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Journal articles on the topic 'Leaf rust'
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1
Hanzalová, A., and P. Bartoš. "Resistance of triticale to wheat leaf rust (Puccinia triticina)." Czech Journal of Genetics and Plant Breeding 47, No. 1 (2011): 10–16. http://dx.doi.org/10.17221/100/2010-cjgpb.
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Reactions of winter triticale cultivars mostly from central Europe to recent and old leaf rust isolates were tested in the greenhouse. In one trial 20 cultivars were tested with 8 leaf rust isolates, collected recently from official wheat and triticale trials in the Czech Republic and Slovakia. In another trial 15 cultivars were tested with 6 old leaf rust isolates, used to identify leaf rust resistance genes in wheat. The cultivars Cando, Hortenso and Tricolor, registered in the Czech Republic, were resistant to the majority of the recent isolates. The Hungarian cultivar Tatra was resistant to all the recent isolates. The old leaf rust isolates were virulent only to a few of the triticale cultivars. Randomly selected isolates from wheat and triticale were tested on triticale cultivars and on Thatcher near isogenic lines with different Lr genes. On average, leaf rust isolates from triticale were virulent to a higher number of triticale cultivars than isolates collected from wheat and vice versa.
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Malau, Sabam. "Genotypic and Phenotypic Correlations between Leaf-Rust Disease and Leaf Morphology and its Ratio in Arabica Coffee." Jurnal Ilmu Pertanian Indonesia 25, no. 3 (2020): 468–77. http://dx.doi.org/10.18343/jipi.25.3.468.
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 Selection parameter in coffee breeding for leaf rust (Hemeleia vastatrix) resistance is very important. Breeders used leaf-rust severity and leaf-rust incidence as parameters of direct selection. However, scientific proof is not yet available whether leaf morphology can be used as a parameter of indirect selection. The objective of this research was to seek the possibility of leaf morphology parameter and its ratio to be used as selection criteria through analyses of genotypic and phenotypic correlations of parameter of rust disease and parameter of leaf morphology and its ratio. The result revealed that genotypes showed significant variations in leaf-rust severity (5.21–25.84%), leaf morphology, and leaf-morphology ratio. Leaf length to leaf width ratio, leaf length to leaf area ratio, and leaf width to leaf weight ratio were not affected by the environment. Leaf-rust severity performed highly significant positive genotypic and phenotypic correlations the ratio of with leaf length to leaf area. For selection criteria, leaf-rust severity could be better used rather than leaf-rust incidence and branch-rust incidence. The ratio of leaf length to leaf area could also be used as an indirect selection criterion because the ratio showed a highly significant genotypic correlation with leaf-rust severity (rGab = 0.254**). However, the ratio of leaf length to leaf area is even better chosen for selection criteria rather than leaf-rust severity because the ratio was not affected by the environment.
 
 Keywords: fungus, Hemeleia vastatrix, indirect selection
3
Ydyrys, A. A., A. T. Sarbayev, R. A. Iskendirova, S. B. Dubekova, and A. K. Eserkenov. "RESISTANCE OF SPRING WHEAT TO LEAF RUST IN KAZAKHSTAN." Bulletin of the Korkyt Ata Kyzylorda University 62, no. 3 (2022): 138–46. http://dx.doi.org/10.52081/bkaku.2022.v62.i3.089.
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The article presents the results of immunological evaluation of spring wheat samples with Lr genes for resistance to leaf rust. The purpose of the performed studies was the immunological evaluation and selection of sources of spring wheat resistance to leaf rust. The bjects of the study were samples of spring wheat from nurseries 6th ILRTN-15 and 18KASIB-LR-RES. Its scientific novelty consisted in the identification of effective Lr genes of resistance of spring wheat to the Kazakh population of leaf rust. Immunological studies were carried out in 2019-2020 in the conditions of the Kostanay region against a natural background of infection of wheat and in the conditions of the Almaty region against an artificially infectious background of infection of spring wheat. As a result of screening in the conditions of the regions of our study, 70 varieties and lines with effective Lr genes were identified as resistant. Thus, varieties and lines with Lr genes selected for leaf rust resistance are recommended by us as sources of resistance to the local leaf rust population.
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Věchet, L. "Development of powdery mildew and leaf rust epidemics in winter wheat cultivars." Plant, Soil and Environment 49, No. 10 (2011): 439–42. http://dx.doi.org/10.17221/4154-pse.
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Development of powdery mildew and leaf rust epidemics was examined on three winter wheat cultivars with different predispositions to powdery mildew in three-year experiments. The progress of powdery mildew and leaf rust on the same cultivar was conditioned by its dissimilar susceptibility to the respective disease. Fit temperature played an important role at the beginning of the particular disease and during its progress. Significant differences in the disease severity of powdery mildew and leaf rust were recorded on single leaves. Disease severity of leaf rust was higher on upper leaves while disease severity of powdery mildew was higher on lower leaves.
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Rosa, Silvia B., Brent McCallum, Anita Brûlé-Babel, et al. "Inheritance of Leaf Rust and Stripe Rust Resistance in the Brazilian Wheat Cultivar ‘Toropi’." Plant Disease 100, no. 6 (2016): 1132–37. http://dx.doi.org/10.1094/pdis-10-15-1128-re.
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Leaf rust (Puccinia triticina) and stripe rust (P. striiformis f. tritici) affect wheat production worldwide. Brazilian ‘Toropi’ wheat has demonstrated durable leaf rust resistance in South America since its release in 1965. It was previously found to have up to two adult plant leaf rust resistance genes. The leaf and stripe rust resistance of Toropi were studied by analyzing a doubled-haploid population made by crossing with susceptible ‘Thatcher’. Toropi expressed good resistance to leaf rust in Canada, Brazil, and New Zealand. Based on field and greenhouse testing, the leaf rust resistance of Toropi is conferred by two race-nonspecific complementary adult plant genes and a race-specific adult plant gene. The stripe rust resistance of Toropi analyzed in New Zealand and in Canada is based on up to two resistance genes. Toropi should provide an important contribution to rust resistance because it expressed good leaf rust and stripe rust resistance in different parts of the world.
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Tsilo, Toi J., James A. Kolmer, and James A. Anderson. "Molecular Mapping and Improvement of Leaf Rust Resistance in Wheat Breeding Lines." Phytopathology® 104, no. 8 (2014): 865–70. http://dx.doi.org/10.1094/phyto-10-13-0276-r.
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Leaf rust, caused by Puccinia triticina, is the most common and widespread disease of wheat (Triticum aestivum) worldwide. Deployment of host-plant resistance is one of the strategies to reduce losses due to leaf rust disease. The objective of this study was to map genes for adult-plant resistance to leaf rust in a recombinant inbred line (RIL) population originating from MN98550-5/MN99394-1. The mapping population of 139 RILs and five checks were evaluated in 2005, 2009, and 2010 in five environments. Natural infection occurred in the 2005 trials and trials in 2009 and 2010 were inoculated with leaf rust. Four quantitative trait loci (QTL) on chromosomes 2BS, 2DS, 7AL, and 7DS were detected. The QTL on 2BS explained up to 33.6% of the phenotypic variation in leaf rust response, whereas the QTL on 2DS, 7AL, and 7DS explained up to 15.7, 8.1, and 34.2%, respectively. Seedling infection type tests conducted with P. triticina races BBBD and SBDG confirmed that the QTL on 2BS and 2DS were Lr16 and Lr2a, respectively, and these genes were expressed in the seedling and field plot tests. The Lr2a gene mapped at the same location as Sr6. The QTL on 7DS was Lr34. The QTL on 7AL is a new QTL for leaf rust resistance. The joint effects of all four QTL explained 74% of the total phenotypic variation in leaf rust severity. Analysis of different combinations of QTL showed that the RILs containing all four or three of the QTL had the lowest average leaf rust severity in all five environments. Deployment of these QTL in combination or with other effective genes will lead to successful control of leaf rust.
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Oelke, L. M., and J. A. Kolmer. "Characterization of Leaf Rust Resistance in Hard Red Spring Wheat Cultivars." Plant Disease 88, no. 10 (2004): 1127–33. http://dx.doi.org/10.1094/pdis.2004.88.10.1127.
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Leaf rust, caused by Puccinia triticina Eriks., is the most common disease of wheat (Triticum aestivum L.) in the United States and worldwide. The objective of this study was to characterize seedling and adult plant leaf rust resistance in hard red spring wheat cultivars grown in Minnesota, North Dakota, and South Dakota, and postulate the identity of the seedling leaf rust resistance genes in the cultivars. Twenty-six cultivars, near-isogenic lines of Thatcher wheat that differ for single leaf rust resistance genes, and three wheat cultivars with known leaf rust resistance genes, were tested with 11 different isolates of leaf rust collected from the United States and Canada. The leaf rust infection types produced on seedling plants of the cultivars in greenhouse tests were compared with the infection types produced by the same isolates on the Thatcher near-isogenic lines to postulate which seedling leaf rust resistance genes were present. Seedling leaf rust resistance genes Lr1, Lr2a, Lr10, Lr16, Lr21, and Lr24 were postulated to be present in spring wheat cultivars. Seedling genes Lr3, Lr14a, and Lr23 likely were present in some cultivars but could not be clearly identified in this study. Most of the cultivars had some level of adult plant leaf rust resistance, most likely due to Lr34. Cultivars that had seedling resistance genes Lr1, Lr2a, Lr10, or Lr16 had poor to intermediate levels of leaf rust resistance in field plots. Cultivars with combinations of seedling resistance genes Lr16 and Lr24 with additional adult plant resistance were highly resistant to leaf rust.
