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A high-yielding and well-adapted wheat variety for central and peninsular India HD2932 was improved for three types of wheat rusts by introgressing genes Lr19/Sr25, Lr24/Sr24 and Yr10 and a new variety HD3407 (Unnat HD2932) was developed. The linked genes, Lr19/Sr25 and Lr24/Sr24, were derived from Thinopyrum (syn. Agropyron), whereas Yr10 was derived from Moro wheat (Triticum aestivum L.). NILs (> 90% RPG) with Lr19/Sr25 and Lr24/Sr24 in BC2F1 generation were intercrossed to produce two gene combinations Lr19/Sr25 + Lr24/Sr24. The two genes carrying plants were crossed with the third NIL with Yr10 for stripe rust resistance. Three-way cross NILF1s were selfed and a large F2 generation was produced to select plants with three genes. A single plant with all three genes in the homozygous state and maximum phenotypic and genotypic similarity (RPG = 98.14%) was identified and nominated in all India coordinated trials as HD3407. The proposed entry HD3407 yielded at par as that of the recurrent parent and check variety HD2932 during both the years of testing, 2020–21 and 2021–22, and displayed a high degree of resistance to leaf, stem and stripe rusts at seedling and adult plant stages. The average coefficient of infection for leaf rust (1.95), stem rust (3.45) and stripe rust (6.4) in HD3407 is found to be very low in artificial conditions in comparison with recurrent parent and check HD2932. Variety HD3407 (Unnat HD2932) was released for cultivation in 2023 for the central zone of India with Gazette notification S.O. 1056(E), dated 6th March, 2023. [ABSTRACT FROM AUTHOR]

Yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst), is one of the most damaging wheat diseases because of their widespread distribution and ability to produce new races that can attack cultivars that were previously resistant. In this study characterization of 48 wheat genotypes was done using 51 primers comprised of stripe rust gene-specific markers and found that WH730 and WH1142 possess the highest number of rust resistant genes while WH1263 bears the lowest Yr genes. These identified resistant Yr genes were exhibited at different frequencies. The resistant genes like, Yr6, Yr18, Yr46, Yr53 and Yr61 were absent in all the 48 studied wheat genotypes. Yr35 and Yr51 had the highest frequency (95.3 and 91.6%, respectively), while Yr16 related to xwmc177 and xwmc18 had lower frequencies (8.0 and 10.4%, respectively). Genetic diversity analysis using 61 molecular markers, and population structure analysis grouped the population into three clusters. Association study of morph-physiological traits showed that the marker xgdm160 was strongly associated with two traits i.e. days to anthesis and days to heading at P value 0.0031 and 0.0048 (P < 0.01), respectively, and showed the highest phenotypic variance (R2). These assessed markers might help develop novel genotypes with numerous genes of resistance against yellow rust races in wheat genotypes by marker-assisted pyramiding. [ABSTRACT FROM AUTHOR]

Cronartium pini and C. ribicola are rust fungi that cause destructive diseases of pines (Pinus spp.). These rusts spread via alternate hosts, among which Melampyrum spp., Veronica spp. and Impatiens spp. are important for C. pini and Ribes spp. for C. ribicola. Congeneric alternate hosts vary in their susceptibility to Cronartium rusts, but the reasons for this variation are not clear. To clarify whether internal, endophytic fungi could explain these differences, we investigated the temporal and spatial variation in fungal endophyte composition of C. pini-resistant M. pratense, V. chamaedrys and I. glandulifera, C. pini-susceptible M. sylvaticum, V. longifolia and I. balsamina, C. ribicola-resistant R. rubrum and C. ribicola-susceptible R. nigrum. In total, 2695 fungal endophytic isolates were obtained and classified into 37 morphotypes, with 1373 cultures isolated in early summer and 1322 in late summer. Fifty-two isolates were identified to species or genus level. The most common morphotypes were identified as Heterophoma sp. Some variation in the abundance of morphotypes occurred between collection sites, but the same morphotypes dominated across the sites and species. The diversity of morphotypes was higher in early September than in late June in all species and the same morphotypes dominated in both early and late season. The diversity of fungal endophytes was higher in resistant Veronica and Ribes than in susceptible congeneric species, but the results suggest that the diversity or abundance of culturable fungal endophytes does not explain the differences in the congeneric species' susceptibility to rust fungi. [ABSTRACT FROM AUTHOR]

Wheat is a major staple food worldwide yet numerous yield limiting agents affect its productivity. Stripe rust is a major culprit in this context and efforts have been made to culminate this pathogen using conventional as well as advanced innovative techniques. Transgenic technology is of significant importance in this context and numerous success stories are evident to prove its worth. In the current study, two novel genes HSFA2 and DREB2C were expressed in an elite wheat genotype Akbar, Fakhre-e-Bhakhar under constitutive CAMV35S promoter and stress inducible rd29 Promoters. The shoot cut method was used for the Agrobacterium-mediated transformation and putative transformants were selected on kanamycin 50 mg/L. The resultant transformants were tested through PCR for transgene integration whereas expression analysis was carried out through realtime qPCR. Expression of both of the aforementioned genes was found to be higher under rd29 promoter as compared with transgene(s) expression under CAMV35S promoter. In the bioassay, transgenic wheat plants demonstrated significant tolerance to stress, exhibiting only minor spotting under constitutive expression conditions. Upon exposure to stress, these plants showed exceptional resistance to stripe rust, producing large, bold grains compared to individual trait expressions and negative controls. Subsequently, the DREB2C gene was knocked out to determine if stripe rust control was specifically attributed to this gene. Following the knockout, the onset of stripe rust was comparable to that of the negative control. This led to the conclusion that pyramiding the DREB2C gene with HSFA2 through dual expression represents a novel and highly effective strategy for controlling the widespread stripe rust in wheat. This approach also offers resistance to high temperatures (above 32 °C) from the pollination stage through to maturity.

