scholarly journals First detailed report on Puccinia graminis f. sp. avenae virulence structure and Pg resistance genes effective in Poland

2021 ◽  
Author(s):  
Sylwia Sowa ◽  
Joanna Toporowska ◽  
Aneta Koroluk ◽  
Edyta Paczos-Grzęda
Keyword(s):  
Resistance Genes ◽  
High Frequency ◽  
Specific Resistance ◽  
Puccinia Graminis ◽  
Eastern European ◽  
Yield Losses ◽  
Detailed Report ◽  
Breeding Programmes ◽  
Significant Yield ◽  
Growing Conditions

AbstractOccurrence of stem rust, caused by Puccinia graminis f. sp. avenae, on oat fields in Europe may lead to significant yield losses. The last P. graminis virulence research in this region had been carried out in the years 1988 to 1996, therefore the aim of this study was the update of pathogen’s virulence structure as well as the evaluation of Pg race-specific resistance genes and their potential for use in practical breeding in central and eastern European growing conditions. To assess the pathotype structure of P. graminis in Poland and evaluate the potential of Pg resistance genes, 148 isolates were collected during 2017–2020. Their virulence structure was determined in laboratory conditions on 12 Pg differentials as well as oat lines ‘Pg-a’, ‘Alpha’, ‘Omega’ and ‘Wisconsin X-1588-2’. In total, 57 pathotypes were detected, of which the most dominant race was SSK. High frequency was also recorded for TSK, TKK and TTK. Puccinia graminis isolates were able to overcome from 5 to 11 Pg resistance genes with an average virulence complexity of 8.6. There was no isolate virulent to Pg12, ‘Pg-a’, ‘Alpha’ and ‘Omega’, hence these genes can be used in the breeding programmes. Gene Pg10 was also relatively effective, overcome by 33 out of 148 P. graminis isolates. The virulence profile observed may be representative of eastern Europe and beyond.

Virulence structure of Puccinia coronata f. sp. avenae and effectiveness of Pc resistance genes in Poland during 2017-2019

2020 ◽  
Author(s):  
Sylwia Sowa ◽  
Edyta Paczos-Grzeda
Keyword(s):  
Resistance Genes ◽  
Specific Resistance ◽  
Resistance Breeding ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
Yield Losses ◽  
Development Of Resistance ◽  
Significant Yield ◽  
Rust Resistance Genes ◽  
High Diversity

Crown rust caused by Puccinia coronata f. sp. avenae is one of the most destructive diseases of oat, regularly occurring worldwide and leading to significant yield losses. This paper characterises the pathotype structure of P. coronata in Poland and evaluates the potential of crown rust race-specific resistance genes for use in practical breeding conditions in this region. Four hundred sixty-six isolates were derived from four locations of intensive oat breeding in Poland during 2017-2019, representing P. coronata populations from West, East, South and Central Poland. Their virulence structure was determined on 35 Pc differential lines in laboratory conditions. In each year and location, high pathotype diversity was observed. In total, 347 (75%) pathotypes were detected. On average P. coronata isolates collected in 2017 and 2018 were virulent to 11% of the oat differentials. In 2019 isolates from East and South of Poland were able to overcome 18.3% and 18.5% of the oat differentials, respectively. There was no isolate virulent against Pc51, Pc52 and Pc91 crown rust resistance genes. P. coronata isolates displayed modest virulence levels, high diversity, and no prevailing pathotype. The information provided here may be helpful for development of resistance breeding strategies, as well as in choosing the most effective major genes for pyramiding into cultivars.

scholarly journals Vulnerability of Barley to African Pathotypes of Puccinia graminis f. sp. tritici and Sources of Resistance

2017 ◽  
Vol 107 (8) ◽  
pp. 950-962 ◽  
Author(s):  
B. J. Steffenson ◽  
A. J. Case ◽  
Z. A. Pretorius ◽  
V. Coetzee ◽  
F. J. Kloppers ◽  
...  
Keyword(s):  
Resistance Genes ◽  
High Frequency ◽  
Wild Barley ◽  
Durable Resistance ◽  
Global Scale ◽  
Puccinia Graminis ◽  
Wild Progenitor ◽  
Sources Of Resistance ◽  
Cultivated Barley ◽  
Moderately Resistant

