Races distribution of Pyrenophora tritici-repentis in Algeria and consequences of a new virulence type identification in some basis of P. tritici-repentis / Wheat pathosystem
Abrachium, a new genus in the Clathraceae, and Itajahya reassessedRhudson Cruz
Molecular and morphological analyses have elucidated phylogenetic relationships of two remarkable species in the Phallales: Aseroe floriformis and Phallus roseus. Genes from ATPase subunit 6 (atp6), the nuclear large subunit ribossomal DNA (nuc-LSU), and the second largest RNA polymerase II subunit (RPB2) underwent Bayesian and parsimony molecular analyses. Molecular datasets combined with morphological characters, support a new genus (Abrachium for Aseroe floriformis), reassessment Itajahya, and emendation of Clathraceae.
Marker Assisted Gene Pyramiding for Disease Resistance in RiceIndrapratap1
Why marker assisted gene pyramiding?
For traits that are simply inherited, but that are difficult or expensive to measure phenotypically, and/or that do not have a consistent phenotypic expression under specific selection conditions, marker-based selection is more effective than phenotypic selection.
Traits which are traditionally regarded as quantitative and not targeted by gene pyramiding program can be improved using gene pyramiding if major genes affecting the traits are identified.
Genes with very similar phenotypic effects, which are impossible or difficult to combine in single genotype using phenotypic selection, can be pyramided through marker assisted selection.
Markers provides a more effective option to control linkage drag and make the use of genes contained in unadapted resources easier.
Pyramiding is possible through conventional breeding but is extremely difficult or impossible at early generations..
DNA markers may facilitate selection because DNA marker assays are non destructive and markers for multiple specific genes/QTLs can be tested using a single DNA sample without phenotyping.
CONCLUSION:
• Molecular marker offer great scope for improving the efficiency of conventional plant breeding.
• Gene pyramiding may not be the most suitable strategy when many QTL with small effects control the trait and other methods such as marker-assisted recurrent selection should be considered.
• With MAS based gene pyramiding, it is now possible for breeder to conduct many rounds of selections in a year.
• Gene pyramiding with marker technology can integrate into existing plant breeding program all over the world to allow researchers to access, transfer and combine genes at a rate and with precision not previously possible.
• This will help breeders get around problems related to larger breeding populations, replications in diverse environments, and speed up the development of advance lines.
For further queries please contact at isag2010@gmail.com
Saffron Crocus Genetics and Genomics - University of California Davis SeminarPat (JS) Heslop-Harrison
Saffron is the world's most expensive agricultural crop. Here I discuss challenges with the crop, discovery of its relatives, and possible approaches to crop improvement.
Phylotype Analysis of Ralstonia Solanacearum Causing Bacterial wilt in Eggpla...ijtsrd
Eggplant is prone to attack by several pests including bacteria, fungi, nematodes and insects. In this study, we have analyzed phylotype of bacterial wilt Ralstonia solanacearum infection in eggplant plants collected from Bhubaneswar Orissa in India. Bacterial wilt symptomatic five plant samples were collected from brinjal field in Bhubaneswar in 2016. The samples were macerated in sterile distilled water and grown on Kelman's triphenyltetrazolium chloride TZC agar media. Total genomic DNA of the bacterium were extracted and subjected to PCR amplification using the R. solanacearum specific universal primer pair 759 760. An expected single 280 bp fragment amplified in all the samples confirmed the identity of these as Ralstonia. To reconfirmed isolate of bacterium, the amplicon was sequenced in sequencer. In NCBI blast, the nucleotide sequence was 100 similar with Ralstonia solanacearum strain RS lpxC DOB 1 AB910593 and the sequence was submitted in NCBI database under Acc. No. KY393266. To determined phylotype of strain used specific multiplex PCR with phylotype specific primers Nmult 21F1 2, Nmult 22InF, Nmult 23AF, Nmult 22RR revealed that all the five infected samples belonged to phylotype I as a 144 bp amplicon were observed in agarose gel. On the basis of above finding concluded that the bacterial wilt infected eggplant collected from Bhubaneswar was Ralostonia solanacearum, Phylotype I. Rakesh Kumar | Ramachandran, E. | Koteshwar Yadav "Phylotype Analysis of Ralstonia Solanacearum Causing Bacterial wilt in Eggplants in Orissa in India" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd21580.pdf
Shigella flexneri serotype 1c derived from serotype 1a by acquisition of gtrI...Swee Seong TANG
Background
Shigella spp. are the primary causative agents of bacillary dysentery. Since its emergence in the late 1980s, the S. flexneri serotype 1c remains poorly understood, particularly with regard to its origin and genetic evolution. This article provides a molecular insight into this novel serotype and the gtrIC gene cluster that determines its unique immune recognition.