Abstract Hybrid development is one of the most promising strategies for boosting crop yields. Parental lines used to create hybrids must have good per se performance and disease resistance for developing superior hybrids. Indian wheat line HD3209 was developed by introducing the rust resistance genes Lr19/Sr25 into the background of popular wheat variety HD2932. The wheat line HD3209 carrying Lr19/Sr25 has been successfully and rapidly converted to the CMS line A-HD3209, with 96.01% background genome recovery, based on selection for agro-morphological traits, rust resistance, pollen sterility, and foreground and background analyses utilizing SSR markers. The converted CMS line A-HD3209 was completely sterile and nearly identical to the recurrent parent HD3209. Based on high per se performance and rust resistance, the study concludes that the derived CMS line A-HD3209 is promising and can be employed successfully in hybrid development.

Hybrid development is one of the most promising strategies for boosting crop yields. Parental lines used to create hybrids must have good per se performance and disease resistance for developing superior hybrids. Indian wheat line HD3209 was developed by introducing the rust resistance genes Lr19/Sr25 into the background of popular wheat variety HD2932. The wheat line HD3209 carrying Lr19/Sr25 has been successfully and rapidly converted to the CMS line A-HD3209, with 96.01% background genome recovery, based on selection for agro-morphological traits, rust resistance, pollen sterility, and foreground and background analyses utilizing SSR markers. The converted CMS line A-HD3209 was completely sterile and nearly identical to the recurrent parent HD3209. Based on high per se performance and rust resistance, the study concludes that the derived CMS line A-HD3209 is promising and can be employed successfully in hybrid development. [ABSTRACT FROM AUTHOR]

Austropuccinia psidii causes rust disease on species within the family Myrtaceae. It was first detected in Australia in 2010, with the first detection in Western Australia in 2022. While species within the genus Melaleuca from eastern Australia show variable responses to the pathogen, little is known of the response of species from Western Australia. This study established that 13 previously unscreened species of Melaleuca, including Threatened and Priority listed species that were grown from seeds sourced from Western Australian populations, were susceptible four months post-germination to the pandemic strain of the pathogen. The proportion of highly susceptible plants within a single species ranged from 2 to 94%, with several species displaying highly variable levels of resistance to A. psidii. These results highlight the importance of disease screening and may direct conservation efforts. [ABSTRACT FROM AUTHOR]

Wheat leaf rust, caused by Puccinia triticina, is reported annually in southern Russia, the main wheat production region in Russia. The effect of biotic (types of cultivar resistance) and abiotic (northern, central and southern agro‐ecological zones) factors on virulence variability of the pathogen was analysed with 43 Lr differentials. Virulence frequencies to Lr genes 1, 2c, 3, 3bg, 11, 14a, 14b, 16, 17, 18, 23, 25, 26, 33, 34, 40 and Kanr exceeded 50% in all populations. A total of 81 virulence phenotypes (based on the standard set of 20 differentials) were identified among 108 isolates. The most common phenotypes were PHSTQ, THTTR, PHTTR and TKTTR. The minimum genetic distance (the highest similarity) was established between the P. triticina populations from susceptible cv. Krasnodarskaya 99 and cv. Brigada with race‐specific resistance. P. triticina populations from the susceptible cultivar in the three agro‐ecological zones were less variable and more similar than the cultivar‐specific and natural pathogen populations. Resistance types of host cultivars seem to have a greater effect on the pathogen population than abiotic factors. Nevertheless, abiotic factors need to be considered when making decisions about deployment of wheat varieties. Our results support the paradigm of a shift in the population of an obligate parasite towards increased virulence in response to the selection pressure of cultivars with race‐specific resistance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wheat yellow (stripe) rust (Puccinia striiformis f. sp. tritici) is a dominant type of winter wheat disease. Developing new, highly productive varieties with increased immunological indicators helps to minimize the threat of rust spread. The progressive study searched the sources of resistance to the Pst populations and determined the effectiveness of Yr genes in Southeast Kazakhstan. Immunological studies ensued during 2018-2022 at the Kazakh Research Institute of Agriculture and Plant growing, Almaty, Kazakhstan. Wheat's 23 isogenic lines and 193 winter wheat genotypes attained evaluation for their reactions against an artificially infectious background of infection mixed with Pst pathotypes. Determining the intensity of virulence, the effectiveness of Yr genes, and the resistance of genotypes to the Pst population transpired in the said region. During the vegetation period, based on weather conditions, the accumulated flow of the source, and the period of infection, wheat genotypes responded differently to the rust disease manifestation. The wheat genotypes found resistant to P. striiformis and promising for selection with immunity reached nomination. Their practical use centered on increasing the immunological potential of the new winter wheat cultivars for creation and further reducing the large-scale use of fungicides and the negative environmental consequences. [ABSTRACT FROM AUTHOR]

One of the major tasks faced by wheat breeders in Uzbekistan is to enhance wheat genotypes' adaptability to soil and other environmental conditions and improve the grain quality, making the country self-sufficient in wheat grains and later becoming an exporter. Better results are achievable using the world wheat collection, including the CIMMYT germplasm. Determination of the positive correlation of physiological traits of new wheat cultivars, the importance of physiological indicators of water balance with productivity, and the vital role of these indicators in productivity level were the chief concerns. The timely study evaluated heat resilience, rust resistance, and grain yield in bread wheat genotypes. Bread wheat germplasm obtained from CIMMYT with a background of artificial infection of yellow rust incurred scrutiny for their rust resistance. A 15% incidence was detectable in seven genotypes; however, necrosis quickly formed around the symptoms of the disease in plant leaves, preventing its further development. Resistant wheat accessions, i.e., 1088, 1164 (R), 1006, and 1251 (MR), occurred as moderately resistant, showing high leaf area and grain yield. The average value of the genotypes was low, mainly due to the two rust-resistant samples, and the 1000-grain weight was 34.8 g and 34.6 g, respectively, and the grains per spike and grain yield were lower than the average. The chlorophyll a and b, total chlorophyll, carotenoid content, relative water content, flag leaf area, and production traits of the genotypes K-1088 and K-1164 gained assessment, revealed to be physiologically effective under the field conditions of Tashkent, Uzbekistan. Quantitative indicators of the productivity of these wheat genotypes indicated positive differentiation. Selection ensued for promising accessions to develop initial sources for producing the wheat genotypes with rust resistance and high grain yield under the environmental conditions of Uzbekistan. [ABSTRACT FROM AUTHOR]