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Pinto da Silva, Gerarda Beatriz, Camila Martini Zanella, José Antônio Martinelli, et al. "Quantitative Trait Loci Conferring Leaf Rust Resistance in Hexaploid Wheat." Phytopathology® 108, no. 12 (2018): 1344–54. http://dx.doi.org/10.1094/phyto-06-18-0208-rvw.
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Leaf rust, caused by the fungal pathogen Puccinia triticina, is a major threat to wheat production in many wheat-growing regions of the world. The introduction of leaf rust resistance genes into elite wheat germplasm is the preferred method of disease control, being environmentally friendly and crucial to sustained wheat production. Consequently, there is considerable value in identifying and characterizing new sources of leaf rust resistance. While many major, qualitative leaf rust resistance genes have been identified in wheat, a growing number of valuable sources of quantitative resistance have been reported. Here we review the progress made in the genetic identification of quantitative trait loci (QTL) for leaf rust resistance detected primarily in field analyses, i.e., adult plant resistance. Over the past 50 years, leaf rust resistance loci have been assigned to genomic locations through chromosome analyses and genetic mapping in biparental mapping populations, studies that represent 79 different wheat leaf rust resistance donor lines. In addition, seven association mapping studies have identified adult plant and seedling leaf rust resistance marker trait associations in over 4,000 wheat genotypes. Adult plant leaf rust resistance QTL have been found on all 21 chromosomes of hexaploid wheat, with the B genome carrying the greatest number of QTL. The group 2 chromosomes are also particularly rich in leaf rust resistance QTL. The A genome has the lowest number of QTL for leaf rust resistance. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
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Gál, M., L. Szunics, G. Vida, Lu Szunics, O. Veisz, and Z. Bedő. "Efficiency of leaf rust resistance genes in Martonvásár." Plant Protection Science 38, SI 2 - 6th Conf EFPP 2002 (2017): 593–95. http://dx.doi.org/10.17221/10564-pps.
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The efficiency of leaf rust resistance genes in adult plants was studied on near-isogenic lines of Thatcher carrying known leaf rust resistance genes in the artificially inoculated leaf rust nursery of the Agricultural Research Institute of the Hungarian Academy of Sciences in Martonvásár over a five-year period (1997–2001). Eight of the wheat lines tested (Lr9, Lr19, Lr23, Lr24, Lr25, Lr29, Lr35, Lr37) exhibited little or no infection. Lines carrying genes Lr13, Lr44 and LrB were resistant in two years and those carrying Lr34, Lr38 and LrW in three years, after which they suffered moderate or heavy infection. Three lines (Lr12, Lr17, Lr32) proved to be moderately resistant. The majority of the wheat lines tested became heavily infected.
10
Dyck, P. L. "Inheritance of leaf rust and stem rust resistance in 'Roblin' wheat." Genome 36, no. 2 (1993): 289–93. http://dx.doi.org/10.1139/g93-040.
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The Canadian common wheat (Triticum aestivum L.) cultivar 'Roblin' is resistant to both leaf rust (Puccinia recondita Rob. ex. Desm.) and stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn.). To study the genetics of this resistance, 'Roblin' was crossed with 'Thatcher', a leaf rust susceptible cultivar, and RL6071, a stem rust susceptible line. A set of F6 random lines was developed from each cross. The random lines and the parents were grown in a field rust nursery artificially inoculated with a mixture of P. recondita and P. graminis isolates and scored for rust reaction. The same material was tested with specific races of leaf rust and stem rust. These data indicated that 'Roblin' has Lr1, Lr10, Lr13, and Lr34 for resistance to P. recondita and Sr5, Sr9b, Sr11, and possibly Sr7a and Sr12 for resistance to P. graminis. In a 'Thatcher' background, the presence of Lr34 contributes to improve stem rust resistance, which appears also to occur in 'Roblin'.Key words: Triticum aestivum, wheat, leaf rust resistance, stem rust resistance.
11
Zhao, Duli, Neil C. Glynn, Barry Glaz, Jack C. Comstock, and Sushma Sood. "Orange Rust Effects on Leaf Photosynthesis and Related Characters of Sugarcane." Plant Disease 95, no. 6 (2011): 640–47. http://dx.doi.org/10.1094/pdis-10-10-0762.
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Orange rust of sugarcane (Saccharum spp. hybrids), caused by Puccinia kuehnii, is a relatively new disease in the Western Hemisphere that substantially reduces yields in susceptible sugarcane genotypes. The objective of this study was to determine the physiological mechanisms of orange rust–induced reductions in sugarcane growth and yield by quantifying effects of the disease on leaf SPAD index (an indication of leaf chlorophyll content), net photosynthetic rate, dark respiration, maximum quantum yield of CO2 assimilation, carbon fixation efficiency, and the relationships between these leaf photosynthetic components and rust disease ratings. Plants growing in pots were inoculated with the orange rust pathogen using a leaf whorl inoculation method. A disease rating was assigned using a scale from 0 to 4 with intervals of 0.5. At disease ratings ≥2, the rust-infected leaf portion of inoculated plants showed significant reductions in SPAD index, maximum quantum yield, carbon fixation efficiency, stomatal conductance, leaf transpiration rate, and net photosynthetic rate; but the rusted portion of the infected leaves had increased intercellular CO2 concentration and leaf dark respiration rate. Although leaf SPAD index, photosynthetic rate, stomatal conductance, and transpiration rate at the rust-infected portion decreased linearly with increased rust rating, the effect of orange rust on photosynthetic rate was much greater than that on stomatal conductance and transpiration. Unlike earlier reports on other crops, reduction in leaf photosynthesis by orange rust under low light was greater than that under high light conditions. These results help improve the understanding of orange rust etiology and physiological bases of sugarcane yield loss caused by orange rust.
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Anikster, Y., J. Manisterski, D. L. Long, and K. J. Leonard. "Resistance to Leaf Rust, Stripe Rust, and Stem Rust in Aegilops spp. in Israel." Plant Disease 89, no. 3 (2005): 303–8. http://dx.doi.org/10.1094/pd-89-0303.
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In all, 1,323 single plant accessions of Aegilops bicornis, A. kotschyi, A. longissima, A. ovata, A. searsii, A. sharonensis, A. speltoides, and A. variabilis collected from 18 regions in Israel and 2 adjacent regions in Lebanon and Egypt were evaluated for leaf rust (Puccinia triticina) and stripe rust (P. striiformis) resistance in field plots and for seedling resistance to leaf rust and stem rust (P. graminis f. sp. tritici) in greenhouse tests. Nearly all accessions of A. speltoides were highly resistant to leaf rust, stripe rust, and stem rust. A. longissima and A. ovata were highly resistant to stripe rust, whereas A. bicornis and A. kotschyi were highly susceptible. A. searsii was highly susceptible to stem rust, but 24 to 51% of accessions of A. bicornis, A. longissima, A. ovata, and A. variabilis were resistant to stem rust. Except for A. ovata and A. speltoides, more than 95% of the Aegilops accessions were susceptible to leaf rust caused by P. recondita alternating on Anchusa spp. Only Aegilops ovata was susceptible to P. recondita from Echium spp. A. bicornis, A. koschyi, and A. searsii were highly susceptible as seedlings to common wheat leaf rust caused by P. triticina. Most accessions of A. variabilis and about half of the accessions of A. longissima had good seedling resistance to P. triticina. Few accessions of A. ovata showed seedling resistance to the P. triticina population in Israel, but 30% were resistant to U.S. isolates. In field tests, A. bicornis showed high susceptibility to common wheat leaf rust, but more than 90% of the accessions of the other Aegilops spp. developed little or no leaf rust on adult plants. The Aegilops spp. in Israel and adjoining countries provide a rich and varied source of rust resistance for wheat breeding.
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Amgai, Resham Babu, Sumitra Pantha, and Madan Raj Bhatta. "Characterization of Nepalese Barley Gene Pool for Leaf Rust Resistance." Nepal Journal of Biotechnology 4, no. 1 (2016): 13–18. http://dx.doi.org/10.3126/njb.v4i1.16341.
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Barley (Hordeum vulagare L) is the major crop for the people living in the high hills and mountainous region of Nepal. Leaf rust (caused by Puccinia hordei) is one of the major production threats for barley cultivation. A lot of variation can be observed on Nepalese barley accessions with respect to leaf rust resistance characteristics. Two hundred and forty one barley accessions were screened for leaf rust resistance characteristics on heading stage at Khumaltar, Lalitpur, Nepal. Among them, one hundred and nine Nepalese barley accessions showing promising for disease resistance were screened using six SSR markers linked to leaf rust resistance genes. Bonus and Local Jau was used as the resistant and susceptible check respectively. Leaf rust resistance genes Rph1, Rph2, Rph3, Rph7, QBLR-P and QTL on chromosome 5HS were detected on Nepalese barley accessions using respective SSR markers. Eight Nepalese barley accessions showed presence of three and more leaf rust resistant genes. The poor relationship between the field disease resistance and molecular markers linked with specific leaf rust resistance gene proved that Nepalese barley gene pool contains other leaf resistance genes.
