leonora’, ‘Indianápolis’ y ‘Codorniz’ se comportaron como las variedades más susceptibles, mientras que ‘Puma’ y ‘Spider’ exhibieron cierta tolerancia.
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The blink reflex is the neural response elicited in the orbicular oculi muscle after single or paired supraorbital nerve stimulation, by either electrical, mechanical, acoustic, thermal, chemical or magnetic stimulation. It is made up of three responses called R1, R2 and R3. R1 is an early response that follows A beta fibers, and does not habituate. R2 is a middle-latency response that follows A beta and A delta fibers, tends to habituate and is modulated by sensorimotor suprasegmental structures.
R3 is a long-latency response, generated by stimulation of a multisynaptic chain of neurons that involve type C fibers belonging to a complex pontothalamic-amigdalo-cerebellar pathway. It is also possible to record three silent periods if the blink reflex is obtained while the subject makes a voluntary facial muscle effort.
The functional study of this reflex allows to define with certainty whether the lesion is in afferent or efferent pathways or if it involves an abnormal sensorimotor integration due to disorders of the central, autonomic or peripheral nervous systems. A correct execution of these studies, and their appropriate interpretation, based on the underlying mechanisms of neural plasticity, will guide toward better neurorehabilitation protocols.
El reflejo de parpadeo es la respuesta neural que se obtiene en el músculo orbicular de los ojos, luego de estimular el nervio trigeminal, bien sea de manera simple o pareada, por medios eléctricos, mecánicos, acústicos, térmicos, químicos o magnéticos; cuando se estimula dicho nervio se obtienen tres respuestas llamadas R1, R2 y R3. R1 tiene latencia corta, viaja por fibras A beta y no se habitúa.
R2 es de latencia mediana, viaja por fibras A beta o A delta, tiende a habituarse y la modulan estructuras suprasegmentales sensorimotoras. R3 es de latencia larga, se genera al estimular vías multisinápticas que involucran fibras tipo C, en una ruta compleja ponto-amígdalo-talámico-cerebelar.
También se pueden registrar tres períodos silentes cuando el reflejo del parpadeo se obtiene mientras el individuo hace una contracción voluntaria muscular facial. El estudio funcional de este reflejo permite identificar con certeza si la lesión está en las vías aferentes o en las eferentes o si involucra una integración anormal sensorimotora debida a trastornos de los sistemas nerviosos central, autonómico o periférico. La ejecución correcta de estos estudios, así como su interpretación apropiada, con base en los mecanismos subyacentes de plasticidad neural, son guías para orientar mejor los protocolos de neurorrehabilitación.
Rahmatov, Mahbubjon; Rouse, Matthew N; Nirmala, Jayaveeramuthu; Danilova, Tatiana; Friebe, Bernd; Steffenson, Brian J; Johansson, Eva
A new stem rust resistance gene Sr59 from Secale cereale was introgressed into wheat as a 2DS·2RL Robertsonian translocation. Emerging new races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici), from Africa threaten global wheat (Triticum aestivum L.) production. To broaden the resistance spectrum of wheat to these widely virulent African races, additional resistance genes must be identified from all possible gene pools. From the screening of a collection of wheat-rye (Secale cereale L.) chromosome substitution lines developed at the Swedish University of Agricultural Sciences, we described the line 'SLU238' 2R (2D) as possessing resistance to many races of P. graminis f. sp. tritici, including the widely virulent race TTKSK (isolate synonym Ug99) from Africa. The breakage-fusion mechanism of univalent chromosomes was used to produce a new Robertsonian translocation: T2DS·2RL. Molecular marker analysis and stem rust seedling assays at multiple generations confirmed that the stem rust resistance from 'SLU238' is present on the rye chromosome arm 2RL. Line TA5094 (#101) was derived from 'SLU238' and was found to be homozygous for the T2DS·2RL translocation. The stem rust resistance gene on chromosome 2RL arm was designated as Sr59. Although introgressions of rye chromosome arms into wheat have most often been facilitated by irradiation, this study highlights the utility of the breakage-fusion mechanism for rye chromatin introgression. Sr59 provides an additional asset for wheat improvement to mitigate yield losses caused by stem rust.
Full Text Available Wheat stem rust, caused by Puccinia graminis f. sp. tritici Eriks. & E. Henn, can incur yield losses in susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf. Husnot. Although several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effective against emerging virulent races have not been described. Durum line 8155-B1 confers resistance against the P. graminis f. sp. tritici race TTKST, the variant race of the Ug99 race group with additional virulence to wheat stem rust resistance gene Sr24. However, 8155-B1 does not confer resistance to the first-described race in the Ug99 race group: TTKSK. We mapped a single gene conferring resistance in 8155-B1 against race TTKST, Sr8155B1, to chromosome arm 6AS by utilizing Rusty/8155-B1 and Rusty*2/8155-B1 populations and the 90K Infinium iSelect Custom bead chip supplemented by KASP assays. One marker, KASP_6AS_IWB10558, cosegregated with Sr8155B1 in both populations and correctly predicted Sr8155B1 presence or absence in 11 durum cultivars tested. We confirmed the presence of Sr8155B1 in cultivar Mountrail by mapping in the population Choteau/Mountrail. The marker developed in this study could be used to predict the presence of resistance to race TTKST in uncharacterized durum breeding lines, and also to combine Sr8155B1 with resistance genes effective to Ug99 such as Sr13. The map location of Sr8155B1 cannot rule out the possibility that this gene is an allele at the Sr8 locus. However, race specificity indicates that Sr8155B1 is different from the known alleles Sr8a and Sr8b.
Draper, John; Mur, Luis A.J.; Jenkins, Glyn; Ghosh-Biswas, Gadab C.; Bablak, Pauline; Hasterok, Robert; Routledge, Andrew P.M.
A new model for grass functional genomics is described based on Brachypodium distachyon, which in the evolution of the Pooideae diverged just prior to the clade of “core pooid” genera that contain the majority of important temperate cereals and forage grasses. Diploid ecotypes of B. distachyon (2n = 10) have five easily distinguishable chromosomes that display high levels of chiasma formation at meiosis. The B. distachyon nuclear genome was indistinguishable in size from that of Arabidopsis, making it the simplest genome described in grasses to date. B. distachyon is a self-fertile, inbreeding annual with a life cycle of less than 4 months. These features, coupled with its small size (approximately 20 cm at maturity), lack of seed-head shatter, and undemanding growth requirements should make it amenable to high-throughput genetics and mutant screens. Immature embryos exhibited a high capacity for plant regeneration via somatic embryogenesis. Regenerated plants display very low levels of albinism and have normal fertility. A simple transformation system has been developed based on microprojectile bombardment of embryogenic callus and hygromycin selection. Selected B. distachyon ecotypes were resistant to all tested cereal-adapted Blumeria graminis species and cereal brown rusts (Puccinia reconditia). In contrast, different ecotypes displayed resistance or disease symptoms following challenge with the rice blast pathogen (Magnaporthe grisea) and wheat/barley yellow stripe rusts (Puccinia striformis). Despite its small stature, B. distachyon has large seeds that should prove useful for studies on grain filling. Such biological characteristics represent important traits for study in temperate cereals. PMID:11743099
Ely Oliveira Garcia
Full Text Available A sazonalidade na manifestação da ferrugem da cana dificulta a obtenção de esporos em quantidades adequadas para inoculações em qualquer época do ano, restringindo os trabalhos envolvendo o patógeno aos meses nos quais a doença esta presente no campo. O trabalho visou desenvolver uma metodologia para preservar os esporos por períodos prolongados, mantendo sua viabilidade e infectividade. Esporos foram coletados a partir de folhas naturalmente infectadas, com bomba de vácuo. Parte dos esporos foi desidratada por liofilização ou em sílica gel e outra parte não passou por desidratação. Armazenaram-se estes esporos em diferentes temperaturas (temp. ambiente, 5ºC, -20 ºC, -80ºC. Periodicamente, a viabilidade dos esporos foi avaliada por meio de plaqueamento em ágar-água. Após o quarto mês, foi também avaliada a infectividade dos esporos armazenados por meio de inoculações na variedade suscetível SP70-1143, seguida da avaliação da área foliar atacada. Os esporos armazenados à temperatura ambiente e a 5ºC, independentemente da desidratação, permaneceram viáveis por períodos máximos de 1 mês e 2 meses, respectivamente. Os melhores tratamentos consistiram na desidratação em sílica gel, seguida pelo armazenamento à -20ºC e -80ºC. Mesmo após um ano de armazenamento nestas condições, os esporos provocaram ferrugem nas plantas inoculadas, em níveis de severidade adequados para um teste de discriminação de reações à ferrugem.The seasonality in the appearance of sugarcane rust makes it difficult to obtain in any season of year, adequate quantities uredospores for artificial inoculations in a breeding program. This research aimed to develop a long-term storage methodology to preserve uredospores of Puccicinia melanocephala to keep their viability and infectivity. Uredospores were collect using a vacuum pump from naturally rusted leaves. Part of these uredospores was dehydrated in silica gel or lyophilized and the other part was not dehydrated. Then they were all stored at different temperatures (room temperature, 5ºC, -20ºC and -80ºC. Subsequently, uredospores viability was periodically evaluated using the water-agar method. After the fourth month, the infectivity was also evaluated through inoculations in leaves of the sugarcane susceptible variety SP70-1143 following disease evaluation. Regardless of the dehydration treatment used, uredospores stored at room temperature and at 5ºC were viable for the maximum periods of 1 and 2 months, respectively. The best results were obtained with the silica gel dehydration treatment followed by storage at -20ºC or -80ºC. Even after one year of storage, these uredospores were able to cause rust in inoculated plants at levels of severity which are adequate to start screening tests for sugarcane resistance to rust.
Barbieri, M.; Marcel, T.C.; Niks, R.E.
Purple false brome grass (Brachypodium distachyon) has recently emerged as a model system for temperate grasses and is also a potential model plant to investigate plant interactions with economically important pathogens such as rust fungi. We determined the host status of five Brachypodium species
The genetic basis of nonhost resistance is one of the most intriguing questions in the field of infectious diseases. The inheritance is very hard to study, since it typically requires interspecific crosses between host and nonhost species. Until now, mutagenesis and transformation have lead to
Yeo, F. K. S.; Wang, Y.; Vozábová, Tereza; Huneau, C.; LeRoy, P.; Chalhoub, B.; Qi, X. Q.; Niks, R. E.; Marcel, T. C.
Roč. 129, č. 2 (2016), s. 289-304 ISSN 0040-5752 Institutional support: RVO:67985939 Keywords : cartial resistance genes * cloning * Hordeum vulgare Subject RIV: EF - Botanics Impact factor: 4.132, year: 2016
Morris, C. E.; Sands, D. C.; Glaux, C.; Samsatly, J.; Asaad, S.; Moukahel, A. R.; Gonçalves, F. L. T.; Bigg, E. K.
In light of various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause that illustrate the important role of rainfall in their life history, we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections from 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-grown wheat in France, the USA, Turkey and Syria. Immersion freezing was used to determine freezing onset temperatures and the abundance of ice nuclei in suspensions of washed spores. Microbiological analyses of spores and subsequent tests of the ice nucleation activity of the bacteria associated with spores were deployed to quantify the contribution of bacteria to the ice nucleation activity of the spores. All samples of spores were ice nucleation active having freezing onset temperatures as warm as -4 °C. Spores in most of the samples carried cells of ice nucleation-active strains of the bacterium Pseudomonas syringae (at rates of less than 1 bacterial cell per 100 urediospores), but bacterial INA accounted for only a small fraction of the INA observed in spore suspensions. Changes in the INA of spore suspensions after treatment with lysozyme suggest that the INA of urediospores involves a polysaccharide. Based on data from the literature, we have estimated the concentrations of urediospores in air at cloud height and in rainfall. These quantities are very similar to those reported for other biological ice nucleators in these same substrates. We suggest that air sampling techniques have ignored the spatial and temporal variability of atmospheric concentrations that occur under conditions propitious for precipitation that could increase their local abundance intermittently. Nevertheless, we propose that the relative low abundance of warm-temperature biological ice nucleators in the atmosphere corresponds to optimal conditions for the processes of evolution to positively select for INA.
Walter, Stephanie; Ali, Sajid; Kemen, Eric
.g., the spreading of two aggressive and high temperature adapted strains to three continents since 2000. The combination of sequence-characterized amplified region (SCAR) markers, which were developed from two specific AFLP fragments, differentiated the two invasive strains, PstS1 and PstS2 from all other P....... striiformis strains investigated at a worldwide level. The application of the SCAR markers on 566 isolates showed that PstS1 was present in East Africa in the early 1980s and then detected in the Americas in 2000 and in Australia in 2002. PstS2 which evolved from PstS1 became widespread in the Middle East...... as the most plausible origin of the two invasive strains. The SCAR markers developed in the present study provide a rapid, inexpensive, and efficient tool to track the distribution of P. striiformis invasive strains, PstS1 and PstS2....
Full Text Available El presente estudio tuvo como finalidad el desarrollar la técnica de inoculación in vitro de la roya blanca, con el objeto de ahorrar tiempo y espacio en la caracterización de los distintos cultivares de crisantemo respecto al grado de susceptibilidad o resistencia a este patógeno. En Tenancingo, Estado de México, en el periodo 2004-2005 se colectaron hojas de crisantemo que presentaban daños por la enfermedad, se desinfectaron para posteriormente inocular las pústulas sobre plantas creciendo bajo condiciones in vitro. El recipiente de cultivo se mantuvo a una humedad relativa alrededor del 95% y temperaturas entre los 13 y 27 ºC, bajo condiciones de luz y oscuridad. Los daños por la enfermedad se manifestaron a los 20 días después de la inoculación. Los tratamientos a 17 ºC y oscuridad generaron un mayor número de pústulas (18,7. El diámetro de las pústulas fluctuó entre los 0,71 mm (tratamientos con 17 ºC y luz a los 1,79 mm en los tratamientos con 19 ºC y bajo oscuridad.
Dean, Ralph; Van Kan, Jan A L; Pretorius, Zacharias A; Hammond-Kosack, Kim E; Di Pietro, Antonio; Spanu, Pietro D; Rudd, Jason J; Dickman, Marty; Kahmann, Regine; Ellis, Jeff; Foster, Gary D
The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.
Han, Jae Woo; Shim, Sang Hee; Jang, Kyoung Soo; Choi, Yong Ho; Dang, Quang Le; Kim, Hun; Choi, Gyung Ja
As an alternative to synthetic pesticides, natural materials such as plant extracts and microbes have been considered to control plant diseases. In this study, methanol extracts of 120 plants were explored for in vivo antifungal activity against Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia triticina, and Blumeria graminis f. sp. hordei. Of the 120 plant extracts, eight plant extracts exhibited a disease control efficacy of more than 90% against at least one of five plant diseases. In particular, a methanol extract of Curcuma zedoaria rhizomes exhibited strong activity against wheat leaf rust caused by P. triticina. When the C. zedoaria methanol extracts were partitioned with various solvents, the layers of n-hexane, methylene chloride, and ethyl acetate showed disease control values of 100, 80, and 43%, respectively, against wheat leaf rust. From the C. zedoaria rhizome extracts, an antifungal substance was isolated and identified as a sesquiterpene ketolactone based on the mass and nuclear magnetic resonance spectral data. The active compound controlled the development of rice sheath blight, wheat leaf rust, and tomato late blight. Considering the in vivo antifungal activities of the sesquiterpene ketolactone and the C. zedoaria extracts, these results suggest that C. zedoaria can be used as a potent fungicide in organic agriculture.
Forster, Brian P.
The wheat black stem rust disease is a virulent race of fungus, Puccinia graminis, which affects wheat plants and is caused by a strain of fungus known as Ug99. Named for its place and year of origin, Ug99 was first discovered on wheat in Uganda in 1999. The spores of this plant disease are airborne and can be easily spread by wind. If not prevented, the disease can destroy 70 to 100 per cent of the yield of wheat crops. Annually on average 8.3 million tonnes of wheat grain is lost to this disease, costing US $1.23 billion per year. Ethiopia, Kenya and Uganda are hot spots for this disease. In 2009, growing international concern regarding the horrific impact of Ug99 on wheat led to the establishment of IAEA project INT/5/150, Responding to the Transboundary Threat of Wheat Black Stem Rust (Ug99). This project has involved over 18 countries and 5 national and international institutions, and examined possible mutation induction treatments to deal with the challenges posed by Ug99. Meetings and workshops to facilitate the project efforts have been held in Kenya and Turkey. Ug99 continues to spread globally and has now reached the Islamic Republic of Iran. There are also reports of suspected disease occurrences in Europe. It is essential that work continues on developing mutant lines for further crop protection that can be utilized worldwide to safeguard the wheat crop from this devastating disease
Full Text Available Wheat cv. Grana grown under field conditions, in the early phase of the first node formation, was sprayed with Ethrel (0.35 ml/m2 and with the fungicides: Sportak 45 EC (0.1 ml/m2 and Bayleton Triple (0.2 g/m2 - separately and in conjunction with Ethrel. It was found that Ethrel reduced the plant's susceptibility to infection by Cercosporella herpotrichoides and by species of the genus Fusarium. The fungicides were more active and also reduced the susceptibility to infection by Erysiphe graminis and Puccinia triticina. The fungistatic effect of Ethrel and Sportak was synergistic only in the case of Cercosporella herpotrichoides. Other interactions between Ethrel and fungicides were not found. Ethrel and fungicides only slightly affected the mycoflora of the root but they completely eliminated the fungi of the genus Mucor from the rhizosphere and reduced the participation of isolates of the genus Alternaria and Cladosporium in the rhizosphere and rhizoplane of wheat. The fungicides were more active than Ethrel. An interaction between Ethrel and fungicides in the reduction of fungi of the genus Fusarium in the rhizosphere was shown.
Full Text Available Abstract. The study was conducted to examine the variation in the agronomic and morphological traits in spring barley. For this purpose, 22 lines from the ICARDA High Input Barley Program for favorable environment and 3 check varieties (Rihane-03, VMorales and Veslets were tested in an alpha-lattice design with two replications at the Institute of Agriculture – Karnobat, Bulgaria in 2014 and 2015 growing season. The traits days to heading, plant height, number of tillers per plant, flag leaf length, flag leaf width, spike length, awn length, peduncle length, spikelet number per spike, grain number per spike, grain weight per spike, 1000 grains weight, grain yield, powdery mildew (Erysiphe graminis f. sp. hordei, net blotch (Pyrenophora teres f. teres and stripe rust (Puccinia striiformis f. sp. hordei infection were studied. Significant differences between lines for all studied traits were found. The number of fertile tillers per plant was significantly positively correlated with grain yield. Lines expressed higher grain yields, shorter stem, better tolerance to net blotch and stripe rust than Bulgarian check variety Veslets were identified. These genotypes can, therefore, be used as parents for the improvement of spring barley.
The present study was conducted to assess the susceptibility of seven local wheat cultivars from Palestine to infection with black stem rust caused by Puccinia graminis f. sp. tritici. Two techniques of disease inoculation were applied during bioassays: global inoculation of entire wheat plants with urediospores and localized inoculation with urediospores and localized inoculation with urediospores on wheat leaf-pieces incubated under humid conditions. Susceptibility of tested cultivars was evaluated according to disease scale based on number and size of typical unredial pustules that appeared after inoculation on entire plants or leaf pieces. Results obtained on bioassay of susceptibility and disease rating on entire plants indicated that Anbar, Kamata and Hetiya safra cultivars were the least susceptible to P. g. tritici infection, whereas Debiya beda cultivar was the most susceptible. The other tested cultivars such as Nab-El-Jama, sawda and Senf 870 were moderately susceptible. On leaf-pieces, Anbar and Kamatat were the least susceptible cultivars, whereas Debiya beda and Nab-El-Jamal were the most susceptible cultivars. The other tested cultivars such as Debiya swada, Senf 870 and Hetiya safra were moderately susceptible. Significant reductions were obtained for the size of unredial postules formed on leaf-pieces when inoculated in an unwounded state compared to the wounded indicating the importance of wounds during inoculation. The global results indicated the possibility of using above method of disease inoculating, scaling and rating for evaluation of wheat cultivars susceptibility for the eventual use in breeding program for resistant varieties in Palestine. (author)
Cho, Jun Young; Kim, Hae Young; Choi, Gyung Ja; Jang, Kyoung Soo; Lim, He Kyoung; Lim, Chi Hwan; Cho, Kwang Yun; Kim, Jin-Cheol
The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1). Copyright 2006 Society of Chemical Industry.
Since the 1970s there are several long-term monitoring programmes for plant diseases and pests in Germany. Within the framework of a national research project, some otherwise confidential databases comprising 77 111 samples from numerous sites accross Eastern Germany could be accessed and analysed. The pest data covered leaf rust (Puccinia triticina) and powdery mildew (Blumeria graminis) in winter wheat, aphids (Aphididae, four genera) on wheat and other cereal crops, late blight (Phytophthora infestans) in potatoes, and pollen beetles (Brassicogethes aeneus) on rape. These data were complemented by daily weather observations from the German Weather Service (DWD). In a first step, Pearson correlations between weather variables and pest frequencies were calculated for seasonal time periods of different start months and durations and ordered into so-called correlograms. This revealed principal weather effects on disease spread - e. g. that wind is favourable for mildew throughout the year or that rape pollen beetles like it warm, but not during wintertime. Secondly, the pest frequency samples were found to resemble gamma distributions, and a generalised linear model was fitted to describe their parameter shift depending on end-of-winter temperatures for aphids on cereals. The method clearly shows potential for systematic pest risk assessments regarding climate change.