The use of ML methods with the objective of selecting wheat varieties that have a higher level of rust resistance encoded in their genomes is referred to as rust selection. In addition to that, the categorization of wheat illnesses by means of machine learning It has been attempted to classify wheat diseases by making use of a wide variety of machine learning techniques. In this paper, we develop an enhanced deep learning model to classify the disease present in the wheat plant. The study uses an improved convolutional neural network to classify the plant disease using a series of layers. The simulation is conducted in terms of the accuracy, precision, recall and f-measure. The results show that the proposed method achieves higher rate of accuracy than its predecessor.

Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), has re-emerged as one of the major concerns for global wheat production since the evolution of Ug99 and other virulent pathotypes of Pgt from East Africa, Europe, Central Asia, and other regions. Host resistance is the most effective, economic, and ecofriendly approach for managing stem rust. Understanding the virulence nature, genetic diversity, origin, distribution, and evolutionary pattern of Pgt pathotypes over time and space is a prerequisite for effectively managing newly emerging Pgt isolates through host resistance. In the present study, we monitored the occurrence of stem rust of wheat in India and neighboring countries from 2016 to 2022, collected 620 single-pustule isolates of Pgt from six states of India and Nepal, analyzed them on Indian stem rust differentials, and determined their virulence phenotypes and molecular genotypes. The Ug99 type of pathotypes did not occur in India. Pathotypes 11 and 40Aweremost predominant during these years. Virulence phenotyping of these isolates identified 14 Pgt pathotypes, which were genotyped using 37 Puccinia spp.-specific polymorphic microsatellites, followed by additional phylogenetic analyses using DARwin. These analyses identified three major molecular groups, demonstrating fewer lineages, clonality, and long-distance migration of Pgt isolates in India. Fourteen of the 40 recently released Indian wheat varieties exhibited complete resistance to all 23 Pgt pathotypes at the seedling stage. Twelve Sr genes were postulated in 39 varieties based on their seedling response to Pgt pathotypes. The values of slow rusting parameters i.e. coefficient of infection, area under disease progress curve, and infection rates, assessed at adult plant stage at five geographically different locations during two crop seasons, indicated the slow rusting behavior of several varieties. Six Sr genes (Sr2, Sr57, Sr58, Sr24, Sr31, and Sr38) were identified in 24 wheat varieties using molecular markers closely linked to these genes. These findings will guide future breeding programs toward more effective management of wheat stem rust. [ABSTRACT FROM AUTHOR]

Pyramiding multiple resistant genes has been proposed as the most effective way to control wheat rust diseases globally. Identifying the most effective pyramids is challenged by the large pool of rust resistance genes and limited information about their mechanisms of resistance and interactions. Here. using a high-density genetic map, a double haploid population, and multi -rust field testing. we aimed to systematically characterize the most effective gene pyramids for rust resistance from highthe durable multi-rust resistant CIMMYT cultivar Parula. We revealed that the Parula resistance gene pyramid contains L)·34/Yr] 8/Sr57 (L, 34), Lr46/Yr29/S,·58 (L,·46). Li-27/Yr30/S,-2 (Srl). and L,-68. The efficacy. magnitude of effect. and interactions varied for the three I-lIst diseases. A subpopulation mapping approach was applied to characterize the complex interactions of the resistance genes by controlling for the effect of Li·34. Using this approach. we found that Lr34 and L}·68 have a strong additive effect for leaf rust. whereas no additive effects were observed for any rusts between L,·34 and Lr46. Lr34 combined synergistically with Sr\1 from Thatcher for stem rust. whereas the additive effect of Li·34 and Sr2 was dependent on the type of rust and environment. Two novel leaf rust quantitative trait loci (QTLE) from Parula were identified in this study. a stable QTL QLr-7BS and QL,·-5AS. which showed Lr34 dependent expression. With these findings. we propose combining two to three highthe value genes from Canadian wheat (e. g ., Srj2 from Thatcher) with a foundational multi -adult plant resistance cassette for desirable and durable resistance to ai] three rusts in Canadian wheat. [ABSTRACT FROM AUTHOR]

Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), has re-emerged as one of the major concerns for global wheat production since the evolution of Ug99 and other virulent pathotypes of Pgt from East Africa, Europe, Central Asia, and other regions. Host resistance is the most effective, economic, and eco-friendly approach for managing stem rust. Understanding the virulence nature, genetic diversity, origin, distribution, and evolutionary pattern of Pgt pathotypes over time and space is a prerequisite for effectively managing newly emerging Pgt isolates through host resistance. In the present study, we monitored the occurrence of stem rust of wheat in India and neighboring countries from 2016 to 2022, collected 620 single-pustule isolates of Pgt from six states of India and Nepal, analyzed them on Indian stem rust differentials, and determined their virulence phenotypes and molecular genotypes. The Ug99 type of pathotypes did not occur in India. Pathotypes 11 and 40A were most predominant during these years. Virulence phenotyping of these isolates identified 14 Pgt pathotypes, which were genotyped using 37 Puccinia spp.-specific polymorphic microsatellites, followed by additional phylogenetic analyses using DARwin. These analyses identified three major molecular groups, demonstrating fewer lineages, clonality, and long-distance migration of Pgt isolates in India. Fourteen of the 40 recently released Indian wheat varieties exhibited complete resistance to all 23 Pgt pathotypes at the seedling stage. Twelve Sr genes were postulated in 39 varieties based on their seedling response to Pgt pathotypes. The values of slow rusting parameters i.e. coefficient of infection, area under disease progress curve, and infection rates, assessed at adult plant stage at five geographically different locations during two crop seasons, indicated the slow rusting behavior of several varieties. Six Sr genes (Sr2, Sr57, Sr58, Sr24, Sr31, and Sr38) were identified in 24 wheat varieties using molecular markers closely linked to these genes. These findings will guide future breeding programs toward more effective management of wheat stem rust.