Results
A PCR of the gtrIC cluster showed that serotype 1c isolates from different geographical origins were genetically conserved. An analysis of sequences flanking the gtrIC cluster revealed remnants of a prophage genome, in particular integrase and tRNAPro genes. Meanwhile, Southern blot analyses on serotype 1c, 1a and 1b strains indicated that all the tested serotype 1c strains may have had a common origin that has since remained distinct from the closely related 1a and 1b serotypes. The identification of prophage genes upstream of the gtrIC cluster is consistent with the notion of bacteriophage-mediated integration of the gtrIC cluster into a pre-existing serotype.
Conclusions
This is the first study to show that serotype 1c isolates from different geographical origins share an identical pattern of genetic arrangement, suggesting that serotype 1c strains may have originated from a single parental strain. Analysis of the sequence around the gtrIC cluster revealed a new site for the integration of the serotype converting phages of S. flexneri. Understanding the origin of new pathogenic serotypes and the molecular basis of serotype conversion in S. flexneri would provide information for developing cross-reactive Shigella vaccines.
Keywords
Shigella flexneri, Bacillary dysentery, Serotype-conversion , Evolutionary origin, Glucosyltransferase, Serotype 1c
Dioscorea rotundata is a staple food crop for millions of people in the tropical and subtropical regions. In vitro germplasm conservation is a very useful tool in yam improvement strategies but very little is known about the genetic integrity and stability of in-vitro conserved yam plants. In this study, 42 accessions from in vitro and field populations were genotyped using 11 microsatellite markers and 23 morphological descriptors to assess variability within and between accessions. Out of the 23 morphological variables used, 13 were identified as most discriminate and were used to cluster the accessions into 4 clusters using the unweighted pair group arithmetic mean average (UPGMA). Accession maintained in field as well as in in-vitro showed high genetic similarity (R2 = 0.91, p-value: 1e-04). Out of the 42 accessions analyzed, nine accessions maintained in the field and in-vitro displayed different genetic profiles. This study provided basic information on the possible somaclonal variation of yam accessions maintained through in-vitro. Further study with advanced tools such as next-generation sequencing is required to elucidate the nature of the observed variation within clones.
Identification of Race/strain of Phytopathogenic Fungi through Conventional A...Sarda Konjengbam
Detection and identification of fungi has relied on a combination of microscopy and culture based techniques. Conventional methods often rely on identification of disease symptoms, isolation and culturing of environmental organisms, and laboratory identification by morphology and biochemical tests. These methods, although the cornerstone of fungal diagnostics, can lead to problems in identification, resulting in incorrect interpretation, diagnosis and ultimately treatment. The methods rely on experienced, skilled laboratory staff, the ability of the organism to be cultured, are time consuming, non quantitative, prone to contamination and error and often delay management (Atkins and Clark, 2004). During the last decades, the advent of molecular biology promised to offer radical alternatives in the detection and enumeration of fungal pathogens. Molecular technology increases understanding of the biology and population structures of plant pathogens, provides quick and accurate answers to epidemiological questions about plant diseases, and supports disease management decisions. New, rapid screening methods are being developed and increasingly used in all aspects of fungal diagnostics.
Abrachium, a new genus in the Clathraceae, and Itajahya reassessedRhudson Cruz
Molecular and morphological analyses have elucidated phylogenetic relationships of two remarkable species in the Phallales: Aseroe floriformis and Phallus roseus. Genes from ATPase subunit 6 (atp6), the nuclear large subunit ribossomal DNA (nuc-LSU), and the second largest RNA polymerase II subunit (RPB2) underwent Bayesian and parsimony molecular analyses. Molecular datasets combined with morphological characters, support a new genus (Abrachium for Aseroe floriformis), reassessment Itajahya, and emendation of Clathraceae.
