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A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature.

Spain has a great landrace diversity of the subspecies of the tetraploid species Triticum turgidum L., namely, durum (or durum wheat), turgidum (or rivet wheat) and dicoccon (or domesticated emmer wheat). These wheats have to confront several foliar diseases such as the leaf rust. In this work, a core collection of 94 landraces of tetraploid wheats were inoculated with three leaf rust isolates. Besides, a larger collection (of 192 accessions) was evaluated in the field. Although the majority of landraces were susceptible, approximately 20% were resistant, especially domesticated emmer wheat landraces. Several variables, such as late heading and red coat seeds were associated to resistant accessions. Regarding ecogeographic variables, a higher rainfall from October to February and more uniform temperature were found in the area of origin of resistant landraces. Based on these results, several resistant landraces were identified that potentially may be used in durum wheat breeding programs. In addition, a predictive model was elaborated to develop smaller subsets for future screening with a higher hit rate for rust resistance.

Rusts are important wheat diseases worldwide. The three rust diseases of wheat are yellow rust, leaf rust and stem rust, and each has characteristic features. The Guadalquivir valley in the south–west and Girona in the north–east are the areas Spain most affected by these diseases. Key factors for understanding the history of wheat rust epidemics in Spain are historical weather records in the rust–prone areas and characterization of rust resistance in historical varieties currently preserved in seed banks. These diseases in Spain have been of moderate importance, with stem rust being the most significant disease. During the second half of the 20th century several major epidemics occurred. In 1958 and 1978 severe outbreaks of yellow rust occurred in the Guadalquivir valley. These were probably associated with crop intensification, especially a large number of host landraces replaced by just a few cultivars, as well as immigration of external pathogen inoculum. From the early 1970s, CIMMYT elite cultivars arrived in Spain. These possessed good resistance to leaf and stem rust (Sr2), and had early heading dates. Subsequently, stem rust severity rapidly decreased in Spanish fields, but leaf rust epidemics became frequent during 1998–2008 on durum wheat in south–west Spain. In 2013, races virulent on Lr14a gene were first reported in Spain, but they did not result in disease epidemics. In 2012–16 yellow rust epidemics were recorded at many locations due to incursion of the ‘Warrior’ race. Despite the availability of effective fungicides and resistant cultivars to manage the three rust diseases, these diseases continue to threaten wheat production in Spain. In 2016, stem rust caused epidemics on durum wheat in Sicily (Italy), which has similar climatic conditions to those found in the south and east of Spain. Alert systems and international co-operation are needed to characterize the resistance of cultivars, and to monitor the movement and virulence of the wheat rust fung

Rusts are important wheat diseases worldwide. The three rust diseases of wheat are yellow rust, leaf rust and stem rust, and each has characteristic features. The Guadalquivir valley in the south–west and Girona in the north–east are the areas Spain most affected by these diseases. Key factors for understanding the history of wheat rust epidemics in Spain are historical weather records in the rust–prone areas and characterization of rust resistance in historical varieties currently preserved in seed banks. These diseases in Spain have been of moderate importance, with stem rust being the most significant disease. During the second half of the 20th century several major epidemics occurred. In 1958 and 1978 severe outbreaks of yellow rust occurred in the Guadalquivir valley. These were probably associated with crop intensification, especially a large number of host landraces replaced by just a few cultivars, as well as immigration of external pathogen inoculum. From the early 1970s, CIMMYT elite cultivars arrived in Spain. These possessed good resistance to leaf and stem rust (Sr2), and had early heading dates. Subsequently, stem rust severity rapidly decreased in Spanish fields, but leaf rust epidemics became frequent during 1998–2008 on durum wheat in south–west Spain. In 2013, races virulent on Lr14a gene were first reported in Spain, but they did not result in disease epidemics. In 2012–16 yellow rust epidemics were recorded at many locations due to incursion of the ‘Warrior’ race. Despite the availability of effective fungicides and resistant cultivars to manage the three rust diseases, these diseases continue to threaten wheat production in Spain. In 2016, stem rust caused epidemics on durum wheat in Sicily (Italy), which has similar climatic conditions to those found in the south and east of Spain. Alert systems and international co-operation are needed to characterize the resistance of cultivars, and to monitor the movement and virulence of the wheat rust fung

Rusts are important wheat diseases worldwide. The three rust diseases of wheat are yellow rust, leaf rust and stem rust, and each has characteristic features. The Guadalquivir valley in the south–west and Girona in the north–east are the areas Spain most affected by these diseases. Key factors for understanding the history of wheat rust epidemics in Spain are historical weather records in the rust–prone areas and characterization of rust resistance in historical varieties currently preserved in seed banks. These diseases in Spain have been of moderate importance, with stem rust being the most significant disease. During the second half of the 20th century several major epidemics occurred. In 1958 and 1978 severe outbreaks of yellow rust occurred in the Guadalquivir valley. These were probably associated with crop intensification, especially a large number of host landraces replaced by just a few cultivars, as well as immigration of external pathogen inoculum. From the early 1970s, CIMMYT elite cultivars arrived in Spain. These possessed good resistance to leaf and stem rust (Sr2), and had early heading dates. Subsequently, stem rust severity rapidly decreased in Spanish fields, but leaf rust epidemics became frequent during 1998–2008 on durum wheat in south–west Spain. In 2013, races virulent on Lr14a gene were first reported in Spain, but they did not result in disease epidemics. In 2012–16 yellow rust epidemics were recorded at many locations due to incursion of the ‘Warrior’ race. Despite the availability of effective fungicides and resistant cultivars to manage the three rust diseases, these diseases continue to threaten wheat production in Spain. In 2016, stem rust caused epidemics on durum wheat in Sicily (Italy), which has similar climatic conditions to those found in the south and east of Spain. Alert systems and international co-operation are needed to characterize the resistance of cultivars, and to monitor the movement and virulence of the wheat rust fung

Rusts are important wheat diseases worldwide. The three rust diseases of wheat are yellow rust, leaf rust and stem rust, and each has characteristic features. The Guadalquivir valley in the south–west and Girona in the north–east are the areas Spain most affected by these diseases. Key factors for understanding the history of wheat rust epidemics in Spain are historical weather records in the rust–prone areas and characterization of rust resistance in historical varieties currently preserved in seed banks. These diseases in Spain have been of moderate importance, with stem rust being the most significant disease. During the second half of the 20th century several major epidemics occurred. In 1958 and 1978 severe outbreaks of yellow rust occurred in the Guadalquivir valley. These were probably associated with crop intensification, especially a large number of host landraces replaced by just a few cultivars, as well as immigration of external pathogen inoculum. From the early 1970s, CIMMYT elite cultivars arrived in Spain. These possessed good resistance to leaf and stem rust (Sr2), and had early heading dates. Subsequently, stem rust severity rapidly decreased in Spanish fields, but leaf rust epidemics became frequent during 1998–2008 on durum wheat in south–west Spain. In 2013, races virulent on Lr14a gene were first reported in Spain, but they did not result in disease epidemics. In 2012–16 yellow rust epidemics were recorded at many locations due to incursion of the ‘Warrior’ race. Despite the availability of effective fungicides and resistant cultivars to manage the three rust diseases, these diseases continue to threaten wheat production in Spain. In 2016, stem rust caused epidemics on durum wheat in Sicily (Italy), which has similar climatic conditions to those found in the south and east of Spain. Alert systems and international co-operation are needed to characterize the resistance of cultivars, and to monitor the movement and virulence of the wheat rust fung