Leaf compounds may contribute to plant defense against Cronartium rusts. Secondary compounds are either natural or induced in leaves. We studied the variation of compounds in leaves of six alternate hosts of Cronartium pini and two of C. ribicola that represented either susceptible or resistant species to these rusts. Extracts from the plant leaves were analyzed using LC-MSMS (liquid chromatography tandem mass spectrometry) and compounds were compared between susceptible and resistant species of the same plant genera to identify significant differences between resistant and susceptible species. Also, LC–MS (liquid chromatography mass spectrometry) with external calibration was used to quantify 12 candidate compounds known from the literature. Among these compounds, the most abundant significant ones in C. pini -resistant Melampyrum pratense were chlorogenic acid and quercitrin, in Veronica chamaedrys ferulic acid, quercitrin and luteolin and in Impatiens glandulifera quercitrin, ferulic acid, kaempferol, rutin and hyperoside. In C. ribicola -resistant Ribes rubrum the most abundant significant compounds were caffeic acid, p-coumaric acid and quercitrin. Among all extracted leaf compounds, concentrations of three compounds were over 1000 times greater in rust-resistant M. pratense, three compounds in V. chamaedrys, eight compounds in I. glandulifera, and one compound in R. rubrum than in rust-susceptible species. Among the compounds, the most promising possibly linked to rust resistance were chlorogenic acid and quercitrin. [ABSTRACT FROM AUTHOR]

Thinopyrum intermedium (2n = 6x = 42, JJJSJSStSt) has been hybridized extensively with common wheat and proven to be a valuable germplasm source for improving disease resistance and yield potential of wheat. A novel disease-resistant wheat-Th. intermedium double substitution line X479, carrying 1St(1B) and 4St-4JS (4B), was identified using multi-color non-denaturing fluorescence in situ hybridization (ND-FISH). With the aim of transferring Thinopyrum-specific chromatin to wheat, a total of 573 plants from F2 and F3 progenies of X479 crossed with wheat cultivar MY11 were developed and characterized using sequential ND-FISH with multiple probes. Fifteen types of wheat-Thinopyrum translocation chromosomes were preferentially transmitted in the progenies, and the homozygous wheat-1St, and wheat-4JSL translocation lines were identified using ND-FISH, Oligo-FISH painting and CENH3 immunostaining. The wheat-4JSL translocation lines exhibited high levels of resistance to stripe rust prevalent races in field screening. The gene for stripe rust resistance was found to be physically located on FL0–0.60 of the 4JSL, using deletion lines and specific DNA markers. The new wheat-Th. intermedium translocation lines can be exploited as useful germplasms for wheat improvement. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Crop Wild Relatives (CWR) are a valuable source of genetic diversity that can be transferred to commercial crops, so their conservation will become a priority in the face of climate change. Bizarrely, in situ conserved CWR populations and the traits one might wish to preserve in them are themselves vulnerable to climate change. In this study, we used a quantitative machine learning predictive approach to project the resistance of CWR populations of lentils to a common disease, lentil rust, caused by fungus Uromyces viciae-fabae. Resistance is measured through a proxy quantitative value, DSr (Disease Severity relative), quite complex and expensive to get. Therefore, machine learning is a convenient tool to predict this magnitude using a well-curated georeferenced calibration set. Previous works have provided a binary outcome (resistant vs. non-resistant), but that approach is not fine enough to answer three practical questions: which variables are key to predict rust resistance, which CWR populations are resistant to rust under current environmental conditions, and which of them are likely to keep this trait under different climate change scenarios. We first predict rust resistance in present time for crop wild relatives that grow up inside protected areas. Then, we use the same models under future climate IPCC (Intergovernmental Panel on Climate Change) scenarios to predict future DSr values. Populations that are rust-resistant by now and under future conditions are optimal candidates for further evaluation and in situ conservation of this valuable trait. We have found that rust-resistance variation as a result of climate change is not uniform across the geographic scope of the study (the Mediterranean basin), and that candidate populations share some interesting common environmental conditions. [ABSTRACT FROM AUTHOR]

The use of ML methods with the objective of selecting wheat varieties that have a higher level of rust resistance encoded in their genomes is referred to as rust selection. In addition to that, the categorization of wheat illnesses by means of machine learning It has been attempted to classify wheat diseases by making use of a wide variety of machine learning techniques. In this paper, we develop an enhanced deep learning model to classify the disease present in the wheat plant. The study uses an improved convolutional neural network to classify the plant disease using a series of layers. The simulation is conducted in terms of the accuracy, precision, recall and f-measure. The results show that the proposed method achieves higher rate of accuracy than its predecessor. [ABSTRACT FROM AUTHOR]

Cowpea variety VBN 3 (VCP 09-013) is derived from TLS 38 x VCP 16-1. The average yield of VBN 3 is 1013 kg / ha. It is a 17.0 and 17.2 per cent yield increase over VBN 1 (866 kg/ha) and CO (CP) 7 (864 kg/ha), respectively. Duration is 75 – 80 days. It recorded the grain yield of 1148 kg/ha under the irrigated condition which is a 13.8 and 18.0 per cent yield increase over the check varieties VBN 1 (1009 kg/ha) and CO (CP) 7 (973 kg/ ha), respectively. In rainfed conditions, this variety recorded the seed yield of 1013 kg/ha. It is a 17.0 and 17.2 per cent yield increase over the check varieties VBN 1 (866 kg/ha) and CO (CP) 7 (864 kg/ha, respectively. It is having the special features of determinate plant type, synchronized maturity, multiple resistance to bean common mosaic virus, rust and anthracnose diseases. It is resistant to pod borer and pod bug. The cowpea VBN3 is having a protein content of 25.22 per cent. It recorded 100 grain weight of 13.0 g with preferable brown seed colour. It is suitable for cultivation during Rabi season (Purattasi pattam) in Tamil Nadu.