Li, Feng; Li, Yinghui; Cao, Lirong; Liu, Peiyuan; Geng, Miaomiao; Zhang, Qiang; Qiu, Lina; Sun, Qixin; Xie, Chaojie
Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici , and wheat leaf rust, caused by Puccinia triticina Eriks, are two important diseases that severely threaten wheat production. Sorento, a hexaploid triticale cultivar from Poland, shows high resistance to the wheat powdery mildew isolate E09 and the leaf rust isolate PHT in Beijing, China. To introduce resistance genes into common wheat, Sorento was crossed with wheat line Xuezao, which is susceptible to both diseases, and the F 1 hybrids were then backcrossed with Xuezao as the recurrent male parent. By marker analysis, we demonstrate that the long arm of the 2R (2RL) chromosome confers resistance to both the leaf rust and powdery mildew isolates at adult-plant and seedling stages, while the long arm of 4R (4RL) confers resistance only to powdery mildew at both stages. The chromosomal composition of BC 2 F 3 plants containing 2R or 2RL and 4R or 4RL in the form of substitution and translocation were confirmed by GISH (genomic in situ hybridization) and FISH (fluorescence in situ hybridization). Monosomic and disomic substitutions of a wheat chromosome with chromosome 2R or 4R, as well as one 4RS-4DL/4DS-4RL reciprocal translocation homozigote and one 2RL-1DL translocation hemizigote, were recovered. Such germplasms are of great value in wheat improvement.
Parodi, P.C.; Nebreda, I.M.
Use of gamma-ray-induced variability in wheat has proved to be a valuable breeding methodology. Results with triticale are still inconclusive. After several years of research a number of wheat mutants have been developed which possess an improved protein content, high yield, good agronomic type and wide adaptability. A change in the stem rust (Puccinia graminis f. sp. tritici) population, however, rendered most of the mutants susceptible to this disease. One mutant, recently named Carolina, which was able to withstand the effects of stem rust without serious yield deterioration, was registered and released to farmers. Efforts are being made to add stem rust resistance to the susceptible mutants by conventional backcrossing. Also, new material and the most outstanding susceptible mutants were gamma irradiated in an effort to induce resistance. Other mutants, not necessarily with an improved protein content, were grouped according to disease reaction and phenotypic similarity to form multilineal composites, some of which have had a superior performance and may be released to farmers in late 1984. A study conducted under four nitrogen levels with six wheat protein mutants showed a weak and inconsistent negative correlation between yield and protein content. The mutants could be differentiated by their increased protein content under most nitrogen rates. (author)
Full Text Available The field experiment was carried out in 2010–2012 at the Dłoń Agricultural Research Station, the Poznań University of Life Sciences, Poland. The study was designed to evaluate the degree of infection by powdery mildew, brown rust, and septoria leaf blotch in 61 spring wheat genotypes differing in their resistance to Fusarium ssp. The vast majority of spring wheat genotypes in the collection of gene resources in the USA defined as resistant to Fusarium ssp. confirmed their resistance under Polish climatic conditions. The B .graminis infection rate of genotypes that are considered to be resistant to Fusarium head blight was high. The resistance ranged from 7 for Sumai 3 (PL2 up to 8.8 for Ning 8331 (in a 9-point scale. Most of the genotypes (56.5% were infected by Puccinia recondita at a level of 1–3 (in a 9-point scale. The genotypes of Sumai 3 exhibited high resistance to septoria leaf blotch, amounting to 1–2 in a 9-point scale; the resistance of Frontana ranged from 1 to 3.5, while the genotypes of Ning were infected by Mycosphaerella graminicola at 5–6.
Full Text Available The work was done in years 1998/1999 - 2000/2001 on plantations and field plot experiments. Aim of the work was evaluation of take-all occurrence on winter wheat in milk-wax growth stage in dependence on forecrop (oilseed rape, wheat or barley as well as seed treatment with Latitude 125 FS when wheat was planted on fields after wheat or barley. Percentage of infected plants when seeds were not treated with Latitude 125 FS varied from 82-100 on fields after wheat or barley, and 54-69 on fields after oilseed rape. In treatments with wheat grown after wheat or barley the percentage of infected plants amounted 20-100 when seeds were not treated with Latitude 125 FS and 13-86 when seeds were treated with Latitude 125 FS. Mean degree of infection was low when percentage of infected plants was low and high when percentage of infected plants was high.
Jørgensen, Jørgen Helms; Mortensen, K.
by the hosts. An average of about 60% of the germinated conidia formed haustoria, 50% formed hyphae, and 40% formed mildew colonies on the susceptible hosts. In contrast, only about 0.7% formed haustoria, 0.4% formed hyphae, and 0.2% formed colonies on the resistant hosts, on which the great majority...
Věchet, L.; Burketová, Lenka; Šindelářová, Milada
Roč. 28, č. 2 (2009), s. 151-154 ISSN 0261-2194 R&D Projects: GA MZe QH72117 Institutional research plan: CEZ:AV0Z50380511 Keywords : Winter wheat * Powdery mildew * Induced resistance Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.331, year: 2009
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EI hongo Sclerotinia sclerotiorum ocasiona perdidas apreciables en diversos cultivos de flores y hortalizas. La investigación consistió en evaluar la capacidad antagónica de algunos aislamientos de Trichoderma sp. Y Gliocladium sp. Sobre Sclerotinia sclerotiorum, tanto in vitro, como en plantas de crisantemo. Los mejores antagonistas del patógeno in vitro fueron los aislamientos G-8B y G-98 de Gliocladium sp. y los aislamientos T-2IB y T-34B de Trichoderma sp. Los dos aislamientos de Gliocladium sp. Formaron un halo de inhibición alrededor de la colonia del patógeno, mientras que los aislamientos de Trichoderma sp. Produjeron esporulación abundante sobre las colonias del patógeno. Los mejores tratamientos en el control de la enfermedad en plantas de crisantemo fueron los aislamientos T-2IB y T-34B de Trichoderma sp. y el aislamiento G-8B de Gliocladium sp., con un menor índice y una menor severidad de la enfermedad. La metodología de evaluación in vitro utilizada en la investigación fue confiable, ya que los resultados encontrados en el laboratorio fueron bastante similares a los obtenidos en el ensayo de invernadero. Además, los aislamientos de Trichoderma y de Gliocladium utilizados ocasionaron un estimulo apreciable en el crecimiento de las plantas y un adelanto en la floración.
Palabras claves: Antagonismo in vitro, estimulo crecimiento, adelanto floración
Lehlohonolo Benedict Qhanya
Full Text Available Fungi are an exceptional source of diverse and novel cytochrome P450 monooxygenases (P450s, heme-thiolate proteins, with catalytic versatility. Agaricomycotina saprophytes have yielded most of the available information on basidiomycete P450s. This resulted in observing similar P450 family types in basidiomycetes with few differences in P450 families among Agaricomycotina saprophytes. The present study demonstrated the presence of unique P450 family patterns in basidiomycete biotrophic plant pathogens that could possibly have originated from the adaptation of these species to different ecological niches (host influence. Systematic analysis of P450s in basidiomycete biotrophic plant pathogens belonging to three different orders, Agaricomycotina (Armillaria mellea, Pucciniomycotina (Melampsora laricis-populina, M. lini, Mixia osmundae and Puccinia graminis and Ustilaginomycotina (Ustilago maydis, Sporisorium reilianum and Tilletiaria anomala, revealed the presence of numerous putative P450s ranging from 267 (A. mellea to 14 (M. osmundae. Analysis of P450 families revealed the presence of 41 new P450 families and 27 new P450 subfamilies in these biotrophic plant pathogens. Order-level comparison of P450 families between biotrophic plant pathogens revealed the presence of unique P450 family patterns in these organisms, possibly reflecting the characteristics of their order. Further comparison of P450 families with basidiomycete non-pathogens confirmed that biotrophic plant pathogens harbour the unique P450 families in their genomes. The CYP63, CYP5037, CYP5136, CYP5137 and CYP5341 P450 families were expanded in A. mellea when compared to other Agaricomycotina saprophytes and the CYP5221 and CYP5233 P450 families in P. graminis and M. laricis-populina. The present study revealed that expansion of these P450 families is due to paralogous evolution of member P450s. The presence of unique P450 families in these organisms serves as evidence of how a host
Triticale has been considered as resistant to diseases over a long time. Although, many authors perpetuate this opinion, it is no longer true. However, in comparison to wheat and rye triticale still may look as a healthy crop, but its healthiness has been steadily declining. It could be explained by steady expansion of the growing area and longer exposure to pathogens. On the other hand, triticale is a crop on which meet pathogens of wheat and rye, but there is evidence that on triticale embedded more so called "wheat pathogens", than rye ones. For such an notable example may serve races of Puccinia recondita. In the latter respect triticale also appears to be a bridge facilitating a direct contact between the pathogens, e.g. between physiological forms of the most important cereal rusts. Such contacts stimulate somatic hybridization on bridging triticale plant and may finally result in new hybrid pathotypes carrying virulence genes (factors) to all three hosts, i.e. triticale, wheat and rye. In addition to all triticale commercial and agronomical values, triticale still is and it will continue to be bridging transfers of resistance genes to various pathogens and pests mainly from rye to wheat. The paper will describe main diseases affecting triticale worldwide. The first disease which occurred on this cereal in epidemic proportions was stem rust (Pucinia graminis f. sp. tritici) in Australia. Leaf and stripe rusts (P. recondita f. sp. tritici and P. striiformis) are also have gained in importance everywhere triticale is grown. In recent years, at least in Poland, powdery mildew caused by Blumeria graminis occurred in epidemic proportions in quite a number of winter triticale cultivars. Similar phenomenon has been observed with quite a number of other diseases caused by facultative pathogens, such as the most damaging to triticale the Stagonospora spp. leaf and glume blotch disease complex and other pathogens like Cochliobolus sativus, Fusarium culmorum, and F
Zhang, Hong; Hu, Weiguo; Hao, Jilei; Lv, Shikai; Wang, Changyou; Tong, Wei; Wang, Yajuan; Wang, Yanzhen; Liu, Xinlun; Ji, Wanquan
Stripe rust (Puccinia striiformis f. sp. tritici; Pst) and powdery mildew (Blumeria graminis f. sp. tritici; Bgt) are important diseases of wheat (Triticum aestivum) worldwide. Increasingly evidences suggest that long intergenic ncRNAs (lincRNAs) are developmentally regulated and play important roles in development and stress responses of plants. However, identification of lincRNAs in wheat is still limited comparing with functional gene expression. The transcriptome of the hexaploid wheat line N9134 inoculated with the Chinese Pst race CYR31 and Bgt race E09 at 1, 2, and 3 days post-inoculation was recapitulated to detect the lincRNAs. Here, 283 differential expressed lincRNAs were identified from 58218 putative lincRNAs, which account for 31.2% of transcriptome. Of which, 254 DE-LincRNAs responded to the Bgt stress, and 52 lincRNAs in Pst. Among them, 1328 SnRNP motifs (sm sites) were detected and showed RRU4-11RR sm site element and consensus RRU1-9VU1-7RR SnRNP motifs, where the total number of uridine was more than 3 but less than 11. Additionally, 101 DE-lincRNAs were predicted as targets of miRNA by psRNATarget, while 5 target mimics were identified using target mimicry search in TAPIR. Taken together, our findings indicate that the lincRNA of wheat responded to Bgt and Pst stress and played important roles in splicesome and inter-regulating with miRNA. The sm site of wheat showed a more complex construction than that in mammal and model plant. The mass sequence data generated in this study provide a cue for future functional and molecular research on wheat-fungus interactions.
Full Text Available In the last years fluorescence spectroscopy has come to be viewed as an essential approach in key research fields of applied plant sciences. However, the quantity and particularly the quality of information produced by different equipment might vary considerably. In this study we investigate the potential of three optical devices for the proximal sensing of plant-pathogen interactions in four genotypes of spring barley. For this purpose, the fluorescence lifetime, the image-resolved multispectral fluorescence and selected indices of a portable multiparametric fluorescence device were recorded at 3, 6, and 9 days after inoculation (dai from healthy leaves as well as from leaves inoculated with powdery mildew (Blumeria graminis or leaf rust (Puccinia hordei. Genotype-specific responses to pathogen infections were revealed already at 3 dai by higher fluorescence mean lifetimes in the spectral range from 410 to 560 nm in the less susceptible varieties. Noticeable pathogen-induced modifications were also revealed by the ‘Blue-to-Far-Red Fluorescence Ratio’ and the ‘Simple Fluorescence Ratio’. Particularly in the susceptible varieties the differences became more evident in the time-course of the experiment i.e., following the pathogen development. The relevance of the blue and green fluorescence to exploit the plant-pathogen interaction was demonstrated by the multispectral fluorescence imaging system. As shown, mildewed leaves were characterized by exceptionally high blue fluorescence, contrasting the values observed in rust inoculated leaves. Further, we confirm that the intensity of green fluorescence depends on the pathogen infection and the stage of disease development; this information might allow a differentiation of both diseases. Moreover, our results demonstrate that the detection area might influence the quality of the information, although it had a minor impact only in the current study. Finally, we highlight the relevance of
Diane G O Saunders
Full Text Available Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i contain a secretion signal, (ii are encoded by in planta induced genes, (iii have similarity to haustorial proteins, (iv are small and cysteine rich, (v contain a known effector motif or a nuclear localization signal, (vi are encoded by genes with long intergenic regions, (vii contain internal repeats, and (viii do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components.
Yu, Guotai; Zhang, Qijun; Friesen, Timothy L; Rouse, Matthew N; Jin, Yue; Zhong, Shaobin; Rasmussen, Jack B; Lagudah, Evans S; Xu, Steven S
Mapping studies confirm that resistance to Ug99 race of stem rust pathogen in Aegilops tauschii accession Clae 25 is conditioned by Sr46 and markers linked to the gene were developed for marker-assisted selection. The race TTKSK (Ug99) of Puccinia graminis f. sp. tritici, the causal pathogen for wheat stem rust, is considered as a major threat to global wheat production. To address this threat, researchers across the world have been devoted to identifying TTKSK-resistant genes. Here, we report the identification and mapping of a stem rust resistance gene in Aegilops tauschii accession CIae 25 that confers resistance to TTKSK and the development of molecular markers for the gene. An F2 population of 710 plants from an Ae. tauschii cross CIae 25 × AL8/78 were first evaluated against race TPMKC. A set of 14 resistant and 116 susceptible F2:3 families from the F2 plants were then evaluated for their reactions to TTKSK. Based on the tests, 179 homozygous susceptible F2 plants were selected as the mapping population to identify the simple sequence repeat (SSR) and sequence tagged site (STS) markers linked to the gene by bulk segregant analysis. A dominant stem rust resistance gene was identified and mapped with 16 SSR and five new STS markers to the deletion bin 2DS5-0.47-1.00 of chromosome arm 2DS in which Sr46 was located. Molecular marker and stem rust tests on CIae 25 and two Ae. tauschii accessions carrying Sr46 confirmed that the gene in CIae 25 is Sr46. This study also demonstrated that Sr46 is temperature-sensitive being less effective at low temperatures. The marker validation indicated that two closely linked markers Xgwm210 and Xwmc111 can be used for marker-assisted selection of Sr46 in wheat breeding programs.
Laidò, Giovanni; Panio, Giosuè; Marone, Daniela; Russo, Maria A; Ficco, Donatella B M; Giovanniello, Valentina; Cattivelli, Luigi; Steffenson, Brian; de Vita, Pasquale; Mastrangelo, Anna M
Stem rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn. (Pgt), is one of the most destructive diseases of wheat. Races of the pathogen in the "Ug99 lineage" are of international concern due to their virulence for widely used stem rust resistance genes and their spread throughout Africa. Disease resistant cultivars provide one of the best means for controlling stem rust. To identify quantitative trait loci (QTL) conferring resistance to African stem rust race TTKSK at the seedling stage, we evaluated an association mapping (AM) panel consisting of 230 tetraploid wheat accessions under greenhouse conditions. A high level of phenotypic variation was observed in response to race TTKSK in the AM panel, allowing for genome-wide association mapping of resistance QTL in wild, landrace, and cultivated tetraploid wheats. Thirty-five resistance QTL were identified on all chromosomes, and seventeen are of particular interest as identified by multiple associations. Many of the identified resistance loci were coincident with previously identified rust resistance genes; however, nine on chromosomes 1AL, 2AL, 4AL, 5BL, and 7BS may be novel. To validate AM results, a biparental population of 146 recombinant inbred lines was also considered, which derived from a cross between the resistant cultivar "Cirillo" and susceptible "Neodur." The stem rust resistance of Cirillo was conferred by a single gene on the distal region of chromosome arm 6AL in an interval map coincident with the resistance gene Sr13, and confirmed one of the resistance loci identified by AM. A search for candidate resistance genes was carried out in the regions where QTL were identified, and many of them corresponded to NBS-LRR genes and protein kinases with LRR domains. The results obtained in the present study are of great interest as a high level of genetic variability for resistance to race TTKSK was described in a germplasm panel comprising most of the tetraploid wheat sub-species.
Babiker, E M; Gordon, T C; Chao, S; Newcomb, M; Rouse, M N; Jin, Y; Wanyera, R; Acevedo, M; Brown-Guedira, G; Williamson, S; Bonman, J M
A new gene for Ug99 resistance from wheat landrace PI 374670 was detected on the long arm of chromosome 7A. Wheat landrace PI 374670 has seedling and field resistance to stem rust caused by Puccinia graminis f. sp tritici Eriks. & E. Henn (Pgt) race TTKSK. To elucidate the inheritance of resistance, 216 BC1F2 families, 192 double haploid (DH) lines, and 185 recombinant inbred lines (RILs) were developed by crossing PI 374670 and the susceptible line LMPG-6. The parents and progeny were evaluated for seedling resistance to Pgt races TTKSK, MCCFC, and TPMKC. The DH lines were tested in field stem rust nurseries in Kenya and Ethiopia. The DH lines were genotyped with the 90K wheat iSelect SNP genotyping platform. Goodness-of-fit tests indicated that a single dominant gene in PI 374670 conditioned seedling resistance to the three Pgt races. The seedling resistance locus mapped to the long arm of chromosome 7A and this result was verified in the RIL population screened with the flanking SNP markers using KASP assays. In the same region, a major QTL for field resistance was detected in a 7.7 cM interval and explained 34-54 and 29-36% of the variation in Kenya and Ethiopia, respectively. Results from tests with specific Pgt races and the csIH81 marker showed that the resistance was not due to Sr22. Thus, a new stem rust resistance gene or allele, either closely linked or allelic to Sr15, is responsible for the seedling and field resistance of PI 374670 to Ug99.
Fellers John P
Full Text Available Abstract Background Wheat leaf rust (Puccinia triticina Eriks; Pt and stem rust fungi (P. graminis f.sp. tritici; Pgt are significant economic pathogens having similar host ranges and life cycles, but different alternate hosts. The Pt genome, currently estimated at 135 Mb, is significantly larger than Pgt, at 88 Mb, but the reason for the expansion is unknown. Three genomic loci of Pt conserved proteins were characterized to gain insight into gene content, genome complexity and expansion. Results A bacterial artificial chromosome (BAC library was made from P. triticina race 1, BBBD and probed with Pt homologs of genes encoding two predicted Pgt secreted effectors and a DNA marker mapping to a region of avirulence. Three BACs, 103 Kb, 112 Kb, and 166 Kb, were sequenced, assembled, and open reading frames were identified. Orthologous genes were identified in Pgt and local conservation of gene order (microsynteny was observed. Pairwise protein identities ranged from 26 to 99%. One Pt BAC, containing a RAD18 ortholog, shares syntenic regions with two Pgt scaffolds, which could represent both haplotypes of Pgt. Gene sequence is diverged between the species as well as within the two haplotypes. In all three BAC clones, gene order is locally conserved, however, gene shuffling has occurred relative to Pgt. These regions are further diverged by differing insertion loci of LTR-retrotransposon, Gypsy, Copia, Mutator, and Harbinger mobile elements. Uncharacterized Pt open reading frames were also found; these proteins are high in lysine and similar to multiple proteins in Pgt. Conclusions The three Pt loci are conserved in gene order, with a range of gene sequence divergence. Conservation of predicted haustoria expressed secreted protein genes between Pt and Pgt is extended to the more distant poplar rust, Melampsora larici-populina. The loci also reveal that genome expansion in Pt is in part due to higher occurrence of repeat-elements in this species.
Mourad, Amira M I; Sallam, Ahmed; Belamkar, Vikas; Wegulo, Stephen; Bowden, Robert; Jin, Yue; Mahdy, Ezzat; Bakheit, Bahy; El-Wafaa, Atif A; Poland, Jesse; Baenziger, Peter S
Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat ( Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ∼35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in Nebraska (QFCSC) in two replications. Marker-trait association identified 32 SNP markers, which were significantly (Bonferroni corrected P < 0.05) associated with the resistance on chromosome 2D. The chromosomal location of the significant SNPs (chromosome 2D) matched the location of Sr6 gene which was expected in these genotypes based on pedigree information. A highly significant linkage disequilibrium (LD, r 2 ) was found between the significant SNPs and the specific SSR marker for the Sr6 gene ( Xcfd43 ). This suggests the significant SNP markers are tagging Sr6 gene. Out of the 32 significant SNPs, eight SNPs were in six genes that are annotated as being linked to disease resistance in the IWGSC RefSeq v1.0. The 32 significant SNP markers were located in nine haplotype blocks. All the 32 significant SNPs were validated in a set of 60 different genotypes (V-set) using single marker analysis. SNP markers identified in this study can be used in marker-assisted selection, genomic selection, and to develop KASP (Kompetitive Allele Specific PCR) marker for the Sr6 gene. Novel SNPs for Sr6 gene, an important stem rust resistant gene, were identified and validated in this study. These SNPs can be used to improve stem rust resistance in wheat.
Hiebert, Colin W; Kolmer, James A; McCartney, Curt A; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N; Spielmeyer, Wolfgang
Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34.