Rusts are important wheat diseases worldwide. The three rust diseases of wheat are yellow rust, leaf rust and stem rust, and each has characteristic features. The Guadalquivir valley in the south–west and Girona in the north–east are the areas Spain most affected by these diseases. Key factors for understanding the history of wheat rust epidemics in Spain are historical weather records in the rust–prone areas and characterization of rust resistance in historical varieties currently preserved in seed banks. These diseases in Spain have been of moderate importance, with stem rust being the most significant disease. During the second half of the 20th century several major epidemics occurred. In 1958 and 1978 severe outbreaks of yellow rust occurred in the Guadalquivir valley. These were probably associated with crop intensification, especially a large number of host landraces replaced by just a few cultivars, as well as immigration of external pathogen inoculum. From the early 1970s, CIMMYT elite cultivars arrived in Spain. These possessed good resistance to leaf and stem rust (Sr2), and had early heading dates. Subsequently, stem rust severity rapidly decreased in Spanish fields, but leaf rust epidemics became frequent during 1998–2008 on durum wheat in south–west Spain. In 2013, races virulent on Lr14a gene were first reported in Spain, but they did not result in disease epidemics. In 2012–16 yellow rust epidemics were recorded at many locations due to incursion of the ‘Warrior’ race. Despite the availability of effective fungicides and resistant cultivars to manage the three rust diseases, these diseases continue to threaten wheat production in Spain. In 2016, stem rust caused epidemics on durum wheat in Sicily (Italy), which has similar climatic conditions to those found in the south and east of Spain. Alert systems and international co-operation are needed to characterize the resistance of cultivars, and to monitor the movement and virulence of the wheat rust fung

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.

Disease resistance is critical in soft red winter wheat (Triticum aestivum L.) cultivars. Leaf rust caused by Puccinia triticina Eriks and stripe rust caused by Puccinia striiformis Westend. f.sp. tritici Eriks. are destructive pathogens of wheat. From 2014 to 2015 phenotypic data was collected at diverse locations for resistance to leaf rust (North Carolina, Texas, and Virginia) and stripe rust (Arkansas, North Carolina, Georgia, Texas, and Virginia) in a Pioneer ‘25R47’ /‘Jamestown’ (P47/JT) population composed of 186 F5:9 recombinant inbred lines (RILs). Analysis of the P47/JT population identified two quantitative trait loci (QTL) for leaf rust resistance on chromosome 5B and two QTL for stripe rust resistance on chromosomes 3B and 6A. Phenotypic variation (%) explained by the putative leaf rust resistance QTL of Jamestown on 5B was as high as 22.1%. Variation explained by the putative stripe rust resistance QTL of Jamestown on 3B and 6A was as high as 11.1 and 14.3%, respectively. Jamestown is postulated to contain gene Lr18. Seedlings of 186 F5:9 recombinant inbred lines from the P47/JT population and 200 F2 seedlings from eight other crosses including Jamestown and/or the Lr18 host differential line RL6009 (Thatcher*6/Africa 43) were screened with P. triticina race TNRJJ. Genetic analysis of the populations was conducted to validate the presence of Lr18 in Jamestown. Results of linkage analysis identified SNP maker IWB41960 linked within 5 cM of gene Lr18 in all three populations. From 2016 to 2017 phenotypic data was collected at diverse locations for resistance to leaf rust (Illinois, North Carolina, and Virginia) in a ‘2013412’ (PI 667644) / VA10W-21 (PI 676295) population (412/21) composed of 157 doubled haploid (DH) lines. The 412/21 DH lines were genotyped via genotyping by sequence (GBS). Analysis of the 412/21 population identified one quantitative trait loci (QTL) region associated with adult plant resistance to leaf rust on chromosome 1B. Phenotypic

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Leaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies.

Warming of the climate system is clear, as shown by the increase in global average temperature of both air and ocean. Particularly, the crops may be favoured by increases in atmospheric carbon dioxide; that help to optimize the photosynthetic process. However, an increase in temperature could also create proper conditions for the development of various pests and diseases. This could affect between 12 and 13% yield in the eight major crops for food and industry, which occupy more than half of the cultivated area in the world. In this study we characterized and quantified the impact of climate change on the favourable conditions for infection diseases such as leaf rust (Puccinia triticina) and stripe rust (P. striiformis f. sp. Tritici) in wheat and on the pecan nut casebearer (Acrobasis nuxvorella). The data used were those published by the interdisciplinary group comprising the Lawrence Livermore National Laboratory of Climate Central, the California Nevada Applications Program, and the University of Santa Clara in United States of America. The outputs of the years 2020 and 2050 for the general circulation model of the atmosphere known as ECHAM (http://www.ipcc-data.org/ar4/model-CCCMACGCM3_1-T47-change.html). The 2010 maps were made by staff of SIAFESON, using data from the network of meteorological stations of Sonora (www.agroson.org. mx). The results show an increase of 100% on days with favourable conditions for leaf rust (from 60 to 120 days with favourable conditions). For the stripe rust, the temperature increase makes an unfavourable development. In the case of thepecan nut casebearer, there was an increase in the number of generations (average 5.4 to 6) as a clear consequence of a larger number of heat units., El calentamiento del sistema climático es claro, así lo demuestran los aumentos del promedio mundial de la temperatura tanto del aire como del océano. Particularmente, los cultivos pueden verse favorecidos por los aumentos de bióxido de carbono atmosférico; que ayudan a optimizar el proceso fotosintético. Sin embargo, un aumento de la temperatura podría generar también las condiciones propicias para el desarrollo de diversas plagas y enfermedades. Esto podría afectar entre el 12 y el 13% del rendimiento en los ocho cultivos de mayor importancia para la alimentación y la industria, los cuales ocupan más de la mitad de la superficie cultivada en el mundo. En este estudio se caracterizó y cuantificó el impacto del cambio climático sobre las condiciones favorables para la infección de enfermedades como roya de la hoja (Puccinia triticina) y roya lineal (P. striiformis f. sp. tritici) en trigo y sobre las poblaciones de la plaga llamada gusano barrenador de la nuez Acrobasis nuxvorella en nogal pecanero. Los datos utilizados fueron los publicados por el grupo interdisciplinario que conforman el Laboratorio Nacional Lawrence Livermore, el Programa de Aplicaciones California Nevada, la Central Climática y la Universidad de Santa Clara en Estados Unidos de América. Se utilizaron las salidas de los años 2020 y 2050 para el modelo de circulación general de la atmósfera conocido como ECHAM (http://www.ipcc-data.org/ar4/modelCCCMA-CGCM3_1-T47-change.html). Los mapas de 2010 se hicieron por personal del SIAFESON con datos de la red de estaciones meteorológicas de Sonora (www.agroson. org.mx). Los resultados evidencian un incremento de 100% en los días con condiciones favorables para roya de la hoja (pasando de 60 a 120 días con condiciones favorables). Para la roya lineal, el incremento de la temperatura plantea un escenario no favorable para su desarrollo. En el caso del gusano barrenador de la nuez, se observa un incremento en el número de generaciones (promedio de 5.4 a 6) co