Crop Wild Relatives (CWR) are a valuable source of genetic diversity that can be transferred to commercial crops, so their conservation will become a priority in the face of climate change. Bizarrely, in situ conserved CWR populations and the traits one might wish to preserve in them are themselves vulnerable to climate change. In this study, we used a quantitative machine learning predictive approach to project the resistance of CWR populations of lentils to a common disease, lentil rust, caused by fungus Uromyces viciae-fabae. Resistance is measured through a proxy quantitative value, DSr (Disease Severity relative), quite complex and expensive to get. Therefore, machine learning is a convenient tool to predict this magnitude using a well-curated georeferenced calibration set. Previous works have provided a binary outcome (resistant vs. non-resistant), but that approach is not fine enough to answer three practical questions: which variables are key to predict rust resistance, which CWR populations are resistant to rust under current environmental conditions, and which of them are likely to keep this trait under different climate change scenarios. We first predict rust resistance in present time for crop wild relatives that grow up inside protected areas. Then, we use the same models under future climate IPCC (Intergovernmental Panel on Climate Change) scenarios to predict future DSr values. Populations that are rust-resistant by now and under future conditions are optimal candidates for further evaluation and in situ conservation of this valuable trait. We have found that rust-resistance variation as a result of climate change is not uniform across the geographic scope of the study (the Mediterranean basin), and that candidate populations share some interesting common environmental conditions.

【Objective】To identify the characteristics of rust pathogens in Hemerocallis citrina and the rust resistance of different Hemerocallis citrina varieties.【Methods】32 Hemerocallis citrina rust samples were collected from Hunan Province, Gansu Province, Shaanxi Province and Jiangsu Province. The uredinium and urediniospores of Hemerocallis citrina were observed and measured under microscope. One of the Hemerocallis citrina rust sample (yx-30) was then selected and the telia and teliospores were observed and measured. The rust resistance of 50 samples of Hemerocallis citrina germplasm resources to strain yx-26 was identified by artificial inoculation. 【Results】The uredinium of Hemerocallis citrina rust samples were mostly on the abaxial side of leaves, forming orange or yellow-brown spots with diameters of 0.28-1.96 mm. The urediniospores were almost spherical or oval, yellow and unicellular and 16.0 to 21.5 μm by 17.2 to 32.4 μm in size. The wall thickness was 1 to 3 μm. The telia of Hemerocallis citrina rust sample was dark brown and flocculent. The teliospores were oval, rod-shaped, yellow, bicellular, with constriction in the middle, and shaped like gourd. The size was 68.0 to 81.0 μm by 19.4 to 22.2 μm. The length of sporocyst stalk was 11 to 16 μm. The rust resistance to yx-26 strain of the 50 Hemerocallis citrina germplasm resources were 11 cultivars with high resistance, 21 cultivars with moderate resistance, 8 cultivars susceptible, and 10 cultivars highly susceptible.【Conclusion】The morphological characteristics of uredinium of Hemerocallis citrina were similar, while the morphological sizes of urediniospores were slightly different. The telia of Hemerocallis citrina rust sample was dark brown and flocculent. The teliospores were yellow, bicellular and shaped like gourd. The rust-resistant varieties accounted for 3/5 of the 50 samples of Hemerocallis citrina germplasm resources, which could provide reference for the planting of rust resistant varieties of Hemerocallis citrina in different regions. [ABSTRACT FROM AUTHOR]

Donalda, a hard red spring wheat (Triticum aestivum L.), was developed at the University of Alberta, Edmonton, Canada. It is an awned, hollow-stemmed cultivar with high yield potential, short in stature with good lodging tolerance. During the 3 years of testing in the Western Bread Wheat Registration tests during 2018–2020, Donalda yielded 4.3% higher than Carberry and displayed similar physiological maturity. Additional features of Donalda that paralleled the performance of Carberry included plant height, tolerance to lodging, and quality parameters related to test weight, grain weight, and grain protein content. Overall, during the 3 years of testing, Donalda was rated "resistant" to the prevalent races of leaf, stem, and stripe rusts, "moderately susceptible" to common bunt and "intermediate" to Fusarium head blight. Three years of the end-use quality evaluation indicated that Donalda met the quality guidelines for the Canada Western Red Spring wheat market class. La variété de blé roux vitreux de printemps (Triticum aestivum L.) Donalda a été créée à l'Université de l'Alberta, à Edmonton (Canada). Ce cultivar barbu de courte taille, à tige creuse, se caractérise par un rendement potentiel élevé. La variété résiste bien à la verse. Au cours des trois années qu'ont duré les essais d'homologation du blé panifiable de l'Ouest (de 2018 à 2020), Donalda a enregistré un rendement de 4,3 % plus élevé que celui de Carberry à une maturité physiologique analogue. Parmi les autres particularités de Donalda correspondant à celles de Carberry, mentionnons la taille du plant, la tolérance à la verse et les paramètres qualitatifs (poids spécifique, poids du grain et teneur en protéines du grain). Dans l'ensemble, au cours des trois années d'essai, la variété Donalda a été qualifiée de « résistante » aux races prévalentes de la rouille des feuilles, de la rouille de la tige et de la rouille jaune, de « modérément sensible » à la carie et de « moyennement résistante » à la fusariose de l'épi. L'évaluation triennale de la qualité du cultivar en regard de son usage final correspond aux valeurs de la classe marchande « blé roux de printemps de l'Ouest canadien ». [Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The polyethylene oxide segment is introduced into the epoxy resin molecular chain by reacting the polyethylene glycol containing the hydrophilic oxide segment to the epoxy group, and a nonionic hydrophilic epoxy resin emulsion is obtained. Using this emulsion with auxiliary epoxy anti-corrosion coating, waterborne anti-corrosion epoxy coating is prepared, and the effects of each auxiliary, anti-rust pigment and anti-laminar on coating properties are studied. Finally, awaterborne anti-corrosion epoxy coating with strong adhesion to the substrate, no flash rust during construction in a high humidity environment, and with excellent water resistance, medium resistance and salt spray resistance properties was prepared, which solvel the problems of easy foaming, flash rust and short anti-corrosion period of the water-based epoxy coating. [ABSTRACT FROM AUTHOR]