Hiebert, Colin W.; Kolmer, James A.; McCartney, Curt A.; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N.; Spielmeyer, Wolfgang
Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. ‘Thatcher’ wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in ‘Thatcher’ and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for ‘Thatcher’-derived APR in several environments and this resistance was enhanced in the presence of Lr34. PMID:27309724
Singh, Ravi P; Hodson, David P; Jin, Yue; Lagudah, Evans S; Ayliffe, Michael A; Bhavani, Sridhar; Rouse, Matthew N; Pretorius, Zacharias A; Szabo, Les J; Huerta-Espino, Julio; Basnet, Bhoja R; Lan, Caixia; Hovmøller, Mogens S
Race Ug99 (TTKSK) of Puccinia graminis f. sp. tritici, detected in Uganda in 1998, has been recognized as a serious threat to food security because it possesses combined virulence to a large number of resistance genes found in current widely grown wheat (Triticum aestivum) varieties and germplasm, leading to its potential for rapid spread and evolution. Since its initial detection, variants of the Ug99 lineage of stem rust have been discovered in Eastern and Southern African countries, Yemen, Iran, and Egypt. To date, eight races belonging to the Ug99 lineage are known. Increased pathogen monitoring activities have led to the identification of other races in Africa and Asia with additional virulence to commercially important resistance genes. This has led to localized but severe stem rust epidemics becoming common once again in East Africa due to the breakdown of race-specific resistance gene SrTmp, which was deployed recently in the 'Digalu' and 'Robin' varieties in Ethiopia and Kenya, respectively. Enhanced research in the last decade under the umbrella of the Borlaug Global Rust Initiative has identified various race-specific resistance genes that can be utilized, preferably in combinations, to develop resistant varieties. Research and development of improved wheat germplasm with complex adult plant resistance (APR) based on multiple slow-rusting genes has also progressed. Once only the Sr2 gene was known to confer slow rusting APR; now, four more genes-Sr55, Sr56, Sr57, and Sr58-have been characterized and additional quantitative trait loci identified. Cloning of some rust resistance genes opens new perspectives on rust control in the future through the development of multiple resistance gene cassettes. However, at present, disease-surveillance-based chemical control, large-scale deployment of new varieties with multiple race-specific genes or adequate levels of APR, and reducing the cultivation of susceptible varieties in rust hot-spot areas remains the best
Tian Ya Li
Full Text Available Stem rust is one of the most potentially harmful wheat diseases, but has been effectively controlled in China since 1970s. However, the interest in breeding wheat with durable resistance to stem rust has been renewed with the emergence of Ug99 (TTKSK virulent to the widely used resistance gene Sr31, and by which the wheat stem rust was controlled for 40 years in wheat production area worldwide. Yunnan Province, located on the Southwest border of China, is one of the main wheat growing regions, playing a pivotal role in the wheat stem rust epidemic in China. This study investigated the levels of resistance in key wheat cultivars (lines of Yunnan Province. In addition, the existence of Sr25, Sr26, Sr28, Sr31, Sr32, and Sr38 genes in 119 wheat cultivars was assessed using specific DNA markers. The results indicated that 77 (64.7% tested wheat varieties showed different levels of resistance to all the tested races of Puccinia graminis f. sp. tritici. Using molecular markers, we identified the resistance gene Sr31 in 43 samples; Sr38 in 10 samples; Sr28 in 12 samples, and one sample which was resistant against Ug99 (avirulent to Sr32. No Sr25 or Sr26 (effective against Ug99 was identified in any cultivars tested. Furthermore, 5 out of 119 cultivars tested carried both Sr31 and Sr38 and eight contained both Sr31 and Sr28. The results enable the development of appropriate strategies to breed varieties resistant to stem rust.
Harder, D.E.; McKenzie, R.I.H.; Martens, J.W.; Brown, P.D.
During the history of breeding oats for rust resistance in Canada the known sources of resistance proved inadequate to counter the virulence potential of both stem rust (Puccinia graminis avenae) and crown rust (P. coronata avenae). A major programme to overcome the rust problem was undertaken at Winnipeg, involving four alternate approaches: (1) A search for new resistance in wild oat species, particularly Avena sterilis, has provided a wealth of good resistance to crown rust, but less to stem rust. Much of the A. sterilis-derived crown rust resistance is now being used world-wide; (2) Efforts at synthesizing new resistance by mutation breeding methods have not been successful. Of about seven million plants examined, only one showed significant new resistance, but this was associated with poor plant type; (3) Resistance with low levels of expression but which appears broadly effective has been observed against both stem and crown rusts. It appears that numbers of these low-level genes exist, and that they can be accumulated to provide increasingly effective resistance. Problems in using this type of resistance in a practical way are discussed; (4) Excellent rust resistance has been found in lower ploidy species such as A. barbata, but it was not previously possible to stabilize this resistance in hexaploid species. By using mutagenic treatments attempts have been made to translocate smaller portions of the A. barbata chromosome carrying the resistance to the hexaploid cultivar Rodney. In conclusion, mutation breeding methods at present appear to have limited application in synthesizing new rust-resistant genotypes in oats. The search for already existing genetic resistance and its synthesis into multi-genic resistant lines appears to be the most effective way at present of resolving the rust problem in oats. (author)
Full Text Available Plant pathogens cause severe losses to crop plants and threaten global food production. One striking example is the wheat stem rust fungus, Puccinia graminis f. sp. tritici, which can rapidly evolve new virulent pathotypes in response to resistant host lines. Like several other filamentous fungal and oomycete plant pathogens, its genome features expanded gene families that have been implicated in host-pathogen interactions, possibly encoding effector proteins that interact directly with target host defence proteins. Previous efforts to understand virulence largely relied on the prediction of secreted, small and cysteine-rich proteins as candidate effectors and thus delivered an overwhelming number of candidates. Here, we implement an alternative analysis strategy that uses the signal of adaptive evolution as a line of evidence for effector function, combined with comparative information and expression data. We demonstrate that in planta up-regulated genes that are rapidly evolving are found almost exclusively in pathogen-associated gene families, affirming the impact of host-pathogen co-evolution on genome structure and the adaptive diversification of specialised gene families. In particular, we predict 42 effector candidates that are conserved only across pathogens, induced during infection and rapidly evolving. One of our top candidates has recently been shown to induce genotype-specific hypersensitive cell death in wheat. This shows that comparative genomics incorporating the evolutionary signal of adaptation is powerful for predicting effector candidates for laboratory verification. Our system can be applied to a wide range of pathogens and will give insight into host-pathogen dynamics, ultimately leading to progress in strategies for disease control.
Das, Subha Narayan; Wagenknecht, Martin; Nareddy, Pavan Kumar; Bhuvanachandra, Bhoopal; Niddana, Ramana; Balamurugan, Rengarajan; Swamy, Musti J.; Moerschbacher, Bruno M.; Podile, Appa Rao
We report here the role and mechanism of specificity of a family 32 carbohydrate binding module (CBM32) of a glycoside hydrolase family 8 chitosanase from Paenibacillus elgii (PeCsn). Both the activity and mode of action of PeCsn toward soluble chitosan polymers were not different with/without the CBM32 domain of P. elgii (PeCBM32). The decreased activity of PeCsn without PeCBM32 on chitosan powder suggested that PeCBM32 increases the relative concentration of enzyme on the substrate and thereby enhanced enzymatic activity. PeCBM32 specifically bound to polymeric and oligomeric chitosan and showed very weak binding to chitin and cellulose. In isothermal titration calorimetry, the binding stoichiometry of 2 and 1 for glucosamine monosaccharide (GlcN) and disaccharide (GlcN)2, respectively, was indicative of two binding sites in PeCBM32. A three-dimensional model-guided site-directed mutagenesis and the use of defined disaccharides varying in the pattern of acetylation suggested that the amino groups of chitosan and the polar residues Glu-16 and Glu-38 of PeCBM32 play a crucial role for the observed binding. The specificity of CBM32 has been further elucidated by a generated fusion protein PeCBM32-eGFP that binds to the chitosan exposing endophytic infection structures of Puccinia graminis f. sp. tritici. Phylogenetic analysis showed that CBM32s appended to chitosanases are highly conserved across different chitosanase families suggesting their role in chitosan recognition and degradation. We have identified and characterized a chitosan-specific CBM32 useful for in situ staining of chitosans in the fungal cell wall during plant-fungus interaction. PMID:27405759
Schubert, J. (Akademie der Landwirtschaftswissenschaften der DDR, Aschersleben. Inst. fuer Phytopathologie)
Accumulation of nuclides (/sup 32/P, /sup 14/C), /sup 14/CO/sub 2/ assimilation and /sup 14/C transport were studied in several barley cultivars differing in their resistance to yellow rust. Increased matter accumulation was found in the rust pustules. Mycelium was proved by means of autoradiography. Infection causes changes with regard to /sup 14/CO/sub 2/ assimilation, carbohydrate regime and transport of /sup 14/C assimilation products. Certain relationships exist between these changes and plant resistance to yellow rust. During germination the rust uredospores release substances, particularly amino acids, to be transported in the plant.
Sørensen, Chris Khadgi; Hovmøller, Mogens Støvring; Leconte, Marc
isolates, one representing an aggressive and high-temperature-adapted strain (PstS2) and another representing a virulence phenotype new to Europe since 2011 (new). The RILs carried different combinations of quantitative trait loci (QTL) for resistance to P. striiformis. Under greenhouse conditions...
Niks, R.E.; Alemu, Sisay K.; Marcel, T.C.; Heyzen, van Skye
Barley (Hordeum vulgare L.) mapping populations have been developed that are useful to study the inheritance of quantitative resistance to adapted and unadapted rust fungi. In a recent host range study, we found that the parents of those mapping populations also differed in their resistance to
Marisa E. Miller
Full Text Available Oat crown rust, caused by the fungus Pucinnia coronata f. sp. avenae, is a devastating disease that impacts worldwide oat production. For much of its life cycle, P. coronata f. sp. avenae is dikaryotic, with two separate haploid nuclei that may vary in virulence genotype, highlighting the importance of understanding haplotype diversity in this species. We generated highly contiguous de novo genome assemblies of two P. coronata f. sp. avenae isolates, 12SD80 and 12NC29, from long-read sequences. In total, we assembled 603 primary contigs for 12SD80, for a total assembly length of 99.16 Mbp, and 777 primary contigs for 12NC29, for a total length of 105.25 Mbp; approximately 52% of each genome was assembled into alternate haplotypes. This revealed structural variation between haplotypes in each isolate equivalent to more than 2% of the genome size, in addition to about 260,000 and 380,000 heterozygous single-nucleotide polymorphisms in 12SD80 and 12NC29, respectively. Transcript-based annotation identified 26,796 and 28,801 coding sequences for isolates 12SD80 and 12NC29, respectively, including about 7,000 allele pairs in haplotype-phased regions. Furthermore, expression profiling revealed clusters of coexpressed secreted effector candidates, and the majority of orthologous effectors between isolates showed conservation of expression patterns. However, a small subset of orthologs showed divergence in expression, which may contribute to differences in virulence between 12SD80 and 12NC29. This study provides the first haplotype-phased reference genome for a dikaryotic rust fungus as a foundation for future studies into virulence mechanisms in P. coronata f. sp. avenae.
Loope, Lloyd L.; Uchida, Janice Y.
Most rust fungi are highly host specific, but Puccina psidii has an extremely broad host range within Myrtaceae and gained notoriety with a host jump in its native Brazil from common guava (Psidium guajava) to commercial Eucalyptus plantations. When detected in Hawaiʻi in April 2005, the first invasion outside the neotropics/subtropics, there was immediate concern for ʻōhiʻa (Metrosideros polymorpha). ʻŌhiʻa composes 80% of native forest statewide, providing stable watersheds and habitat for most Hawaiian forest birds and plants. Within months, rust spores spread statewide on wind currents, but ʻōhiʻa was found to be only a minor host, showing very light damage. The primary host was nonnative rose apple (Syzygium jambos), severely affected at a landscape scale, but the epiphytotic subsided as rose apple was largely defoliated or killed within several years. The limited and stable host range in Hawaiʻi (versus elsewhere) led the local conservation community to explore possibilities for excluding new genetic strains of P. psidii. Although national/international phytosanitary standards require strong scientific justification for regulations involving an infraspecific taxonomic level, hopes were buoyed when genetic studies showed no apparent genetic variation/evolution in Hawaiʻi's rust strain. A sophisticated genetic study of P. psidii in its home range is near completion; genetic variation is substantial, and host species strongly influences rust population structure. To prevent introduction of new strains, the Hawaiʻi Department of Agriculture is moving ahead with establishing stringent measures that restrict entry of Myrtaceae into Hawaiʻi. Meanwhile, P. psidii poses a major threat to Myrtaceae biodiversity worldwide.
Burnett, Kimberly; D'Evelyn, Sean; Loope, Lloyd; Wada, Christopher A.
Since its first documented introduction to Hawai‘i in 2005, the rust fungus P. psidii has already severely damaged Syzygium jambos (Indian rose apple) trees and the federally endangered Eugenia koolauensis (nioi). Fortunately, the particular strain has yet to cause serious damage to ‘ōhi‘a, which comprises roughly 80% of the state’s native forests and covers 400,000 ha. Although the rust has affected less than 5% of Hawaii’s ‘ōhi‘a trees thus far, the introduction of more virulent strains and the genetic evolution of the current strain are still possible. Since the primary pathway of introduction is Myrtaceae plant material imported from outside the state, potential damage to ‘ohi‘a can be minimized by regulating those high-risk imports. We discuss the economic impact on the state’s florist, nursery, landscaping, and forest plantation industries of a proposed rule that would ban the import of non-seed Myrtaceae plant material and require a one-year quarantine of seeds. Our analysis suggests that the benefits to the forest plantation industry of a complete ban on non-seed material would likely outweigh the costs to other affected sectors, even without considering the reduction in risk to ‘ōhi‘a. Incorporating the value of ‘ōhi‘a protection would further increase the benefit-cost ratio in favor of an import ban.
Marcel, T.C.; Varshney, R.K.; Barbieri, M.; Jafary, H.; Kock, de M.J.D.; Graner, A.; Niks, R.E.
A consensus map of barley was constructed based on three reference doubled haploid (DH) populations and three recombinant inbred line (RIL) populations. Several sets of microsatellites were used as bridge markers in the integration of those populations previously genotyped with RFLP or with AFLP
Osmany de la Caridad Aday Díaz
Full Text Available The characterization of the symptoms of the orange rust was carried out on the Sugar Cane Research Territorial Station (ETICA Centro Villa Clara, of the Sugarcane Research Institute (INICA in Cuba. Ten infected stalks of the cultivars B52107, CSG398-92, C01-227 and Clon218-2011 were evaluated. With a photographic camera the image of the three thirds of 236 leaves infected was captured on a squared paper with well-known distances. By means of the processing of images ImageJ® 1.43u the Affected Foliate Area (AFA was determined to in each third and of the complete leaf, later on the long, wide and area occupied by 554 pustules of the P. kuehnii. In the leaves from +3 at +7 were the intermediate values of AFA for P. kuehnii and this it was significantly major in the superior third of the leaves and minor in the basal part. The most frequent dimensions in the pustules of P. kuehnii reached the length understood between 0.75 and 3.0 mm, between 0.24 and 0.61 mm wide and an area of 1.39 mm2, with differences among cultivars. The emergency of the pustules was generally presented in to add form and with collapsed areas of 2.97 mm2 to 979.8 mm2.
Nicholas Le Maitre
Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of ... Key words: Prevalence, microsatellite, amplified fragment length polymorphisms (AFLP), phylogeny, Puccinia. INTRODUCTION. Puccinia triticina Eriks ..... Genetic distances and reconstruction phylogenetic trees from microsatellite DNA.
Jensen, Michael Krogh; Hagedorn, Peter; De Torres-Zabala, Marta
-representation of abscisic acid (ABA)-responsive genes, including the ABA biosynthesis gene AAO3, which is significantly induced in ataf1 plants compared to wild-type plants following inoculation with Bgh. Additionally, we show that Bgh inoculation results in decreased endogenous ABA levels in an ATAF1-dependent manner...
Wichmann, F; Hug, B Müller; Widmer, F
) and in virulence (intensity of disease symptoms) among Xtg isolates (P 0Æ05) could be observed using linear regression modelling. However, additive main effects and multiplicative interaction effects...... (AMMI) analysis revealed five genotypes which did not cluster close to the origin of the biplot, indicating specific interactions between these genotypes and some bacterial isolates. Simple sequence repeat (SSR) markers were used to identify marker-resistance associations using the same plant genotypes...
Efeito de fungicidas cúpricos, aplicados isoladamente ou em combinação com mancozeb, na expressão de sintomas de fitotoxicidade e controle da ferrugem causada por Puccinia psidii em goiabeira Effect of copper fungicides, sprayed alone or in combination with mancozeb, in expression of phytotoxicity symptoms and rust control caused by Puccinia psidii in guava
Antonio de Goes
Full Text Available Dois experimentos foram conduzidos em pomares de goiabeira 'Paluma', nos municípios de Monte Alto e Vista Alegre do Alto-SP. No primeiro experimento, avaliou-se o efeito de formulações de fungicidas cúpricos, aplicados isoladamente e em mistura com mancozeb, quanto ao efeito fitotóxico em botões florais e em frutos de goiabeira, em três estádios de desenvolvimento. No segundo experimento, foram avaliados os mesmos fungicidas usados no primeiro experimento, sendo, porém, acrescido do tratamento constituído por tebuconazole, cujo alvo foi sua eficiência no controle da ferrugem. No primeiro experimento, verificou-se que nenhum dos fungicidas testados causou abortamento de flores ou outros tipos de sintomas de fitotoxicidade em frutos de tamanho inferior a 15 mm de diâmetro. Contrariamente, estes fungicidas, quando aplicados isoladamente, em frutos entre 25 a 35 mm de diâmetro, causaram sintomas severos de fitotoxicidade. Em frutos de tamanho superior a 40 mm de diâmetro, estes fungicidas causaram sintomas de fitotoxicidade de níveis leves a moderados. A combinação de fungicidas cúpricos com mancozeb causou sintomas de fitotoxicidade em níveis leves, enquanto com mancozeb isoladamente não foram verificados sintomas de fitotoxicidade. No segundo experimento, verificou-se que os fungicidas cúpricos, aplicados isoladamente, foram eficientes no controle da ferrugem da goiabeira, apresentando eficiência comparável ao tratamento-padrão representado por tebuconazole. Esta eficiência foi também observada mediante o emprego da combinação mancozeb e óxido cuproso ou hidróxido de cobre.Two experiments were carried out in guava orchards cv. 'Paluma' at Monte Alto and Vista Alegre do Alto/SP. In Experiment 1 it was used copper fungicides applied alone and in combination with mancozeb to evaluate the effect of phytotoxicity on floral buds and guava fruits in three developmental stages. In Experiment 2 it was used the same fungicides used in Experiment 1, plus a treatment with tebucunazole in order to evaluate the rust control. In Experiment 1 none of the fungicides tested caused phytotoxicity symptoms and abortion of fruits less than 15 mm in diameter. The fungicides caused higher phytotoxicity in fruits between 25 and 35 mm but not in fruits larger than 40 mm diameter. Copper fungicides combined with mancozeb lead to a slight toxicity, but when applied the mancozeb alone did not lead to phytotoxicity sympton. In The Experiment 2, it was observed that copper fungicides applied alone were efficient to control rust as well as the combination of mancozeb and cuprous oxide or hydroxide and the fungicide tebuconazole.
Estimación de incidencia de daños provocados por larvas de Diatraea saccharalis (Lepidoptera: Crambidae en tallos de maíz mediante evaluación de signos externos de infestación Estimating the incidence of corn stem damage produced by Diatraea saccharalis (Lepidoptera: Crambidae larva through assessment of external infestation signs
Full Text Available Diatraea saccharalis es la plaga del cultivo de maíz de mayor impacto económico en la región pampeana de la Argentina. Las larvas ocasionan pérdidas por daños de tipo fisiológico y mecánico. Las pérdidas por daño mecánico aumentan a medida que se retrasa la fecha de cosecha, y una de las medidas culturales para prevenirlas es la cosecha anticipada. El objetivo de este trabajo fue estudiar la relación entre el número de entrenudos con galerías producidas por larvas grandes y el número de orificios por planta ocasionados por D. saccharalis. El estudio se realizó en Manfredi (Córdoba, Argentina durante la campaña agrícola 1999/2000. Se siguió un diseño experimental en parcelas divididas con cinco fechas de siembra y dos niveles de protección con insecticidas (protección total y libre infestación, como factores. Se evaluaron los ajustes a seis modelos mediante análisis de regresión lineal y no lineal. El porcentaje de plantas quebradas por debajo de la espiga varió de 3,4 a 30%. El modelo lineal explicó muy bien la relación entre el número de orificios por planta y el número de entrenudos con galerías del barrenador (R2 =0,95, y para fines predictivos resultó el más adecuado.Diatraea saccharalis is economically the most important pest to corn crops in the Pampa region in Argentina. The tunneling produced by the larvae has negative consequences due to both physiological and mechanical damage (stem falling and ear dislodging. Losses caused by mechanical injuries increase as harvest is delayed, so one of the cultural methods to prevent them is to anticipate harvest. The objective of this work was to study the relationship between the number of bored internodes and the number of holes produced by large D. saccharalis larvae in the stem. The study was perfomed in Manfredi (Córdoba, Argentina during the 1999/2000 growing season. It was carried out using a split plot design with five planting dates and protection category (with and without insecticide as treatments. Six models were evaluated by means of linear and non linear regression. The percentage of stems broken below the ear ranged from 3.4 to 30%. The linear model provided a good description of the relationship between the number of bored internodes and the number of holes per plant (R² =0.95 and resulted in the best option for predictive purposes.
Pinel-Raffaitin , Pauline
Landfilling is still nowadays the most used way of municipal solid waste (MSW) management with incineration. MSW landfills remain « black boxes » in which physical, chemical and biological phenomena interact simultaneously. Two effluents are produced during the waste degradation: leachates and biogases. Even if there are limited contact between effluents and the surrounding ecosystem, effluent monitoring is required to improve their treatments and to prevent sanitary and environmental risks. ...