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Wang, Z. Z., and K. H. Lin. "Modeling Leaf Age-Related Susceptibility and Rust Eruption Dynamics in Peanut." Peanut Science 27, no. 1 (2000): 7–10. http://dx.doi.org/10.3146/i0095-3679-27-1-2.
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Abstract To improve simulation of epidemics of peanut rust, information on the effects of leaf age and pustule eruption dynamics is needed. An analysis was made of the change of leaf susceptibility of rust with leaf aging using plants exposed to field inoculum. The youngest leaf was most susceptible to rust infection. As leaves aged, susceptibility decreased quickly. The relationship of infection frequency (Y, relative number of pustules) to leaf age (X, leaf position downward on the main stem) was described by a mathematical model Y = 2.17X(-0.83). The dynamics of pustule eruption also was studied using artificial inoculation. Analysis showed that after inoculation, pustule eruption over time was distributed in a logistic pattern. Rust eruption began at 130 and reach a peek at 250 rust degree days—that is, between 7 and 15 d after inoculation. Mathematical models of leaf age-related susceptibility and rust eruption dynamics will be incorporated into simulation model of rust epidemics.
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Malau, Sabam. "Variability of Genotypes of Arabica Coffee (Coffea arabica L.) in Coffee Leaf Rust (Hemileia vastatrix)." Jurnal Agro Industri Perkebunan 8, no. 1 (2020): 21. http://dx.doi.org/10.25181/jaip.v8i1.1285.
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Coffee leaf rust (Hemileia vastatrix) caused large damage on Arabica coffee in Asia, Africa, and America. The resistant genotypes released to farmers in Brazil were developed from the existing cultivars. However, the cultivars of Arabica coffee existing in North Sumatra Province of Indonesia is not yet researched to find resistant genotypes. The goal of this reseach was to determine variability of coffee leaf rust and leaf morphology. In total of 84 genotypes growing in this Province were selected using nested design. Data was analyzed using nested design, correlation, stepwise regression, and hierarchical cluster analysis. This research revealed leaf rust severity had high genotypic variation, low heritability, and high genetic adveance. Ratios of leaf morhology showed moderate to high genotypic variation and heritabilities. Leaf rust severity (y) significantly correlated with both ratio of leaf length with leaf area (x1) and ratio of leaf length with leaf width (x2) with equation y = 2,04 + 62,48x1 3,95x2 with coefficient of multiple correlation R = 0,470**. By using leaf rust severity and these two ratios in cluster analysis, one cluster comprised 18 genotypes with medium leaf rust severity. It could be concluded that resistant genotypes of Arabica coffee might be possible to develop from the existing cultivars. Leaf rust severity might not be used as selection parameter in breeding for leaf rust resistance.
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Kolmer, J. A. "Genetics of Leaf Rust Resistance in the Soft Red Winter Wheat Cultivars Coker 9663 and Pioneer 26R61." Plant Disease 94, no. 5 (2010): 628–32. http://dx.doi.org/10.1094/pdis-94-5-0628.
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Leaf rust, caused by the fungus Puccinia triticina, is an important disease of soft red winter wheat cultivars that are grown in the southern and eastern United States. The objectives of this study were to identify the leaf rust resistance genes in two soft red winter wheat cultivars, Coker 9663 and Pioneer 26R61, that have been widely grown and were initially highly resistant to leaf rust. Both cultivars were crossed with the leaf-rust-susceptible spring wheat cv. Thatcher and the F1 plants were crossed to Thatcher to obtain backcross (BC1) F2 families. In seedlings, the Thatcher/Coker 9663 BC1F2 families segregated for three independent seedling resistance genes when tested with different leaf rust isolates. The leaf rust infection types of selected BC1F3 lines, when tested with different leaf rust isolates, indicated that seedling resistance genes Lr9, Lr10, and Lr14a were present. In field plot tests, BC1F4 lines that were seedling susceptible had some adult plant resistance to leaf rust. Seedlings of the Thatcher/Pioneer 26R61 BC1F2 families segregated for two independent resistance genes. Infection types of selected BC1F3 lines indicated the presence of Lr14b and Lr26. The adult plant gene Lr13 was determined to be present in selected BC1F4 lines that were tested with different leaf rust isolates in greenhouse tests.
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Bai, Dapeng, and D. R. Knott. "Genetic studies of leaf and stem rust resistance in six accessions of Triticum turgidum var. dicoccoides." Genome 37, no. 3 (1994): 405–9. http://dx.doi.org/10.1139/g94-057.
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Six accessions of Triticum turgidum var. dicoccoides L. (4x, AABB) of diverse origin were tested with 10 races of leaf rust (Puccinia recondita f.sp. tritici Rob. ex Desm.) and 10 races of stem rust (P. graminis f.sp. tritici Eriks. &Henn.). Their infection type patterns were all different from those of lines carrying the Lr or Sr genes on the A or B genome chromosomes with the same races. The unique reaction patterns are probably controlled by genes for leaf rust or stem rust resistance that have not been previously identified. The six dicoccoides accessions were crossed with leaf rust susceptible RL6089 durum wheat and stem rust susceptible 'Kubanka' durum wheat to determine the inheritance of resistance. They were also crossed in diallel to see whether they carried common genes. Seedlings of F1, F2, and BC1F2 generations from the crosses of the dicoccoides accessions with RL6089 were tested with leaf rust race 15 and those from the crosses with 'Kubanka' were tested with stem rust race 15B-1. The F2 populations from the diallel crosses were tested with both races. The data from the crosses with the susceptible durum wheats showed that resistance to leaf rust race 15 and stem rust race 15B-1 in each of the six dicoccoides accessions is conferred by a single dominant or partially dominant gene. In the diallel crosses, the dominance of resistance appeared to be affected by different genetic backgrounds. With one exception, the accessions carry different resistance genes: CI7181 and PI 197483 carry a common gene for resistance to leaf rust race 15. Thus, wild emmer wheat has considerable genetic diversity for rust resistance and is a promising source of new rust resistance genes for cultivated wheats.Key words: wheat rust, leaf rust, stem rust, rust resistance, genetic diversity.
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Anderson, J. A., and J. A. Kolmer. "Rust Control in Glyphosate Tolerant Wheat Following Application of the Herbicide Glyphosate." Plant Disease 89, no. 11 (2005): 1136–42. http://dx.doi.org/10.1094/pd-89-1136.
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In greenhouse and field trials, transgenically modified wheat (Triticum aestivum) genotypes with tolerance to glyphosate had extremely low infection types to leaf rust caused by Puccinia triticina when treated with a labeled rate of the herbicide glyphosate prior to inoculation with leaf rust. A surfactant solution and a nonglyphosate herbicide had no effect on leaf rust development on the glyphosate tolerant wheat. Glyphosate had a systemic effect in reducing leaf rust development. The leaf rust control by glyphosate decreased with reduced application rates and longer periods of time between glyphosate application and leaf rust infections. The field and greenhouse tests indicated that control of leaf rust in wheat conditioned by glyphosate is transitory and is effective for at least 21, but not more than 35, days after application. Application of glyphosate also reduced infection types on wheat caused by the stem rust fungus, Puccinia graminis f. sp. tritici. Given these results and evidence from the literature that glyphosate can have adverse effects on other pathogens, including other rust fungi, additional investigation of the fungicidal properties of glyphosate are warranted, with particular attention to the timing of glyphosate application relative to fungal infection. The effects of glyphosate on the soybean rust fungus, Phakopsora pachyrhizi, an emerging pathogen in North America, merit immediate investigation.
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Malau, Sabam, Albiner Siagian, and Maria Rumondang Sihotang. "Stability of Arabica coffee genotype (Coffea arabica L.) against leaf rust (Hemileia vastatrix)." IOP Conference Series: Earth and Environmental Science 748, no. 1 (2021): 012002. http://dx.doi.org/10.1088/1755-1315/748/1/012002.
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Abstract Coffee is now experiencing a serious threat from fungus Hemileia vastatrix which caused epidemic of rust disease in America, Africa, and Asia. As solution, the use of resistant cultivars is the best way. However, interaction between genotype and environment can change the rank of genotypes that shows instability of these genotypes against leaf rust. Purpose of this research was to study stability of genotypes of Arabica coffee against coffee leaf rust. A field experiment was arranged as factorial randomized complete block design with 2 factors (genotypes and climate zones) with three replication. The observed parameters were branch rust incidence, leaf rust incidence, and leaf rust severity. This research result showed significant genotype x environment interaction in all variables. Length of dry season is the most important factor affecting coffee leaf rust because it had the highest correlation coefficient with leaf rust severity (r = 0.662**). Less length of dry season should be the first criteria for selection of coffee farms. The most desired genotype was G7 which performed low leaf rust severity (7.71%) and had a stable resistance indicated by the same leaf rust severity in all environments and 6 SMg. Due to the significant interaction between genotypes and the environment, the genotype to be planted in a region must be tested in that region first.
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Din, Ghulam M. U., Amjad Ali, Amjad Abbas, Muhammad Naveed, Javed Anwar, and Muhammad H. Tanveer. "EFFECT OF LEAF RUST DISEASE ON VARIOUS MORPHO-PHYSIOLOGICAL AND YIELD ATTRIBUTES IN BREAD WHEAT." Pakistan Journal of Phytopathology 29, no. 1 (2017): 117. http://dx.doi.org/10.33866/phytopathol.029.01.0302.