Leaf (Puccinia triticina; Pt) and stem (Puccinia graminis tritici; Pgt) rust are important constraints to wheat production. The leaf and stem rust resistance in the Brazilian wheat varieties 'Toropi' and 'BRS194' was evaluated using a 'Toropi/BRS194' doubled-haploid (DH) population. Parents evaluated at the seedling stage with Pt race MCJ-HN displayed infection type (IT) = ;1 for 'BRS194' and IT = 3 for 'Toropi'. The DH progeny fit a 1R:1S ratio, indicating a single Lr gene in 'BRS194' was effective against race MCJ-HN. Adult plant testing with isolate 18-96-1 CCDS found that 'BRS194' displayed an IT = 3 and 'Toropi' IT = 1−, with segregating progeny consistent for multigenic adult plant resistance in 'Toropi'. The parents and DH progeny were screened for the 1BL.1RS translocation (Sr31) with marker PE061, with 'Toropi' negative and 'BRS194' positive for the presence of Sr31. 'BRS194' was also tested against Pgt races MCCF, QTHJ, RHTS, RTHJ, TMRT, TPMK, and TTKSK at the seedling stage. BRS194 was resistant to all Pgt races, and an IT = 0 to TTKSK suggested the presence of Sr36. The presence of Sr36 in 'BRS194' was supported by the molecular marker STM773-2 (+) and 'Arthur 71' (Sr36 carrier) in its pedigree. Most resistant lines carried the Sr36-associated allele of STM773-2, while a few did not, indicating the presence of a second gene conferring resistance to TTKSK. Seedling resistance to Pgt in 'Toropi' was effective against races RHTS, MCCF, QTHJ, and RTHJ, postulated to be Sr9e. The variety 'BRS194' has effective rust-resistance genes that can be used in wheat-breeding programmes. [ABSTRACT FROM AUTHOR]

Improvement of grain protein content (GPC), loaf volume, and resistance to rusts was achieved in 11 Indian wheat cultivars that are widely grown in four different agro-climatic zones of India. This involved use of marker-assisted backcross breeding (MABB) for introgression and pyramiding of the following genes: (i) the high GPC gene Gpc-B1; (ii) HMW glutenin subunits 5 + 10 at Glu-D1 loci, and (iii) rust resistance genes, Yr36, Yr15, Lr24, and Sr24. GPC increased by 0.8 to 3.3%, although high GPC was generally associated with yield penalty. Further selection among high GPC lines allowed identification of progenies with higher GPC associated with improvement in 1000-grain weight and grain yield in the backgrounds of the following four cultivars: NI5439, UP2338, UP2382, and HUW468. The high GPC progenies (derived from NI5439) were also improved for grain quality using HMW glutenin subunits 5 + 10 at Glu-D1 loci. Similarly, progenies combining high GPC and rust resistance were obtained in the backgrounds of following five cultivars: Lok1, HD2967, PBW550, PBW621, and DBW1. The improved pre-bred lines developed following multi-institutional effort should prove a valuable source for the development of cultivars with improved nutritional quality and rust resistance in the ongoing wheat breeding programmes. [ABSTRACT FROM AUTHOR]

Crop wild relatives are species related to cultivated plants, whose populations have evolved in natural conditions and confer them valuable adaptive genetic diversity, that can be used in introgression breeding programs. Targeting four wild lentil taxa in Europe, we applied the predictive characterization approach through the filtering method to identify populations potentially tolerant to drought, salinity, and waterlogging. In parallel, the calibration method was applied to select wild populations potentially resistant to lentil rust and broomrape, using, respectively, 351 and 204 accessions evaluated for these diseases. An ecogeographic land characterization map was used to incorporate potential genetic diversity of adaptive value. We identified 13, 1, 21, and 30 populations potentially tolerant to drought, soil salinity, waterlogging, or resistance to rust, respectively. The models targeting broomrape resistance did not adjust well and thus, we were not able to select any population regarding this trait. The systematic use of predictive characterization techniques may boost the efficiency of introgression breeding programs by increasing the chances of collecting the most appropriate populations for the desired traits. However, these populations must still be experimentally tested to confirm the predictions. [ABSTRACT FROM AUTHOR]

Key message: New genomic regions for high accumulation of 10 minerals were identified. The 1B:1R and 2NS translocations enhanced concentrations of four and two minerals, respectively, in addition to disease resistance. Puccinia species, the causal agents of rust diseases of wheat, have the potential to cause total crop failures due their high evolutionary ability to acquire virulence for resistance genes deployed in commercial cultivars. Hence, the discovery of genetically diverse sources of rust resistance is essential. On the other hand, biofortification of wheat for essential nutrients, such as zinc (Zn) and iron (Fe), is also an objective in wheat improvement programs to tackle micronutrient deficiency. The development of rust-resistant and nutrient-concentrated wheat cultivars would be important for sustainable production and the fight against malnutrition. The HarvestPlus association mapping panel (HPAMP) that included nutrient-dense sources from diverse genetic backgrounds was genotyped using a 90 K Infinium SNP array and 13 markers linked with rust resistance genes. The HPAMP was used for genome-wide association mapping to identify genomic regions underpinning rust resistance and mineral accumulation. Twelve QTL for rust resistance and 53 for concentrations of 10 minerals were identified. Comparison of results from this study with the published QTL information revealed the detection of already known and some putatively new genes/QTL underpinning stripe rust and leaf rust resistance in this panel. Thirty-six new QTL for mineral concentration were identified on 17 chromosomes. Accessions carrying the 1B:1R translocation accumulated higher concentrations of Zn, Fe, Copper (Cu) and sulphur (S). The 2NS segment showed enhanced accumulation of grain Fe and Cu. Fifteen rust-resistant and biofortified accessions were identified for use as donor sources in breeding programs. [ABSTRACT FROM AUTHOR]