Warming of the climate system is clear, as shown by the increase in global average temperature of both air and ocean. Particularly, the crops may be favoured by increases in atmospheric carbon dioxide; that help to optimize the photosynthetic process. However, an increase in temperature could also create proper conditions for the development of various pests and diseases. This could affect between 12 and 13% yield in the eight major crops for food and industry, which occupy more than half of the cultivated area in the world. In this study we characterized and quantified the impact of climate change on the favourable conditions for infection diseases such as leaf rust (Puccinia triticina) and stripe rust (P. striiformis f. sp. Tritici) in wheat and on the pecan nut casebearer (Acrobasis nuxvorella). The data used were those published by the interdisciplinary group comprising the Lawrence Livermore National Laboratory of Climate Central, the California Nevada Applications Program, and the University of Santa Clara in United States of America. The outputs of the years 2020 and 2050 for the general circulation model of the atmosphere known as ECHAM (http://www.ipcc-data.org/ar4/model-CCCMACGCM3_1-T47-change.html). The 2010 maps were made by staff of SIAFESON, using data from the network of meteorological stations of Sonora (www.agroson.org. mx). The results show an increase of 100% on days with favourable conditions for leaf rust (from 60 to 120 days with favourable conditions). For the stripe rust, the temperature increase makes an unfavourable development. In the case of thepecan nut casebearer, there was an increase in the number of generations (average 5.4 to 6) as a clear consequence of a larger number of heat units., El calentamiento del sistema climático es claro, así lo demuestran los aumentos del promedio mundial de la temperatura tanto del aire como del océano. Particularmente, los cultivos pueden verse favorecidos por los aumentos de bióxido de carbono atmosférico; que ayudan a optimizar el proceso fotosintético. Sin embargo, un aumento de la temperatura podría generar también las condiciones propicias para el desarrollo de diversas plagas y enfermedades. Esto podría afectar entre el 12 y el 13% del rendimiento en los ocho cultivos de mayor importancia para la alimentación y la industria, los cuales ocupan más de la mitad de la superficie cultivada en el mundo. En este estudio se caracterizó y cuantificó el impacto del cambio climático sobre las condiciones favorables para la infección de enfermedades como roya de la hoja (Puccinia triticina) y roya lineal (P. striiformis f. sp. tritici) en trigo y sobre las poblaciones de la plaga llamada gusano barrenador de la nuez Acrobasis nuxvorella en nogal pecanero. Los datos utilizados fueron los publicados por el grupo interdisciplinario que conforman el Laboratorio Nacional Lawrence Livermore, el Programa de Aplicaciones California Nevada, la Central Climática y la Universidad de Santa Clara en Estados Unidos de América. Se utilizaron las salidas de los años 2020 y 2050 para el modelo de circulación general de la atmósfera conocido como ECHAM (http://www.ipcc-data.org/ar4/modelCCCMA-CGCM3_1-T47-change.html). Los mapas de 2010 se hicieron por personal del SIAFESON con datos de la red de estaciones meteorológicas de Sonora (www.agroson. org.mx). Los resultados evidencian un incremento de 100% en los días con condiciones favorables para roya de la hoja (pasando de 60 a 120 días con condiciones favorables). Para la roya lineal, el incremento de la temperatura plantea un escenario no favorable para su desarrollo. En el caso del gusano barrenador de la nuez, se observa un incremento en el número de generaciones (promedio de 5.4 a 6) co

Wheat leaf rust race specific resistance controlling genes (Lr) caused 0.01-0.03 decrease of SAGR = divided first two internodes with stem length. In addition, nitrogen transport in upper parts by those genes was 3-19% higher in comparison to near isogenic lines with nonspecific Lr 22a and Lr 22b genes. RAR (divided root nitrogen content with sum of up ground and root ones) values of Lr16, Lr29 and Lr37 between Lr1, Lr15 or Lr19 and nonspecific genes were explained by hydrolytic stability of endo-proteases responsible for cleaving of glutens disulphide bridges. According to RAR, Lr 34 seemed to be specific Lr gene but increased SAGR as was by nonspecific Lr genes focused SUTs as adequate for its conformity. Two different drought and heat stress respond systems were linked to Lr genes; one based on gluten degradation consequential through photosynthesis decrease and another on accelerated transfer of starch products and water in stem., Geni za specifičnu otpornost prema prouzrokovaču lisne rđe pšenice (Lr) smanjivali su rast sledećih delova stabla (SAGR) za 0,01-0,03 u poređenju sa osnovnom sortom Tačer ili Lr 22b linijom. RAR, odnosno podeljen sadržaj azota u korenu sa zbirom navedene vrednosti i one u nadzemnom delu u stadijumu sejanaca, bio je umanjen u odnosu na poslednje pomenute genotipove. Ubrzanje transporta proteina u nadzemne delove preko gena za specifičnu otpornost je bilo 3-19%. Enzimi za specifičnu otpornost su svrstani u glutenaze, odnosno endoproteaze, odgovorne za oslobađanje sumpora iz disulfidnih mostova pri prolasku proteina kroz klicu. Razlike po RAR-u između Lr 1, Lr 15, Lr 19 sa istim vrednostima i nešto različitih Lr 16, Lr 29 i Lr 37 od Lr 22b i Lr 38 linija nosilaca nespecifičnih Lr gena bilo je objašnjeno različitom hidrolitičkom stabilnošću. Lr 34 je po RAR-u bio sličan grupi specifičnih gena, ali povišen SAGR u odnosu na Tačer i produžen LP ukazivali su na enzimatsku familiju transportera šećera pre nego ABC transportere. Dva različita sistema za tolerantnost prema suši odnosno stresu usled visokih temperatura vazduha povezana su sa genima za otpornost prema Puccinia triticina. Rasno specifični geni su umanjivali fotosintezu preko produkata degradacije glutena u listu, ujedno povišujući LGR i snižavajući SAGR, dok su nespecifični delovali obrnuto i stoga povezani sa degradacijom skroba. Kod linija sa poslednje pomenutim genima primećeno je ranije gubljenje fotosintetičke aktivnosti postojećih organa i brži rast sledećih na uštrb prethodno formiranih.

Wheat leaf rust caused by Puccinia triticina is regularly observed in Belgian fields. This fungus produces wind-dispersed urediospores that infect host plants many kilometers from their source plant, but the origin of the primary inoculum and the factors involved in disease occurrence and severity are not well known. In order to better understand the epidemiology of the disease, the dispersion of P. triticina airborne inoculum and the relationship with disease incidence in fields were studied. A network of Burkard 7-day spore-recording traps was set up in wheat fields in the Walloon region, in Belgium, to monitor the airborne inoculum. Total DNA from each fragment of spore trap tape, corresponding to 1 day of sampling, was extracted and the quantity of P. triticina on the tape fragments was assessed using a specific real-time polymerase chain reaction (PCR) assay. The disease incidence was recorded weekly in experimental fields from March 2012 onwards. Initial analysis revealed that the real-time PCR assay was highly specific and repeatable. The detection threshold was determined at 7 spores per m3. This method (spore traps coupled with real-time PCR) allows airborne inoculum to be detected before the appearance of symptoms in fields and could be used in a model for predicting wheat leaf rust epidemics.