Meyer, M; Cox, J A; Hitchings, M D T; Burgin, L; Hort, M C; Hodson, D P; Gilligan, C A
Infectious crop diseases spreading over large agricultural areas pose a threat to food security. Aggressive strains of the obligate pathogenic fungus Puccinia graminis f.sp. tritici (Pgt), causing the crop disease wheat stem rust, have been detected in East Africa and the Middle East, where they lead to substantial economic losses and threaten livelihoods of farmers. The majority of commercially grown wheat cultivars worldwide are susceptible to these emerging strains, which pose a risk to global wheat production, because the fungal spores transmitting the disease can be wind-dispersed over regions and even continents 1-11 . Targeted surveillance and control requires knowledge about airborne dispersal of pathogens, but the complex nature of long-distance dispersal poses significant challenges for quantitative research 12-14 . We combine international field surveys, global meteorological data, a Lagrangian dispersion model and high-performance computational resources to simulate a set of disease outbreak scenarios, tracing billions of stochastic trajectories of fungal spores over dynamically changing host and environmental landscapes for more than a decade. This provides the first quantitative assessment of spore transmission frequencies and amounts amongst all wheat producing countries in Southern/East Africa, the Middle East and Central/South Asia. We identify zones of high air-borne connectivity that geographically correspond with previously postulated wheat rust epidemiological zones (characterized by endemic disease and free movement of inoculum) 10,15 , and regions with genetic similarities in related pathogen populations 16,17 . We quantify the circumstances (routes, timing, outbreak sizes) under which virulent pathogen strains such as 'Ug99' 5,6 pose a threat from long-distance dispersal out of East Africa to the large wheat producing areas in Pakistan and India. Long-term mean spore dispersal trends (predominant direction, frequencies, amounts) are
Chen, Shisheng; Guo, Yan; Briggs, Jordan; Dubach, Felix; Chao, Shiaoman; Zhang, Wenjun; Rouse, Matthew N; Dubcovsky, Jorge
The new stem rust resistance gene Sr60 was fine-mapped to the distal region of chromosome arm 5A m S, and the TTKSK-effective gene SrTm5 could be a new allele of Sr22. The emergence and spread of new virulent races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici; Pgt), including the Ug99 race group, is a serious threat to global wheat production. In this study, we mapped and characterized two stem rust resistance genes from diploid wheat Triticum monococcum accession PI 306540. We mapped SrTm5, a previously postulated gene effective to Ug99, on chromosome arm 7A m L, completely linked to Sr22. SrTm5 displayed a different race specificity compared to Sr22 indicating that they are distinct. Sequencing of the Sr22 homolog in PI 306540 revealed a novel haplotype. Characterization of the segregating populations with Pgt race QFCSC revealed an additional resistance gene on chromosome arm 5A m S that was assigned the official name Sr60. This gene was also effective against races QTHJC and SCCSC but not against TTKSK (a Ug99 group race). Using two large mapping populations (4046 gametes), we mapped Sr60 within a 0.44 cM interval flanked by sequenced-based markers GH724575 and CJ942731. These two markers delimit a 54.6-kb region in Brachypodium distachyon chromosome 4 and a 430-kb region in the Chinese Spring reference genome. Both regions include a leucine-rich repeat protein kinase (LRRK123.1) that represents a potential candidate gene. Three CC-NBS-LRR genes were found in the colinear Brachypodium region but not in the wheat genome. We are currently developing a Bacterial Artificial Chromosome library of PI 306540 to determine which of these candidate genes are present in the T. monococcum genome and to complete the cloning of Sr60.
Wang, Bao-Lei; Zhu, Hong-Wei; Li, Zheng-Ming; Wang, Li-Zhong; Zhang, Xiao; Xiong, Li-Xia; Song, Hai-Bin
In recent years, pyridylpyrazole derivatives, such as pyridylpyrazole-containing anthranilic diamide have attracted much attention by virtue of their useful insecticidal properties and unique action mode. Moreover, some pyridylpyrazole-containing compounds have also been found to possess significant fungicidal activities. With the aim of discovering new bioactive agrochemicals for crop protection, a series of poly-heterocyclic compounds containing pyridylpyrazole and aziridine, or β-lactam, or thiazolinone moieties were synthesized. A series of pyridylpyrazole-containing poly-heterocyclic compounds were obtained, and confirmed through IR, 1 H NMR, 13 C NMR, HRMS and elemental analysis. The crystalline structure of 4-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazol-5-yl)-3-chloro-1-mesitylazetidin-2-one (compound 13f) was determined to further illustrate a trans- configuration of the β-lactam motif. In addition, bioassays showed that most of these new compounds exhibited modest insecticidal activity towards Mythimna separate Walker at 200 µg mL -1 . Some of the compounds displayed excellent fungicidal activity towards some plant fungi, including Cercospora arachidicola (13j: EC 50 = 14.5 µg mL -1 ), Physalospora piricola (12d and 13d: EC 50 = 10.5 and 9.70 µg mL -1 ), Alternaria solani Sorauer (13j: EC 50 = 7.29 µg mL -1 ), Puccinia sorghi Schw. (13d: control efficacy 99.0 ± 2.1% at 200 µg mL -1 ) and Erysiphe graminis (14d: control efficacy 95.0 ± 1.4% at 200 µg mL -1 ). Compounds 12b-12e, 13a, 13d, 13f, 13j, 13 k and 14d could be considered potential fungicidal lead compounds to do further structural optimization. The structure-activity relationship analysis in this study brings some new understanding to the biological activities of N-pyridylpyrazole-containing compounds, and provides important information for the research and development of novel agricultural fungicides with poly-heterocyclic structures. © 2017 Society of Chemical Industry. © 2017 Society
Qi, L L; Pumphrey, M O; Friebe, Bernd; Zhang, P; Qian, C; Bowden, R L; Rouse, M N; Jin, Y; Gill, B S
Stem rust (Puccinia graminis f. sp. tritici Eriks. & E. Henn.) (the causal agent of wheat stem rust) race Ug99 (also designated TTKSK) and its derivatives have defeated several important stem rust resistance genes widely used in wheat (Triticum aestivum L.) production, rendering much of the worldwide wheat acreage susceptible. In order to identify new resistance sources, a large collection of wheat relatives and genetic stocks maintained at the Wheat Genetic and Genomic Resources Center was screened. The results revealed that most accessions of the diploid relative Dasypyrum villosum (L.) Candargy were highly resistant. The screening of a set of wheat-D. villosum chromosome addition lines revealed that the wheat-D. villosum disomic addition line DA6V#3 was moderately resistant to race Ug99. The objective of the present study was to produce and characterize compensating wheat-D. villosum whole arm Robertsonian translocations (RobTs) involving chromosomes 6D of wheat and 6V#3 of D. villosum through the mechanism of centric breakage-fusion. Seven 6V#3-specific EST-STS markers were developed for screening F(2) progeny derived from plants double-monosomic for chromosomes 6D and 6V#3. Surprisingly, although 6D was the target chromosome, all recovered RobTs involved chromosome 6A implying a novel mechanism for the origin of RobTs. Homozygous translocations (T6AS·6V#3L and T6AL·6V#3S) with good plant vigor and full fertility were selected from F(3) families. A stem rust resistance gene was mapped to the long arm 6V#3L in T6AS·6V#3L and was designated as Sr52. Sr52 is temperature-sensitive and is most effective at 16°C, partially effective at 24°C, and ineffective at 28°C. The T6AS·6V#3L stock is a new source of resistance to Ug99, is cytogenetically stable, and may be useful in wheat improvement.
Li, Tianya; Liao, Kai; Xu, Xiaofeng; Gao, Yue; Wang, Ziyuan; Zhu, Xiaofeng; Jia, Baolei; Xuan, Yuanhu
Ammonium transporter (AMT) proteins have been reported in many plants, but no comprehensive analysis was performed in wheat. In this study, we identified 23 AMT members (hereafter TaAMTs) using a protein homology search in wheat genome. Tissue-specific expression analysis showed that TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a were relatively more highly expressed in comparison with other TaAMTs . TaAMT1;1a, TaAMT1;1b, and TaAMT1;3a-GFP were localized in the plasma membrane in tobacco leaves, and TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a successfully complemented a yeast 31019b strain in which ammonium uptake was deficient. In addition, the expression of TaAMT1;1b in an Arabidopsis AMT quadruple mutant ( qko ) successfully restored [Formula: see text] uptake ability. Resupply of [Formula: see text] rapidly increased cellular [Formula: see text] contents and suppressed expression of TaAMT1;3a , but not of TaAMT;1;1a and TaAMT1;1b expressions. Expression of TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a was not changed in leaves after [Formula: see text] resupply. In contrast, nitrogen (N) deprivation induced TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a gene expressions in the roots and leaves. Expression analysis in the leaves of the stem rust-susceptible wheat line "Little Club" and the rust-tolerant strain "Mini 2761" revealed that TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a were specifically induced in the former but not in the latter. Rust-susceptible wheat plants grown under N-free conditions exhibited a lower disease index than plants grown with [Formula: see text] as the sole N source in the medium after infection with Puccinia graminis f. sp. tritici , suggesting that [Formula: see text] and its transport may facilitate the infection of wheat stem rust disease. Our findings may be important for understanding the potential function TaAMTs in wheat plants.
Verreet, J A; Heger, M; Oerke, E; Dehne, H W; Finger, I; Busse, C; Klink, H
Under the primary utilisation of phytosanitary production factors such as selection of variety, crop rotation and N fertilisation according to plant requirements, the IPM Wheat Model comprises the elements diagnosis (qualitative = type of pathogen, quantitative = disease severity), scientifically grounded treatment thresholds which, as critical values in pathogen development, can be applied to define the optimum time of fungicide application, and pathogen-specific effective fungicides and application amounts. This leads to the location and year-specific optimised control of the pathogen and of the associated yield performance. After several years of development in Bavaria (from 1985 on) and Schleswig-Holstein (1993-1999), the model was tested as part of a project involving the Universities of Bonn and Kiel and the plant protection services of the German states of Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein in a three-year study (1999-2001) in interregional locations (usually nine per state) with the winter wheat variety Ritmo (interregional indicator variety) and a further variety of regional importance in different variations (untreated control, three to four times growth stage-oriented variants for the determination of the absolute damage potential, IPM-variant). In exact records (approx. 12 dates per vegetation period), the disease epidemics were recorded weekly. With the genetically uniform indicator variety Ritmo, the results documented substantially differing year- and location-specific disease and yield patterns. Interregionally, a broad wheat pathogen spectrum (Puccinia striiformis, P. recondita, Septoria tritici, Stagonospora (syn. Septoria) nodorum, Blumeria (syn. Erysiphe) graminis, Pseudocercosporella herpotrichoides, Drechslera tritici-repentis) in differing composition, disease severity and damage effect was demonstrated. The heterogeneity of the infection and damage patterns was increased in the case of the second variety, in
Hernández-Restrepo, M.; Groenewald, J.Z.; Elliott, M.L.; Canning, G.; McMillan, V.E.; Crous, P.W.
Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in
Hernández-Restrepo, M.; Groenewald, J.Z.; Elliott, M.L.; Canning, G.; McMillan, V.E.; Crous, P.W.
Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces
Pedersen, Carsten; Themaat, Emiel Ver Loren van; McGuffin, Liam J.
Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses Blumeria graminis causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute...
Artiklite autorid: Andrus Ansip Reformierakonnast, Tõnu Kauba Keskerakonnast, Jüri Kumar ERL-ist, Ivar Tallo Mõõdukatest, Tõnis Lukas Isamaaliidust, Teet Jagomägi Res Publicast. Parlamendisaadik
Feldmanis, Andris, 1982-
Eesti e-riigi ja e-valitsuse projekt saavutas neljanda koha rahvusvahelise poliitikaportaali Politics Online korraldatud küsitluses. E-riigi akadeemia juhi Ivari Tallo kommentaare. Lisad: Politics Online kirjeldab Eestit; Interneti ja poliitikamaailma mõjutajad
Astrid Johanna Sabogal Rico
micropropagación de aráceas útiles en el sector floricultor. Para cada una de las especies propagadas se tuvo en cuenta su porcentaje de enraizamiento, el tiempo de enraizamiento y el tiempo que tardaron en producir tallos con los parámetros de calidad previamente establecidos. Los tallos fueron sometidos a las evaluaciones de cuarto frío, viaje simulado y evaluación en florero.
Skottrup, Peter Durand
.sp. tritici, the cause of wheat yellow rust and Phytophthora infestans, the cause of late blight disease in potato. As no antibody existed against urediniospores from P. striiformis, mouse monoclonal antibodies (mAbs) were produced and characterised. IgM-isotype mAbs from nine hybridoma cell lines were...... to the initial cell concentration. Assay performance was investigated by cross-reactivity studies against other rust fungi. Cross-reactivity was found with Puccinia recondita and Puccinia hordei, suggesting that the ~ 39 kDa mAb8-antigen might be a conserved structural component in the surface of Puccinia...
Carlos Eduardo de Oliveira Camargo
Full Text Available Compararam-se entre si vinte e quatro linhagens de triticale e o cultivar de trigo IAC-21, através de ensaios em diferentes localidades do Estado de São Paulo, nos anos de 1986 e 1987, analisando-se os seguintes parâmetros: rendimento de grãos, altura de plantas, ciclo em dias da emergência ao florescimento, porcentagem de plantas acamadas, peso de cem grãos e resistência à ferrugem-da-folha e às manchas-foliares em condições de campo. A linhagem de triticale Nutria 7272 foi a mais produtiva (3.098kg/ha, diferindo do 'IAC-21' (2.241 kg/ha e das demais linhagens de triticale, com exceção da Merino"S" - JLO"S" (T-20 e 21, Nutria 440 e Juanillo 159, com 2.891, 2.870, 2.805 e 2.645kg/ha respectivamente. As linhagens de triticale exibiram maior resistência à ferrugem-da-folha com relação ao 'IAC-21'. A Panche 7287 mostrou-se moderadamente resistente às manchas-foliares e, as demais, suscetíveis. As linhagens M2A-KLA"S" x MA (T-6, Faro"S" e Panche 7287 apresentaram ciclo da emergência ao florescimento significativamente maior que o 'IAC-21', e M2A-CML 360 x M2A (T-2, Turk DWF-V 127 x 6TA 204/IA 146, M2A-CML x IA, TCEP 77138, BGL "S"-IGA x PND"S" e BCM"S"-Addax"S" exibiram plantas significativamente mais baixas. A Juanillo 159 apresentou o maior peso de cem grãos, diferindo do 'IAC-21' e das demais linhagens, com exceção da Nutria 7272 e Merino"S" - JLO"S" (T-21.Twenty four triticale inbred lines and the wheat cultivar IAC-21 were evaluated in field experiments carried out at different locations of the State of São Paulo, Brazil, during the years of 1986 and 1987. Grain yield, plant height, number of days from emergence to flowering, percentage of layed plants, weight of 100 grains, resistance to leaf rust (Puccinia graminis sp. tritici and to leaf spots (Helminthosporium sp. and Septoria sp. were evaluated under field conditions. The triticale inbred line Nutria 7272 pre-sented the best grain yield (3,098 kg/ha, showing
César I. Godínez-Hernández
Full Text Available Los fructanos son polímeros de fructosa con grandes aplicaciones en la industria de alimentos funcionales. Aunque los fructanos de Agave angustifolia spp. tequilana ya se producen industrialmente y comienzan a tener demanda en EE. UU., para su extracción se sigue utilizando la cabeza o piña de maguey (tallo y bases foliares con madurez variable, lo cual repercute en la calidad y en procesos que encarecen la producción. En este trabajo se describe un método alternativo para la extracción de fructanos de tallos de Agave salmiana, el cual es más simple y facilita la obtención de manera natural u orgánica. Se evaluaron los rendimientos absoluto y relativo del concentrado de fructanos (CF, referidos tanto al tallo como a la cabeza de maguey, así como su calidad mediante el análisis por cromatografía líquida de alta resolución (HPLC. El rendimiento de CF (95 % MS de materia seca del tallo fresco fue de 21 % y casi 80 % del tallo seco. El CF libre de humedad está compuesto por cerca de 80 % de fructanos y el resto por trisacáridos (cerca de 9.5 %, cenizas (5 %, sacarosa (1 % y sapogeninas (0.85 %; cantidades de glucosa y fructosa no fueron detectables (< 0.002 %.
Wetenschapelijke haarkloverij over gele roest (Puccinia striiformis) in tarwe. De Zweed J. Erikson beschreef "latente kiemen" van de gele roest van tarwe in 1901 als "mycoplasma". Hij wilde hiermee de overwintering van de gele roest verklaren. Hij had ongelijk
Víctor Manuel Pardo Cardona
Full Text Available Treinta especies de Uredinales (royas se han registrado en Colombia parasitando a veintiseis especies de plantas cultivadas de interés floral comprendidas en 21 géneros y 15 familias botánicas. Se registra para Colombia y la zona andina de Sudamérica a Puccinia hemerocallidis Thuemen. Se confirma la presencia en Colombia de Puccinia antirrhini Dietel & Holway y Uromyces gladioli P. Hennings.Thirty species of Uredinales (rust fungi are registered in Colombia parasitizing 26 species of cultivated flowers belonging to 21 genera and 15 botanical families. Puccinia hemerocallidis Thuemen is a new record for Colombia and the Andean zone of South America. Puccinia antirrhini Dietel & Holway and Uromyces gladioli P. Hennings are first records for Colombia.
Aug 22, 2011 ... germ tube growth of Puccinia coronata f.sp. avenae urediosopores ... and can provide incorrect conclusions in case of strong interactions among the ..... resistance, grain yield, test weight, and seed weight in oat. Crop Sci.
Feng, Paul C. C.; Baley, G. James; Clinton, William P.; Bunkers, Greg J.; Alibhai, Murtaza F.; Paulitz, Timothy C.; Kidwell, Kimberlee K.
Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. ...
Mustafa, G; Randoux, B; Tisserant, B; Fontaine, J; Magnin-Robert, M; Lounès-Hadj Sahraoui, A; Reignault, Ph
A potential alternative strategy to chemical control of plant diseases could be the stimulation of plant defense by arbuscular mycorrhizal fungi (AMF). In the present study, the influence of three parameters (phosphorus supply, mycorrhizal inoculation, and wheat cultivar) on AMF protective efficiency against Blumeria graminis f. sp. tritici, responsible for powdery mildew, was investigated under controlled conditions. A 5-fold reduction (P/5) in the level of phosphorus supply commonly recommended for wheat in France improved Funneliformis mosseae colonization and promoted protection against B. graminis f. sp. tritici in a more susceptible wheat cultivar. However, a further decrease in P affected plant growth, even under mycorrhizal conditions. Two commercially available AMF inocula (F. mosseae, Solrize®) and one laboratory inoculum (Rhizophagus irregularis) were tested for mycorrhizal development and protection against B. graminis f. sp. tritici of two moderately susceptible and resistant wheat cultivars at P/5. Mycorrhizal levels were the highest with F. mosseae (38 %), followed by R. irregularis (19 %) and Solrize® (SZE, 8 %). On the other hand, the highest protection level against B. graminis f. sp. tritici was obtained with F. mosseae (74 %), followed by SZE (58 %) and R. irregularis (34 %), suggesting that inoculum type rather than mycorrhizal levels determines the protection level of wheat against B. graminis f. sp. tritici. The mycorrhizal protective effect was associated with a reduction in the number of conidia with haustorium and with an accumulation of polyphenolic compounds at B. graminis f. sp. tritici infection sites. Both the moderately susceptible and the most resistant wheat cultivar were protected against B. graminis f. sp. tritici infection by F. mosseae inoculation at P/5, although the underlying mechanisms appear rather different between the two cultivars. This study emphasizes the importance of taking into account the considered
Romero Castañeda Rafael
Full Text Available Especie bien caracterizada, fácilmente distinguible de las hasta ahora conocidas, por sus hojas verticiladas de a tres, espatuladas y el tallo completamente glabro lo mismo que las ramas. Por sus hojas carinadas y el tallo glabro se acerca a Aragoa occidentalis, siendo distinta en lo demás; por las hojas carinadas es afín de A. cupressina. pero presenta con ésta y las restantes especies, notable diferencia. Especie dedicada al doctor Armando Dugand Gnecco, botánico colombiano cuyos estudios sobre la flora nacional son de gran importancia.
Assessing a sustainable sugar cane production system in Tucumán, Argentina: Part 2: Soil water and thermal regime, stalk population dynamics and sugarcane production Evaluación de un sistema sustentable de producción de caña de azúcar en Tucumán, R. Argentina: Parte II: Contenido de humedad y temperatura del suelo, dinámica de la población de tallos y producción de caña de azúcar
Patricia A. Digonzelli; M. Javier Tonatto; Eduardo R. Romero; G. Agustín Sanzano; Juan Fernández de Ullivarri; Juan A. Giardina; Jorge Scandaliaris
The need to implement sustainable and productive systems compatible with populations leads to the elimination of burning as a practice associated with sugarcane harvesting. This work is part of a study where two sugarcane production systems were compared: a) with trash blanket (mulching) and b) without trash blanket (burnt residue). Macroplots were established in a commercial field planted with LCP 85-384, in Albarracín (Cruz Alta, Tucumán, Argentina). A split-plot experimental design with th...
bajo condiciones controladas. Los inoculantes obtenidos se aplicaron en el material vegetal mencionado, efectuando mediciones durante tres meses. Los resultados muestran un efecto positivo de estimulación de crecimiento medido en longitud del tallo en las plantas tratadas con los inoculantes, específicamente en patilla y propágulos de A. germinans mantenidos en vivero.