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Leaf rust of wheat caused by Puccinia triticina is one of the most important diseases in the Pakistan and cause both yield and quality reduction. To investigate the effect of leaf rust of wheat on morph-physiological processes and grain yield, a field experiment was conducted using different wheat lines and varieties. The morpho-physiological attributes of the infected plant leaves were badly affected by the infection of leaf rust of wheat. The experiment comprised two treatments, one was inoculated with leaf rust spores manually and Morocco as a spreader while other keeping as a control. The results showed that there was -42.92, -23.72, -23.01, and -11.42, % decrease in chlorophyll content, flag leaf area, specific flag leaf area and relative water content in leaf rust (diseased) plot respectively while 21.24, 160.16% increase in relative dry weight and relative membrane permeability in the leaf rust plot. The results also revealed that leaf rust of wheat also reduces the yield components like number of grains per spike, spike length and 1000 grain weight (-52.38, -43.37 and -45.50 respectively). Thus, it could be concluded that leaf rust of wheat affect the morph-physiological process of wheat plants and badly reduce the yield as well.
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Anikster, Y., J. Manisterski, D. L. Long, and K. J. Leonard. "Leaf Rust and Stem Rust Resistance in Triticum dicoccoides Populations in Israel." Plant Disease 89, no. 1 (2005): 55–62. http://dx.doi.org/10.1094/pd-89-0055.
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A total of 742 single plant accessions of Triticum dicoccoides were collected from 26 locations in Israel. All accessions were evaluated for leaf rust (Puccinia triticina) resistance in field plots at Tel Aviv, and subsets of 284 and 468 accessions were tested in the greenhouse in Tel Aviv and St. Paul, MN, respectively, for seedling resistance to leaf rust; 460 accessions were also tested for seedling resistance to stem rust (Puccinia graminis f. sp. tritici) in St. Paul. One accession was highly resistant to leaf rust in seedling tests in Tel Aviv, and 21 others had moderately susceptible to moderately resistant seedling resistance. Four accessions were highly resistant to leaf rust in seedling tests in St. Paul, and 11 were resistant to at least one stem rust race. Adult resistance to leaf rust was more common than seedling resistance among the accessions; 21 accessions had less than 25% leaf rust severity in field plots compared with 80 to 90% severity for highly susceptible accessions. Most of the accessions with effective adult plant resistance came from two nearby locations in Upper Galilee, a region where populations of T. dicoccoides are most extensive and genetically diverse. These accessions may provide valuable new partial resistance genes for durable protection against leaf rust in cultivated wheat.
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Suenaga, K., R. P. Singh, J. Huerta-Espino, and H. M. William. "Microsatellite Markers for Genes Lr34/Yr18 and Other Quantitative Trait Loci for Leaf Rust and Stripe Rust Resistance in Bread Wheat." Phytopathology® 93, no. 7 (2003): 881–90. http://dx.doi.org/10.1094/phyto.2003.93.7.881.
Full textAbstract:
Leaf rust and stripe rust, caused by Puccinia triticina and P. striiformis, respectively, are important diseases of wheat in many countries. In this study we sought to identify molecular markers for adult plant resistance genes that could aid in incorporating such durable resistance into wheat. We used a doubled haploid population from a Japanese cv. Fukuho-komugi × Israeli wheat Oligoculm cross that had segregated for resistance to leaf rust and stripe rust in field trials. Joint and/or single-year analyses by composite interval mapping identified two quantitative trait loci (QTL) that reduced leaf rust severity and up to 11 and 7 QTLs that might have influenced stripe rust severity and infection type, respectively. Four common QTLs reduced stripe rust severity and infection type. Except for a QTL on chromosome 7DS, no common QTL for leaf rust and stripe rust was detected. QTL-7DS derived from ‘Fukuho-komugi’ had the largest effect on both leaf rust and stripe rust severities, possibly due to linked resistance genes Lr34/Yr18. The microsatellite locus Xgwm295.1, located almost at the peak of the likelihood ratio contours for both leaf and stripe rust severity, was closest to Lr34/Yr18. QTLs located on 1BL for leaf rust severity and 3BS for stripe rust infection type were derived from ‘Oligoculm’ and considered to be due to genes Lr46 and Yr30, respectively. Most of the remaining QTLs for stripe rust severity or infection type had smaller effects. Our results indicate there is significant diversity for genes that have minor effects on stripe rust resistance, and that successful detection of these QTLs by molecular markers should be helpful both for characterizing wheat genotypes effectively and combining such resistance genes.
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Bai, D., and D. R. Knott. "Suppression of rust resistance in bread wheat (Triticum aestivum L.) by D-genome chromosomes." Genome 35, no. 2 (1992): 276–82. http://dx.doi.org/10.1139/g92-043.
Full textAbstract:
Several tests were done in bread wheat (Triticum aestivum L.) to demonstrate the occurrence of genes on D-genome chromosomes that suppress resistance to leaf rust (Puccinia recondita f. sp. tritici Rob. ex Desm.) and stem rust (Puccinia graminis f. sp. tritici Eriks. &Henn.). Ten rust-resistant wild tetraploid wheats (T. turgidum var. dicoccoides) were crossed with both durum (T. turgidum var. durum) and bread wheats. In all cases, resistance to leaf rust and stem rust was expressed in the hybrids with durum wheats but suppressed in the hybrids with bread wheats. Crosses were made between five diverse durum wheats and four diverse bread wheats. The pentaploid hybrid seedlings of 12 crosses were tested with leaf rust race 15 and in all cases the resistance of the durum parents was suppressed. Fourteen D-genome disomic chromosome substitution lines in the durum wheat 'Langdon' were tested with stem rust race 15B-1 and leaf rust race 15. Chromosomes 1B, 2B, and 7B were found to carry genes for resistance to stem rust but no suppressors were detected. Chromosomes 2B and 4B carried genes for resistance to leaf rust, and 1D and 3D carried suppressors. Crosses between seven D-genome monosomies of 'Chinese Spring' and three dicoccoides accessions showed that 'Chinese Spring' possesses genes on 1D, 2D, and 4D, which suppress the stem rust resistance of all three dicoccoides accessions. All three chromosomes must be present to suppress resistance, indicating that some form of complementary gene interaction is involved. In addition, 'Chinese Spring' carries a gene or genes on 3D that suppresses the leaf rust resistance of all three dicoccoides accessions, plus a gene or genes on 1D that suppresses the leaf rust resistance of only one of them. The data raise some interesting questions about the specificity of the suppressors. The high frequency of occurrence of suppressors in the bread wheat population suggests that they must have a selective advantage.Key words: Triticum aestivum, stem rust, leaf rust, rust resistance, suppressor.
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Gultyaeva, Elena, Ekaterina Shaydayuk, Ekaterina Shreyder, Igor Kushnirenko, and Vladimir Shamanin. "Genetic Diversity of Promising Spring Wheat Accessions from Russia and Kazakhstan for Rust Resistance." Plants 13, no. 17 (2024): 2469. http://dx.doi.org/10.3390/plants13172469.
Full textAbstract:
Spring bread wheat (Triticum aestivum) is a major crop in Russia and in Kazakhstan. The rust pathogens, leaf rust caused by the fungus Puccinia triticina, stem rust incited by P. graminis and yellow rust caused by P. striiformis, are the significant biotic factors affecting wheat production. In this study, 40 new promising spring wheat genotypes from the Kazakhstan-Siberia Network for Spring Wheat Improvement (KASIB) were tested for resistance to leaf, stem and yellow rust at the seedling stage, and for identification of rust resistance genes using molecular markers. In addition, the collection was tested for leaf rust resistance and grain yields in the South Urals agroclimatic zone of Russia in 2023. As a result, 16 accessions with seedling resistance to leaf rust, 21 to stem rust and 4 to yellow rust were identified. Three breeding accessions were resistant to all rust species, and nine to P. triticina and P. graminis. Wheat accessions resistant to leaf rust at the seedling stage were also resistant in the field. Molecular analysis showed the presence of cataloged resistance genes, Lr1, Lr3a, Lr9, Lr10, Lr19, Lr20, Lr24, Lr26, Sr15, Sr24, Sr25, Sr31, Sr38, Yr9 and Yr18; uncatalogued genes Lr6Agi1 and Lr6Agi2 from Thinopyrum intermedium and LrAsp from Aegilops speltoides; and 1AL.1RS translocation. The current analysis showed an increase in leaf and stem rust resistance of new KASIB genotypes and their genetic diversity due to the inclusion of alien genetic material in breeding.
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Khan, M. A., and R. G. Saini. "Non-hypersensitive leaf rust resistance of bread wheat cultivar PBW65 conditioned by genes different fromLr34." Czech Journal of Genetics and Plant Breeding 45, No. 1 (2009): 26–30. http://dx.doi.org/10.17221/51/2008-cjgpb.