The emergence of widely virulent pathotypes (e.g., TTKSK in the Ug99 race group) of the stem rust pathogen (Puccinia graminis f. sp. tritici) in Africa threatens wheat production on a global scale. Although intensive research efforts have been advanced to address this threat in wheat, few studies have been conducted on barley, even though pathotypes such as TTKSK are known to attack the crop. The main objectives of this study were to assess the vulnerability of barley to pathotype TTKSK and identify possible sources of resistance. From seedling evaluations of more than 1,924 diverse cultivated barley accessions to pathotype TTKSK, more than 95% (1,844) were found susceptible. A similar high frequency (910 of 934 = 97.4%) of susceptibility was found for the wild progenitor (Hordeum vulgare subsp. spontaneum) of cultivated barley. Additionally, 55 barley lines with characterized or putative introgressions from various wild Hordeum spp. were also tested against pathotype TTKSK but none was found resistant. In total, more than 96% of the 2,913 Hordeum accessions tested were susceptible as seedlings, indicating the extreme vulnerability of the crop to the African pathotypes of P. graminis f. sp. tritici. In total, 32 (1.7% of accessions evaluated) and 13 (1.4%) cultivated and wild barley accessions, respectively, exhibited consistently highly resistant to moderately resistant reactions across all experiments. Molecular assays were conducted on these resistant accessions to determine whether they carried rpg4/Rpg5, the only gene complex known to be highly effective against pathotype TTKSK in barley. Twelve of the 32 (37.5%) resistant cultivated accessions and 11 of the 13 (84.6%) resistant wild barley accessions tested positive for a functional Rpg5 gene, highlighting the narrow genetic base of resistance in Hordeum spp. Other resistant accessions lacking the rpg4/Rpg5 complex were discovered in the evaluated germplasm and may possess useful resistance genes. Combining rpg4/Rpg5 with resistance genes from these other sources should provide more durable resistance against the array of different virulence types in the Ug99 race group.

scholarly journals Comparative Genomics Used to Predict Virulence Factors and Metabolic Genes among Monilinia Species

2021 ◽  
Vol 7 (6) ◽  
pp. 464
Author(s):  
Marina Marcet-Houben ◽  
Maria Villarino ◽  
Laura Vilanova ◽  
Antonieta De Cal ◽  
Jan A. L. van Kan ◽  
...  
Keyword(s):  
Brown Rot ◽  
Weather Conditions ◽  
Genomic Variation ◽  
Disease Development ◽  
Stone Fruits ◽  
Yield Losses ◽  
Future Studies ◽  
Metabolic Genes ◽  
Pome Fruits ◽  
Significant Yield

Brown rot, caused by Monilinia spp., is among the most important diseases in stone fruits, and some pome fruits (mainly apples). This disease is responsible for significant yield losses, particularly in stone fruits, when weather conditions favorable for disease development appear. To achieve future sustainable strategies to control brown rot on fruit, one potential approach will be to characterize genomic variation among Monilinia spp. to define, among others, the capacity to infect fruit in this genus. In the present work, we performed genomic and phylogenomic comparisons of five Monilinia species and inferred differences in numbers of secreted proteins, including CAZy proteins and other proteins important for virulence. Duplications specific to Monilinia were sparse and, overall, more genes have been lost than gained. Among Monilinia spp., low variability in the CAZome was observed. Interestingly, we identified several secondary metabolism clusters based on similarity to known clusters, and among them was a cluster with homology to pyriculol that could be responsible for the synthesis of chloromonilicin. Furthermore, we compared sequences of all strains available from NCBI of these species to assess their MAT loci and heterokaryon compatibility systems. Our comparative analyses provide the basis for future studies into understanding how these genomic differences underlie common or differential abilities to interact with the host plant.

scholarly journals Seedling Stage Resistance of Iranian Bread Wheat Germplasm to Race Ug99 of Puccinia graminis f. sp. tritici