Vastus küsimusele: mis on see, mis aitaks teil olukorras, kus Andrus Ansipit toetab 64% tartlastest, tõusta Tartu meeritoolile? Vastavad Ivar Tallo, Malle Salupere, Jüri Kumar, Tõnu Kauba, Teet Jagomägi, Tõnis Lukas. Parlamendisaadik
Elizangela Leite Vargas
La capacidad de Trichospilus diatraeae Cherian y Margabandhu, 1942 (Hymenoptera: Eulophidae para buscar y parasitar las pupas de Diatraea saccharalis (Fabricius, 1794 (Lepidoptera: Crambidae en los tallos de la caña de azúcar fue estudiada. Para analizar la habilidad de búsqueda y parasitismo fueron utilizados tallos de la caña de azúcar (20 cm donde se introdujo una pupa de D. saccharalis (T1; pupas y orugas (T2 o pupa y residuos fecales (T3. Cada tallo fue colocado en una botella plástica transparente con 21 hembras de T. diatraeae. Esas pupas fueron individualizadas, luego de 72 h, en tubos de vidrio a 25 ± 1°C, 70 ± 10 % UR y 14 h de foto período. El experimento se desarrolló en un diseño completamente al azar, con tres tratamientos y 12 repeticiones. Los porcentajes de pupas de D. saccharalis parasitados por T. diatraeae fueron del 50,00 %, 83,33 % y 16,66 % en el T1, T2 y T3, respectivamente (c2 = 3.896, p = 0,04. La presencia de D. saccharalis en los tallos de caña de azúcar favorecieron la búsqueda y parasitismo de su hospedero.
Keskerakonna esimehele Edgar Savisaarele Keila-Joal asuva suvila müümisest alla turuhinna. Kommenteerivad Ivar Tallo ja Margus Leivo. Lisad: Savisaare majatehing; Tehing; Savisaarel teine majaskandaal. Vt. samas: Hannes Krause, Jaanus Piirsalu. Aruanne võib näidata maja õiget hinda; Hannes Krause, Kristjan Jõevere. Savisaare omaga sarnane maja müügis 3 miljoniga
Apr 8, 2016 ... Licensee: AOSIS. This work ... the eastern coastline of Africa. Muslim .... In this regard the Dutch West India and Dutch. East India .... She descended from a noble family from the Tallo kingdom. .... however, determined solely from the perspective of ..... religions, tries to create a balance between plurality and.
Full Text Available Producción y calidad de la biomasa de morera (Morus alba cosechada en diferentes modalidades de poda. Una plantación establecida en 1993, con un distanciamiento entre plantas de 60, 90 y 120 cm entre hileras y plantas, fue cosechada 26 veces a diferentes intervalos (56 a 112 días de poda durante cinco años consecutivos, a la altura de 60 cm sobre el nivel del suelo. Se practicaron tres tipos de poda: testigo, semilimpio y limpio. Con un intervalo de 84 días de crecimiento se cosecharon los rebrotes y se determin ó el contenido de materia seca, proteína cruda, fibra neutro detergente y cenizas totales. La poda semilimpia provocó una pérdida del 10% en la producción de materia seca de hoja por hectárea y un 13% en el rendimiento de tallo con respecto al tratamiento testigo. La cosecha conjunta de hojas y tallos decreció un 11%. La poda limpia provocó una disminuci ón de 32% en el rendimiento de materia seca de hoja por hectárea y 36% en la producción de tallo con relación al tratamiento testigo. La producción compuesta decreció 33%. La calidad nutricional de los rebrotes, hojas y tallos, fue similar entre los diferentes tratamientos de poda
Barrera Vázquez, María Fernanda
Tesis (DCI)--FCEFN-UNC, 2015 Aborda el estudio de métodos de extracción para obtener antraquinonas de los tallos y hojas de Heterophylloe Hook pustulata (Rubiaceae). Estas antraquinonas han manifestado ser altamente bioactivas y potencialmente útiles desde el punto de vista terapeútico, siendo sus posibles usos como agentes antimicrobianos, antivirales, antiparasitarios y/o antitumorales.
Leitmaa, Dannar, 1982-
Slovakkia ärimehed annetasid Eesti Keskerakonnale 1,4 mln. krooni, avaliku teenistuse eetikakoodeksi autor Ivar Tallo peab välismaistelt annetajatelt raha saamist taunitavaks. Annetustest teistele erakondadele I kvartalis. Vt. samas lühiintervjuud Milan Bališiga
Ana Lorena Amador R.
Full Text Available Fenología productiva y nutricional de maíz para la producción de forraje. El experimento se llevó a cabo en la Estación Experimental Alfredo Volio Mata de la Universidad de Costa Rica. Se empleó semilla de maíz criolla forrajera. Alos 37 días de edad se realizó el primer muestreo de plantas y los siguientes se efectuaron cada 14 días hasta los 149 días de edad. Se determinó el contenido de materia seca, la proteína cruda, las cenizas totales, la fibra neutro detergente (FND, la fibra ácido detergente (FAD y la lignina así como los valores de hemicelulosa y celulosa. Antes de los 65 días de crecimiento, la producción de hojas fue superior a la de tallo. Posterior a esta edad, la planta fue mayor productora de tallo. Las flores emergieron después de los 100 días y ellas tuvieron un alto contenido de materia seca, contribuyendo poco en el rendimiento global del cultivo. Alos 120 días, la producción de materia seca en las mazorcas fue ligeramente mayor a la acumulada por las hojas. El contenido de materia seca en el tallo, antes de los 120 días, y en la hoja antes de los 80 días fue bajo, para ser empleado como forraje en la alimentación del ganado. El contenido de proteína cruda comenzó a decrecer drásticamente a los 65 días en el tallo y a los 90 días en la hoja. Sólo en los primeros 50 días de crecimiento, la pared celular de los tallos fue menor a 50%. El contenido de cenizas fue mayor en el tallo que en la hoja en los primeros 90 días. Por las cualidades fenológicas observadas y la concentración de nutrientes en tallos y hojas, se recomienda la cosecha y el aprovechamiento del forraje de maíz entre 80 y 90 días de crecimiento. En edades posteriores, se puede obtener el beneficio de un mayor tonelaje por unidad de superficie, sacrificando la calidad nutricional
Almacellas Gort, Jaume
La cendrosa de l'ordi, causada pel fong Blumeria graminis (D.C.) E. O. Speer f. sp. hordei Em. Marchal, sin. Erysiphe graminis D.C.: Fr. f. sp. hordei Em. Marchal, anamorf: Oidium monilioides (Nees) Link, és la malaltia aèria més important en aquest conreu a Catalunya. El 1987 es van iniciar les investigacions sobre l'etiologia de les principals malalties dels cereals. Es realitzà una prospecció per tota la l’àrea cerealícola de la geografia catalana, que va permetre estimar la distribuci...
Posada D. Adolfo
Full Text Available The behavior and agricultural characteristics of two kinds of Chrysanthemum (White Marble and Yellow Polaris were evaluated in terms of yield and quality of the product. Two different kinds of planting systems were applied (single stem and pinched stem. The experimental design in randomized whole blocks for each variety and system including four density treatments (80, 90, 110 and 115 sterns per 1.05 m2 was repeated six times. The experimental unit was of 2.10 m2; 1.26 m2 were harvested. A strong discrepancy between the quantity and quality of the product was observed. The highest yields were obtained with densities of 110 and 115 stems per 1.05 m2. However, the experimental units dis not always met both requirements of a diameter greater than seven cm and three or more marketable flowers per stem. If maximizing production of acceptable bunches is taken as a decision variable, a density of 90 sterns per 1.05 m2 with a 3/3/2/2/2/3/3 arrangement with pinched stern for Yellow Polar is seems a better alternative. As for White Marble, it would be better to have 80 stems per 1.05 m2 with a 3/2/2/2/2/2/3 arrangement in the single stem, but the probability of acceptance is only 0.666. In addition, White Marble showed more susceptibility to dwarfism.Se evaluó el comportamiento y características agronómicas asociadas con el rendimiento y la calidad del producto en las variedades White Marble y Yellow Polaris, en los sistemas de tallo único y tallo despuntado. El diseño experimental de bloques completos al azar para cada variedad y sistema incluía cuatro tratamientos de densidad (80, 90, 110 Y 115 tallos por 1.05 m2, con seis repeticiones. La unidad experimental fue de 2.10 m2, cosechando 1. 26m2(1.05 x 1.20. Se observó marcado antagonismo entre la cantidad y la calidad del producto comercial. Los mayores rendimientos se obtuvieron con densidades de 110 y 115 tallos por 1.05 m2, pero no siempre la producción cumplía con los requisitos de di
Wheat take-all disease, caused by Gaeumannomyces graminis var tritici (Ggt), has been observed in different areas of Iran in recent years. Current biocontrol studies have confirmed the effectiveness of the. Trichoderma species against many fungal phytopathogens. In this study, biocontrol effects of Trichoderma isolates ...
Raaijmakers, J.M.; Weller, D.M.; Thomashow, L.S.; Cook, R.J.
Fluorescent Pseudomonas spp. are described which are effective for the control of diseases caused by the soil-borne fungus, Gaeumannomyces graminis (Gg), such as take-all, in small grain crops or turf grass. The subject biocontrol strains have a unique genotype as shown by a characteristic banding
Hausknecht, Anton; Kalamees, Kuulo; Knudsen, Henning Jørgen
. En række arter repræsenterer nye fund for Asien, for Sibirien eller for Georgien, Tadjikistan, Turkmenistan eller Kazakstan. Et mycogeografisk element repræsenteres af C. enderlei, C. herbarum, C. graminis, C. leporina og C. subxerophytica, som er knyttet til tørre, steppeagtige områder med høj pH...
Lyngkjær, M.F.; Jensen, H.P.; Østergård, Hanne
A Japanese field isolate (Race I) of Erysiphe graminis f,sp. hordei was tested on 17 barley lines carrying the mlo powdery mildew resistance gene. Race I produced many successful infections with infection type larger than or equal to 2 on six lines (M66, MC20, SR1, SR7, Atem and Totem). On the re...
Hovmøller, M.S.; Munk, L.; Østergård, Hanne
Gene frequencies in samples of aerial populations of barley powdery mildew (Erysiphe graminis f.sp. hordei), which were collected in adjacent barley areas and in successive periods of time, were compared using mobile and stationary sampling techniques. Stationary samples were collected from trap ...
The structure of the U.S. wheat powdery mildew population (Blumeria graminis f. sp. tritici) has not been investigated, and the global evolutionary history of B. g. tritici is largely unknown. After gathering 141 single-ascoporic B. g. tritici isolates from 10 eastern U.S. locations, 34 isolates fr...
Fusarium graminearum is a necrotrophic plant pathogen that leads to severe infections of cereals contaminating them with mycotoxins harmful to human and animal. Blumeria graminis f. sp. hordei is an obligate biotroph that causes powdery mildew infections of barley. In this thesis, lifecycles and ...
Wheat powdery mildew, causal agent Erysiphe graminis f. sp. tritici , has been a serious disease in central China since the late 1970s.
The wheat growing area in central China can be divided into three zones defined by altitude.
Three dose levels of five candidate extracts sprayed at three pre-infectional time intervals were compared under low and high inoculum pressures of the late blight, Phytophthora infestans, of tomatoes and powdery mildew, Blumeria graminis, of wheat. In general, extracts from B. trilobata and D. albicans showed better ...
Microsatellite markers were used to differentiate P. triticina and P. striiformis pathotypes. Amplified fragment length polymorphisms (AFLP) were used to differentiate stem rust P. graminis pathotypes. Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of leaf, stem and yellow rust were collected ...
Shtaya, M.J.Y.; Marcel, T.C.; Sillero, J.C.; Niks, R.E.; Rubiales, D.
A population of 103 recombinant inbred lines (RILs, F9-derived lines) developed from the two-row spring barley cross L94 × `Vada¿ was evaluated under field conditions for resistance against powdery mildew (Blumeria graminis f.sp. hordei) and scald (Rhynchosporium secalis). Apart from the major
Powdery mildews infect over 9,500 plant species, causing critical yield loss. Powdery mildew disease of barley is caused by the Ascomycete fungus, Blumeria graminis f. sp. hordei (Bgh) and has become a model for the interactions among obligate biotrophs and their cereal hosts. Successful infection r...
Wheat powdery mildew (PM), caused by Blumeria graminis f. sp. tritici, is a major fungal disease of wheat worldwide. It can cause considerable yield losses when epidemics occur. Use of genetic resistance is the most effective approach to control the disease. To determine the genomic regions responsi...
Aghnoum, R.; Marcel, T.C.; Johrde, A.; Pecchioni, N.; Schweizer, P.; Niks, R.E.
The basal resistance of barley to powdery mildew (Blumeria graminis f. sp. hordei) is a quantitatively inherited trait that is based on nonhypersensitive mechanisms of defense. A functional genomic approach indicates that many plant candidate genes are involved in the defense against formation of
O'Hara, R.B.; Brown, J.K.M.
Aggregation in the distribution of pathotypes of Erysiphe graminis f.sp. hordei, the barley powdery mildew pathogen, was investigated in field plots of 'Golden Promise', 'Proctor' and 'Tyra'. 'Golden Promise' and 'Proctor' have no effective mildew resistance alleles, whereas 'Tyra' has Mla1, which...
Jiang, W.M.; Jørgensen, Jørgen Helms; Torp, J
A collection of 24 'Spontaneum' barley [H. vulgare ssp. spontaneum] entries and one comprising 244 Ethiopian barleys [H. vulgare ssp. vulgare] were tested for resistance to 4 powdery mildew [used by Erysiphe graminis f. sp. hordei] cultures that carried genes for virulence corresponding to most...
Schwarz, G.; Michalek, W.; Mohler, V.
The complex Mla locus of barley determines resistance to the powdery mildew pathogen Erysiphe graminis f. sp. hol dei. With a view towards gene isolation, a population consisting of 950 F-2 individuals derived from a cross between the near-isogenic lines 'P01' (Mla1) and 'P10' (Mla12) was used to...
Pedersen, L.H.; Jacobsen, S.; Hejgaard, J.
The plasma membrane bound beta-1,3-D-glucan (callose) synthase. assumed to be involved in the resistance to the powdery mildew fungus (Erysiphe graminis f.sp. hordei), was partially purified from a microsomal fraction of green barley leaves (Hordeum vulgare L.). Plasma membranes were enriched...
Centrum voor genetische bronnen (CGN) in Nederland- -,
By 2014-14-07 data on experiments was available for the following traits. / Annuality 2120 observations on 1905 accessions / Awnedness - hoodedness 2570 observations on 2099 accessions / Early growth tendency 1717 observations on 1425 accessions / Erysiphe graminis 3832 observations on 1794
Blumeria graminis f. sp. tritici, the cause of powdery mildew, can generate serious grain yield losses in wheat. To expand the range of resistance genes freely available to wheat breeders, a Haynaldia villosa derived resistance gene Pm21 was transferred to chromosome 6AS of wheat by homoeologous rec...
Eichmann, Ruth; Bischof, Melanie; Weis, Corina; Shaw, Jane; Lacomme, Christophe; Schweizer, Patrick; Duchkov, Dimitar; Hensel, Götz; Kumlehn, Jochen; Hückelhoven, Ralph
BAX INHIBITOR-1 (BI-1) is one of the few proteins known to have cross-kingdom conserved functions in negative control of programmed cell death. Additionally, barley BI-1 (HvBI-1) suppresses defense responses and basal resistance to the powdery mildew fungus Blumeria graminis f. sp. hordei and enhances resistance to cell death-provoking fungi when overexpressed in barley. Downregulation of HvBI-1 by transient-induced gene silencing or virus-induced gene silencing limited susceptibility to B. graminis f. sp. hordei, suggesting that HvBI-1 is a susceptibility factor toward powdery mildew. Transient silencing of BI-1 did not limit supersusceptibility induced by overexpression of MLO. Transgenic barley plants harboring an HvBI-1 RNA interference (RNAi) construct displayed lower levels of HvBI-1 transcripts and were less susceptible to powdery mildew than wild-type plants. At the cellular level, HvBI-1 RNAi plants had enhanced resistance to penetration by B. graminis f. sp. hordei. These data support a function of BI-1 in modulating cell-wall-associated defense and in establishing full compatibility of B. graminis f. sp. hordei with barley.
This document reports the use of gamma radiation to induce resistance to the fungus Puccina graminis tritici in wheat (Triticum). A resistant wheat mutant was produced, and its genetic properties are reported. The mutant was evaluated for use as a crop and for application in further crop improvement programms
A study was conducted to detect the presence of disease resistance genes to infection of wheat powdery mildew (Blumeria graminis f. sp. tritici) in selected wheat cultivars from China using molecular markers. Genomic DNA of sixty cultivars was extracted and tested for the presence of selected prominent resistance genes to ...
Wicker, T.; Oberhaensli, S.; Parlange, F.; Buchmann, J.; Shatalina, M.; Roffler, S.; Ben-David, R.; Doležel, Jaroslav; Šimková, Hana; Schulze-Lefert, P.; Keller, B.
Roč. 45, č. 9 (2013), s. 1092-1098 ISSN 1061-4036 Institutional research plan: CEZ:AV0Z50380511 Keywords : EFFECTOR CANDIDATES * PATHOGEN * BLUMERIA-GRAMINIS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 29.648, year: 2013
Rust fungi are obligate biotrophic pathogens causing considerable damage on crop plants. P. graminis f. sp. tritici, the causal agent of wheat stem rust, and M. larici-populina, the poplar rust pathogen, have strong deleterious impact on wheat and poplar wood production, respectively. The recently r...
Alejandra Nieto Garibay
Full Text Available La germinaciÃ³n en semillas estÃ¡ comÃºnmente afectada por el estrÃ©s hÃdrico. El objetivo de este estudio fue comparar el efecto del estrÃ©s hÃdrico en el porcentaje final de germinaciÃ³n, tasa media de germinaciÃ³n, y longitud de epicotilo e hipocotilo, Ãndice de radÃcula:tallo de las especies de chile semi-domesticado Capsicum frutescens L. y cultivado Capsicum annuum L. Las semillas fueron expuestas a ocho niveles de potencial hÃdrico (Î¨ inducidas con polietilen glicol (PEG 8000. Capsicum annuum presentÃ³ el porcentaje final de germinaciÃ³n de 73%; sin embargo, se presentaron diferencias no significativas (P=0.01 entre tratamientos en cada especie. La tasa media de germinaciÃ³n fue menor en C. frutescens que en C. annuum. El Ãndice de la relaciÃ³n radÃcula:tallo fue mayor para C. annuum que para C. frutescens. Las diferencias entre el Ãndice radÃcula:tallo fue significativa entre tratamientos en el caso de C. annuum, mientras que para C. frutescens no. El Ãndice radÃcula:tallo fue un indicador relevante de tolerancia a la sequÃaÂ en ambas especies de chile. Un incremento en el Ãndice radÃcula:tallo como una funciÃ³n de los niveles de estrÃ©s hÃdrico sugiere un efecto promotor en C. annuum mejorando el crecimiento de plÃ¡ntula bajo estrÃ©s hÃdrico. En el caso de C. frutescens, no se evidenciÃ³ una disminuciÃ³n en el Ãndice radÃcula:tallo. Lo cual sugiere una caracterÃstica adaptativa del crecimiento bajo condiciones climÃ¡ticas aridas y semiaridas en Baja California Sur.
Carlos Eduardo de Oliveira Camargo
Full Text Available Foram comparadas entre si vinte e uma linhagens e quatro cultivares comerciais de trigo através de ensaios instalados em diferentes localidades paulistas, analisando-se os seguintes parâmetros: rendimento de grãos, altura de plantas, ciclo em dias da emergência ao florescimento e da emergência à maturação, porcentagem de plantas acamadas, comprimento da espiga, número de grãos por espiga e por espigueta, número de espiguetas por espiga, peso de cem grãos, resistência à ferrugem do-colmo e da-folha em condições de campo e de casa de vegetação. Em condições de laboratório, foram realizados estudos da tolerância ao alumínio, em soluções nutritivas. Nos ensaios conduzidos em Campinas, em condição de irrigação por aspersão, destacaram-se, quanto à produção de grãos, as linhagens IAC-60 e IAC-67, e, nos de Capão Bonito, IAC-66, IAC-60 e IAC-69 apresentaram maior produtividade. As linhagens IAC-64, IAC-68, IAC-71 e IAC-60 destacaram-se em Tietê, e as linhagens IAC-67, IAC-63 e IAC-64 evidenciaram alta produção de grãos em Maracaí. As linhagens IAC-52, IAC-53, IAC-54, IAC-55, IAC-56, IAC-57, IAC-58, IAC-60, IAC-64, IAC-65, IAC-67, IAC-71 e o 'Alondra-S-46' mostraram plantas de porte semi-anão, diferindo significativamente do 'BH-1146', de porte alto. Em relação à ferrugem-do-colmo (Puccinia graminis f. sp. fruir, as linhagens IAC-62 e IAC-65 e o cultivar Alondra-S-46 foram resistentes às sete raças testadas em estádio de plântula em casa de vegetação e também em condições de campo. Em casa de vegetação, a linhagem IAC-64 foi resistente a quatro raças de P. recondita, agente da ferrugem-da-folha, e IAC-52 e IAC-55, a três raças desse patógeno. Em condição de infecção natural no estádio de planta adulta, as linhagens IAC-51, IAC-56, IAC-61, IAC-62, IAC-63 e IAC-67 apresentaram menor grau de infecção dessa ferrugem, enquanto IAC-51, IAC-60, IAC-63, IAC-68 e IAC-70, bem como 'BH-1146' e 'IAC
Martyniuk, Stefan; Stochmal, Anna; Macías, Francisco A; Marín, David; Oleszek, Wieslaw
The benzoxazolinones benzoxazolin-2(3H)-one (BOA) and 6-methoxybenzoxazolin-2(3H)-one (MBOA) and selected degradation products of these compounds were examined for their in vitro antifungal activity against Cephalosporium gramineum, Gaeumannomyces graminis var. graminis, and Fusarium culmorum. BOA was also applied to the soil-incorporated inoculum of C. gramineum to test its capability of reducing Cephalosporium stripe disease in winter wheat. MBOA reduced the mycelial growth of G. graminis var. tritici, C. gramineum, and F. culmorum by 50% (EC50) at the concentrations of 77, 134, and 271 microg/mL of corn meal agar, respectively, and the corresponding BOA EC50 values for the fungi were 11, 189, and 456 microg/mL. BOA degradation products 2-amino-3H-phenoxazin-3-one (APO), 2-acetylamino-3H-phenoxazin-3-one (AAPO), and o-aminophenol (o-AP) were much more inhibitory to the growth of C. gramineum and G. graminis var. tritici than the parent compounds. APO, AAPO, and o-AP EC50 values were found to be as low as 0.58, 4.57, and 1.4 microg/mL, respectively, for C. gramineum and 0.78, 2.18, and 0.80 microg/mL for G. graminis var. tritici. These compounds applied at the corresponding concentrations did not significantly affect the mycelial growth of F. culmorum. The treatment of C. gramineum inoculum with a 1% water solution of BOA resulted in a significant reduction infection of winter wheat with C. gramineum as compared to the control with the untreated inoculum,but this treatment was not as effective as the application of a commercial fungicide.