Thinopyrum intermedium (2n = 6x = 42, JJJSJSStSt) has been hybridized extensively with common wheat and proven to be a valuable germplasm source for improving disease resistance and yield potential of wheat. A novel disease-resistant wheat-Th. intermedium double substitution line X479, carrying 1St(1B) and 4St-4JS (4B), was identified using multi-color non-denaturing fluorescence in situ hybridization (ND-FISH). With the aim of transferring Thinopyrum-specific chromatin to wheat, a total of 573 plants from F2 and F3 progenies of X479 crossed with wheat cultivar MY11 were developed and characterized using sequential ND-FISH with multiple probes. Fifteen types of wheat-Thinopyrum translocation chromosomes were preferentially transmitted in the progenies, and the homozygous wheat-1St, and wheat-4JSL translocation lines were identified using ND-FISH, Oligo-FISH painting and CENH3 immunostaining. The wheat-4JSL translocation lines exhibited high levels of resistance to stripe rust prevalent races in field screening. The gene for stripe rust resistance was found to be physically located on FL0–0.60 of the 4JSL, using deletion lines and specific DNA markers. The new wheat-Th. intermedium translocation lines can be exploited as useful germplasms for wheat improvement.

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The present study involved incorporation of two major QTLs for pre-harvest sprouting tolerance (PHST) in an Indian wheat cultivar named Lok1, which happens to be PHS susceptible. For transfer of two QTLs, two independent programmes with two different donors (AUS1408, CN19055) were utilized. The recipient cv. Lok1 was crossed with each of the two donors, followed by a number of backcrosses. Each backcross progeny was subjected to foreground and background selections. KASP assay was also used for confirming the presence of PHST QTL. In one case, PHST QTL was later also pyramided with a gene for high grain protein content (Gpc-B1) and a gene for leaf rust resistance (Lr24). The MAS derived lines were screened for PHS using simulated rain chambers leading to selection of 10 PHST lines. Four of these advanced lines carried all the three QTL/genes and exhibited high level of PHST (PHS score 2–3) associated with significant improvement in GPC and resistance against leaf rust. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is an important cereal crop globally as well as in India and yield improvement programs encounter a strong impediment from ever-evolving rust pathogens. Hence, durable rust resistance is always a priority trait for wheat breeders globally. Grain weight, represented as thousand grain weight (TGW), is the most important yield-contributing trait in wheat. In the present study high TGW has been transferred into two elite Indian wheat cultivars PBW343 and PBW550 from a high TGW genotype, Rye selection 111, selected from local germplasm. In the background of PBW343 and PBW550, an increase in TGW upto 27.34 and 18% was observed, respectively (with respect to recipient parents), through conventional backcross breeding with phenotypic selections in 3 years replicated RBD trials. Resistance to leaf rust and stripe rust has been incorporated in the high TGW version of PBW550 through marker assisted pyramiding of stripe rust resistance gene Yr15 using marker Xuhw302, and a pair of linked leaf rust and stripe rust resistance genes Lr57-Yr40 using marker Ta5DS-2754099_kasp23. Improved versions of PBW550 with increased TGW ranging from 45.0 to 46.2 g (up to a 9% increase) and stacked genes for stripe and leaf rust resistance have been developed. This study serves as proof of utilizing conventional breeding and phenotypic selection combined with modern marker assisted selection in improvement of important wheat cultivars as a symbiont of conventional and moderan techniques.

Rust diseases (leaf, stripe and stem rust) of wheat constitute a major threat to wheat production worldwide including Romania. Durable rusts resistance is a significant component for food security and combining/pyramiding of rusts resistance genes into new wheat cultivars is the main strategy to increase durability of resistance. This work reports a gene pyramiding wheat breeding approach assisted by DNA markers used to develop new breeding rust resistant lines. In this study 60 breeding lines were analyzed for the presence of resistant haplotypes Lr34/Yr18//Sr57/Ltn1, Lr37/Yr17/Sr38, Lr46/ Yr29//Sr58/Ltn2 and Lr68/Ltn4 using DNA markers. The results showed that 17 wheat breeding lines carried the Lr genes pyramided in homozygous or heterozygous state, other 13 lines carried only one Lr gene, while 30 breeding lines had no resistant alleles Lr, from the analyzed Lr genes. In homozygous state we found the following combinations: Lr34+Lr37 (one line); Lr37+Lr46 (six lines), Lr37+Lr68 (one line) and only one line, GCO2- 12, with three resistant alleles in homozygous state Lr34+Lr37+Lr46. This line also carried heterozygous alleles for Lr68 gene, so, this result suggest that it is possible to obtain a line with four resistance Lr alleles (Lr34+Lr37+Lr46+Lr68) using markers-assisted selection (MAS). The wheat breeding lines with two, three or four resistance alleles were identified in the F5 generation and will be used to accelerate the rust resistance breeding program at NARDI Fundulea. Furthermore, this study proves the value of MAS breeding strategy, for the acceleration of wheat rusts resistance cultivars development. [ABSTRACT FROM AUTHOR]