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Mohsen Mohammadi ◽  
Davoud Torkamaneh ◽  
Mehran Patpour
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Wheat Germplasm ◽  
Stem Rust Resistance Genes ◽  
Rust Resistance Genes

Following emergence of Ug99, the new virulent race of Puccinia graminis f. sp. tritici in Africa, a global effort for identification and utilization of new sources of Ug99-resistant germplasm has been undertaken. In this study, we conducted replicated experiments to evaluate the resistance of Iranian wheat germplasm to the TTKSK lineage of the Ug99 race of P. graminis f. sp. tritici. We also evaluated for presence of stem rust resistance genes (i.e., Sr2, Sr24, Sr26, Sr38, Sr39, Sr31, and Sr1RSAmigo) in wheat cultivars and breeding lines widely cultivated in Iran. Our phenotyping data revealed high levels of susceptibility to Ug99 in Iranian bread wheat germplasm. Our genotyping data revealed that Iranian cultivars do not carry Sr24, Sr26, or Sr1RSAmigo. Only a few salt-tolerant cultivars and breeding lines tested positively for Sr2, Sr31, Sr38, or Sr39 markers. In conclusion, the genetic basis for resistance to Ug99 in Iranian wheat cultivars was found to be vulnerable. Acquiring knowledge about existing resistance genes and haplotypes in wheat cultivars and breeding lines will help breeders, cereal pathologists, and policy makers to select and pyramid effective stem rust resistance genes.

scholarly journals Inheritance of Antibiosis Resistance to the Dectes Stem Borer, Dectes texanus, in Soybean PI165673

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 738
Author(s):  
Lina M. Aguirre-Rojas ◽  
Lawrent L. Buschman ◽  
Brian McCornack ◽  
William T. Schapaugh ◽  
Erin D. Scully ◽  
...  
Keyword(s):  
North America ◽  
Larval Stage ◽  
Stem Borer ◽  
Plant Introduction ◽  
Lower Number ◽  
Soybean Plant ◽  
Yield Losses ◽  
First Instar ◽  
Significant Yield ◽  
Antibiosis Resistance

Dectes texanus larvae girdles the stems of soybean and cultivated sunflowers causing significant yield losses in North America. The soybean Plant Introduction (PI) 165673 exhibits antibiosis resistance to the larval stage. The objectives of this study were: (1) to determine the inheritance of D. texanus resistance in PI165673; (2) evaluate PI165673 antibiosis resistance before 21 d post infestation; (3) evaluate girdling damage in PI16563 at the end of the season. K07-1544/PI165673 F2 and F2:3 populations were tested for resistance to D. texanus in 2011 and 2012, and PI165673 antibiosis resistance and girdling damage were evaluated in 2014. Segregation for resistance to D. texanus and heritability estimates in the F2 and F2:3 populations indicated that resistance was controlled by two genes with dominant and recessive epistasis. Antibiosis evaluations indicated: (1) PI165673 contained lower number of larvae and eggs relative to the number of oviposition punctures at 15 d post infestation; (2) the proportion of first-instar larvae was higher in PI165673 at 15 d post infestation; (3) larvae reach the sixth-instar stage in PI165673. None of the PI165673 plants were girdled at the end of the season. Identification of additional sources of D. texanus resistance is required to impair larval development in the stem.

Fungicide efficacy on tar spot and yield of corn in the Midwestern United States

2022 ◽  
Author(s):  
Darcy E. P. Telenko ◽  
Martin I. Chilvers ◽  
Adam Byrne ◽  
Jill Check ◽  
Camila Rocco Da Silva ◽  
...  
Keyword(s):  
United States ◽  
Growth Stage ◽  
Field Trials ◽  
Corn Belt ◽  
Yield Losses ◽  
Single Application ◽  
Midwestern United States ◽  
Tar Spot ◽  
Significant Yield ◽  
Foliar Fungicide