Full textAbstract:
: The bread wheat (Triticum aestivum L.) cultivar PBW65 has shown hight levels of resistance to the most frequent and highly virulent Indian race 77-5 of leaf rust (Puccinia triticina). The infection type and disease severity indicated a non-hypersensitive type of resistance against the race 77-5 in PBW65. The cultivar PBW65 was crossed with the leaf rust susceptible cultivar WL711 to determine the mode of inheritance of the resistance. The segregation for resistant and susceptible plants in the F<sub>2</sub> and F<sub>3</sub> generations revealed, that two genes, each showing additive effects, were likely to confer resistance to leaf rust in PBW65. Intercrossing of PBW65 with Cook (Lr34), RL6058 (Lr34) and HD2009, possessing a similar resistance level like PBW65, revealed that the genes for leaf rust resistance in PBW65 were non-allelic to Cook (Lr34), RL6058 (Lr34) as well as to the gene(s) in HD2009. It is concluded that the cultivar PBW65 is a novel source of non-hypersensitive leaf rust resistance.
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Knott, D. R., Dapeng Bai, and Janice Zale. "The transfer of leaf and stem rust resistance from wild emmer wheats to durum and common wheat." Canadian Journal of Plant Science 85, no. 1 (2005): 49–57. http://dx.doi.org/10.4141/p03-212.
Full textAbstract:
Wild emmer wheats (Triticum turgidum var. dicoccoides L.) are potentially valuable sources of leaf rust (Puccinia triticina Eriks.) and stem rust (Puccinia graminis f. sp. tritici Eriks. & Henn.) resistance in breeding both durum (T. turgidum var. durum L.) and common wheat (T. aestivum L.). In an extension of previous work, 11 rust resistant accessions of wild emmer wheat were crossed and backcrossed from two to five times to susceptible durum or common wheats. Genes for leaf or stem rust resistance were transferred singly into several susceptible genotypes. Backcross lines homozygous for resistance to leaf rust were tested with a set of either 9 or 10 leaf rust races and those homozygous for resistance to stem rust were tested with a set of either 10 or 13 stem rust races. The emmer wheats proved to carry a number of genes for resistance to each rust. In most cases, when a cross was made to a hexaploid wheat, resistance to both rusts was suppressed in the F1 seedlings, even when resistance was dominant in the tetraploids. Nevertheless, resistance was successfully transferred from several accessions to the hexaploids, indicating that suppressors on the A or B genome chromosomes were involved and segregation occurred for them. Rust resistance tended to decrease when it was transferred to another species, particularly hexaploid wheat. A number of lines carrying genes for either leaf rust or stem rust resistance were resistant to all races with which they were tested and have potential in wheat breeding. Key words: Emmer wheat, Triticum turgidum var. dicoccoides, stem rust, leaf rust, suppressors
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Liu, J. Q., and J. A. Kolmer. "Inheritance of Leaf Rust Resistance in Wheat Cultivars Grandin and CDC Teal." Plant Disease 81, no. 5 (1997): 505–8. http://dx.doi.org/10.1094/pdis.1997.81.5.505.
Full textAbstract:
The hard red spring wheat cultivars Grandin and CDC Teal were genetically examined to determine the number and identity of the leaf rust resistance genes present in both wheats. The two cultivars were crossed with the leaf rust susceptible cultivar Thatcher, and the F1 plants were backcrossed to Thatcher. Fifty-four and 80 BC1F1 plants derived respectively from Grandin and CDC Teal were selfed to produce BC1F2 families. The BC1F2 families were tested as seedlings with isolates of Puccinia recondita f. sp. tritici that differed for virulence to specific leaf rust resistance genes. The BC1F2 families were also tested in the adult-plant stage in field rust nursery tests. Segregation of BC1F2 families in the seedling tests indicated that Grandin had resistance genes Lr2a, Lr3, and Lr10, and was heterogeneous for Lr16. CDC Teal was shown to have the seedling leaf rust gene Lr1. In field rust nursery tests, both Grandin and CDC Teal were shown to have adult-plant resistance genes Lr13 and Lr34. Additional leaf rust resistance genes that condition effective field resistance should be incorporated into hard red spring wheat cultivars to diversify the leaf rust resistance in this wheat class.
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Sopialena, Sopialena, Suyadi Suyadi, and Septri Alfian Noor. "Ecosystem Monitoring on Leaves of Leaf Rust Disease of Maize (Zea mays L.)." Caraka Tani: Journal of Sustainable Agriculture 37, no. 1 (2022): 89. http://dx.doi.org/10.20961/carakatani.v37i1.34920.
Full textAbstract:
Endemic leaf rust disease always occurs in almost all maize plantations in Indonesia. Furthermore, the development of this disease differs concurrently and is greatly influenced by the ecological conditions of maize cultivation. Therefore, this study fills the epidemiological gap of diseases that has not been conducted against the epidemiology of maize rust. This identifies the causes of leaf rust that attacked the maize plants in two locations, namely Bayur and Muang Dalam, Lempake, Samarinda, Indonesia. This study also analyzed the relationship or model between ecological factors of temperature, humidity, and soil fertility on the intensity of leaf rust and the infection rate of maize leaf rust. Measurement of disease intensity, the rate at which it developed, soil fertility and temperature and humidity of the area are conducted in this study. Meanwhile, soil fertility also influenced disease progression and the nutrient-poor soils in two sites cause leaf rust disease to develop well. The identification results showed that the cause of maize leaf rust was <em>Puccinia sorghi</em> Schw. Therefore, the temperature accompanied by the increased humidity is directly proportional to the development of the leaf rust.
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Araaf, Raka Thoriq, Arkar Minn, and Tofael Ahamed. "Coffee Leaf Rust Disease Detection and Implementation of an Edge Device for Pruning Infected Leaves via Deep Learning Algorithms." Sensors 24, no. 24 (2024): 8018. https://doi.org/10.3390/s24248018.
Full textAbstract:
Global warming and extreme climate conditions caused by unsuitable temperature and humidity lead to coffee leaf rust (Hemileia vastatrix) diseases in coffee plantations. Coffee leaf rust is a severe problem that reduces productivity. Currently, pesticide spraying is considered the most effective solution for mitigating coffee leaf rust. However, the application of pesticide spray is still not efficient for most farmers worldwide. In these cases, pruning the most infected leaves with leaf rust at coffee plantations is important to help pesticide spraying to be more efficient by creating a more targeted, accessible treatment. Therefore, detecting coffee leaf rust is important to support the decision on pruning infected leaves. The dataset was acquired from a coffee farm in Majalengka Regency, Indonesia. Only images with clearly visible spots of coffee leaf rust were selected. Data collection was performed via two devices, a digital mirrorless camera and a phone camera, to diversify the dataset and test it with different datasets. The dataset, comprising a total of 2024 images, was divided into three sets with a ratio of 70% for training (1417 images), 20% for validation (405 images), and 10% for testing (202 images). Images with leaves infected by coffee leaf rust were labeled via LabelImg® with the label “CLR”. All labeled images were used to train the YOLOv5 and YOLOv8 algorithms through the convolutional neural network (CNN). The trained model was tested with a test dataset, a digital mirrorless camera image dataset (100 images), a phone camera dataset (100 images), and real-time detection with a coffee leaf rust image dataset. After the model was trained, coffee leaf rust was detected in each frame. The mean average precision (mAP) and recall for the trained YOLOv5 model were 69% and 63.4%, respectively. For YOLOv8, the mAP and recall were approximately 70.2% and 65.9%, respectively. To evaluate the performance of the two trained models in detecting coffee leaf rust on trees, 202 original images were used for testing with the best-trained weight from each model. Compared to YOLOv5, YOLOv8 demonstrated superior accuracy in detecting coffee leaf rust. With a mAP of 73.2%, YOLOv8 outperformed YOLOv5, which achieved a mAP of 70.5%. An edge device was utilized to deploy real-time detection of CLR with the best-trained model. The detection was successfully executed with high confidence in detecting CLR. The system was further integrated into pruning solutions for Arabica coffee farms. A pruning device was designed using Autodesk Fusion 360® and fabricated for testing on a coffee plantation in Indonesia.
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Adhikari, K. N., and R. A. McIntosh. "Identification of stem rust and leaf rust resistance genes in Amagalon oats." Australian Journal of Agricultural Research 52, no. 10 (2001): 1011. http://dx.doi.org/10.1071/ar01084.
Full textAbstract:
Studies were undertaken to identify the genes conferring stem rust and leaf rust resistances in Amagalon and to determine the usefulness of this line as a source of rust resistance in oat breeding programs. Amagalon was crossed with certain rust-resistant and rust-susceptible lines and segregating populations were tested with pathotypes of Puccinia graminis avenae and P. coronata avenae. Tests with the widely virulent P. graminis avenae pt 94+Pg-13 indicated that resistance in Amagalon was governed by the complementary recessive gene complex known as Pg-a. This hypothesis was further substantiated by temperature sensitivity tests and by a test of induced susceptibility to stem rust, known to be unique to lines possessing Pg-a. However, Amagalon yielded a unique source of resistance to leaf rust that was effective against current pathotypes of P. coronata avenae in Australia. This gene, assumed to be Pc91, was inherited independently of a second leaf rust resistance gene present in cv. Culgoa. It was concluded that Amagalon is a useful source of resistance to leaf rust that should be used in combination with other genes for resistance to prolong its effectiveness.
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Hanzalová, A., T. Sumíková, J. Huszár, and P. Bartoš. "Physiologic specialization of wheat leaf rust (Puccinia triticina Eriks.) in the Slovak Republic in 2009–2011." Czech Journal of Genetics and Plant Breeding 48, No. 3 (2012): 101–7. http://dx.doi.org/10.17221/28/2012-cjgpb.