English: The Bowman-Birk family of plant protease inhibitors are serine protease inhibitors that can simultaneously inhibit trypsin and/or chymotrypsin. Unique features include an unusually high thermal stability, tolerance towards low pH and resistance towards the action of proteases. Bowman-Birk protease inhibitors have been implicated in various biotic and abiotic stress conditions in plants. LRW222 was recently identified by means of SSH in Puccinia triticina-infected wheat and was found to be homologous to Wali5, a wound- and aluminium stress-induced Bowman-Birk type protease inhibitor. The aim of this study was to determine the expression levels and role of the LRW222 protein in Pucciniainfected wheat. This study identified and validated stable reference genes for qPCR gene expression analysis in rust-infected wheat. qPCR is the preferred method to quantify mRNA levels, but requires validated reference genes for data normalisation. As prescribed by the MIQE guidelines, the GeNorm-Plus algorithm was used to examine the expression stability of six candidate reference genes in resistant Avocet Yr1 wheat infected with P. triticina, P. striiformis and P. graminis f. sp. tritici respectively. These reference genes were used in the gene expression analysis of LRW222. Results indicated induced expression in both resistant and susceptible wheat, indicating its possible involvement in the early general defence response of wheat. Co-immunoprecipitation and mass spectrometry was used in an attempt to identify LRW222-interacting proteins to shed light on its specific role in plant defence. Protein identification was inconclusive, but results indicated that under natural conditions, LRW222 may exist as multimers in wheat., Afrikaans: Die Bowman-Birk familie van plant protease inhibeerders is serien protease inhibeerders wat gelyktydig tripsien en/of chimotripsien kan inhibeer. Hul unieke kenmerke sluit 'n buitengewoon hoë termiese stabiliteit, toleransie teenoor lae pH en weerstand teenoor die aksie van proteases in. Bowman-Birk protease-inhibeerders is by verskeie biotiese en abiotiese strestoestande in plante betrokke. LRW222 is onlangs deur middel van SSH geïdentifiseer in Puccinia triticina-geïnfekteerde koring en homologie was met 'n wonden aluminium stres-geïnduseerde Bowman-Birk tipe protease inhibitor, naamlik Wali5, gevind. Die doel van hierdie studie was om die uitdrukking en rol van die LRW222 proteïen in Puccinia-geïnfekteerde koring vas te stel. Hierdie studie het stabiele verwysingsgene vir qPCR geenuitdrukking-analise in roesgeïnfekteerde koring geïdentifiseer en bevestig. qPCR is die voorkeur metode om mRNA transkripsie-vlakke te kwantifiseer, maar vereis die gebruik van stabiele verwysingsgene vir data normalisering. Soos voorgeskryf deur die MIQE riglyne, was die GeNorm-Plus algoritme gebruik om die uitdrukkings-stabiliteit van ses moontlike verwysingsgene in Avocet Yr1 koring geïnfekteer met P. triticina, P. striiformis en P. graminis f. sp. Tritici onderskeidelik, te ondersoek. Hierdie verwysingsgene was tydens die geenuitdrukkingsanalise van LRW222 gebruik. Die resultate het geïnduseerde uitdrukking in beide weerstandbiedende en vatbare koringlyne aangedui, wat op die moontlike betrokkenheid van LRW222 in die vroeë algemene verdedigingsrespons van koring dui. Koimmunopresipitering en massa-spektrometrie was gebruik in 'n poging om proteïene wat interaksie met LRW222 toon te identifiseer, om sodoende lig te werp op sy spesifieke rol in plantverdediging. Proteïen identifikasie was onoortuigend, maar die resultate het aangedui dat LRW222 moontlik as multi-grootte multimere onder natuurlike toestande in koring teenwoordig is., University of the Free State (UFS)

Wheat leaf rust race specific resistance controlling genes (Lr) caused 0.01-0.03 decrease of SAGR = divided first two internodes with stem length. In addition, nitrogen transport in upper parts by those genes was 3-19% higher in comparison to near isogenic lines with nonspecific Lr 22a and Lr 22b genes. RAR (divided root nitrogen content with sum of up ground and root ones) values of Lr16, Lr29 and Lr37 between Lr1, Lr15 or Lr19 and nonspecific genes were explained by hydrolytic stability of endo-proteases responsible for cleaving of glutens disulphide bridges. According to RAR, Lr 34 seemed to be specific Lr gene but increased SAGR as was by nonspecific Lr genes focused SUTs as adequate for its conformity. Two different drought and heat stress respond systems were linked to Lr genes; one based on gluten degradation consequential through photosynthesis decrease and another on accelerated transfer of starch products and water in stem., Geni za specifičnu otpornost prema prouzrokovaču lisne rđe pšenice (Lr) smanjivali su rast sledećih delova stabla (SAGR) za 0,01-0,03 u poređenju sa osnovnom sortom Tačer ili Lr 22b linijom. RAR, odnosno podeljen sadržaj azota u korenu sa zbirom navedene vrednosti i one u nadzemnom delu u stadijumu sejanaca, bio je umanjen u odnosu na poslednje pomenute genotipove. Ubrzanje transporta proteina u nadzemne delove preko gena za specifičnu otpornost je bilo 3-19%. Enzimi za specifičnu otpornost su svrstani u glutenaze, odnosno endoproteaze, odgovorne za oslobađanje sumpora iz disulfidnih mostova pri prolasku proteina kroz klicu. Razlike po RAR-u između Lr 1, Lr 15, Lr 19 sa istim vrednostima i nešto različitih Lr 16, Lr 29 i Lr 37 od Lr 22b i Lr 38 linija nosilaca nespecifičnih Lr gena bilo je objašnjeno različitom hidrolitičkom stabilnošću. Lr 34 je po RAR-u bio sličan grupi specifičnih gena, ali povišen SAGR u odnosu na Tačer i produžen LP ukazivali su na enzimatsku familiju transportera šećera pre nego ABC transportere. Dva različita sistema za tolerantnost prema suši odnosno stresu usled visokih temperatura vazduha povezana su sa genima za otpornost prema Puccinia triticina. Rasno specifični geni su umanjivali fotosintezu preko produkata degradacije glutena u listu, ujedno povišujući LGR i snižavajući SAGR, dok su nespecifični delovali obrnuto i stoga povezani sa degradacijom skroba. Kod linija sa poslednje pomenutim genima primećeno je ranije gubljenje fotosintetičke aktivnosti postojećih organa i brži rast sledećih na uštrb prethodno formiranih.

La variedad CEVY Oro C2008 fue desarrollada en el campo experimental Norman E. Borlaug, en un proyecto colaborativo entre INIFAP y CIMMYT, para las áreas productoras de los estados de Sinaloa, Sonora, Baja California Sur y Baja California en México. Su pedigrí es SCRIP_1//DIPPER_2/BUSHEN_3/4/ ARMENT// SRN_3/NIGRIS_4/3/CANELO_9.1, y su historial de selección CDSS02Y00381S-0Y-0M-19Y-0M. CEVY Oro C2008 cuenta con el registro TRI-111 -240209 del Catalogo Nacional de Variedades Vegetales del Servicio Nacional de Inspección y Certificación de Semillas. Esta variedad es de hábito de crecimiento primaveral y resistente a la roya de la hoja (Puccinia triticina), con rendimiento experimental promedio de grano de 5.6 t ha-1 con tres riegos de auxilio, en cuatro fechas de siembra. En parcelas con agricultores cooperantes del sur de Sonora, CEVY Oro C2008 promedió 7.1, 7.4 y 7.2 t ha-1 en los ciclos agrícolas 2008-2009, 2009-2010 y 2010-2011, respectivamente, por lo que representa una nueva opción de trigo cristalino para los agricultores del noroeste del país, The commercial variety CEVY Oro C2008 was developed at the Norman E. Borlaug Experimental Station in a collaboration between INIFAP and CIMMYT, for the wheat-producing areas of the states of Sinaloa, Sonora, Baja California Sur, and Baja California in Mexico. Its pedigree is SCRIP_1//DIPPER_2/BUSHEN_3/4/ ARMENT//SRN_3/NIGRIS_4/3/ CANELO_9.1, CDSS02Y00381S-0Y-0M-19Y-0M and its selection history is CDSS02Y00381S-0Y-0M-19Y-0M. CEVY Oro C2008 has the registration TRI-111-240209 in the catalogue of cultivars feasible for registration. This wheat variety has a springtime growth habit and is resistant to leaf rust (Puccinia triticina), with an experimental average grain yield of 5.6 t ha-1 with three complementary irrigations, in four sowing dates. CEVY Oro C2008 averaged 7.1, 7.4, and 7.2 t ha-1 in 2008-2009, 2009-2010, and 2010-2011, respectively, in commercial fields of cooperating wheat producers from southern Sonora; therefore, this cultivar is a new option of durum wheat for wheat producers of northwest Mexico