Vaz Patto, M.C.; Aardse, A.; Buntjer, J.; Rubiales, D.; Martin, A.; Niks, R.E.
In Hordeum chilense Roem. & Schult., a high variation in the level of avoidance to infection of barley leaf rust (Puccinia hordei Otth) occurs. Probably resulting from the properties of the stomata, the rust germ tube overgrows stomata, and the infection process fails in an early stage. In the
Gray leaf spot (Cercospora zeae-maydis), Turcicum leaf blight (Exserohilum turcicum) and common rust. (Puccinia sorghi) were scored on a scale of 1 (clean, no infestation) to 5 (severely diseased). Grain yield was recorded from all ears in the harvest area at harvest. Then grain yield (t ha-1) was calculated using average ...
Yeo, F.K.S.; Bouchon, R.; Kuijken, R.; Loriaux, A.; Boyd, C.; Niks, R.E.; Marcel, T.C.
Partial resistance quantitative trait loci (QTLs) Rphq11 and rphq16 against Puccinia hordei isolate 1.2.1 were previously mapped in seedlings of the mapping populations Steptoe/Morex and Oregon Wolfe Barleys, respectively. In this study, QTL mapping was performed at adult plant stage for the two
Leaf rust (Puccinia triticina Eriks. & Henn.) is a major disease affecting durum wheat production. The Lr14a leaf rust resistant gene present in the durum wheat cv. Creso and its derivative Colosseo is one of the best characterized leaf rust resistance sources presently deployed in durum wheat breed...
Orange rust, caused by Puccinia kuehnii, is an economically important disease in the Florida sugarcane industry. In this study, orange rust reactions of seedlings in progenies originating from 12 crosses between female and male parents with differing resistance to orange rust (three of each categor...
Leaf rust caused by Puccinia triticina is a common and important disease of hard red winter wheat in the Great Plains of the United States. The hard red winter wheat cultivars 'Santa Fe' and 'Duster' have had effective leaf rust resistance since their release in 2003 and 2006, respectively. Both cul...
In modern wheat cultivars, resistance to wheat leaf rust, Puccinia triticina , is either based on hypersensitivity resistance or on partial resistance. Hypersensitivity resistance in wheat is monogenic, often complete and posthaustorial: it is induced after the
Orange rust of sugarcane (Saccharum spp. hybrids), caused by Puccinia kuehnii (W. Krüger) E.J. Butler, appeared in the Western Hemisphere ten years ago. Orange rust substantially reduces yields in susceptible sugarcane genotypes. Majority of the commercial cultivars were susceptible at the time of o...
Leaf rust, caused by Puccinia triticina Eriks., is one of the most widespread diseases of wheat worldwide and breeding for resistance is one of the most effective methods of control. Lr16 is a wheat leaf rust resistance gene that provides resistance at both the seedling and adult stages. Simple s...
In the semi-arid zones of Uganda, pearl millet (Pennisetum glaucum (L.) R. Br.) is mainly grown for food and income; but rust (Puccinia substriata var indica (L.) R. Br.) is the main foliar constraint lowering yield. The objective of the study was to genetically improve grain yield and rust resistance of two locally adapted ...
J. E. Stewart; A.L. Ross-Davis; R. N. Graҫa; A. C. Alfenas; T. L. Peever; J. W. Hanna; J. Y. Uchida; R. D. Hauff; C. Y. Kadooka; M.-S. Kim; P. G. Cannon; S. Namba; S. Simeto; C. A. Pérez; M. B. Rayamajhi; D.J. Lodge; M. Arguedas; R. Medel-Ortiz; M. A. López-Ramirez; P. Tennant; M. Glen; P. S. Machado; A. R. McTaggart; A. J. Carnegie; N. B. Klopfenstein; M. Cleary
Since the myrtle rust pathogen (Austropuccinia psidii) was first reported (as Puccinia psidii) in Brazil on guava (Psidium guajava) in 1884, it has been found infecting diverse myrtaceous species. Because A. psidii has recently spread rapidly worldwide with an extensive host range,...
J. W. Hanna; R. N. Graca; M. -S. Kim; A. L. Ross-Davis; R. D. Hauff; J. W. Uchida; C. Y. Kadooka; M. B. Rayamajhi; M. Arguedas Gamboa; D. J. Lodge; R. Medel Medel-Ortiz; A. Lopez Ramirez; P. G. Cannon; A. C. Alfenas; N. B. Klopfenstein
Puccinia psidii, the cause of eucalypt-guava-'ohi'a-myrtle rust, can infect diverse plants within the Myrtaceae, and this rust pathogen has the potential to threaten numerous forest ecosystems worldwide. Known occurrence records from Brazil, Uruguay, Paraguay, Costa Rica, USA (Hawaii, Florida, and Puerto Rico), and Japan were used to develop bioclimatic...
Technical Abstract: Sugarcane rust diseases, brown rust caused by Puccinia melanocephala, and orange rust caused by P. kuehnii, are agronomically important diseases in Florida. Cultivar resistance is the best means of controlling these diseases. Natural infection has been the primary means of asses...
Infections of Puccinia melanocephala, the causal agent of brown rust, appear on Louisiana sugarcane in the spring. Disease expression is usually limited to 2 to 3 months until temperatures exceed those favorable for spore production. The affected sugarcane is harvested 4 to 6 months after rust sympt...
Brown rust, caused by Puccinia melanocephala has had devastating effects on sugarcane (Saccharum spp.) breeding programs and on commercial production. The discovery of Bru1, a major gene conferring resistance to brown rust represented a substantial breakthrough and markers for the detection of Bru1 ...
Brown rust, caused by Puccinia melanocephala, is an important disease of sugarcane in Louisiana. The adaptability of the pathogen has repeatedly resulted in resistant cultivars becoming susceptible once they are widely grown. The frequency of the brown rust resistance gene Bru1 was low in the breedi...
Brown rust of sugarcane caused by, Puccinia melanocephala, is a serious problem in the US sugarcane industry. A major resistance gene, Bru1 was identified and methodology for detecting it was developed by French scientists at CIRAD. The majority of the research resulting in the discovery of Bru1 res...
Brown leaf rust in sugarcane is caused by Puccinia melanocephala (Syd. & P. Syd.), which is major cause of cultivar withdrawal. We attempted to analyze the RAPD diversity of two discrete phenotypic classes i.e. rust resistant (R) and rust susceptible (S) of six commercially available sugarcane elite...
Over the past decade, the Louisiana sugarcane industry has experienced increasing levels of pressure from brown rust (Puccinia melanocephala). In 2000, an epidemic spread throughout the Louisiana industry, severely affecting the state’s top yielding variety, previously resistant LCP85-384, which at ...
Sugarcane (Saccharum spp.) brown rust (caused by Puccinia melanocephala H. & P. Sydow) was first reported in the United States in 1978 and is still one of great challenges for sugarcane production. A better understanding of sugarcane genotypic variation in response to brown rust will help optimize b...
Susceptibility to brown rust caused by Puccinia melanocephala is a major reason for the withdrawal of sugarcane cultivars from production. An efficient way to control the disease is to breed cultivars with durable resistance. Our aim was to identify random amplified polymorphic DNA (RAPD) markers ...
Technical Abstract: Brown and orange rust diseases cause substantial yield reductions on sugarcane (Saccharum spp.) in Florida and other regions where sugarcane is grown. Brown rust caused by Puccinia melanocephala Syd. & P. Syd has been present in Florida since 1978 and orange rust caused by Pucci...
Brown rust, caused by Puccinia melanocephala, is an important disease of sugarcane worldwide. Molecular markers for a major brown rust resistance gene, Bru1, were used to screen a total of 1,282 clones in the World Collection of Sugarcane and Related Grasses (WCSRG) to determine the distribution and...
Brown rust, caused by the fungus Puccinia melanocephala, is a major disease of sugarcane (Saccharum spp.) in Florida, Louisiana, and other sugarcane growing regions. The Bru1 locus has been used as a durable and effective source of resistance, and markers are available to select for the trait. The...
Brown rust, caused by the fungus Puccinia melanocephala, is an important disease of sugarcane posing an increasing threat to sugarcane industries worldwide. A major gene, Bru1, has been shown to contribute a significant proportion of brown rust resistance in multiple sugarcane industries. The recent...
A new highly effective resistance to oat crown rust (Puccinia coronata f. sp. avenae) was identified in the diploid oat Avena strigosa PI 258731 and introgressed into hexaploid cultivated oat. Young plants with this resistance show moderate susceptibility, whereas older plant tissues and adult plant...
Hrabětová, M.; Kolařík, Miroslav; Marková, J.
Roč. 14, č. 3 (2015) ISSN 1617-416X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Rust fungi * Pucciniales * Puccinia Subject RIV: EE - Microbiology, Virology Impact factor: 1.572, year: 2015
A Triticum timopheevii-derived bread wheat line, Selection G12, was screened with 40 pathotypes of leaf rust pathogen, Puccinia triticina at seedling stage and with two most commonly prevalent pathotypes 77-5 and 104-2 at adult plant stage. Selection G12 showed resistance at both seedling and adult plant stages.
Luiz Carlos Federizzi
Full Text Available The cultivar URS Brava, obtained from a simple cross between the line ‘UFRGS 995078-2’ and the cultivar ‘URS 21’, shows high grain yield and stability, high grain quality, desirable agronomical traits and partial resistance to crown rust, caused by the fungus Puccinia coronata f. sp. avenae.
'Caldwell' is a U.S. soft red winter wheat that has partial, adult plant resistance to the leaf rust pathogen Puccinia triticina. A line of 'Thatcher*2/Caldwell' with adult plant resistance derived from Caldwell was crossed with 'Thatcher' to develop a population of recombinant inbred lines (RILs). ...
Unraveling possible association between quantitative trait loci (QTL) for partial resistance and nonhost resistance in food barley ( Hordeum vulgaris L.) ... Abstract. Many quantitative trait loci (QTLs) in different barley populations were discovered for resistance to Puccinia hordei and heterologous rust species. Partial ...
Stripe rust caused by Puccinia striiformis Westend. f. sp. tritici Erikks. is an economically important disease of wheat (Triticum aestivum L.). Hexaploid spring wheat landrace PI 480035 was highly resistant to stripe rust in the field in Washington during 2011 and 2012. The objective of this resear...
Hernádez, José R; Aime, M Catherine; Newbry, Brad
A rust fungus found on cultivars of Kalanchoe blossfeldiana (Crassulaceae) is described as a new species, Aecidium kalanchoe sp. nov., and compared to the other described rusts on members of the Crassulaceae. Only one other rust is known to parasitize Kalanchoe spp. A DNA sequence of A. kalanchoe suggests that the teleomorph is related to Puccinia.
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most damaging diseases of wheat worldwide. It is essential to identify new genes for effective resistance against the disease. Durum wheat PI 480148, originally from Ethiopia, was resistant in all seedling tests with s...
Anatomía foliar y caulinar de Stemodia hassleriana (Scrophulariaceae, una especie endémica del Paraguay Foliar and caulinar anatomy of Stemodia hassleriana (Scrophulariaceae, a species endemic to Paraguay
María de las Mercedes Sosa
Full Text Available Se estudia la anatomía foliar y caulinar de Stemodia hassleriana Chodat, especie endémica del Paraguay. Esta especie se distingue de las restantes Stemodia del Paraguay por presentar el tallo con colénquima y seis costillas notorias. Se describe y compara la estructura anatómica de la hoja y el tallo con la de otras especies del género. Se ilustran algunos caracteres útiles para su reconocimiento.Foliar and caulinar anatomy of Stemodia hassleriana Chodat, a species endemic to Paraguay is studied. This species is distinguished from the remaining species of Stemodia from Paraguay since it presents the stems with collenchyma and six notorious ribs. Stem and leaves anatomical structures are described and compared with other species of the genus. Some useful characters for the recognition of this species are illustrated.
Full Text Available Con el fin de evaluar el comportamiento a nivel del tallo de la enzima fenilalanina amonio liasa (PAL, por su nombre en inglés phenylalanine ammonia liase, durante la interacción clavel-Fusarium oxysporum f. sp. dianthi raza 2, se seleccionaron las condiciones para su extracción y cuantificación de la actividad. Para la extracción a partir de tallos y raíces se seleccionó un tratamiento previo del material vegetal con acetona y posterior extracción con buffer borato pH 8,8 con EDTA 2mMy -mercaptoetanol 18 mM. Para su cuantificación a nivel del tallo se debe realizar un ensayo discontinuo por 10 min, a 37 oC, pH 8,0 y a una concentración de sustrato de 35 mM. Adicionalmente se muestra mediante un ensayo in vivo el efecto que tiene, como inductor de esta enzima, la aplicación de un extracto crudo del patógeno. Los resultados observados indican que esta enzima se induce significativamente en tallos de claveles de la variedad tolerante “Kiss” durante el tratamiento por aspersión con el extracto crudo del patógeno, mientras que dicha inducción fue inexistente para la infección directamente con el patógeno. La inducción en esta variedad indica que en este extracto del patógeno se presentan elicitores potenciales para la inducción de esta enzima y por ende de la ruta fenilpropanoide.
Carlos Enrique Ail-Catzim
Full Text Available Para el control de Bemisia tabaci (Genn. en los cultivos agrícolas se usan repetidas aplicaciones de insecticidas, lo que ha provocado problemas de resistencia y contaminación ambiental. Los insumos provenientes de especies vegetales son una alternativa para reducir esta problemática. Las plantas son una fuente de químicos bioactivos, que pueden tener efecto insecticida, repelente, atrayente, antialimenticio o regulador de crecimiento. El objetivo fue determinar la actividad insecticida y repelente de extractos etanólicos, acetónicos y acuosos, tanto de hojas como de tallos de Pluchea sericea (Nutt. sobre Bemisia tabaci (Genn.. Se estimó la CL50 de cada uno de los extractos, mediante bioensayos con la técnica de película residual, sobre adultos de mosquita blanca. Además, se evaluó el efecto repelente a partir de la CL50 de cada extracto, se estimó el índice de repelencia (IR, si IR = 1 el efecto es neutro, IR 1, el efecto es atrayente. Los extractos de hoja-etanol, hoja-agua y hoja-acetona presentaron valores menores de CL50 700, 1,190 y 1,250 ppm respectivamente, lo que indica alta eficiencia sobre B. tabaci, seguidos del extracto tallo-agua, por último los extractos tallo-etanol y tallo-acetona presentaron menor efectividad. Todos los extractos tuvieron acción repelente, independientemente del disolvente y órgano de la planta a 24 y 48 h. Sin embargo, los extractos a base de agua podrían tener mayor potencial para el control de la mosquita blanca en sistemas de manejo integrado de plagas, debido a que presentaron efecto insecticida y repelente, además el disolvente es inocuo y de bajo costo.
D. E. García
Full Text Available Con el objetivo de determinar el efecto de la fertilización orgánica (0, 100, 300 y 500 kg N/ha/año, la variedad (Cubana, Indonesia, Tigreada y Acorazonada y la época (periodo lluvioso y poco lluvioso en el contenido total de saponinas esteroidales (SE de la fracción comestible de la morera, se llevó a cabo una investigación con un diseño de bloques al azar con arreglo factorial 4 x 4 x 2 (n=5. No se observaron interacciones significativas de ningún orden entre los factores en estudio (P<0,05 y, tanto en las hojas como en los tallos tiernos, los niveles de abonado no afectaron significativamente las concentraciones. La variedad Acorazonada presentó el máximo contenido de SE en las hojas (11,57a mg/gMS, mientras que la Indonesia, Cubana y Tigreada mostraron niveles más bajos (11,00ab; 10,65b y 9,30c mg/gMS, respectivamente. En los tallos tiernos no se observaron diferencias significativas entre las variedades. La mayor concentración de SE (en las hojas se observó en el periodo lluvioso (14,38 mg/gMS, mientras que en los tallos tiernos el nivel más elevado correspondió con el periodo poco lluvioso (2,52 mg/gMS. Los resultados permiten concluir que, entre los factores evaluados en las hojas, la época y la variedad, mostraron la mayor importancia. En los tallos tiernos sólo la época ocasionó variaciones marcadas. En ambas partes de la planta, los niveles de fertilización no produjeron efecto en las concentraciones de las SE.
Carlos Boschini F.
Full Text Available Composición química de la morera (Morus alba, para uso en la alimentación animal: densidades y frecuencias de poda. El presente trabajo se llevó a cabo en la Estación Experimental de Ganado Lechero Alfredo Volio Mata, Cartago, Costa Rica. Las muestras fueron obtenidas de una plantación de morera dividida en tres lotes, con un distanciamiento entre plantas de 60, 90 y 120 cm entre hileras y plantas. Cada parcela se uniformó en dos alturas de poda, 30 y 60 cm sobre el nivel del suelo. Las subparcelas se podaron en forma consecutiva cada 56, 84 y 112 días durante 336 días. Los factores distancia se siembra, altura de poda y frecuencia de corte, influyeron sobre los contenidos químicos de la materia seca. La distancia de siembra y la altura de poda produjeron pequeñas variaciones en la composición de la hojas y en los tallos de la morera. La frecuencia de corte produjo cambios en la composición del las hojas y tallos de la morera; sin embargo, las diferencias en materia seca, proteína, carbohidratos estructurales o en las cenizas totales de las hojas no fueron superiores al 3% entre las frecuencias experimentadas. En el tallo los cambios mayores fueron de un 9% y se produjeron en los contenidos de materia seca, pared celular y en algunos de sus constituyentes estructurales como la celulosa. El número de corte dentro de cada frecuencia influyó de manera significativa sobre las proporciones químicas de hojas y tallos
Full Text Available Introducción: el género Garcinia produce una gran variedad de metabolitos secundarios representados por xantonas, acilfloroglucinoles y biflavonoides fundamentalmente. Sin embargo, existe muy poca información sobre la composición química de las especies cubanas pertenecientes a este género. Objetivo: determinar la presencia de 11 biflavonoides en las hojas, la corteza del tallo y el látex de Garcinia bakeriana (Urb Borhidi. Métodos : los extractos de las hojas, látex y la corteza del tallo de G. bakeriana fueron comparados empleando un método de cromatografía líquida de ultra alta eficacia (CLUAE y 11 biflavonoides como sustancias de referencia. Resultados: los biflavonoides GB-1A, GB-2A, glicósido de GB-2A, glicósido de morelloflavona, 4´´´metoxi- I3,II8-biapigenina, I3,II8-biapigenina, amentoflavona y 4´´´-metoxiamentoflavona fueron detectados como constituyentes de las hojas y la corteza del tallo de G. bakeriana. Conclusiones: la especie G. bakeriana presenta biflavonoides como constituyentes de las hojas y la corteza del tallo. Además, la metodología de trabajo desarrollada contribuye al conocimiento de la composición química de la flora cubana y podría constituir una alternativa, rápida y de bajo consumo de disolventes, para el estudio comparativo de especies endémicas cubanas de escasa distribución y abundancia.
John J. Arévalo-H
Full Text Available Determinar el requerimiento de agua y el momento adecuado de distribución, es un factor fundamental para el cultivo de flores. El objetivo del presente trabajo fue determinar el efecto de la aplicación de tres láminas de riego sobre el desarrollo y producción del cultivo de la Rosa cv. Freedom, bajo invernadero. El experimento se realizó con tres láminas de riego en un cultivo de rosa (Rosa spp. cv. Freedom. Se analizó el crecimiento de los tallos florales, la vida en florero, la producción y la eficiencia en el uso del agua. Los tratamientos se basaron en tres niveles de evapotranspiración de cultivo (ETc (70, 80 y 100%. Durante el estudio, el cultivo se mantuvo en producción constante. Se aplicaron 384,87, 254,25 y 218,97 m³ correspondiente a 100, 80 e 70% de ETc respectivamente, significando un ahorro de agua de 14,0 y 21,8% en el 80 e 70% de ETc respectivamente. El coeficiente de cultivo (Kc vario entre 0,58 y 1,65, con una media de 1,13. No se encontraron diferencias en la producción. Las curvas de crecimiento presentaron incremento continuo, con ajuste al modelo logístico. El 70% de ETc presentó la mayor eficiencia en el uso del agua, con 185 tallos m-3. La conservación media de los tallos florales fue de 12 a 15 días. La mayor causa de pérdida fue la deshidratación, que inició en el día 11, comportamiento normal del tallo floral.
Full Text Available Verbena bonariensis es una especie autóctona que por la persistencia de la inflorescencia sería apta como planta de flor para maceta. Con el objetivo de lograr plantas bajas y de buena arquitectura, se probaron los reguladores de crecimiento (BAP-citoquinina y cycocel y el corte de los ápices o pinzado. Durante el ensayo se midió la longitud del tallo principal, se contó el número de días a floración (DAF, de nudos, de ramificaciones surgidas de la base y de ramificaciones totales. También se contó el número de inflorescencias totales surgidas de brotes axilares y de yemas brotadas en el tallo principal. Cada planta se consideró una repetición y se contó con 10 repeticiones para cada tratamiento. En las plantas pinzadas, DAF y el número de inflorescencias totales y axilares fue menor y el número de ramificaciones basales al inicio de la floración fue mayor. El pinzado produjo plantas de mal aspecto y de escasa calidad ya que los tallos no ocuparon el centro de la planta. La BAP no favoreció el brotado lateral y el cycocel no originó plantas de menor altura que los otros tratamientos. Ninguna de las alternativas culturales elegidas fue efectiva para lograr el objetivo.