Full textAbstract:
In 2009&ndash;2011 virulence of the wheat leaf rust population was studied on Thatcher near-isogenic lines with Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr11, Lr13, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. Samples of leaf rust were obtained from different parts of the Slovak Republic. A total of 122 wheat leaf rust isolates were analysed. Resistance gene Lr19 was effective to all tested isolates. Virulence to Lr9 was found, however only in one isolate. Gene Lr24 conditioned resistance to almost all rust collections. A lower frequency of virulence to Lr2a and Lr28 was also observed. Nineteen winter wheat cultivars grown in Slovakia were tested with 8 leaf rust isolates. Winter wheat cultivar Bona Dea was resistant to all isolates applied in the greenhouse test. Presence of Lr genes was estimated according to the reactions of the tested cultivars. Presence of Lr10, Lr26, Lr34 and Lr37 was studied by molecular markers.
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Ismail, M., M. Azeem Asad, J. A. Tariq, R. M. Memon, and M. A. Sial. "Assessment of Leaf Rust Resistance in Wheat Genotypes in Natural Environmental Conditions of Tandojam." Nucleus 55, no. 1 (2018): 33–37. https://doi.org/10.71330/thenucleus.2018.49.
Full textAbstract:
Identification of sources of resistance and their incorporation in crop germplasm is the most effective method for disease management. Therefore, present work has been conducted to find out resistance in thirty two (32) wheat genotypes against leaf rust during wheat season 2015-2016 and 2016-2017. The results of the study revealed significant variation among these genotypes against leaf rust in both seasons. In 2015-16 wheat season genotypes C217 and C228 were free of leaf rust, T11, T12, T16 and T18 were found resistant and T1, T2 and T19 showed moderately resistant reaction. Maximum leaf rust severity of 50S has been noticed on T14. In 2016-17 normal sowing trial, less rust development has been observed on all genotypes due to late appearance of disease. While in late sowing trial, seventeen genotypes have been found susceptible with maximum rust severity of 60S on T20. Twelve are rated moderately susceptible to susceptible. While the genotypes T1and T2 showed moderately resistant -moderately susceptible reaction against the disease in late sowing trial. Among thirty two genotypes, T16 has been found free of leaf rust in both trials. Thus the potential of T1, T2 and T16 as source of resistance against leaf rust can be investigated further. These results can be used in wheat breeding program to incorporate leaf rust resistance in wheat genotypes.
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Praptana, R. H., S. Jauhari, Samijan, and M. N. Setiapermas. "The leaf rust disease development of hybrid corn on shaded agroecosystem." IOP Conference Series: Earth and Environmental Science 1253, no. 1 (2023): 012007. http://dx.doi.org/10.1088/1755-1315/1253/1/012007.
Full textAbstract:
Abstract The research objective was to determine the development of hybrid corn leaf rust disease in shaded agro-ecosystems. The research was carried out in the albasia forest area of Kalices Village, Patehan District, Kendal Regency, Central Java, Indonesia in March-September 2020. Three hybrid corn varieties, namely JH 37, Nasa 29 and Bisi 18, were used as treatments, as well as three levels of shade density, namely 0, 20 and 40%. Observations were made on the incidence and intensity of leaf rust disease at the age of 40, 60 and 80 days after planting (DAP). The incidence and intensity of leaf rust disease were observed by scoring according to the modified 2012 DMRI method. The results showed that all three varieties had been attacked by leaf rust disease since 40 DAP with an incidence of 13.33–56.67% and disease intensity between 12.59–17.41% at all levels of shade density. The leaf rust disease continues to develop in all varieties with an intensity of around 30.00-56.67%. The highest incidence and intensity of leaf rust disease occurred in JH 37 variety at all levels of shade density. The development of leaf rust disease is more influenced by the genetic characteristics of each variety.
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Yehuda, Pnina Ben, Tamar Eilam, Jacob Manisterski, Ayelet Shimoni, and Yehoshua Anikster. "Leaf Rust on Aegilops speltoides Caused by a New Forma Specialis of Puccinia triticina." Phytopathology® 94, no. 1 (2004): 94–101. http://dx.doi.org/10.1094/phyto.2004.94.1.94.
Full textAbstract:
A leaf rust attacking Aegilops speltoides in its natural habitat is reported for the first time. It was found in two locations in northern and central Israel. The two collections from A. speltoides resemble wheat leaf rust, Puccinia triticina, in most spore dimensions, in the morphology of the substomatal vesicle of the urediniospore, and in DNA content in pycniospore nuclei. Similarly to P. triticina isolates from wheat, isolates taken from A. speltoides are compatible with Thalictrum speciosissimum as an aecial host and they are crossed easily with wheat leaf rust isolates. However, isolates from A. speltoides differ from wheat leaf rust in their telial host range. They are avirulent to cultivated wheat cultivars, but attack hundreds of A. speltoides accessions that were immune to wheat leaf rust. This distinct host preference justifies delineation of the newly found leaf rust as a forma specialis (f. sp. speltoides) within P. triticina.
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Dyck, P. L. "The transfer of leaf rust resistance from Triticum turgidum ssp. dicoccoides to hexaploid wheat." Canadian Journal of Plant Science 74, no. 4 (1994): 671–73. http://dx.doi.org/10.4141/cjps94-121.
Full textAbstract:
Accession 8404 of Triticum turgidum ssp. dicoccoides was shown to have excellent resistance to leaf rust. Genetic analysis of the F3 of 8404 and RL6089, a leaf rust susceptible durum, indicated that 8404 had three genes for leaf rust resistance. Two of these genes were transferred to hexaploid wheat (Thatcher) by a series of backcrosses. One of the genes transferred was the same as Lr33 (RL6057). The second gene, which gives a fleck reaction to avirulent P. recondita races, appears to be fully incorporated into the hexaploid where it segregated to fit a one-gene ratio. Backcross lines with this gene give excellent resistance to leaf rust, although race MBG is virulent to this gene. This may be a previously unidentified leaf rust resistance gene and should increase the genetic diversity available for wheat breeders. Key words:Triticum aestivum, wheat, Triticum turgidum ssp. dicoccoides, leaf rust resistance
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Steffenson, Brian J., Pablo Olivera, Joy K. Roy, Yue Jin, Kevin P. Smith, and Gary J. Muehlbauer. "A walk on the wild side: mining wild wheat and barley collections for rust resistance genes." Australian Journal of Agricultural Research 58, no. 6 (2007): 532. http://dx.doi.org/10.1071/ar07123.
Full textAbstract:
Leaf rust, stem rust, and stripe rust are among the most important diseases of wheat and barley worldwide and are best controlled using genetic resistance. To increase the diversity of rust resistance in wheat and barley, a project was initiated to identify and characterise rust resistance genes from the wild species of Aegilops sharonensis (Sharon goatgrass) and Hordeum vulgare ssp. spontaneum (wild barley), respectively. One hundred and two accessions of Sharon goatgrass from Israel and 318 Wild Barley Diversity Collection (WBDC) accessions from the Fertile Crescent, Central Asia, North Africa, and the Caucasus region were evaluated for resistance to leaf rust, stem rust, and/or stripe rust. Sharon goatgrass exhibited a wide range of infection types (ITs) in response to leaf rust, stem rust, and stripe rust. The percentage of resistant accessions in Sharon goatgrass was 58.8–78.4% for leaf rust, 11.8–69.6% for stem rust, and 46.1% for stripe rust, depending on the race used and the plant growth stage. Genetic studies with Sharon goatgrass revealed oligogenic resistance to leaf rust and stem rust. Wild barley also exhibited a wide range of ITs to leaf rust and stem rust; however, the overall frequency of resistance was lower than for Sharon goatgrass. The percentage of resistant accessions in wild barley was 25.8% for leaf rust and 5.7–20.1% for stem rust, depending on the race used. Resistance to the new virulent stem rust race TTKS (i.e. Ug99), present in eastern Africa, was found in both Sharon goatgrass (70% of accessions) and wild barley (25% of 20 accessions tested). Association mapping for stem rust resistance was applied in the WBDC using Diversity Arrays Technology (DArT) markers. Using the highly conservative P value threshold of 0.001, 14 and 15 significant marker associations were detected when the number of subpopulations (K value) was set for 10 and 8, respectively. These significant associations were in 9 and 8 unique chromosome bins, respectively. Two significant marker associations were detected for resistance to the wheat stem rust race MCCF in the same bin as the rpg4/Rpg5 complex on chromosome 7(5H). The presence of a major stem rust resistance gene in this bin on chromosome 7(5H) was validated in a bi-parental mapping population (WBDC accession Damon × cv. Harrington) constructed with DArT markers. The results from this study indicate that Sharon goatgrass and wild barley are rich sources of rust resistance genes for cultivated wheat and barley improvement, respectively, and that association mapping may be useful for positioning disease resistance genes in wild barley.
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Martínez-Moreno, Fernando, Patricia Giraldo, Cristina Nieto, and Magdalena Ruiz. "Resistance to Leaf and Yellow Rust in a Collection of Spanish Bread Wheat Landraces and Association with Ecogeographical Variables." Agronomy 12, no. 1 (2022): 187. http://dx.doi.org/10.3390/agronomy12010187.
Full textAbstract:
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.