Marker Assisted Gene Pyramiding for Disease Resistance in RiceIndrapratap1
Why marker assisted gene pyramiding?
For traits that are simply inherited, but that are difficult or expensive to measure phenotypically, and/or that do not have a consistent phenotypic expression under specific selection conditions, marker-based selection is more effective than phenotypic selection.
Traits which are traditionally regarded as quantitative and not targeted by gene pyramiding program can be improved using gene pyramiding if major genes affecting the traits are identified.
Genes with very similar phenotypic effects, which are impossible or difficult to combine in single genotype using phenotypic selection, can be pyramided through marker assisted selection.
Markers provides a more effective option to control linkage drag and make the use of genes contained in unadapted resources easier.
Pyramiding is possible through conventional breeding but is extremely difficult or impossible at early generations..
DNA markers may facilitate selection because DNA marker assays are non destructive and markers for multiple specific genes/QTLs can be tested using a single DNA sample without phenotyping.
CONCLUSION:
• Molecular marker offer great scope for improving the efficiency of conventional plant breeding.
• Gene pyramiding may not be the most suitable strategy when many QTL with small effects control the trait and other methods such as marker-assisted recurrent selection should be considered.
• With MAS based gene pyramiding, it is now possible for breeder to conduct many rounds of selections in a year.
• Gene pyramiding with marker technology can integrate into existing plant breeding program all over the world to allow researchers to access, transfer and combine genes at a rate and with precision not previously possible.
• This will help breeders get around problems related to larger breeding populations, replications in diverse environments, and speed up the development of advance lines.
For further queries please contact at isag2010@gmail.com
Saffron Crocus Genetics and Genomics - University of California Davis SeminarPat (JS) Heslop-Harrison
Saffron is the world's most expensive agricultural crop. Here I discuss challenges with the crop, discovery of its relatives, and possible approaches to crop improvement.
Phylotype Analysis of Ralstonia Solanacearum Causing Bacterial wilt in Eggpla...ijtsrd
Eggplant is prone to attack by several pests including bacteria, fungi, nematodes and insects. In this study, we have analyzed phylotype of bacterial wilt Ralstonia solanacearum infection in eggplant plants collected from Bhubaneswar Orissa in India. Bacterial wilt symptomatic five plant samples were collected from brinjal field in Bhubaneswar in 2016. The samples were macerated in sterile distilled water and grown on Kelman's triphenyltetrazolium chloride TZC agar media. Total genomic DNA of the bacterium were extracted and subjected to PCR amplification using the R. solanacearum specific universal primer pair 759 760. An expected single 280 bp fragment amplified in all the samples confirmed the identity of these as Ralstonia. To reconfirmed isolate of bacterium, the amplicon was sequenced in sequencer. In NCBI blast, the nucleotide sequence was 100 similar with Ralstonia solanacearum strain RS lpxC DOB 1 AB910593 and the sequence was submitted in NCBI database under Acc. No. KY393266. To determined phylotype of strain used specific multiplex PCR with phylotype specific primers Nmult 21F1 2, Nmult 22InF, Nmult 23AF, Nmult 22RR revealed that all the five infected samples belonged to phylotype I as a 144 bp amplicon were observed in agarose gel. On the basis of above finding concluded that the bacterial wilt infected eggplant collected from Bhubaneswar was Ralostonia solanacearum, Phylotype I. Rakesh Kumar | Ramachandran, E. | Koteshwar Yadav "Phylotype Analysis of Ralstonia Solanacearum Causing Bacterial wilt in Eggplants in Orissa in India" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd21580.pdf
Shigella flexneri serotype 1c derived from serotype 1a by acquisition of gtrI...Swee Seong TANG
Background
Shigella spp. are the primary causative agents of bacillary dysentery. Since its emergence in the late 1980s, the S. flexneri serotype 1c remains poorly understood, particularly with regard to its origin and genetic evolution. This article provides a molecular insight into this novel serotype and the gtrIC gene cluster that determines its unique immune recognition.