Rusts are a group of major diseases that have an adverse effect on crop production. Those targeting wheat are found in three principal forms: leaf, stripe, and stem rust. Leaf rust causes foliar disease in wheat; in Egypt, this causes a significant annual yield loss. The deployment of resistant genotypes has proved to be a relatively economical and environmentally sustainable method of controlling the disease. Gene pyramiding can be performed using traditional breeding techniques. Additionally, pathotypes can be introduced to examine specific leaf rust genes, or the breeder may conduct more complex breeding methods. Indirect selection via DNA markers linked to resistance genes may facilitate the transfer of targeted genes, either individually or in combination, even in a disease-free environment. The use of selective crosses to counter virulent races of leaf, stripe, and stem rust has resulted in the transfer of several resistance genes into new wheat germplasm from cultivated or wild species. Quantitative trait locus (QTL) technology has been adopted in a wide variety of novel approaches and is becoming increasingly recognized in wheat breeding. Moreover, several researchers have reported the transference of leaf and stripe rust resistance genes into susceptible wheat cultivars. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is an important cereal crop globally as well as in India and yield improvement programs encounter a strong impediment from ever-evolving rust pathogens. Hence, durable rust resistance is always a priority trait for wheat breeders globally. Grain weight, represented as thousand grain weight (TGW), is the most important yield-contributing trait in wheat. In the present study high TGW has been transferred into two elite Indian wheat cultivars PBW343 and PBW550 from a high TGW genotype, Rye selection 111, selected from local germplasm. In the background of PBW343 and PBW550, an increase in TGW upto 27.34 and 18% was observed, respectively (with respect to recipient parents), through conventional backcross breeding with phenotypic selections in 3 years replicated RBD trials. Resistance to leaf rust and stripe rust has been incorporated in the high TGW version of PBW550 through marker assisted pyramiding of stripe rust resistance gene Yr15 using marker Xuhw302 , and a pair of linked leaf rust and stripe rust resistance genes Lr57-Yr40 using marker Ta5DS-2754099_kasp23. Improved versions of PBW550 with increased TGW ranging from 45.0 to 46.2 g (up to a 9% increase) and stacked genes for stripe and leaf rust resistance have been developed. This study serves as proof of utilizing conventional breeding and phenotypic selection combined with modern marker assisted selection in improvement of important wheat cultivars as a symbiont of conventional and moderan techniques. [ABSTRACT FROM AUTHOR]

The study was aimed to develop rust resistant genotypes with genome of prominent wheat variety HS240 by pyramiding of linked leaf rust and stem rust resistance genes Lr19 and Sr25 with stripe rust resistance gene Yr15. The genotypes FLW13 and FLW20 were used as gene donors for transfer of Yr15 and Lr19/Sr25, respectively. The molecular markers scs265, wmc221, PSY1-E1, and Gb linked to Lr19/Sr25 and barc8 and gwm11 linked to Yr15 were used for foreground selection. Background selection, involving 58 simple sequence repeat (SSR) markers polymorphic between HS240 and FLW20; 72 between HS240 and FLW13 was carried out to recover the genome of HS240 in advanced bulks derived from a cross HS240*2/FLW20//HS240*2/FLW13. The SSR based genome recovery in selected advanced breeding lines, WBM3682 and WBM3684 was 90.8% and 93.3%, respectively. The 35 K SNP array based analysis of genomic regions of HS240 also substantiated the results of genomic recovery estimated through SSR markers. The selected line WBM3682 recorded average grain yield of 25.7q/ha and showed its superiority over parental check HS240 under rainfed situations. This study has led to development of rust resistant wheat carrying genome of HS240. [ABSTRACT FROM AUTHOR]

Development of durable resistance to soybean rust (SBR) is challenging due to the pathogenic diversity of Phakopsora pachyrhizi populations. The objective of this research was to investigate and confirm the genomic locations of Rpp genes in the Ugandan line UG‐5 that confer resistance to different SBR pathotypes. Bulked segregant analysis revealed two genomic regions associated with resistance in a cross with rust‐susceptible 'Williams 82'. Composite interval mapping in the F2 and F2:3 populations had a LOD score of 48.7 in a region 0.38 cM away from the estimated location of the Rpp1 locus on chromosome (Chr.) 18. An approximately 23‐Kbp interval spanning the Rpp1 locus was flanked by SNP markers ss715632313 and ss715632318. Another interval was identified at the Rpp3 locus on Chr. 6 between markers Satt100 and ss715594488 (2.4 cM) in the F2 population and between Satt100 and ss715594874 (4.3 cM) in the F2:3 population, with a maximum LOD score of 25.6. UG‐5 was thus confirmed to have SBR resistance genes at the Rpp1 and Rpp3 loci that can be pyramided into other elite cultivars. [ABSTRACT FROM AUTHOR]

In common wheat, genes/QTL for a number of traits including grain quality and resistance against all the three rusts were pyramided in the background of an erstwhile elite Indian wheat cv. PBW343. For this purpose, two improved lines (P1 and P2) each in the background of PBW343 were crossed; these two lines were earlier developed using marker-assisted selection (MAS). The genes carried by line "P1" included Yr70/Lr76 + Lr37/Yr17/Sr38, and the genes carried by line "P2" included Gpc-B1/Yr36+QPhs.ccsu-3A.1+QGw.ccsu-1A.3+Lr24/Sr24+Glu-A1-1/Glu-A1-2. Following foreground MAS in F2 and F3 and SDS-PAGE analysis in F5, 23 lines were selected, each carrying all the genes/QTL for grain quality and resistance to three rusts in homozygous condition. Eleven of the selected lines had relatively higher grain protein content (along with one or more other traits) and were also resistant to five pathotypes of Puccinia triticina (Pt), seven pathotypes of Puccinia graminis f. sp. tritici (Pgt), and two pathotypes (78S84 and 47S103) of Puccinia striiformis f. sp. tritici (Pst) that occur in major wheat-growing areas of India. One line (CCSU-7) out of these 11 selected lines had significantly higher grain yield as well as grain protein content compared with check cv. PBW343, which should prove useful in future wheat breeding programs for improving not only the grain quality but also the durability of resistance against all three rusts. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)