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James, Timothy Y., John A. Marino, Ivette Perfecto, and John Vandermeer. "Identification of Putative Coffee Rust Mycoparasites via Single-Molecule DNA Sequencing of Infected Pustules." Applied and Environmental Microbiology 82, no. 2 (2015): 631–39. http://dx.doi.org/10.1128/aem.02639-15.
Full textAbstract:
ABSTRACTThe interaction of crop pests with their natural enemies is a fundament to their control. Natural enemies of fungal pathogens of crops are poorly known relative to those of insect pests, despite the diversity of fungal pathogens and their economic importance. Currently, many regions across Latin America are experiencing unprecedented epidemics of coffee rust (Hemileia vastatrix). Identification of natural enemies of coffee rust could aid in developing management strategies or in pinpointing species that could be used for biocontrol. In the present study, we characterized fungal communities associated with coffee rust lesions by single-molecule DNA sequencing of fungal rRNA gene bar codes from leaf discs (≈28 mm2) containing rust lesions and control discs with no rust lesions. The leaf disc communities were hyperdiverse in terms of fungi, with up to 69 operational taxonomic units (putative species) per control disc, and the diversity was only slightly reduced in rust-infected discs, with up to 63 putative species. However, geography had a greater influence on the fungal community than whether the disc was infected by coffee rust. Through comparisons between control and rust-infected leaf discs, as well as taxonomic criteria, we identified 15 putative mycoparasitic fungi. These fungi are concentrated in the fungal family Cordycipitaceae and the order Tremellales. These data emphasize the complexity of diverse fungi of unknown ecological function within a leaf that might influence plant disease epidemics or lead to the development of species for biocontrol of fungal disease.
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Soriano, Jose Miguel, and Conxita Royo. "Dissecting the Genetic Architecture of Leaf Rust Resistance in Wheat by QTL Meta-Analysis." Phytopathology® 105, no. 12 (2015): 1585–93. http://dx.doi.org/10.1094/phyto-05-15-0130-r.
Full textAbstract:
Leaf rust is an important disease that causes significant yield losses in wheat. Many studies have reported the identification of quantitative trait loci (QTL) controlling leaf rust resistance; therefore, QTL meta-analysis has become a useful tool for identifying consensus QTL and refining QTL positions among them. In this study, QTL meta-analysis was conducted using reported results on the number, position, and effects of QTL for leaf rust resistance in bread and durum wheat. Investigation of 14 leaf rust resistance traits from 19 studies involving 20 mapping populations and 33 different parental lines provided information for 144 unique QTL that were projected onto the Wheat Composite 2004 reference map. In total, 35 meta-QTL for leaf rust resistance traits were identified in 17 wheat chromosomes and 13 QTL remained as unique QTL. The results will facilitate further work on the cloning of QTL for pyramiding minor- and partial-effect resistance genes to develop varieties with durable resistance to leaf rust.
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Ren, Xiaopeng, Chuyuan Wang, Zhuang Ren, et al. "Genetics of Resistance to Leaf Rust in Wheat: An Overview in a Genome-Wide Level." Sustainability 15, no. 4 (2023): 3247. http://dx.doi.org/10.3390/su15043247.
Full textAbstract:
Due to the global warming and dynamic changes in pathogenic virulence, leaf rust caused by Puccinia triticina has greatly expanded its epidermic region and become a severe threat to global wheat production. Genetic bases of wheat resistance to leaf rust mainly rely on the leaf rust resistance (Lr) gene or quantitative trait locus (QLr). Although these genetic loci have been insensitively studied during the last two decades, an updated overview of Lr/QLr in a genome-wide level is urgently needed. This review summarized recent progresses of genetic studies of wheat resistance to leaf rust. Wheat germplasms with great potentials for genetic improvement in resistance to leaf rust were highlighted. Key information about the genetic loci carrying Lr/QLr was summarized. A genome-wide chromosome distribution map for all of the Lr/QLr was generated based on the released wheat reference genome. In conclusion, this review has provided valuable sources for both wheat breeders and researchers to understand the genetics of resistance to leaf rust in wheat.
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Mallick, Niharika, Shailendra K. Jha, Priyanka Agarwal, et al. "Marker-Assisted Improvement of Bread Wheat Variety HD2967 for Leaf and Stripe Rust Resistance." Plants 11, no. 9 (2022): 1152. http://dx.doi.org/10.3390/plants11091152.
Full textAbstract:
The mega wheat variety HD2967 was improved for leaf and stripe rust resistance by marker-assisted backcross breeding. After its release in 2011, HD2967 became susceptible to stripe rust and moderately susceptible to leaf rust. The leaf rust resistance gene LrTrk was transferred into HD2967 from the durum wheat genotype Trinakria. Then, HD2967 was crossed with Trinakria to produce F1 plant foreground selection for LrTrk and background selection for the recurrent parent genotype was carried out in BC1F1, BC2F1 and BC2F2 generations. Foreground selection was carried out with the linked marker Xgwm234, while polymorphic SSR markers between parents were used for background selection. Background selection resulted in the rapid recovery of the recurrent parent genome. A morphological evaluation of 6 near isogenic lines (NILs)—2 resistant to leaf and stripe rust, and 4 resistant to leaf rust only—showed no significant differences in yields among NILs and the recurrent parent HD2967. All of the 6 NILs showed the presence of 2NS/2AS translocation, carrying the linked genes Lr37/Sr38/Yr17 present in HD2967 and the targeted leaf rust resistance gene LrTrk. Two NILs also showed additional resistance to stripe rust. Therefore, these NILs with rust resistance and an at par yielding ability of H2967 can replace the susceptible cultivar HD2967 to reduce yield losses due to disease.
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Mallick, Niharika, Shailendra K. Jha, Priyanka Agarwal, et al. "Marker-Assisted Improvement of Bread Wheat Variety HD2967 for Leaf and Stripe Rust Resistance." Plants 11, no. 9 (2022): 1152. http://dx.doi.org/10.3390/plants11091152.
Full textAbstract:
The mega wheat variety HD2967 was improved for leaf and stripe rust resistance by marker-assisted backcross breeding. After its release in 2011, HD2967 became susceptible to stripe rust and moderately susceptible to leaf rust. The leaf rust resistance gene LrTrk was transferred into HD2967 from the durum wheat genotype Trinakria. Then, HD2967 was crossed with Trinakria to produce F1 plant foreground selection for LrTrk and background selection for the recurrent parent genotype was carried out in BC1F1, BC2F1 and BC2F2 generations. Foreground selection was carried out with the linked marker Xgwm234, while polymorphic SSR markers between parents were used for background selection. Background selection resulted in the rapid recovery of the recurrent parent genome. A morphological evaluation of 6 near isogenic lines (NILs)—2 resistant to leaf and stripe rust, and 4 resistant to leaf rust only—showed no significant differences in yields among NILs and the recurrent parent HD2967. All of the 6 NILs showed the presence of 2NS/2AS translocation, carrying the linked genes Lr37/Sr38/Yr17 present in HD2967 and the targeted leaf rust resistance gene LrTrk. Two NILs also showed additional resistance to stripe rust. Therefore, these NILs with rust resistance and an at par yielding ability of H2967 can replace the susceptible cultivar HD2967 to reduce yield losses due to disease.
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Sood, Sushma G., Jack C. Comstock, and Neil C. Glynn. "Leaf Whorl Inoculation Method for Screening Sugarcane Rust Resistance." Plant Disease 93, no. 12 (2009): 1335–40. http://dx.doi.org/10.1094/pdis-93-12-1335.
Full textAbstract:
Brown rust, caused by Puccinia melanocephala, and orange rust, caused by P. kuehnii, are agronomically important diseases of sugarcane in Florida. Cultivar resistance is the best means of controlling these diseases. Natural infection has been the primary means of assessing resistance in sugarcane cultivars against rusts; unfortunately, natural infection is not always efficient in identifying resistant cultivars due to variable environmental conditions. Therefore, a more reliable screening method is needed to effectively select resistant genotypes. An inoculation technique was evaluated for identification of brown and orange rust resistance in sugarcane cultivars. Inoculations were performed in the field by placing a 0.5-ml urediniospore suspension in the leaf whorl of three individual sugarcane stalks per plant using a pipette. Symptoms developed on leaves of all the susceptible cultivars after 4 weeks, and appeared as a band of pustules. Plants were rated for their reaction to rust 4 weeks after inoculation. The optimum concentrations of inoculum for expression of brown and orange rust symptoms were determined. The most severe brown rust and orange rust symptoms were observed using inoculum containing 105 and 104 urediniospores/ml, respectively. Clones in several stages of the Canal Point breeding program were screened for their rust reaction by leaf whorl inoculation. The technique enabled rapid screening of a large number of cultivars in field plantings using a small amount of inoculum and limited man hours.
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Kim, Minseo, Aro Lee, Yeon Jin Roh, et al. "Gene Expression and Metabolomics Profiling of the Common Wheat Obtaining Leaf Rust Resistance by Salicylic or Jasmonic Acid through a Novel Detached Leaf Rust Assay." Agronomy 10, no. 11 (2020): 1668. http://dx.doi.org/10.3390/agronomy10111668.