Results
A PCR of the gtrIC cluster showed that serotype 1c isolates from different geographical origins were genetically conserved. An analysis of sequences flanking the gtrIC cluster revealed remnants of a prophage genome, in particular integrase and tRNAPro genes. Meanwhile, Southern blot analyses on serotype 1c, 1a and 1b strains indicated that all the tested serotype 1c strains may have had a common origin that has since remained distinct from the closely related 1a and 1b serotypes. The identification of prophage genes upstream of the gtrIC cluster is consistent with the notion of bacteriophage-mediated integration of the gtrIC cluster into a pre-existing serotype.
Conclusions
This is the first study to show that serotype 1c isolates from different geographical origins share an identical pattern of genetic arrangement, suggesting that serotype 1c strains may have originated from a single parental strain. Analysis of the sequence around the gtrIC cluster revealed a new site for the integration of the serotype converting phages of S. flexneri. Understanding the origin of new pathogenic serotypes and the molecular basis of serotype conversion in S. flexneri would provide information for developing cross-reactive Shigella vaccines.
Keywords
Shigella flexneri, Bacillary dysentery, Serotype-conversion , Evolutionary origin, Glucosyltransferase, Serotype 1c
Dioscorea rotundata is a staple food crop for millions of people in the tropical and subtropical regions. In vitro germplasm conservation is a very useful tool in yam improvement strategies but very little is known about the genetic integrity and stability of in-vitro conserved yam plants. In this study, 42 accessions from in vitro and field populations were genotyped using 11 microsatellite markers and 23 morphological descriptors to assess variability within and between accessions. Out of the 23 morphological variables used, 13 were identified as most discriminate and were used to cluster the accessions into 4 clusters using the unweighted pair group arithmetic mean average (UPGMA). Accession maintained in field as well as in in-vitro showed high genetic similarity (R2 = 0.91, p-value: 1e-04). Out of the 42 accessions analyzed, nine accessions maintained in the field and in-vitro displayed different genetic profiles. This study provided basic information on the possible somaclonal variation of yam accessions maintained through in-vitro. Further study with advanced tools such as next-generation sequencing is required to elucidate the nature of the observed variation within clones.
Similar to Races distribution of Pyrenophora tritici-repentis in Algeria and consequences of a new virulence type identification in some basis of P. tritici-repentis / Wheat pathosystem
Identification of Race/strain of Phytopathogenic Fungi through Conventional A...Sarda Konjengbam
Detection and identification of fungi has relied on a combination of microscopy and culture based techniques. Conventional methods often rely on identification of disease symptoms, isolation and culturing of environmental organisms, and laboratory identification by morphology and biochemical tests. These methods, although the cornerstone of fungal diagnostics, can lead to problems in identification, resulting in incorrect interpretation, diagnosis and ultimately treatment. The methods rely on experienced, skilled laboratory staff, the ability of the organism to be cultured, are time consuming, non quantitative, prone to contamination and error and often delay management (Atkins and Clark, 2004). During the last decades, the advent of molecular biology promised to offer radical alternatives in the detection and enumeration of fungal pathogens. Molecular technology increases understanding of the biology and population structures of plant pathogens, provides quick and accurate answers to epidemiological questions about plant diseases, and supports disease management decisions. New, rapid screening methods are being developed and increasingly used in all aspects of fungal diagnostics.