La variedad CEVY Oro C2008 fue desarrollada en el campo experimental Norman E. Borlaug, en un proyecto colaborativo entre INIFAP y CIMMYT, para las áreas productoras de los estados de Sinaloa, Sonora, Baja California Sur y Baja California en México. Su pedigrí es SCRIP_1//DIPPER_2/BUSHEN_3/4/ ARMENT// SRN_3/NIGRIS_4/3/CANELO_9.1, y su historial de selección CDSS02Y00381S-0Y-0M-19Y-0M. CEVY Oro C2008 cuenta con el registro TRI-111 -240209 del Catalogo Nacional de Variedades Vegetales del Servicio Nacional de Inspección y Certificación de Semillas. Esta variedad es de hábito de crecimiento primaveral y resistente a la roya de la hoja (Puccinia triticina), con rendimiento experimental promedio de grano de 5.6 t ha-1 con tres riegos de auxilio, en cuatro fechas de siembra. En parcelas con agricultores cooperantes del sur de Sonora, CEVY Oro C2008 promedió 7.1, 7.4 y 7.2 t ha-1 en los ciclos agrícolas 2008-2009, 2009-2010 y 2010-2011, respectivamente, por lo que representa una nueva opción de trigo cristalino para los agricultores del noroeste del país, The commercial variety CEVY Oro C2008 was developed at the Norman E. Borlaug Experimental Station in a collaboration between INIFAP and CIMMYT, for the wheat-producing areas of the states of Sinaloa, Sonora, Baja California Sur, and Baja California in Mexico. Its pedigree is SCRIP_1//DIPPER_2/BUSHEN_3/4/ ARMENT//SRN_3/NIGRIS_4/3/ CANELO_9.1, CDSS02Y00381S-0Y-0M-19Y-0M and its selection history is CDSS02Y00381S-0Y-0M-19Y-0M. CEVY Oro C2008 has the registration TRI-111-240209 in the catalogue of cultivars feasible for registration. This wheat variety has a springtime growth habit and is resistant to leaf rust (Puccinia triticina), with an experimental average grain yield of 5.6 t ha-1 with three complementary irrigations, in four sowing dates. CEVY Oro C2008 averaged 7.1, 7.4, and 7.2 t ha-1 in 2008-2009, 2009-2010, and 2010-2011, respectively, in commercial fields of cooperating wheat producers from southern Sonora; therefore, this cultivar is a new option of durum wheat for wheat producers of northwest Mexico

The aim was to study the progress of the yellow spot, brown spot and leaf rust in wheat cultivar FUNDACEP 50 in Passo Fundo. Was evaluated the incidence of yellow spot [Drechslera tritici-repentis (Died) Drechs.] brown spot [Bipolaris sorokiniana (Sacc.)] and leaf rust [Puccinia triticina (Eriks)]. Values obtained were integralized as Area Under the Disease Incidence Progress Curve (AUDIPC) and to analyze the progress of the disease was considered the disease progress rate (r), which was obtained with the Logistic and Gompertz. Determination coefficients were high (0.93 to 0.98), as well as the mean square error (4.0706 to 7.6831). The r were 0.02 to 0.22 units, while the accumulated AUDIPC 787.5, 1216.3 and 1338.8 units for yellow spot, brown spot and leaf rust, respectively. The two models used satisfactorily explain the progress of yellow spot and brown spot, while the Gompertz explains better leaf rust.

The aim was to study the progress of the yellow spot, brown spot and leaf rust in wheat cultivar FUNDACEP 50 in Passo Fundo. Was evaluated the incidence of yellow spot [Drechslera tritici-repentis (Died) Drechs.] brown spot [Bipolaris sorokiniana (Sacc.)] and leaf rust [Puccinia triticina (Eriks)]. Values obtained were integralized as Area Under the Disease Incidence Progress Curve (AUDIPC) and to analyze the progress of the disease was considered the disease progress rate (r), which was obtained with the Logistic and Gompertz. Determination coefficients were high (0.93 to 0.98), as well as the mean square error (4.0706 to 7.6831). The r were 0.02 to 0.22 units, while the accumulated AUDIPC 787.5, 1216.3 and 1338.8 units for yellow spot, brown spot and leaf rust, respectively. The two models used satisfactorily explain the progress of yellow spot and brown spot, while the Gompertz explains better leaf rust., El objetivo fue estudiar el progreso de las manchas amarilla y marrón, y de la roya de la hoja en el cultivar de trigo Fundacep 50 en Passo Fundo. Fue evaluada la incidencia de mancha amarilla [Drechslera tritici-repentis (Died) Drechs.], mancha marrón [Bipolaris sorokiniana (Sacc.)] y roya de la hoja [Puccinia triticina (Eriks)]. Los valores obtenidos fueron integralizados como Área Abajo la Curva de Progreso de la Incidencia de la Enfermedad (AACPIE) y para el análisis del progreso de las enfermedades se consideró la tasa del progreso de la epidemia (r), la cual fue obtenida con los modelos Logístico y de Gompertz. Se obtuvieron coeficientes de determinación altos (0.93 a 0.98), así como también los cuadrados medios del error (4.0706 a 7.6831). Las r fueron de 0.02 a 0.22 unidades, mientras que el AACPIE acumuló 787.5, 1216.3 y 1338.8 unidades para las manchas amarilla y marrón, y roya de la hoja, respectivamente. Los dos modelos utilizados explican satisfactoriamente el progreso de las manchas amarilla y marrón, mientras que el de Gompertz explica mejor la roya de la hoja.

The aim was to study the progress of the yellow spot, brown spot and leaf rust in wheat cultivar FUNDACEP 50 in Passo Fundo. Was evaluated the incidence of yellow spot [Drechslera tritici-repentis (Died) Drechs.] brown spot [Bipolaris sorokiniana (Sacc.)] and leaf rust [Puccinia triticina (Eriks)]. Values obtained were integralized as Area Under the Disease Incidence Progress Curve (AUDIPC) and to analyze the progress of the disease was considered the disease progress rate (r), which was obtained with the Logistic and Gompertz. Determination coefficients were high (0.93 to 0.98), as well as the mean square error (4.0706 to 7.6831). The r were 0.02 to 0.22 units, while the accumulated AUDIPC 787.5, 1216.3 and 1338.8 units for yellow spot, brown spot and leaf rust, respectively. The two models used satisfactorily explain the progress of yellow spot and brown spot, while the Gompertz explains better leaf rust.