Full Text Available Mangroves have ecological functions to absorb, transport and stockpile toxic materials, e.g., heavy metal from surrounding environment. This research aimed to know the accumulation and distribution of heavy metals, i.e. Lead (Pb, Cuprum (Cu and Cadmium (Cd in mangrove vegetation of South Sulawesi. Vegetation samples were collected from four research location, which were Tanjung Bunga Makassar, Tallo River Makassar, Pare-Pare Bay and Bone Bay. Distribution of heavy metals in mangrove tissues was devided into five areas: pneumatophora, cable root, young leaves, old leaves and twig. Heavy metal content in the samples was measured using Atomic Absorption Spectrophotometric (AAS. The results showed that the highest accumulation of Pb was derived from the sample in Tallo River with 36.1 ppm. The highest accumulation of Cu was derived from Tanjung Bunga Makassar with 42.8 ppm. The highest accumulation of Cd was derived from Tallo River with 29.3 ppm. The distribution of heavy metals in mangrove showed that the highest accumulation of Pb was found in the cable roots with 9.5 ppm. The highest concentration of Cd was found in the young leaf with 3.1 ppm. The highest concentration of Cu was found in the cable roots with 10.1 ppm. Generally, Avicennia marina is mangrove species that has the highest concentration of heavy metals with Pb 24.2 ppm, Cd 30.9 ppm and Cu 71.2 ppm.
Á. G. Esquivel-Pool
Full Text Available Se probaron varias concentraciones (1,000, 2,000, 3,000, 4,000 y 5,000 mg·litro-1 de daminozide sobre plantas de crisantemo cv. Polaris White, en maceta y se midieron el incremento del diámetro del tallo, altura de la planta, número de nudos, longitud de entrenudos, diámetro de la inflorescencia, biomasa y área foliar para comparar su efecto contra un testigo. La concentración de 1,000 mg·litro-1 provocó que los tallos incrementaran su diámetro 10.08 % en comparación con el testigo en tanto que con 4,000 mg·litro-1 el diámetro del tallo se redujo 8 %. Los entrenudos disminuyeron su longitud hasta 76 % con 4,000 mg·litro-1 en comparación con el testigo. Concentraciones iguales o mayores a 2,000 mg·litro-1 redujeron hasta en 34.3 % la altura de la planta. El daminozide favoreció el crecimiento de las inflorescencias incrementando su diámetro 31.22 % en promedio
Full Text Available Degradabilidad ruminal de la planta de sorgo negro forrajero (Sorghum almum en diferentes etapas de crecimiento. El trabajo se llevó a cabo con el propósito de conocer la degradabilidad ruminal de la materia seca del sorgo negro forrajero, cultivado en una zona alta de Costa Rica. Se tomaron muestras en diferentes etapas de crecimiento de la planta. El estudio se realizó en la Estación Experimental "Alfredo Volio Mata" de la Universidad de Costa Rica. El cultivo fue sembrado con 18 kg/ha de semilla (88% semilla pura germinable, distribuida a chorro continuo en surcos distanciados a 70 cm. Se fertilizó con 244 kg de la fórmula comercial 10-30-10 (N2, P2O5, K2O y a las seis semanas se aplicaron 45,5 kg/ha de nitrógeno. El primer muestreo se realizó a los 24 días de edad y los siguientes, cada 14 días, hasta los 150 días. Se determinó la degradabilidad potencial de la materia seca en las hojas, tallos, panojas. La degradabilidad potencial de la planta entera disminuyó de 90 a 75% conforme aumentó la edad durante los primeros 94 días. En el tallo, la fracción soluble disminuyó de 32 a 23%, mientras que la hoja bajó de 30 a 16%. La fracción degradable en el tallo disminuy ó de 57 a 46% con el desarrollo de la planta, en tanto que en la hoja aumentó de 56 a 69%. La velocidad de degradaci ón del tallo fue de 4,7 %/h a los 52 días y en la hoja de 8,6 %/h. De 66 a 94 días fue de 2,6%/h en el tallo y en la hoja de 5,4 %/h, 3,3 %/h y 3,8 %/h a los 66, 80 y 94 días, respectivamente
Patricia A. Digonzelli
Full Text Available En Semilleros Registrados de caña azúcar de tres cultivares, provenientes de diferentes orígenes de saneamiento, se compararon los componentes de producción de caña semilla para la edad de soca 1 (segundo corte del semillero. La semilla estaba libre de RSD (Leifsonia xyli subsp. xyli y escaldadura de la hoja (Xanthomonas albilineans. El diseño experimental fue completamente aleatorizado, con cuatro repeticiones. Los tratamientos evaluados fueron: dos orígenes de la semilla, micropropagada e hidrotermotratada (50ºC, 2 h, y tres variedades (LCP 85-384, CP 65-357 y CP 48-103. Cada parcela experimental constaba de cinco surcos de 3 m y se evaluó la caña de los tres surcos centrales. En la cosecha del semillero, se contaron todos los tallos por parcela y se midió su altura hasta hoja +1. En una muestra de 36 tallos por parcela se determinó el peso, el diámetro en la parte media y el número de yemas por tallo. A partir de los datos obtenidos, se calculó el número de yemas por surco de 100 metros de longitud y la producción de caña por parcela. La caña semilla micropropagada presentó mayor altura y peso por tallo y una mayor producción de caña que la semilla termotratada. En cuanto al número de tallos, diámetro y número de yemas por tallo y por surco, no hubo diferencias significativas relacionadas al origen de la semilla. La variedad afectó significativamente a todos los componentes de la producción de caña semilla, a excepción de la altura de tallos, que solo dependió del origen de la simiente.Seedcane production components were assessed in first ratoon (cane from second cut from Registered Nurseries obtained through micropropagation and hot water treatment (50ºC, 2 h of LCP 85-384, CP 65-357 and CP 48-103 cultivars. Micropropagated and hot-water-treated seedcane was free from ratoon stunting disease (RSD (Leifsonia xyli subsp. xyli and leaf scald (Xanthomonas albilineans. A completely randomized factorial design (3x3x2
Wang, X.; Chen, P.; Pang, Y.; Zhao, Z.; Wu, G.; Wang, H.
In order to find novel strobilurin derivatives with good fungicidal activities, a series of (E)-α-(methoxyimino)benzeneacetate analogues containing 1,2,4-triazole Schiff base moiety were designed and synthesized. Their structures were confirmed by IR,1H-NMR, HRMS or elemental analyses. The antifungal activities indicated that compounds 6 showed moderate to good fungicidal activities against Rhizoctonia solani, Botrytis cinereapers, Fusarium graminearum and Blumeria graminis at the concentration 50 μ g/mL. For example, compounds 6e and 6h exhibited promising antifungal activity against Rhizoctonia solani, Botrytis cinereapers and Fusarium graminearum. Compounds 6g and 6j had higher fungicidal activities against Blumeria graminis at the concentration of 50 μ g/ml, inhibitory rate is 95.32 percentage and 89.67 percentage, respectively. (author)
Mikkelsen, Bolette Lind
Climate change will modify the environmental growth conditions for plants, and consequently also their physiology and susceptibility to diseases. However, there is a lack of experimental studies on the effect of climate change on plant diseases, which include several climatic factors in order...... to simulate realistic growth conditions. In this PhD thesis, the complex interplay of elevated CO2, temperature and ozone on the susceptibility of barley to the biotrophic powdery mildew fungus (Blumeria graminis f.sp. hordei) and the hemibiotrophic spot blotch fungus (Bipolaris sorokiniana) was revealed....... The underlying mechanisms hereof was examined by studying changes in photosynthesis, accumulation of secondary metabolites and global gene expression after B. graminis attack...
Chen, Yan-Jun; Perera, Venura; Wagner, Michael
Barley HvNAC6 is a member of the plant-specific NAC (NAM, ATAF1,2, CUC2) transcription factor family and we have shown previously that it acts as a positive regulator of basal resistance in barley against the biotrophic pathogen Blumeria graminis f. sp. hordei (Bgh). In this study, we use a trans...
Rayapuram, C.; Hemzalová, Vendula; Lyngkjaer, M. E.
Roč. 93, č. 3 (2011), s. 613-625 ISSN 1125-4653 R&D Projects: GA MZe QH72117 Institutional research plan: CEZ:AV0Z50380511 Keywords : Blumeria graminis f. sp hordei * Hordeum vulgare * hypersensitive response Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.912, year: 2011 http://sipav.org/main/jpp/index.php/jpp/article/view/1229
Hansen, Nina Eberhardtsen
-throughput phenotyping of whole plants. Additionally, a system for automated confocal microscopy aiming at automated detection of infection thread formation as well as detection of lateral root and nodule primordia is being developed. The objective was to use both systems in genome wide association studies and mutant...... the analysis. Additional phenotyping of defense mutants revealed that MLO, which confers susceptibility towards Blumeria graminis in barley, is also a prime candidate for a S. trifoliorum susceptibility gene in Lotus....
Lei, Peng; Zhang, Xuebo; Xu, Yan; Xu, Gaofei; Liu, Xili; Yang, Xinling; Zhang, Xiaohe; Ling, Yun
Take-all of wheat, caused by the soil-borne fungus Gaeumannomyces graminis var. tritici, is one of the most important and widespread root diseases. Given that take-all is still hard to control, it is necessary to develop new effective agrochemicals. Pyrazole derivatives have been often reported for their favorable bioactivities. In order to discover compounds with high fungicidal activity and simple structures, 1,2,3,4-tetrahydroquinoline, a biologically active group of natural products, was introduced to pyrazole structure. A series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were synthesized, and their fungicidal activities were evaluated. The bioassay results demonstrated that the title compounds displayed obvious fungicidal activities at a concentration of 50 μg/mL, especially against V. mali, S. sclerotiorum and G. graminis var. tritici. The inhibition rates of compounds 10d, 10e, 10h, 10i and 10j against G. graminis var. tritici were all above 90 %. Even at a lower concentration of 16.7 μg/mL, compounds 10d and 10e exhibited satisfied activities of 100 % and 94.0 %, respectively. It is comparable to that of the positive control pyraclostrobin with 100 % inhibition rate. A series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were synthesized and their structures were confirmed by (1)H NMR, (13)C NMR, IR spectrum and HRMS or elemental analysis. The crystal structure of compound 10g was confirmed by X-ray diffraction. Bioassay results indicated that all title compounds exhibited obvious fungicidal activities. In particular, compounds 10d and 10e showed comparable activities against G. graminis var. tritici with the commercial fungicide pyraclostrobin at the concentration of 16.7 μg/mL.Graphical abstractA series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were designed and synthesized. Bioassay results indicated that all these compounds exhibited obvious fungicidal activities.
Bouguennec, Annaig; Trottet, Maxime; du Cheyron, Philippe; Lonnet, Philippe
Powdery mildew has emerged on triticale in the early 2000s in many locations, probably due to a host range expansion of the wheat formae speciales, Blumeria graminis f.sp. tritici. Many triticale cultivars are highly susceptible to powdery mildew, mainly in seedling stage, revealing a probably narrow genetic basis for powdery mildew resistance genes (Pm). Moreover, as Blumeria graminis is an obligate biotrophic fungus, it is very time consuming and difficult to maintain powdery mildew isolates for a non-specialized laboratory and populations can evolve. In order to identify wheat Pm genes efficient against natural populations of powdery mildew, wheat differential hosts and triticale seedlings were inoculated below susceptible triticale crop naturally contaminated by mildew, in several locations and several years. Symptoms on seedlings were measured after approximately two weeks of incubation in favorable fungus growth conditions. According to these data, we classified the Pm genes presents in our wheat differential hosts set in 3 classes: Pm already overcame by triticale powdery mildew, Pm having variable effects and Pm still efficient against triticale mildew. Data on triticale seedlings allowed us to identify some few triticale cultivars resistant to Blumeria graminis in seedling stage. We will try to identify Pm genes present in those cultivars next year by testing them with the characterized isolates of powdery mildew from Gent University. Nevertheless, interspecific crossing of wheat, resistant to powdery mildew in seedling stage, and rye have been initiated to introduce potentially interesting genes for resistance in triticale.
Castanheira, N; Dourado, A C; Kruz, S; Alves, P I L; Delgado-Rodríguez, A I; Pais, I; Semedo, J; Scotti-Campos, P; Sánchez, C; Borges, N; Carvalho, G; Barreto Crespo, M T; Fareleira, P
To search for culturable Burkholderia species associated with annual ryegrass in soils from natural pastures in Portugal, with plant growth-promoting effects. Annual ryegrass seedlings were used to trap Burkholderia from two different soils in laboratory conditions. A combined approach using genomic fingerprinting and sequencing of 16S rRNA and recA genes resulted in the identification of Burkholderia strains belonging to the species Burkholderia graminis, Burkholderia fungorum and the Burkholderia cepacia complex. Most strains were able to solubilize mineral phosphate and to synthesize indole acetic acid; some of them could produce siderophores and antagonize the phytopathogenic oomycete, Phytophthora cinnamomi. A strain (G2Bd5) of B. graminis was selected for gnotobiotic plant inoculation experiments. The main effects were the stimulation of root growth and enhancement of leaf lipid synthesis and turnover. Fluorescence in situ hybridization and confocal laser microscopy evidenced that strain G2Bd5 is a rhizospheric and endophytic colonizer of annual ryegrass. This work revealed that annual ryegrass can naturally associate with members of the genus Burkholderia. A novel plant growth promoting strain of B. graminis was obtained. The novel strain belongs to the plant-associated Burkholderia cluster and is a promising candidate for exploitation as plant inoculant in field conditions. © 2015 The Society for Applied Microbiology.
María Ileana Oloriz
Full Text Available AFLPs (amplified fragment length polymorphism was carried out from genomic DNA of five rust resistant sugar cane somaclons and their susceptible donor, Saccharum officinarum var B 4362, using three combinations of primers (EcoRI/aca: MseI/acc; EcoRI/aca: MseI/atg and EcoRI/aca: MseI/agg. Six polymorphic bands were obtained, two of these only appeared in the resistant genotypes, which are probably DNA sequences, related to rust resistance locus. These fragments have been cloned to study their nucleotide sequence and to investigate their roll in resistance mechanism develop by these mutants during Puccinia melanocephala infection. Key words: molecular markers, Puccinia. melanocephala, Saccharum
Carla Vanessa Borges Castro
Full Text Available Sugarcane (Saccharum spp. cultivation is one of the major agricultural activities in the Brazilian states. This study aimed to molecularly identify the pathogen associated with rust in sugarcane cultivars in the state of Rio de Janeiro and to suggest a control strategy. Among the 14 PCR-tested cultivars, Puccinia kuehnii infection was identified for RB947520, RB92606, RB835486, RB72454, SP89-11I5, SP83-2847, both from infected leaf sample and from urediniospores. Puccinia kuehnii was not detected by PCR for the cultivars RB955971, RB951541, RB92579, RB867515, RB855536, SP91-1049, SP80-3280, SP80-1816. This is the first molecular detection of this fungus in the state of Rio de Janeiro for six of the 14 analyzed cultivars.
María I. Oloriz
Full Text Available The hypersensitive response is one of the most powerful mechanisms for which the plants resist pathogen attack. Mutations carried out previously on the variety B4362, of sugarcane, originated five mutants that express this mechanism towards the attack of rust (Puccinia melanocephala Syd.. By means of a subtractive hybridization among the cDNA obtained starting from the resistant clone inoculated with rust and a pool of cDNA of the susceptible variety (B4362 inoculated and of the resistant clone not inoculated, it was possible to reduce the number of genes expressed during the infection with the fungus. A subtractive library was carried out where we hope that most of the genes are involved in the hypersensitive response that present these mutants towards the infection of the pathogen. Key words: Subtractive hybridization, hypersensitive response, Puccinia melanocephala Syd.
Mahmoud, Amer F; Hassan, Mohamed I; Amein, Karam A
Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 2 rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.
Fofana, Bourlaye; Banks, Travis W.; McCallum, Brent; Strelkov, Stephen E.; Cloutier, Sylvie
In this study, we detail the construction of a custom cDNA spotted microarray containing 7728 wheat ESTs and the use of the array to identify host genes that are differentially expressed upon challenges with leaf rust fungal pathogens. Wheat cultivar RL6003 (Thatcher Lr1) was inoculated with Puccinia triticina virulence phenotypes BBB (incompatible) or TJB (7-2) (compatible) and sampled at four different time points (3, 6, 12, and 24 hours) after inoculation. Transcript expression levels rela...
María I. Oloriz; Luis Rojas; Víctor Gil; Elio Jiménez
The hypersensitive response is one of the most powerful mechanisms for which the plants resist pathogen attack. Mutations carried out previously on the variety B4362, of sugarcane, originated five mutants that express this mechanism towards the attack of rust (Puccinia melanocephala Syd.). By means of a subtractive hybridization among the cDNA obtained starting from the resistant clone inoculated with rust and a pool of cDNA of the susceptible variety (B4362) inoculated and of the resistant c...
Pardo Cardona Víctor Manuel
Full Text Available Se presentan las especies de Uredinales (royas colectadas en Colombia parasitando especies de Cordia L. (Boragillaceae. Se incrementa la información acerca de la flora de Uredinales de Colombia al registrar por primera vez a Puccinia johnstonii Arthur, así como un nuevo hospedante para Uredo cordiorum Kern & Whetzel. Se elaboran claves para los estados anamórficos y teliomórficos de los Uredinales Colombianos sobre Cordia L.
Dec 30, 2013 ... Cette rouille n'a jamais été signalée auparavant sur Mentha viridis (hôte nouvel) dans le. Maroc. Au Maroc, Puccinia menthae Pers. (1801) a été rencontrée sur Mentha rotundifolia au lieu frais près d'Idni sur la route du Tizi n'Test (Haut Atlas), Satureja calamintha subsp. ascendes dans la pelouse au bord.
Vega G, M.G.
The objective of this work was to evaluate the effect of recurrent radiation on agronomic traits in two barley varieties. The research was carried out at experimental fields pertaining to the Instituto de Investigacion Agropecuaria, Acuicola y Forestal of the Estado de Mexico (ICAMEX). The biological material was irradiated in the Gamma Cell 220 at the Instituto Nacional de Investigaciones Nucleares (ININ). The experimental design was divided plots in the randomized blocks, with four replications. The factor varieties (Cerro Prieto and Puebla) was assigned to the big plots mean while in the factor doses was assignated to the small plots (0, 10, 20, 30, 40 and 50 krad of gamma rays). The variables under study were: germination, number of shoots, plant height, incidence of Puccinia striiformis, days to flowering, days to physiological maturity, spike length and yield. The analysis of variance exhibited no significant differences between varieties for all the studied variables. Regarding to dose, most of the studied variables exhibited significant differences, except for incidence of Puccinia striiformis and days to flowering. The interaction variety x doses showed significance only for the variable days to flowering and days to physiological maturity. The mean separation by Tukey test at 0.05 and the regression analysis showed that the variables: germination, number of shoots, plant height, spike length and yield decreased as the dose increased. On the other hand in the variables incidence of Puccinia striiformis, days to flowering and days to physiological maturity exhibited a direct relationship with the dose. (Author)
Producción de caña semilla en Semilleros Registrados provenientes de micropropagación y de hidrotermoterapia de tres cultivares de caña de azúcar Seedcane production in Registered Nurseries obtained through micropropagation and hot water treatment of three sugarcane cultivars
Patricia A. Digonzelli
Full Text Available Se evaluaron los componentes de la producción de caña semilla en Semilleros Registrados de caña de azúcar provenientes de micropropagación e hidrotermoterapia (50ºC, 2 h, en tres variedades (LCP 85-384, CP 65-357 y CP 48-103 y tres épocas de plantación (mayo, agosto y octubre. La semilla micropropagada y la hidrotermotratada estaban libres de achaparramiento de la caña soca (Leifsonia xyli subsp. xyli o RSD, por sus siglas en inglés, y escaldadura de la hoja (Xanthomonas albilineans. El diseño experimental fue un factorial completamente aleatorizado 3x3x2, con tres repeticiones. Los factores fueron: época de plantación (tres niveles, variedad (tres niveles y origen de la semilla (dos niveles. Cada parcela constaba de cinco surcos de 3 metros, evaluando los tres surcos centrales. En la cosecha del semillero se contaron todos los tallos por parcela y se midió su altura hasta hoja TVD. En una muestra de 45 tallos por parcela se determinaron el peso y número de yemas por tallo. A partir de los datos obtenidos se calculó el número de yemas por surco de 100 metros de longitud y por hectárea. El origen de la caña semilla (micropropagada o hidrotermotratada afectó el número de tallos y la altura y número de yemas por tallo, por surco y por hectárea. La época de plantación y la variedad afectaron los componentes de la producción de caña semilla. La micropropagada presentó una mayor población, altura y número de yemas por tallo, permitiendo aumentar entre el 8% y 23% el área que es posible plantar a partir de una hectárea de Semillero Registrado. La magnitud de las diferencias entre la caña semilla micropropagada y termotratada varió según cultivares y época de plantación.Seedcane yield components in sugarcane Registered Nurseries obtained through micropropagation and hot water treatment (50ºC, 2 h were evaluated, considering three varieties (LCP 85-384, CP 65-357 and CP 48-103 and three plantation dates (May, August
Veracruz, Mexico, hasta Brasil y Bolivia. Esta especie posee características anatómicas que no han sido ampliamente estudiadas pero observaciones hechas por artesanos centroamericanos sugieren que los tallos de sitios no perturbados por actividades humanas presentan mayor resistencia al doblado y menos tallos fracturados en el manejo. Las muestras de tallos fueron recolectadas de individuos que crecen en un sitio conservado y uno perturbado por actividades humanas, a tres alturas de la longitud del tallo (basal, media y apical. Se recolectó una rama de cada uno de cinco individuos (n=5 en ambos sitios. Cada rama fue dividida en tres secciones: basal, desde el nivel del suelo hasta los 0.5 m; medio, desde 0.5 a 5.0 m; y apical, desde 5.0 a 10.0 m. Se midió la cantidad por unidad de área y las dimensiones o tamaño (i.e. diámetro radial y diámetro perpendicular de paquetes vasculares, células de parénquima y fibras. La cantidad de paquetes vasculares fue mayor en los tallos del sitio conservado, la cantidad de células de parénquima fue diferente entre sitios y la cantidad de fibras fue mayor en los tallos del sitio perturbado por actividades humanas. Estas características muestran cierta relación con los resultados mecánicos en otro estudio de los autores, los cuales confirman parcialmente las observaciones de los artesanos, lo que puede estar estrechamente relacionado con las características microclimáticas de los sitios de crecimiento.