Glyphosate resistance trait into soybean Cuban varieties: agronomical assessm...Innspub Net
Glyphosate-resistant (GR) soybean was one of the first major applications of genetic engineering in field crops and offered farmers a vital tool in fighting weeds. Weeds are a problem for soybean production in Cuba, so our work aim was the GTS 40-3-2 event introgression into Cuban varieties. Two local cultivars were crossed with transgenic genotypes that carry the event. From F1 to F3 generations, individual plants that produced more than 60 g of seeds per plant were chosen to obtain next generation. Individual lines were selected from F4 generation. F5 and F6 generations of five selected transgenic lines and their relatives were chosen to evaluate seven
agronomic traits throughout the summers of 2012 and 2013. A Random Block experimental design was done. First flowering (R1) and maturity (R8) stages of all genotypes were affected by planting date. Plant height of I1B2- 3, I1B4, I36B4 and RP5 lines ranged from 80 to 111 cm. I1B2-2 and I1B2-3 lines would be suitable for mechanized harvesting because they had the insertion of the first pod at 14.63 cm and 13.93 cm respectively. I36B4 line produced the greatest number of pods per plant (127). Transgenic lines produced more than 180 seeds per plant and 100-seed weight ranged from 13.75 g to 17.46 g. Seed yield per plant of transgenic lines and their parents IncaSoy36, CEB2 and CEB4 weren’t statistically different. These results could be a start point for other studies
involving larger areas, different planting dates and localities. Get more articles at: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/
Elsa Camadro's presentation in the framework of the expert consultation on th...cwr_use
The expert consultation on the use of crop wild relatives for pre-breeding in potato was a workshop organized by the Global Crop Diversity Trust in collaboration with CIP and took place from the 22nd – 24th of February 2012.
Reported some species of plant parasitic nematodes from rhizosphere of peanut...Open Access Research Paper
In order to identify of peanut fields plants parasitic nematodes, 130 samples of soil around the roots of peanut plants were collected in province of Guilan, during the summer and fall of 2011. After extraction, killing, fixation and transferring to anhydrous glycerol, the nematodes were mounted on permanent microscopic slides and nematodes species identified by using light microscope, equipped with digital camera, based on morphological and morphometric characters using valid keys. In this study 20 species belonging 17 genera were identified, that are as followes: 1- Aphelenchoides sacchari 2-Aphelenchus avenae 3- Basiria graminophila 4-Coslenchus costatus 5-Ditylenchus myceliophagus 6-Filenchus vulgaris 7-Helicotylenchus digonichus 8-Heterodera cruciferae 9-Meloidogyne incognita 10-Meloidogyne hapla 11-Merlinius bavaricus 12- Mesocriconemarusticum13- Mesocriconema curvatum 14-Paratylenchus nanus 15-Pratylenchus neglectus 16- Psilenchus hilarulus 17-Quinsulcius capitatus 18-Tylenchorhynchus annulatus 19- Tylenchorhynchus mashhoodi 20- Tylenchus davainei. In thisstudy, 20 species belonging 17 genera were identified that before just 6 Species2-5-7-11-15-16were reported from rhizosphere of Peanut in Iran. Other species (14 Species) are going to report from rhizosphere of Peanut in Iran as a first.
Inheritance of stem rust (Puccinia graminis Pers. F. Sp. Tritici ericks and E...Innspub Net
Stem rust disease caused by Puccinia graminis f.sp. tritici (Pgt) is currently one of the major biotic constraints in wheat (Triticum aestivum) production worldwide. Therefore, objectives of this study were (i) to identify resistant wheat lines with both adult plant resistance (APR) and seedling plant resistance (SPR), and (ii) to determine the kind of resistance to stem rust in KSL18, PCB52, PCB62 and PCB76 wheat lines. A collection of 100 wheat lines was evaluated in the field and greenhouse for stem rust resistance. The following four lines- KSL18, PCB52, PCB62 and PCB76 were identified as resistant and were crossed with known susceptible cultivars Kwale and
Duma. The resulting F1 hybrids and F2 populations alongside the parents were then tested in the greenhouse for response to the stem rust race TTKST. The selected wheat lines exhibited infection types ‘;’ to ‘2’ depicting resistance while Kwale and Duma depicted infection type ‘3+’ to TTKST. In the F2 populations evaluations that derived from Kwale × PCB52 indicated that the resistance is conferred by a single dominant gene. However, all other F2 populations showed that the resistance was conferred by two genes complementing each other (duplicate recessive epistasis) thus the ratios 9R: 7S. These identified resistant lines could be evaluated for other qualities and passed as potential varieties or used as sources of valuable stem rust resistance. Get more articles at: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/
Genetic control and heterosis depend directly on genetic divergence among the parents in generating promising hybrids
required by plant breeders. The purpose of this study was to determine the relative importance of heterosis, combining
abilities, regression and correlation estimates in order to develop hybrid cultivars in maize. The 28 F1 hybrids obtained by
partial diallel cross of 8 inbreds in a randomized complete block design were evaluated at the Lower Niger River Basin
Authority, Oke-Oyi, Nigeria in three years. General (GCA) and specific combining abilities (SCA) produced significant (P
< 0.01) effects for all the characters, while non-additive genetic effects were predominant. The levels of heterosis for grain
yield varied widely among crosses, ranging from -16.83 to 9.76%. Positive and significant genotypic and phenotypic
correlations among grain yield and some related characters (days to anthesis and silking; plant and ear heights; number of
ears plant-1 and 1000 seed weight) showed that each character could be used indirectly to selection of grain yield. These
results also indicated that SCA was more effective than heterosis for describing hybrid performance. The regression of
actual hybrid characters on the expected hybrid characters, based on parental GCA values, was highly significant.