The aim was to study the progress of the yellow spot, brown spot and leaf rust in wheat cultivar FUNDACEP 50 in Passo Fundo. Was evaluated the incidence of yellow spot [Drechslera tritici-repentis (Died) Drechs.] brown spot [Bipolaris sorokiniana (Sacc.)] and leaf rust [Puccinia triticina (Eriks)]. Values obtained were integralized as Area Under the Disease Incidence Progress Curve (AUDIPC) and to analyze the progress of the disease was considered the disease progress rate (r), which was obtained with the Logistic and Gompertz. Determination coefficients were high (0.93 to 0.98), as well as the mean square error (4.0706 to 7.6831). The r were 0.02 to 0.22 units, while the accumulated AUDIPC 787.5, 1216.3 and 1338.8 units for yellow spot, brown spot and leaf rust, respectively. The two models used satisfactorily explain the progress of yellow spot and brown spot, while the Gompertz explains better leaf rust., El objetivo fue estudiar el progreso de las manchas amarilla y marrón, y de la roya de la hoja en el cultivar de trigo Fundacep 50 en Passo Fundo. Fue evaluada la incidencia de mancha amarilla [Drechslera tritici-repentis (Died) Drechs.], mancha marrón [Bipolaris sorokiniana (Sacc.)] y roya de la hoja [Puccinia triticina (Eriks)]. Los valores obtenidos fueron integralizados como Área Abajo la Curva de Progreso de la Incidencia de la Enfermedad (AACPIE) y para el análisis del progreso de las enfermedades se consideró la tasa del progreso de la epidemia (r), la cual fue obtenida con los modelos Logístico y de Gompertz. Se obtuvieron coeficientes de determinación altos (0.93 a 0.98), así como también los cuadrados medios del error (4.0706 a 7.6831). Las r fueron de 0.02 a 0.22 unidades, mientras que el AACPIE acumuló 787.5, 1216.3 y 1338.8 unidades para las manchas amarilla y marrón, y roya de la hoja, respectivamente. Los dos modelos utilizados explican satisfactoriamente el progreso de las manchas amarilla y marrón, mientras que el de Gompertz explica mejor la roya de la hoja.

English: The aim of this study was to study various aspects of the defence response of wheat infected by Puccinia triticina. SSH was used to isolate differentially expressed cDNA fragments from P. triticina infected wheat. Once sequenced, two cDNA clones were selected for further analysis. One of the cDNA clones, LRW268, showed similarity to an EST derived from de-etiolated wheat. It showed a 16.5 fold induced expression at 9 hpi in the P. triticina infected wheat. In P. striiformis infected wheat, an induced expression was found in the resistant Avoset-Yr1 plants. Application of chemical elicitors showed an induction of LRW268 expression for plants treated with H2O2, MeJA and menadione. To obtain the full length gene, 5’-RACE was attempted, but it was unsuccessful. However, a contig was assembled using ESTs present in the GenBank database. This yielded a 603 bp contig encoding a 96 amino acid sequence that showed good homology to a RLK interacting protein. The presence of a putative MAPK docking motif and a phosphorylation site indicated that LRW268 could play a role in cell signalling. The presence of LRW268 in different wheat cultivars signified that it could form part of the general defence response of wheat. The second cDNA clone, LRW222, which was similar to an EST from wheat infected with powdery mildew, showed a 4.6 fold induction of expression at 15 hpi in wheat infected with P. triticina, while the susceptible Thatcher cultivar showed an induction at an earlier time interval. P. striiformis infected wheat showed a more constant expression of LRW222. Putative induced expression of LRW222 was observed in H2O2, MeJA and menadione treated wheat. Assembly of a contig using published ESTs yielded a 668 bp contig which encoded an 89 amino acid polypeptide showing homology to various wound-induced protease inhibitors. The presence of a putative MAPK docking motif on LRW222 suggested that it could be a general or pathogen specific protease inhibitor. The effect of, Afrikaans: Die doel van die studie was om verskillende aspekte van die verdedigingsrespons van koring na infeksie deur Puccinia triticina, te ondersoek. cDNA fragmente wat na infeksie differensieël tot uiting gekom het, is met behulp van SSH geïsoleer. Nadat die klone se basisvolgorde bepaal is, is twee cDNA klone vir verdere analise gekies. Een cDNA kloon, LRW268, het ooreenkoms met ʼn EST wat uit gedeëtioleerde koring gekloneer was, getoon. Kloon LRW268 se uitdrukking was 9 uur na infeksie 16.5-voudig hoër. Geïnduseerde uiting was ook gevind in Avoset-Yr1 koring wat met P. striiformis geïnfekteer was. Verder het die bespuiting van koring met H2O2, MeJA en menadioon ook tot hoër uitdrukking gelei. Hoewel onsuksesvol, is daar met 5’-RACE probeer om die volledige geen te kloneer. Uiteindelik is ’n contig wat die volledige geen verteenwoordig, deur middel van ESTs soos gevind in die GenBank databasis, saamgestel. Die voorgestelde geen was 603 bp lank en het vir ’n polipeptied van 96 aminosure kodeer. Die polipeptied het goeie ooreenkoms met ’n proteïen wat aan RLKs bind, getoon. Aangesien die voorgestelde polipeptied moontlike MAPK-bindingsmotiewe en fosforileringssetels besit, dui dit daarop dat dit by seinoordraging betrokke kan wees. Aangesien die geen ook verder in verskillende kultivars teenwoordig is, is dit ʼn aanduiding dat dit moontlik ’n rol te speel het tydens die algemene verdedigingsrespons van koring. ʼn Tweede cDNA kloon, LRW222, wat ooreenkoms toon met ʼn EST uit poeieragtige meeldou-geïnfekteerde koring, het ʼn 4.6-voudige geïnduseerde uitdrukking na 15 uur in geïnfekteerde Thatcher+Lr34 koring getoon. Die geïnduseerde uitdrukking was vroeër in die vatbare Thatcher kultivar. Koring geïnfekteer met P. striiformis het ʼn meer konstante uiting getoon. Moontlike geïnduseerde uitdrukking is gevind in koring wat behandel was met H2O2, MeJA en menadioon. ’n Contig saamgestel uit beskikbare ESTs was 668 bp lank en het kodeer vir ’n polipeptied van 89 aminosure. Die, National Research Foundation (NRF)

The aim of this study was to investigate the early events following the infection of wheat with leaf rust. An attempt was made to identify and characterize genes putatively involved in these early events. More specifically, the aim was to obtain genes whose role in infected plants could be linked to the resistance locus within the resistant plant. DDRT‐PCR was used to isolate differentially expressed genes from the resistant Thatcher+Lr34 plants during the first 15 h after infection. Four cDNA fragments were cloned and sequenced. The first clone coded for a monosaccharide transporter, while the second clone encoded a cell wall invertase. Both these clones formed part of a different study to postulate a role for these proteins during infection. The third cDNA clone, coded for a putative heat shock protein. Heat shock proteins are molecular chaperones and are normally involved in ensuring cellular homeostasis by preventing the aggregation of denatured proteins and assisting in the folding and transport of new and denatured proteins. The fourth clone encoded an indole‐3‐glycerol phosphate lyase. The expression of the putative heat shock protein increased 86 fold within 9 h.p.i in infected resistant wheat and was chosen for further analysis. The gene shared very high sequence similarity to an O. sativa HSP70 gene and was called TaHlp01 (Triticum aestivum Heat shock Like Protein 01). TaHlp01 was inducibly expressed upon infection of resistant wheat with leaf rust as well as yellow rust but its expression remained constant in the infected susceptible cultivars. This indicated that the regulation of expression is dependent on the presence of the resistance locus within the resistant cultivars. A transient repression of TaHlp01 expression was found during the later stages of infection in both the IR and IS plants that were similar to a transient repression of TaHlp01 expression after Thatcher+Lr34 plants were treated with salicylic acid. TaHlp01 expression was also found to