Tar spot of corn caused by Phyllachora maydis has recently led to significant yield losses in the eastern corn belt of the Midwestern United States. Foliar fungicides containing quinone outside inhibitors(QoI), demethylation inhibitors(DMI), and succinate dehydrogenase inhibitors(SDHI) are commonly used to manage foliar diseases in corn. To mitigate the losses from tar spot thirteen foliar fungicides containing single or multiple modes of action (MOA/FRAC groups) were applied at their recommended rates in a single application at the standard tassel/silk growth stage timing to evaluate their efficacy against tar spot in a total of eight field trials in Illinois, Indiana, Michigan, and Wisconsin during 2019 and 2020. The single MOA fungicides included either a QoI or DMI. The dual MOA fungicides included a DMI with either a QoI or SDHI, and fungicides containing three MOAs included a QoI, DMI, and SDHI. Tar spot severity estimated as the percentage of leaf area covered by P. maydis stroma of the non-treated control at dent growth stage ranged from 1.6 to 23.3% on the ear leaf. Averaged across eight field trials all foliar fungicide treatments reduced tar spot severity, but only prothioconazole+trifloxystrobin, mefentrifluconazole+pyraclostrobin+fluxapyroxad, and mefentrifluconazole+pyraclostrobin significantly increased yield over the non-treated control. When comparing fungicide treatments by the number of MOAs foliar fungicide products that had two or three MOAs decreased tar spot severity over not treating and products with one MOA. The fungicide group that contained all three MOAs significantly increased yield over not treating with a fungicide or using a single MOA.

scholarly journals Identification of Race-Specific Resistance in North American Vitis spp. Limiting Erysiphe necator Hyphal Growth

2012 ◽  
Vol 102 (1) ◽  
pp. 83-93 ◽  
Author(s):  
David W. Ramming ◽  
Franka Gabler ◽  
Joseph L. Smilanick ◽  
Dennis A. Margosan ◽  
Molly Cadle-Davidson ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Specific Resistance ◽  
Hyphal Growth ◽  
Resistance Mechanisms ◽  
Hybrid Breeding ◽  
Erysiphe Necator ◽  
Vitis Rotundifolia ◽  
Resistance Sources

Race-specific resistance against powdery mildews is well documented in small grains but, in other crops such as grapevine, controlled analysis of host–pathogen interactions on resistant plants is uncommon. In the current study, we attempted to confirm powdery mildew resistance phenotypes through vineyard, greenhouse, and in vitro inoculations for test cross-mapping populations for two resistance sources: (i) a complex hybrid breeding line, ‘Bloodworth 81-107-11', of at least Vitis rotundifolia, V. vinifera, V. berlandieri, V. rupestris, V. labrusca, and V. aestivalis background; and (ii) Vitis hybrid ‘Tamiami’ of V. aestivalis and V. vinifera origin. Statistical analysis of vineyard resistance data suggested the segregation of two and three race-specific resistance genes from the two sources, respectively. However, in each population, some resistant progeny were susceptible in greenhouse or in vitro screens, which suggested the presence of Erysiphe necator isolates virulent on progeny segregating for one or more resistance genes. Controlled inoculation of resistant and susceptible progeny with a diverse set of E. necator isolates clearly demonstrated the presence of fungal races differentially interacting with race-specific resistance genes, providing proof of race specificity in the grape powdery mildew pathosystem. Consistent with known race-specific resistance mechanisms, both resistance sources were characterized by programmed cell death of host epidermal cells under appressoria, which arrested or slowed hyphal growth; this response was also accompanied by collapse of conidia, germ tubes, appressoria, and secondary hyphae. The observation of prevalent isolates virulent on progeny with multiple race-specific resistance genes before resistance gene deployment has implications for grape breeding strategies. We suggest that grape breeders should characterize the mechanisms of resistance and pyramid multiple resistance genes with different mechanisms for improved durability.

scholarly journals Response of Sensitive and Resistant Snap Bean Genotypes to Nighttime Ozone Concentration

2020 ◽  
Vol 145 (6) ◽  
pp. 331-339
Author(s):  
Kirsten L. Lloyd ◽  
Donald D. Davis ◽  
Richard P. Marini ◽  
Dennis R. Decoteau
Keyword(s):  
Leaf Age ◽  
Acute Injury ◽  
Yield Response ◽  
Yield Losses ◽  
Foliar Injury ◽  
Snap Bean ◽  
Stirred Tank Reactors ◽  
First Results ◽  
Significant Yield ◽  
The Impact