Regression analysis also showed that all the agronomic characters jointly contributed 19.4% to grain yield of maize. The
inbreds (Pop 66 SR and 2000 EV DT-Y STRC4) and crosses (Pop 66 SR x, 2000 EV DT-Y STRC4, Pop 66 SR x KU1409
and 9006 x KU1409) featured prominently with respect to better GCA × Year and SCA × Year effects with high heterotic
values for maize grain yield and associated characters. These inbreds could serve as donors to obtain early and short
statured hybrids with higher yield, while the crosses may be exploited and adapted to the Nigerian Savannas. This study
also affirmed that genotypic and phenotypic correlation coefficients as well as combining abilities, heterosis and regression
analyses were found to be suitable models for yield improvement in maize breeding.
CHARACTERIZATION OF STREPTOMYCES SCABIES ISOLATESijabjournal
Potato, (Solanum tuberosum L,) have various biotic constraints in its production due to pest attack. Among these, common scab caused by streptomyces scabies in an important disease in potato which causes economic loss with respect to plant yield and quality of tubers. The present study was conducted to determine the pathogenicity, pathogenic variation, characterization of morphological, physiological and
biochemical aspects of Streptomyces specie associated with potato tubers grown in Rawalpindi district.Severity data and pathogenic variation of disease was studied by using different isolation and characterization techniques. Isolation and characterization of Streptomyces spp. From potato tubers will
guide the researchers about the causative strains of common scab of potato present in the particular area.
Similar to Races distribution of Pyrenophora tritici-repentis in Algeria and consequences of a new virulence type identification in some basis of P. tritici-repentis / Wheat pathosystem (20)
Transforming Maize-legume Value Chains –A Business Case for Climate-Smart Ag...CIMMYT
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Races distribution of Pyrenophora tritici-repentis in Algeria and consequences of a new virulence type identification in some basis of P. tritici-repentis / Wheat pathosystem
1. Races distribution of Pyrenophora tritici-repentis in Algeria and consequences of new virulence
type identification in some basis of P. tritici-repentis / Wheat pathosystem
BENSLIMANE1 H., L. LAMARI2, A. BENBELKACEM3, R. SAYOUD4 and Z. BOUZNAD5
1Université M’hamed Bougra, Boumerdès, Faculté des Science, Département de Biologie, Laboratoire de Biologie Moléculaire, 16 Rue de l’indépendance, Boumerdès, Algéria.
2 University of Manitoba, Department of Plant Sciences, Winnipeg, Manitoba, Canada, RT3 2N2.
3 Institut National de la Recherche Agronomique d’Algérie, Unité de Recherche de Constantine, Station ITGC, Elkhroub, Algéria.
4SYNGENTA, 5 chemin des citernes Skikda, Algérie. 5 Ecole Nationale Supérieure d’Agronomie, Département de Botanique, , El-Harrach, Alger, Algéria
Abstract
Tan spot, caused by Pyrenophora tritici-repentis, is a foliar disease of wheat, responsible for high economic losses in several wheat growing areas in the
world. There are eight known races of P. tritici-repentis based on ability to induce necrosis and/or chlorosis on a set of differential cultivars. 55 isolates
originating from diverse wheat growing regions in Algeria were studied to determine which races are present and to identify new races. Races 1, 4, 5, 6, 7
and 8 were found and a new virulence pattern was identified. Isolates with this pattern induced necrosis in durum wheat but failed to induce any disease
in the common wheat genotypes in the differential set.