Fourteen winter wheat varieties obtained from the Czech Republic for testing disease resistance were sown in dishes and grown in the field next to the LRTCW line and variety Rodna of Serbia and Montenegro, 2003. All genotypes were found by the type of reaction to be susceptible to Puccinia triticina at the seedling stage in the greenhouse. In four varieties with comparatively short leaves, Pyrenophora tritici-repentis was found to appear at a frequency of 20% on the leaves below the last two. The following year untreated seeds of all varieties were sown in the field and no Pyrenophora tritici-repentis was found. The average difference in the intensity of Puccinia triticina infection on the last two leaves between the two years was 51% for the varieties with P. tritici-repentis, and 23% for the other group. Even small amounts of toxins decreased the development of the obligate parasite. The hypothesis of a seed-borne character of Pyrenophora tritici-repentis was supported in the other varieties grown in close proximity. They showed early spike maturation, compared with the flag leaf and lower resistance to low temperatures in 2004 and 2005., Četrnaest genotipova ozime pšenice dobijenih iz Češke Republike radi testiranja na otpornost prema prouzrokovačima bolesti, posejano je (2003. godine) u saksije i uzgajano u poljskim uslovima pored LRTCW linije i sorte Rodna iz Srbije i Crne Gore. Po tipovima reakcije svi genotipovi su bili osetljivi prema Puccinia triticina u stadijumu sejanaca u stakleniku. Na sortama sa relativno kraćim trajanjem lisne površine Pyrenophora tritid-repentis je pokrila 20% lisne površine ispod poslednja dva. Sledeće godine seme pomenutih genotipova je posejano u polju, ali nije došlo do pojave žuto-mrke pegavosti. Prosečna razlika po intenzitetu zaraze sa R triticina između dve godine je na sortama sa R tritici-repentis bila 51% a za ostale 23%. Utvrđeno je da su čak i manje doze toksina smanjile razvoj obligatnog patogena R triticina. Hipoteza o prenošenju prouzrokovača žuto-mrke pegavosti semenom podržana je i preko drugih sorti gajenih u blizini. One su ispoljile rano odumiranje klasa u odnosu na zastavičar (u našim uslovima) i slabiju otpornost prema niskim temperaturama u 2005. godini.

U ogledu postavljenom kod Rimskih Šančeva 2003. godine, ispitivano je dvanaest genotipova ozime pšenice. Setva je obavljena 22.10.2003. a žetva 06.07.2004. Parcelice (7m 2) tretirane (T) su preparatom Folicur EC 250 (250 g/I tebukonazol+ 20% dodecilbenzosulfonska kiselina) 24.05. 2004. godine (5 cm 3 preparata na 100 m2), bile su paralelno postavljene, a udaljene dva metra od netretiranih (K) posejanih istim genotipom. Očitavanja intenziteta zaraze su vršena 20.05., 02.06., 10.06 i 21.06 2004. godine. Na srednje kasnoj sorti Pobeda zabeležen je maksimalan intenzitet Puccinia triticina 50, Erysiphe graminis 25, a na parcelicama tretiranim fungicidom 20-30 i 10., In the trial established on the Institutes experimental field located near Novi Sad, twelve winter wheat genotypes were investigated. Sowing was performed on 22.10. 2003. as harvesting on 06.07.2004. Parcels (7 m2) treated (T) with fungicide Folicur EC 250 (250 g/I tebukonazole + 20% dodecilbenzosulfonic acid) on 24.05.2004. (5 cm3 of the fungicide on 100 m2) were parallel with untreated (K) sown by same genotype two meters distanced. Estimation of the infection intensities was on 20.05, 02.06, 10.06. and 21.06.2004. Middle late maturating variety Pobeda allowed the maximal intensity of Puccinia triticina 50, Erysiphe graminis 25 untreated and 20-30 and 10 treated.

Durante las campañas agrícolas 2000-2001 y 2001-2002 cinco variedades de trigo duro (Triticum turgidum L. ssp. durum) y cinco de trigo blando (Triticum aestivum L.) fueron analizadas según un diseño en bloques al azar con cuatro repeticiones en Jerez de la Frontera (Cádiz). Se investigó el efecto del tratamiento fungicida con epoxiconazol sobre la productividad, peso de mil semillas, peso por hectólitro, porcentaje de proteínas y de vitrosidad, índice de caída de Hagberg, fuerza panadera y extensibilidad/tenacidad. Se constató una elevada incidencia de los patógenos foliares Septoria tritici y Puccinia triticina, obteniéndose una elevada correlación entre el nivel de infección de ambas enfermedades sobre trigo duro y su productividad. El peso de mil semillas y el peso por hectólitro de trigos duros son factores de calidad en los que se detectó una correlación significativa con la aplicación o no de fungicidas. No se constató correlación significativa entre los parámetros estudiados en el caso de trigos blandos

The resistance to the Puccinia triticina is of the highest importance for the product quality because of the apperience time. Relative short filling period and early maturation is often eaven without rusting. In years for rust development expected higher wheat yields are also impossible without mentioned resistance. On the May 25th when the attack is usually around IO (modified Cobb scale by Melchers and Parker, 1922) on susceptible varieties and the progress in some years very quick, possibilities for the chemical reduction are poor because of carence. Even if the chemicals were applied, the benefit is not so predictable (Jerkovic, 1997). So if we have to have some resistance to parasites in Serbian wheat varieties it is to the leaf rust cause. Nowadays, the different types of the resistance to Puccinia triticina are present in most of the widespread varieties. Uncomplete resistance expressed throw low infection efficiency is prevalent. Only on few varieties, hypersensitivity appeared at the seedling stage (Pesma, Anastasia, Selekta).

The hypersensitive resistant varieties at seedling stage in the greenhouse (around 20°C) were crossed with partially resistant one Renesansa,. According to F2 simultaneous tests with Lr Nils (Tatcher) and parents, Pesma and Selekta have the at least two same genes for the resistance to applied culture from monopustule isolate in the race type 2 in the greenhouse at the seedling stage. They are not Lr 1 or some of Lr 2 multiple allele serial. At the field conditions in the F1, the difference between the progenies from the crosses Pesma x Renesansa and Selekta x Renesansa lead to the conclusion that they are not completely same corresponding to in the greenhouse at seedling stage of the F2 progenies testing result. The inheritance of the resistance is tree hybrid (Pesma) or monohybrid (Anastasia) in the progenies from the crosses with Renesansa. Last one could be from several reasons in the case of separate observation. According to presented and previous investigation results, the Anastasia is different from Pesma and Selekta according the genetic basis of the resistance. Renesansa have the one to the applied isolate, single at the seedling stage throw the hypersensitivity not expressible gene, same as one of at least two in Anastasia. In the field conditions Anastasia crossed with the Pesma and Selecta decrease the infection severity in F1 in comparison with F1 Pesma x Selecta.

Durante las campañas agrícolas 2000-2001 y 2001-2002 cinco variedades de trigo duro (Triticum turgidum L. ssp. durum) y cinco de trigo blando (Triticum aestivum L.) fueron analizadas según un diseño en bloques al azar con cuatro repeticiones en Jerez de la Frontera (Cádiz). Se investigó el efecto del tratamiento fungicida con epoxiconazol sobre la productividad, peso de mil semillas, peso por hectólitro, porcentaje de proteínas y de vitrosidad, índice de caída de Hagberg, fuerza panadera y extensibilidad/tenacidad. Se constató una elevada incidencia de los patógenos foliares Septoria tritici y Puccinia triticina, obteniéndose una elevada correlación entre el nivel de infección de ambas enfermedades sobre trigo duro y su productividad. El peso de mil semillas y el peso por hectólitro de trigos duros son factores de calidad en los que se detectó una correlación significativa con la aplicación o no de fungicidas. No se constató correlación significativa entre los parámetros estudiados en el caso de trigos blandos