Full textAbstract:
Wheat leaf rust caused by Puccinia triticina is a destructive fungal disease causing considerable grain yield loss. In this study, we developed a novel assay to test the rust resistance of detached wheat leaves on defined media with retarded senescence. We observed that salicylic and jasmonic acid confer leaf rust resistance to a susceptible Keumkang wheat (Triticum aestivium L.). Transcription analysis revealed that atchi8 was highly expressed with an increased chitinase activity in the salicylic acid-treated leaves, while expression of PR-9, atpodL, and PR-5 increased in the jasmonic acid-treated leaves. Additionally, the metabolic profile suggested that the phenylalanine pathway might link flavonoid production to leaf rust resistance in the salicylic acid-treated leaves, while the alanine, aspartate, and glutamate metabolism might control the production of other amino acids to enhance pathogen stress response in the jasmonic acid-treated leaves. Finally, all identified genes and metabolites could be potential targets for screening chemical compounds for leaf rust resistance. Future studies on the underlying mechanisms of leaf rust resistance obtained by exogenous treatment of salicylic and jasmonic acids remain necessary.
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Dyck, P. L. "The inheritance of leaf rust resistance in the wheat cultivar Pasqua." Canadian Journal of Plant Science 73, no. 3 (1993): 903–6. http://dx.doi.org/10.4141/cjps93-118.
Full textAbstract:
The Canadian wheat (Triticum aestivum L.) cultivar Pasqua has good resistance to leaf rust (Puccinia recondita Rob. ex Desm.) and some sprouting resistance. Backcross F2 families were used to study the inheritance of leaf rust resistance in Pasqua. Based on the leaf rust resistance genotypes of its parents, Pasqua could have genes Lr11, Lr13, Lr14b, Lr16, Lr22, and Lr30. Of these, it was found to have Lr11, Lr13, Lr14b, and Lr30. As well, it has Lr34, which must have come from the cultivar Terenzio during the development of a Neepawa backcross line with Lr30. Key words: Triticum aestivum, wheat, leaf rust resistance
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Zewdu, Demeke, Tafesse Solomon, Gadisa Alemu, et al. "Phenotypic Screening of Bread Wheat (Triticum spp L.) Germplasm Collection for Yellow and Leaf Rust Disease Resistance." International Journal of Economic Plants 11, Aug, 3 (2024): 310–15. http://dx.doi.org/10.23910/2/2024.5452a.
Full textAbstract:
The Research was conducted at KARC during June to November, 2023 to phenotypic screening of bread wheat genotypes for yellow and leaf rust resistance. Both rusts were recorded based on the modified Cobb scale. Severity of yellow rust showed from immune to 70%. 826 genotypes showed slow rusting resistance ranging from 0–30%), 575 genotypes observed as slow rusting plant resistance ranging from 31–50%) and 96 genotypes observed as low adult plant resistance (>50% of yellow rust severity). Tested genotypes showed diverse reactions for yellow rust ranging from immune to susceptible responses. 57 genotypes were observed immune, 161 genotypes were showed moderately resistant reaction type. 317 genotypes were observed moderately susceptible reaction and 962 genotypes were observed susceptible reactions for yellow rust response. The leaf rust severity of the studied genotypes showed from immune to 90. 607 genotypes (showed slow rusting resistance ranging from 0–20% of severity), 563 genotypes observed as slow rusting plant resistance ranging from 21–50% of severity) and 326 genotypes observed as low adult plant resistance (>50% of leaf rust severity. Tested genotypes showed diverse reactions for leaf rust ranging from immune to susceptible responses. 58 genotypes were observed immune, 30 genotypes were observed moderately resistant, 80 genotypes were observed moderately resistant to moderately susceptible, 464 genotypes were showed moderately susceptible reaction, 864 genotypes were showed susceptible reactions for leaf rust disease response. Based on yellow rust, leaf rust and agronomic performance 76 genotypes were selected for the next breeding step.
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Bartoš, P., J. Huszár, A. Hanzalová, and E. Herzová. "Wheat leaf rust races/pathotypes in Slovakia in 1999–2000." Plant Protection Science 37, No. 3 (2001): 81–90. http://dx.doi.org/10.17221/8369-pps.
Full textAbstract:
Virulence of the wheat leaf rust populations of 1999 and 2000 from Slovakia was studied on Thatcher near-isogenic lines (NILs) with genes Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr10 (only in 2000), Lr11, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. Seven pathotypes were determined from 36 rust samples in 1999, and 17 pathotypes from 45 rust samples in 2000. The frequency of virulence on Lr1, Lr2a and Lr2b was relatively low, and there was no virulence on Lr9, Lr19, Lr24 and Lr28. The frequency of virulence on Lr2c, Lr15, Lr23 and Lr26 varied between 53.0 and 97.8%. All isolates were virulent on Lr3, Lr11, Lr17 and Lr21. The identified pathotypes conformed with races 61SaBa, 57SaBa, 12SaBa, 6SaBa, 77SaBa, 6, 61 and 2SaBa. In 1999 races 61SaBa, 77SaBa and 57SaBa prevailed, in 2000 races 61SaBa, 57SaBa, 12SaBa, 6SaBa and 77SaBa were prevalent. Data on the reactions of 18 cultivars and advanced lines to six rust isolates of 2000 representing different pathotypes and to one isolate from the collection (race 14) are presented.
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Silva-Acuña, R., L. A. Maffia, L. Zambolim, and R. D. Berger. "Incidence-Severity Relationships in the Pathosystem Coffea arabica-Hemileia vastatrix." Plant Disease 83, no. 2 (1999): 186–88. http://dx.doi.org/10.1094/pdis.1999.83.2.186.
Full textAbstract:
Incidence-severity relationships for coffee rust were studied to determine if the easily assessed incidence could be used to evaluate host resistance and fungicide treatment. At two locations in each of 3 years, the incidence of rust on 300 leaves was compared with two assessments of severity: (i) the average number of sporulating pustules per leaf, and (ii) the estimated leaf area with rust. For nine or 10 assessments in time at one location and pooled over 3 years, the average number of sporulating pustules per leaf (Y sp) was well related with the incidence of leaves with rust (X) as Y sp = 0.02982+ 0.017035X +0.000573X 2; R 2 = 0.87. The leaf area with rust (Y la) was also well related with incidence of leaves with rust as Y la = 0.001 − 0.01076X +0.008376X 2; R 2 = 0.92. For two independent data sets from a second location obtained over two seasons, the above models satisfactorily fit the relationships for the average sporulating pustules per leaf (R 2 = 0.97 and 0.96) and for the estimated leaf area with rust (R 2 = 0.95 and 0.98). Therefore, the readily determined incidence can be used to estimate both measures of disease severity of coffee rust.
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Bai, Dapeng, D. R. Knott, and Janice Zale. "The transfer of leaf rust resistance from Triticum timopheevii to durum and bread wheat and the location of one gene on chromosome 1A." Canadian Journal of Plant Science 78, no. 4 (1998): 683–87. http://dx.doi.org/10.4141/p97-136.
Full textAbstract:
Triticum timopheevii (Zhuk.) Zhuk. is noted for its resistance to diseases including leaf and stem rust of wheat. Only one gene (Lr18) for leaf rust resistance has been transferred from T. timopheevii to bread wheat. The objectives of this work were to study the inheritance of leaf rust resistance in five accessions of T. timopheevii and to transfer genes for resistance into durum and bread wheats. A diallel set of crosses was made among five T. timopheevii accessions that gave a fleck infection type with an isolate of leaf rust race CBB. None of the F2 populations of the 10 crosses segregated for resistance, indicating that the five accessions all had at least one gene for resistance in common. Several accessions were crossed and backcrossed twice to durum and to bread wheat. At least three genes for leaf rust resistance were transferred to durum wheat and one to bread wheat. The gene transferred to bread wheat and one of those transferred to durum wheat conditioned good resistance to a set of 10 diverse races of leaf rust. Resistance conditioned by all three genes was dominant in durum wheat but the one gene was recessive in bread wheat. Monosomic analysis of the bread wheat line showed that the gene is on chromosome 1A. It should be useful in breeding for leaf rust resistance in both durum and bread wheat. Key words: Triticum timopheevii, leaf rust resistance, durum wheat, bread wheat
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Barbetti, M. J., and P. G. H. Nichols. "New sources of resistance in Trifolium subterraneum to rust (Uromyces trifolii-repentis)." Australian Journal of Experimental Agriculture 45, no. 9 (2005): 1163. http://dx.doi.org/10.1071/ea04150.
Full textAbstract:
Fifty-seven genotypes, including 10 cultivars, of Trifolium subterraneum var. subterraneum and var. yanninicum were screened in the field for resistance to rust (Uromyces trifolii-repentis) using artificial inoculation. There was outstanding resistance among the var. yanninicum, types with all but 1 genotype showing no rust symptoms. Several var. subterraneum genotypes also showed only a low rust incidence (≤3.5 on a 0–10 scale) with little or no leaf collapse from rust infection, including 83S19–07, CPI 103906F, EP132Sub-E, 84S20–02, and 84S20–01. Several other lines had a significant incidence of rust, while little leaf collapse from the disease was evident. Several highly susceptible lines were identified, including cultivars Green Range, Seaton Park and York, all with 100% of leaves affected by rust and extensive leaf collapse. There was excellent positive correlation between rust incidence and leaf collapse across the genotypes tested (R2 = 0.91). The excellent rust resistance observed in the majority of var. yanninicum lines and the good resistance in some var. subterraneum lines, indicates that these are useful sources of resistance that can be exploited, either directly as new cultivars to minimise leaf collapse from this disease or as parents in breeding programmes to develop more rust-resistant cultivars.