Materiel and Method
Fungal isolates: Plant material: The differential set was made up of Durum and bread wheat
55 isolates of P. tritici-repentis were used in this study., obtained from several
infected wheat fields (Durum and bread wheat) in different cereal growing areas in Bread wheat A) Glenlea B) 6B-662 C) 6B-365 D) Salamouni
Durum wheat E) 4B-1149 F) Coulter G) 4B-160
Algeria. 3 isolates (Asc1, 86-124, Alg-3-24) corresponding, respectively, to 3 known
races (1, 2, and 5) were used as controls (Benslimane and al., 2011). Inoculum production and Inoculation: Protocols of Lamari and Bernier (1989)
Results and Discussion
Isolates evaluated were grouped into six races New virulence Type (Race 9 ??)
Race 4 Race 5 Race 6 Race 7 Race 8 Race 1
5 isolates from durum wheat showed a new virulence pattern, they were able to attach only durum wheat genotypes. Bread wheat genotypes harbored in their genomes the three gens
(Tsn1, Tsc2, Tsc1) responsible for sensitivity to the three knows toxins (PtrToxA, PtrToxB and PtrToxC). This suggests that isolates with the new virulence pattern are not able to
produce the three HTS.s. However, these isolates could possess a novel toxin(s)( Benslimane et al., 2011)
Distribution of Pyrenophora tritici-repentis races in Algeria Percentage of each race founded in Algeria
The majority of isolates recovered
from the samples represented races
1 and 7, while races 4, 5, 6, and 8
were more rare.
Four races (1, 4, 7, and 8) were
described in Algeria for the first
time.
Consequences in Pyrenophora tritici-repentis/ Wheat Pathosystem Conclusion
The presence of this putative new race, involves a significant impact on some bases of This study reveals that the tan spot fungus is highly variable in Algeria and a new race
wheat / P. tritici-repentis pathosystem. It is recognized that races 2, 3 and 5 are has been identified. This new race should produce a new toxin(s) and should be a
considered as a basic races because they are able to produce a single toxin. While others new basic race. These results showed that the genotypes used in the Algerian fields are
races 1, 6, 7 and 8 are considered as combined from basic races (Strelkov and Lamari, more sensitive to race 7 and race 1. These investigations should be of direct benefit to
2003). The discovery of a new race able to produce a single toxin completely different wheat breeding programs aimed at incorporating resistance to this pathogen. Plant
from those known, imply the existence of a new basic race. Consequence , the model breeders require knowledge of what races are present in the pathogen population in
proposed by Strelkov and Lamari (2003) establishing the relationship between different
order to determine which gene (s) should be present in resistant cultivars. The
races is permissible only when the host / pathogen interaction is considered for bread
development of wheat varieties that resist to this disease under current and future
wheat. The introduction of durum wheat in the host differential set makes the
climates in Algeria is therefore, of great importance.
hypothesis invalid (Benslimane, 2012).
Literature sited
1. Lamari L. and C.C. Bernier, 1989. Evaluation of wheat lines and cultivars to tan spot [Pyrenophora tritici-repentis] based on lesion type. Canadian Journal of Plant Pathology 11, 49–56.
2. Benslimane H. 2012. Etude de la tache bronzée du blé en Algérie: Identification des races de l’agent causal Pyrenophora tritici-repentis (Died.) Drechs et diversité génétique. PhD. Thesis,
ENSA, Algiers,157p.
3. Benslimane H., L. Lamari, A. Benbelkacem, R. Sayoud and Z. Bouznad, 2011. Distribution of races of Pyrenophora tritici-repentis in Algeria and identification of a new virulence type.
Phytopathologia Mediterranea, 50: 203−211.
4. Strelkov S.E. and Lamari L .2003. Host- parasite interactions in tan spot [Pyrenophora tritici- repentis] of wheat. Canadian Journal of Plant Pathology 25:339-349.