English: The objective of this study was not only to improve leaf rust (caused by Puccinia triticina) resistance in selected wheats (Triticum aestivum L.), but to focus on durability as well as agronomic acceptability of resistant lines. This was achieved by traditional breeding techniques as well as with the use of AFLP analysis. Seven bread wheat lines were obtained from ARC-Small Grain Institute (SGI) where they were developed. Six leaf rust resistance sources were obtained from the University of the Free State. The breeding strategy focused on creating lines that contained both seedling and adult plant resistance genes. Lr34 was chosen as the adult plant resistance source as it is an important gene due to its durability and interaction with other leaf rust resistance genes. It is also an easy gene to follow as it is associated with leaf tip necrosis. In an attempt to create genotypes that will remain durable, four seedling leaf rust resistance genes (Lr21, Lr32, Lr36 and Lr41) were each combined with Lr34 in the seven SGI backgrounds. By combining seedling and adult plant genes, and selecting only the lowest infection types throughout all phases of testing, a significant shift in the leaf rust resistance of the population occurred. Greenhouse evaluations of plant architecture and agronomic performance of lines containing both a seedling gene and Lr34, indicated that individual plants, similar or better than the original SGI parent, had been selected. Several of these selections can therefore be incorporated in larger, mainstream breeding programmes. It is, however, imperative that the agronomic and quality value of selections be determined under field conditions. More efficient manipulation of an undesignated Lr gene was also attempted. This gene, which originates from T. monococcum, was incorporated in certain bread wheat lines and cultivars. Since the gene is characterized by an immune response to South African pathotypes of leaf rust, it is considered valuabl, Afrikaans: Die studie het nie net gefokus op die verbetering van blaarroesweerstand van geselekteerde broodkoringlyne nie, maar op die skepping van volhoubare sowel as agronomies aanvaarbare weerstandstandslyne. Dit is moontlik gemaak deur van tradisionele veredelingstegnieke asook AFLP analises gebruik te maak. Sewe broodkoringlyne is verkry vanaf die LNR-Kleingraaninstituut, waar hulle ontwikkel is. Ses blaarroesweerstandslyne (Triticum aestivum) is van die Universiteit van die Vrystaat verkry. Die veredelingstrategie het gefokus op die inkorporering van beide saailing- en volwasseplantweerstandsgene binne dieselfde lyn. Lr34 is gekies as die geenbron van volwasseplantweerstand aangesien dit, vanweë sy volhoubaarheid en sy interaksie met ander weerstandsgene, 'n baie waardevolle geen is. Verder is Lr34 ook 'n maklike geen om te volg aangesien dit met blaarpuntnekrose geassosiëer word. In 'n poging om lyne te skep wat volhoubare weerstand teen blaarroes sal hê, is vier saailingweerstandsgene (Lr21, Lr32, Lr34 en Lr41) elk afsonderlik met die volwasseplantweerstandsgeen Lr34 gekombineer binne die sewe KGI agtergronde. Deur die kombinering van saailing- en volwasseplantweerstandsgene, asook deur deurlopende selektering vir die laagste infeksietipe gedurende alle evalueringsfases, het daar 'n betekenisvolle verskuiwing in die blaarroesweerstand binne die populasie plaasgevind. Glashuisevaluasies van agronomiese prestasie sowel as planttipe van die onderskeie lyne wat beide 'n saaling- en die Lr34 geen bevat, het aangedui dat individuele plante wat dieselfde, of beter, gevaar het as die oorspronklike KGI ouerlyn, geselekteer is. Verskeie van hierdie seleksies kan dus in die hoofstroomveredelingsprogramme geïnkorporeer word. Dit is egter noodsaaklik dat beide die agronomiese en kwaliteitwaarde van die seleksies onder veldtoestande geëvalueer word. 'n Poging is ook aangewend om 'n onbekende Lr geen te manipuleer. Hierdie geen wat afkomstig is vanaf T. monococcum, is geïn

English: Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Eriks., has become an endemic disease of wheat (Triticum aestivum L.) in South Africa after being observed for the first time near Moorreesburg, Western Cape, during August 1996. Pathotypes (pts.) detected in surveys were 6E16A- with virulence to Yr2,6,7,8,11,14,17 and Yr19, and 6E22A- with added virulence to Yr25. Stripe rust isolates found on Hordeum murinum L. in the Western Cape were identified as pt. 6E 16A- whereas both pts. 6E 16A- and 6E22A- were collected from Bromus catharticus Vahl in the eastern Free Sate. The possible role that grass species may play in the over-summering of the stripe rust pathogen has not yet been fully established. However, stripe rust infections have been found on summer-sown wheat in the south Western Cape during 1998, volunteer wheat growing in the summer and autumn months in the eastern Free State from 1998 to 2000, and on summer-sown wheat in Lesotho. The reaction of 55 South African and 18 foreign wheat cultivars was determined to pts. 6E16A- and 6E22A- in both the seedling and adult plant stage. The occurrence of stripe rust head infections was studied using 16 spring wheat cultivars and 17 supplemental lines. Six of the 55 local wheat cultivars expressed seedling resistance, 18 appeared heterogeneous and 31 were susceptible. The mean area under the disease progress curve (AUDPC) determined in the field for 42 cultivars over a three year period showed that 11 cultivars expressed high levels of complete or adult plant resistance (AUDPC <200). Twelve cultivars expressed intermediate levels of resistance (AUDPC 200 to 500) and 19 displayed AUDPC values of 500 to 1598. The percentage head infection was positively correlated to stripe rust severity on flag leaves. Of the 18 foreign cultivars evaluated 10 were resistant in both seedling and adult plant stages. The remaining eight cultivars were susceptible as seedlings but showed high levels of adult plant, Afrikaans: Streeproes, veroorsaak deur Puccinia striiformis Westend. f. sp. tritici Eriks., het In endemiese siekte van koring (Triticum aestivum L.) in Suid-Afrika geword na die eerste waarneming daarvan naby Moorreesburg in die Wes-Kaap gedurende Augustus 1996. Patotipes (pts.) gevind in gereelde opnames was 6E16A- met virulensie vir Yr2,6,7,B, 11,14,17 en Yr19 en 6E22A- met bykomende virulensie vir Yr25. Streeproesisolate verkry vanaf Hordeum murinum L. in die Wes-Kaap is geïdentifiseer as pt. 6E16A-, terwyl beide pts. 6E16A- en 6E22A- geïdentifiseer is vanaf Bromus catharticus Vahl in die Oos-Vrystaat. Die moontlike rol wat grasspesies speel in die oorsomering van die streeproespatogeen kon nie volledig uitgeklaar word nie. Streeproesinfeksies is egter gevind op someraanplantings van koring in die suidelike Wes-Kaap gedurende 1998, asook gedurende 1998-2000 op opslagkoring in die somer- en herfsmaande in die Oos-Vrystaat, sowel as op someraanplantings van koring in Lesotho. Die reaksie van 55 Suid-Afrikaanse en 18 buitelandse koringkultivars is bepaal teen pts. 6E16A- en 6E22A- in die saailing- en volwasseplantstadiums. Die voorkoms van streeproesaarinfeksies is bestudeer deur gebruik te maak van 16 lentekoringkultivars en 17 bykomstige lyne. Ses van die 55 plaaslike kultivars het saailingweerstand getoon, 18 het heterogeen voorgekom en 31 was vatbaar. Die gemiddelde area onder die siekte-ontwikkelingskurwe (AOSOK), soos bepaal in die veld vir 42 kultivars oor In driejaar periode, het getoon dat 11 kultivars oor hoë vlakke van algehele of volwasseplantweerstand beskik (AOSOK <200). Twaalf kultivars het intermediêre vlakke van weerstand getoon (AOSOK 200 tot 500) met 19 kultivars waarvan die AOSOK tussen 500 en 1598 gevarieer het. Die persentasie aarinfeksie was positief gekorreleer met streeproesintensiteit op vlagblare. Van die 18 buitelandse kultivars was 10 weerstandbiedend in beide saailing- en volwasseplantstadiums. Die oorblywende agt kultivars was vatbaar, ARC Small Grain Institute