Effects of nighttime (2000 to 0700 hr) O3 on the pod mass of sensitive (S156) and resistant (R123) snap bean (Phaseolus vulgaris) genotypes were assessed using continuous stirred tank reactors located within a greenhouse. Two concentration-response relationship trials were designed to evaluate yield response to nighttime O3 exposure (10 to 265 ppb) in combination with daytime exposure at background levels (44 and 62 ppb). Three replicated trials tested the impact of nighttime O3 treatment at means of 145, 144, and 145 ppb on yields. In addition, stomatal conductance (gS) measurements documented diurnal variations and assessed the effects of genotype and leaf age. During the concentration-response experiments, pod mass had a significant linear relationship with the nighttime O3 concentration across genotypes. Yield losses of 15% and 50% occurred at nighttime exposure levels of ≈45 and 145 ppb, respectively, for S156, whereas R123 yields decreased by 15% at ≈150 ppb. At low nighttime O3 levels of ≈100 ppb, R123 yields initially increased up to 116% of the treatment that received no added nighttime O3, suggesting a potential hormesis effect for R123, but not for S156. Results from replicated trials revealed significant yield losses in both genotypes following combined day and night exposure, whereas night-only exposure caused significant decreases only for S156. The gS rates ranged from less than 100 mmol·m−2·s−1 in the evening to midday levels more than 1000 mmol·m−2·s−1. At sunrise and sunset, S156 had significantly higher gS rates than R123, suggesting a greater potential O3 flux into leaves. Across genotypes, younger rapidly growing leaves had higher gS rates than mature fully expanded leaves when evaluated at four different times during the day. Although these were long-term trials, gS measurements and observations of foliar injury development suggest that acute injury, occurring at approximately the time of sunrise, also may have contributed to yield losses. To our knowledge, these are the first results to confirm that the relative O3 sensitivity of the S156/R123 genotypes is valid for nighttime exposure.

scholarly journals A BRIEF REVIEW FOR IDENTIFICATION AND DETECTION OF POTATO VIRUSES

2016 ◽  
Vol 1 (1) ◽  
pp. 33 ◽  
Author(s):  
Madiha Urooj ◽  
Uzma Arif ◽  
Anisa Intikhab
Keyword(s):  
Potato Crop ◽  
Abiotic Factors ◽  
Review Article ◽  
Pivotal Role ◽  
Yield Reduction ◽  
Human Consumption ◽  
Yield Losses ◽  
Food Crop ◽  
Potato Viruses ◽  
Significant Yield

Potato is ranked fourth among the food crop and fifth for human consumption. It provides more yield and calories production as compare to cereals. Fungal, viral, viroid, bacteria, nematode, phytoplasmas and abiotic factors play a pivotal role for yield reduction of potato crop. Viruses known to infect potato in Pakistan include PVA, PVM, PVS, PVX, PVY, PLRV and PMTV. Increasing incidence of PVX and PVY in main potato growing areas of Pakistan is getting an alarming position and PLRV has caused significant yield losses. Present review article demonstrate different techniques for diagnostics of major potato viruses.

scholarly journals Weed Mapping in Vineyards Using RGB-D Perception

2021 ◽  
Vol 9 (1) ◽  
pp. 30
Author(s):  
Dimitrios Kateris ◽  
Damianos Kalaitzidis ◽  
Vasileios Moysiadis ◽  
Aristotelis C. Tagarakis ◽  
Dionysis Bochtis
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Field Conditions ◽  
Yield Losses ◽  
Weed Mapping ◽  
Significant Yield ◽  
Different Levels

Weed management is one of the major challenges in viticulture, as long as weeds can cause significant yield losses and severe competition to the cultivations. In this direction, the development of an automated procedure for weed monitoring will provide useful data for understanding their management practices. In this work, a new image-based technique was developed in order to provide maps based on weeds’ height at the inter-row path of the vineyards. The developed algorithms were tested in many datasets from vineyards with different levels of weed development. The results show that the proposed technique gives promising results in various field conditions.

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