Full Text Available El objetivo de este estudio fue evaluar in vitro la actividad fijadora de nitrógeno y solubilizadora de fosfato de bacterias endófitas de pasto colosoana (Bothriochloa pertusa. Se colectó la raíz, los tallos y las hojas del pasto en cuatro zonas agroecológicas del municipio de Corozal, Sucre, Colombia, durante el segundo semestre del año 2012. Cada tejido fue sometido a proceso de desinfección superficial. Se aislaron bacterias endófitas en medio de cultivo agar R2A, a partir de cada tejido se determinó la densidad poblacional (UFC/g de tejido, por conteo en superficie; la separación de morfotipos se realizó mediante la forma, color, tamaño y apariencia. La actividad fijadora de nitrógeno y solubilizadora de fosfato se evaluó in vitro sobre medios de cultivos específicos. Todos los resultados obtenidos fueron analizados utilizando el programa estadístico R. Hubo diferencias significativas para densidades poblacional de bacterias con respecto a tejido, con mayores valores en raíz (1,61 x 1010/g raíz, seguida de tallo (7,44 x 109/g tallo y los valores más bajos se reportaron para hojas (5,42 x 109/g hoja. Se encontró significancia entre la densidad poblacional con relación a los factores de zona, fincas y tipo de tejido analizado. Los resultados de la identificación con kit API20E confirmaron la presencia de las bacterias endófitas Aeromonas salmonicida y Pasteurella pneumotropica con capacidad simultánea de solubilizar fosfatos y fijar nitrógeno.
Caracterización morfológica de mora en los departamentos de Valle del Cauca, Cauca y Nariño, de Colombia Morphologic characterization of blackberry on the departments of Valle, Cauca y Nariño of Colombia
Adriana Zamorano M
Full Text Available Se colectaron 36 materiales de mora pertenecientes a las especies Rubus glaucus , R. urticifolius y R. robustus . La caracterización cualitativa separó las 3 especies y generó descriptores que permitieron identificar forma, tipo, margen, ápice y color del envés en las hojas, y presencia de antocianinas y cerosidad en tallos. La caracterización cuantitativa identificó particularidades de importancia comercial (alto peso de fruto, pocas espinas en el tallo y altos grados Brix en los materiales 3 y 31 de la Colección. El análisis multivariado de caracteres cuantitativos de tallo y fruto conformó 5 grupos que variaron en distancia de entrenudos, longitud de peciolulo en rama macho, longitud de pecíolo en rama hembra y macho, ancho de folíolo, peso de fruto, longitud del corazón del fruto y número de drupas.36 materials of blackberry belonging to three species: R. glaucus , R. urticifolius and R. robustus were collected. The qualitative characterization separated the three species and it generated describers that allowed to identify form, type, margin, apex, color of leaf in the leaves, and presence of antocianinas and serosity in steams. The quantitative characterization identified characteristics of commercial importance (high fruit weight, few thorns in the stem and high Brix degrees in the materials 3 and 31 of the Collection. The multivaried analysis of quantitative characters for stem and fruit conformed 5 groups that varied in distance of internodes, length of pedicels in the male branch, length of petioles in female and male branch, wide of leaf, fruit weight, length of the heart of the fruit and number of drupes.
M. Cristina HERNÁNDEZ
Full Text Available Se da a conocer el comportamiento alimentario de las larvas de algunas especies del grupo truncatus de Thrypticus (Diptera: Dolichopodidae, que se desarrollan en plantas hospedadoras de Pontederiaceae. Los estadios inmaduros de T. circularis Bickel & Hernández se crían en los pecíolos globosos de Eichhornia crassipes (Martius Solms-Laubach (Pontederiaceae, minando cerca de la epidermis y abriendo varios orificios al exterior. La larva de T. romus Bickel & Hernández crece en E. azurea (Sw. Kunth, formando una mina curva, corta en comparación con las otras especies. La larva de T. formosensis Bickel & Hernández se desarrolla en Pontederia cordata L. (Pontederiaceae, excavando la mina entre la epidermis y la gran celda central de los pecíolos. Por último, la larva de T. taragui Bickel & Hernández se cría en tallos sumergidos de P. subovata (Seub. in Mart. Lowden, formando una mina subepidérmica con ramificaciones hacia la estela central del tallo. No se pudieron asociar las minas correspondientes a las especies T. yanayacu, T. chanophalus y T. azuricola. No se encontraron predadores ni parásitos de larvas o pupas, se observaron casos de canibalismo entre larvas cuando el trazado de dos minas confluye. Las especies del grupo truncatus poseen un modo de alimentación sumamente específico, confinadas al aerénquima, se alimentan de la savia extraída de los orificios roídos en los haces vasculares de los pecíolos y tallos, posiblemente con levaduras simbiontes como suplemento para la nutrición. Numerosas colecciones en el campo y pruebas en el laboratorio, indican que estos insectos están asociados con plantas hospedadoras específicas dentro de la misma familia. Esta especialización sugiere una larga asociación insecto-hospedadora.
Full Text Available Objetivos. Evaluar la actividad citotóxica de extractos etanólicos de raíces, tallos, hojas y flores de Gnaphalium spicatum sobre algunas líneas celulares tumorales humanas. Materiales y métodos. Las líneas celulares HT-29, H-460, MCF-7, M-14, PC-3, DU-145, K-562, y 3T3, fueron expuestas a cuatro concentraciones de extractos etanólicos de raíces, tallos, hojas y flores de Gnaphalim spicatum, asimismo, a diferentes concentraciones de cisplatino, que se usó como control positivo. Se halló los porcentajes de crecimiento en 48 horas. Luego se determinó la concentración inhibitoria 50 (CI50 mediante análisis de regresión lineal, el índice de selectividad de cada muestra y finalmente, la relación dosis-respuesta entre las concentraciones de los extractos y cisplatino, con los porcentajes de crecimiento. Resultados. El extracto etanólico de las raíces de Gnaphalium spicatum mostró mayor actividad citotóxica en la líneas celulares MCF-7 y K-562. Los CI50 en μg/mL fueron de 98 (r= -0,98 p a 0,250 mg/mL en todas la líneas celulares evaluadas. Conclusiones. Los extractos etanólicos de tallos, hojas y flores de Gnaphalium spicatum no mostraron actividad citotóxica en este bioensayo. Los extractos de raíces mostraron citotoxicidad en las todas las líneas celulares tumorales, excepto en M-14. Además fueron menos citotóxicos en relación al cisplatino en la línea celular 3T3.
Full Text Available Se evaluó fisiopatías en Brachiaria arrecta expuestas a contenidos tóxicos de cadmio y plomo en el invernadero de la Universidad Nacional de Colombia Sede Palmira, se doparon plántulas sanas de 20 días de edad bajo cultivo hidropónico. El objetivo fue describir síntomas crecientes por intoxicación con el diseño de una escala valorativa de daños crecientes, adicionalmente se evaluaron cambios histológicos de raíz tallo y hojas mediante microscopia de luz de alta resolución (MLAR. Las plantas fueron sometidas a estrés abiótico con los tratamientos de sales de CdCl2 en concentración de 10 ppm, y de Pb (NO32 500 ppm, respectivamente. Los resultados principales mostraron un mayor detrimento cuando las plantas fueron expuestas al metal plomo que al cadmio en las raíces, tallos y hojas. Se apreciaron deformaciones extremas en paredes celulares de las células del cortex y en la endodermis de la raíz; en las hojas los daños fueron notorios para ambos metales sobre todo en el parénquima clorofílico y en la deformación de paredes de la epidermis tanto en haz como envés; en los tallos aparecieron deformaciones de las células del parénquima de relleno cuando ocurre bioacumulación intensa de plomo. Estos resultados sugieren que la bioconcentración en los tejidos vegetales ocasiona trastornos histológicos, que pueden involucrar una red trófica y por consiguiente consecuencias en la Salud Pública.
Full Text Available La calidad en las flores cortadas se ve afectada debido a los largos periodos de exposición a temperaturas cálidas, estrés hídrico y daños mecánicos. Diversas investigaciones han identificado una serie de aspectos técnicos para prolongar la vida de las flores cortadas, entre los que resaltan el uso de soluciones preservadoras que además puedan inhibir la síntesis de etileno. En la presente investigación se evaluaron los efectos del cloruro de cobalto (Co sobre el peso, consumo de solución, unidades SPAD en hojas, contenido de nitrógeno, cobalto, potasio, calcio, magnesio y hierro, así como vida postcosecha, en tallos de Lilium híbrido oriental 'Star Gazer' y 'Star Fighter'. Los tallos florales fueron obtenidos en Villa Guerrero, Estado de México, y transportados en seco al laboratorio, donde se estableció un experimento factorial 2 x 5 en un diseño experimental completamente al azar. Se utilizaron soluciones que contenían como fuente de carbono sacarosa al 4 % y las siguientes concentraciones de Co: 0.0, 0.1, 0.2, 0.4 y 0.8 mM. Lo anterior permitió establecer que Co 0.1 y 0.2 mM retrasaron los síntomas de senescencia de los tallos florales de Lilium.
Jesús Miguel Calzada-Marín
Full Text Available El objetivo de este experimento fue realizar un análisis de crecimiento del pasto “Maralfalfa” ( Pennisetum sp. desde la siembra hasta determinar el momento óptimo de cosecha. La morfología de la planta (MP, tas a de crecimiento (TC, altura, radiación interceptada (RI, relación hoja/tallo (H:T, hoja/no hoja (H:NH y la acumulación de biomasa aérea, se evaluaron a intervalos de 15 días, en un periodo de 180 días, a excepción de lo s dos primeros muestreos que fueron mensuales. Los datos se analizaron mediante el procedimiento GLM de SA S, bajo un diseño experimental de bloques al azar, con medidas repetidas en el tiempo, con tres repeticiones . La MP varió de manera significativa ( P <0.01 a través de los diferentes estados fisiológicos. La máxima producción de biomasa aérea y TC se alcanzó a los 151 días después de la siemb ra con 37,297 kg MS ha -1 y 247 kg MS ha -1 d -1 , respectivamente. También se registró el mayor porcentaje de RI (97.4 %, con una altura de 2.3 m aproximadamente. La producción de biomasa de tallos y la producción de material muerto del pasto mar alfalfa, están correlacionadas de manera positiva con el incremento en la edad de la planta. La máxima tasa d e crecimiento, coincide con la máxima producción de hojas y de tallos, y con la mayor producción de bi omasa total.
Full Text Available Este estudio se realizó en el municipio de San Pablo (Nariño con el objeto de evaluar métodos de propagación de (Alocasia macrorrhiza y determinar el mejor para la obtención de material de siembra. Se utilizó un diseño de bloques completos al azar con 4 tratamientos y 4 repeticiones. Los tratamientos fueron: T1- discos del tallo, T2- yemas del tallo, T3- hijuelos y T4 cogollos. El material de propagación fue obtenido en el vivero municipal de San Pablo (Nariño, donde se encontraba un área aproximada de 400 m2 con bore, cuyo estado sanitario y productivo era aceptable. El análisis de varianza detecto diferencias significativas entre tratamientos para la variable altura de planta, mientras que para hojas/planta no hubo diferencias entre tratamiento. La prueba de Duncan permitió determinar que el método de propagación de cogollos fue el de mejor comportamiento logrando un promedio de 125,8 cm/planta. Al finalizar el ensayo, los métodos de discos del tallo e hijuelos fueron los que menor crecimiento presentaron con un promedio de 96,9 y 105,4 cm/planta, respectivamente. El número de hojas por planta es independiente del método de propagación utilizado, sin importar cual método se utilice la producción de biomasa foliar será la misma.
Peña Giraldo, José Abad; González Peña, Rosa Otilia
El presente informe recoge el análisis de prefactibilidad de la producción de pulpa de fibra larga mecánica para papel, a partir de los desechos fibrosos del seudo tallo del cultivo de plátano en el eje cafetero de Colombia. Con el proyecto se espera hacer una mejor utilización de los recursos naturales y económicos de la región, mejorar el medio ambiente y la calidad de vida de sus habitantes. En el estudio se demuestra la viabilidad técnica, financiera, económica y social del proyecto. E...
Edgardo M. Rengifo
Full Text Available Se describe el nido de Scolomys melanops (Rodentia: Cricetidae, encontrado en el Nororiente de Perú en un hábitat de Colinas bajas. Se identificó tres estructuras en el nido: a Orificio de acceso y salida; b Túnel y c Dormidero, en este último se encontraron restos de frutos, fibras del pedúnculo y tallos de Lepidocaryum tenue (Arecales: Arecaceae “Irapay”. Se sugiere en base al material vegetal encontrado en el nido, la existencia de una relación de depredación entre el roedor Scolomys melanops y la palmera Lepidocaryum tenue.
Malonda Vidal, Elisabeth
En las últimas décadas el estudio sobre el sexismo ha cobrado un gran protagonismo en la investigación en psicología y diversas investigaciones recientes lo avalan (Ferragut, Blanca, & Ortiz-Tallo, 2013; Garaigordobil, 2013; de Lemus, Moya, & Glick, 2010; Pozo, Martos, & Alonso-Morillejo, 2010). Prueba de ello es que se han generado diversas teorías, entre ellas la Teoría del Sexismo Ambivalente (Glick & Fiske, 1996, 1999), que se desarrollará de forma específica en el apartado siguiente. Al ...
Saúl Parra Terraza
Full Text Available Problemas de sanidad en suelos del valle de Culiacán ha ocasionado que la siembra de tomate se realice en suelos cercanos a la costa, donde el agua de riego es de menor calidad, por contener concentraciones de cloro (Cl y sodio (Na con riesgo de toxicidad para las plantas o de interactuar con los nutrimentos de la solución nutritiva (SN, reduciendo su disponibilidad. Esta investigación evaluó en invernadero los efectos de relaciones Cl-/aniones y Na+/cationes en la SN sobre las concentraciones de Na, K, Ca y Mg en hojas y tallos de dos cultivares de tomate (Solanum lycopersicum L. cvs. Polaris e ISIS. El diseño experimental fue completamente al azar con arreglo factorial 32, con cuatro repeticiones. Los factores fueron: 1 relación Cl-/aniones (25, 50 y 75/100, y 2 relación Na+/cationes (25, 50 y 75/100. Se realizó un análisis de varianza y las medias de los tratamientos se compararon con la prueba de Tukey (P ≤ 0.05. En hojas del cultivar ISIS, la combinación 75/100 Na+/cationes y 25/100 Cl-/aniones aumentó la concentración de Na, mientras que las combinaciones 75/100 Na+/cationes con 25, 50 y 75/100 Cl-/aniones redujeron la concentración de K. La relación 75/100 Cl-/aniones en la SN redujo las concentraciones de Na, K, Ca y Mg en hojas del cultivar Polaris, y de Na, Ca y Mg en tallos de cultivar ISIS. La relación 75/100 Na+/cationes en la SN incrementó las concentraciones de Na en hojas y tallos de cultivar Polaris y disminuyó las concentraciones de Ca y Mg en hojas de cultivar ISIS. Los resultados de este estudio indican que una proporción de 75% de Cl- en la SN, respecto al total de aniones, y una proporción de 50-75% de Na+, respecto al total de cationes, afectan las concentraciones nutrimentales en hojas y tallos de tomate de cultivares Polaris e ISIS.
Presentamos un paciente con holoprosencefalia semilobar en quien la imagen potenciada en difusión y la tractografía demostró falla de la inducción ventral del prosencéfalo y fusión anormal de varios fascículos de la sustancia blanca en el cerebro y en el tallo encefálico. De esta forma, las anormalidades de los fascículos de la sustancia blanca en casos de holoprosencefalia se pueden identificar por medio de las imágenes potenciadas en difusión y tractografía fasciculografía.
D. Cabezas; Sandra Pérez; R. Huelva; Dong Haitao; Li Debao
Se utilizó el cDNA microarreglo con 4370 unigenes, provenientes de la biblioteca del endospermo del arroz y de los tejidos de las hojas, para detectar los niveles de expresión del mRNA de los tejidos del tallo del arroz tratados con agua y con la hormona ácido abscísico (ABA). Los resultados mostraron que los niveles de expresión de cinco genes fueron reprimidos por la fitohormona ABA. El Reverse Northern confirmó que uno de los cinco genes (H024g06) fue realmente reprimido por el ABA. Los an...
Armando Payo Hill
Full Text Available Se inicia el trabajo fitoquímico en Pilocarpus racemosus Vahl. (Rutaceae con la finalidad de conocer el contenido de pilocarpina en esta especie. Se extrajeron 1,4 kg de tallos y 1 kg de hojas por los métodos convencionales, y se cromatografiaron los crudos alcaloidales en columnas, de las cuales se obtuvo 2,3036 y 0,6871 g de pilocarpina pura respectivamente. La identificación del alcaloide se realizó por espectroscopia infrarroja contra patrón y cromatografía de capa fina.
Menchaca G, Rebeca A.; Ramos P, José M; Moreno M, David; Luna R, Mauricio; Mata R, Martín; Vázquez G, Luis Miguel; Lozano R, Miguel A
In vitro germination of Vanilla planifolia and V. pompona hybridsResumen El cultivo de la vainilla se lleva a cabo ampliamente por medio de propagación clonal, de manera asexual por cortes de tallos y la producción de frutos se realiza por autopolinización. Esta práctica inhibe la variación genética y la emergencia de nuevos individuos por recombinación sexual. Por lo anterior, se considera necesario realizar cruzas por propagación sexual entre especies para obtener nuevos individuos con cara...
Yuri S. Vanegas Rojas
Full Text Available Colombia es uno de los países que se caracteriza por su gran riqueza en biodiversidad y fuentes hídricas; así mismo es uno de los 10 países con mayor disponibilidad de este recurso en el mundo. Los seres humanos consumen agua diariamente en todo lo que realizan (bienes, productos, servicios. Es así, como la huella hídrica se utiliza como un indicador del consumo directo o indirecto del agua, tanto en el ámbito doméstico como en el industrial. Esta permite determinar el volumen total de agua dulce que se emplea para la elaboración de bienes, en servicios consumidos por los individuos o en una actividad en particular. El objetivo de esta investigación se centró en evaluar la huella hídrica para la producción de flores de Lirio Japonés (Hemerocallis en un predio del municipio de Rondon – Boyacá (Colombia. La propuesta metodológica planteada por los autores para este estudio consta de tres fases: el diagnostico, el modelamiento y el análisis de resultados. El resultado obtenido para la huella hídrica azul es 1.76×10-4L/tallo, para la huella verde es 1×10-8l/tallo y para la huella gris es 2.06x10-4L/ tallo. Finalmente, una huella hídrica total es de 3,82×10-4L/tallo. En conclusión, la huella hídrica total del cultivo de Lirio Japonés (7.64x10-3m3/ton en comparación con la huella hídrica por producción de flores (900m3/ton, aporta tan solo el 0.00085% del total, por lo cual se puede afirmar que este cultivo es uno de los que tiene un menor aporte en dicha huella total para la producción de flores en Colombia.
Luz Angela Peña; Eliseo Avella; Aura María Puentes de Díaz
Dos compuestos, que innovan la química conocida del género Piper, (2'E,6'E)-2- famesilhidroquinona, (2'E,6'E)-2-famesil- 1,4-benzoquinona, y a-D-glucosa fueron aislados de los frutos de Piper bogotense C. DC; los tallos y las hojas presentaron, como constimyentes mayoritarios, lactama del ácido 10-amino-4-hidroxi-2,3-dimetoxifenantreno carboxílico, 1,2-metilendioxi- 6-metil-4H-dibenzo lde,g] quinolina- ,5(6H)-diona (Cefaradiona A), estigmasterol y sitosterol. Adicionalmente de las ho...
Peña, Luz Angela; Avella, Eliseo; Puentes de Díaz, Aura María
Dos compuestos, que innovan la química conocida del género Piper, (2'E,6'E)-2- famesilhidroquinona, (2'E,6'E)-2-famesil- 1,4-benzoquinona, y a-D-glucosa fueron aislados de los frutos de Piper bogotense C. DC; los tallos y las hojas presentaron, como constimyentes mayoritarios, lactama del ácido 10-amino-4-hidroxi-2,3-dimetoxifenantreno carboxílico, 1,2-metilendioxi- 6-metil-4H-dibenzo lde,g] quinolina- ,5(6H)-diona (Cefaradiona A), estigmasterol y sitosterol. Adicionalmente de las ho...
García Llamas, Carmen
El objetivo de este trabajo ha sido desarrollar un protocolo para producir plantas dihaploides de trigo duro, mediante cruzamientos con maíz, que permita acortar la duración de los programas de mejora de esta especie. Entre las variantes de este método se ha elegido el cultivo de tallos cortados, porque permite controlar las condiciones ambientales durante el desarrollo de los embriones y abaratar los costes de aplicación de las hormonas. Se han abordado y mejorado tres aspectos de esta técni...
Ballestero, Jimena A.
En el órgano de Corti, el epitelio sensorial del sistema auditivo de los mamíferos, las células ciliadas internas (CCIs) transducen los estímulos sonoros a señales eléctricas que son enviadas al sistema nervioso central, mientras que las células ciliadas externas (CCEs) participan del proceso de amplificación y sintonización fina de estos estímulos. La actividad de las CCEs es modulada por una inervación eferente que proviene del tallo cerebral, el sistema olivococlear medial (MOC). Durante e...