scholarly journals Pre-breeding for disease resistance in wheat – the stagonospora nodorum blotch example

2012 ◽  
Vol 33 (1) ◽  
pp. 6
Author(s):  
Manisha Shankar ◽  
Michael Francki ◽  
Rob Loughman
Keyword(s):  
Molecular Markers ◽  
Disease Resistance ◽  
Adult Plant Resistance ◽  
Stagonospora Nodorum ◽  
Genetic Enhancement ◽  
Adult Plant ◽  
Genetic Knowledge ◽  
Breeding Programs ◽  
Stagonospora Nodorum Blotch ◽  
Resistance Expression

?Pre-breeding? is an alternative term used for ?genetic enhancement?, and in recent times it has become an essential, planned part of all plant breeding activities. The main objectives of pre-breeding for disease resistance are to increase the efficiency of breeding by providing breeding programs with (i) molecular markers linked to effective disease resistance genes, (ii) improved germplasm and associated genetic knowledge that enhance resistance expression and diversity, (iii) improved parental stocks which can be readily utilised within breeding programs and (iv) improved selection methodologies. This article discusses the various activities involved in a pre-breeding program targeting disease resistance with recent outcomes of genetic enhancement for adult plant resistance to stagonospora nodorum blotch in wheat.

scholarly journals Adult Plant Resistance in Maize to Northern Leaf Spot Is a Feature of Partial Loss-of-function Alleles ofHm1

2018 ◽  
Author(s):  
Sandeep R. Marla ◽  
Kevin Chu ◽  
Satya Chintamanani ◽  
Dilbag Multani ◽  
Antje Klempien ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Resistance Genes ◽  
Plant Resistance ◽  
Leaf Spot ◽  
Adult Plant Resistance ◽  
Plant Diseases ◽  
Adult Plant ◽  
Hc Toxin ◽  
Differential Transcription

ABSTRACTAdult plant resistance (APR) is an enigmatic phenomenon in which resistance genes are ineffective in protecting seedlings from disease but confer robust resistance at maturity. Maize has multiple cases in which genes confer APR to northern leaf spot, a lethal disease caused byCochliobolus carbonumrace 1 (CCR1). The first identified case of APR in maize is encoded by a hypomorphic allele,Hm1A, at thehm1locus. In contrast, wild type alleles ofhm1provide complete protection at all developmental stages and in every part of the maize plant.Hm1encodes an NADPH-dependent reductase, which inactivates HC-toxin, a key virulence effector of CCR1. Cloning and characterization ofHm1Aruled out differential transcription or translation for its APR phenotype and identified an amino acid substitution that reduced HC-toxin reductase (HCTR) activity. The possibility of a causal relationship between the weak nature ofHm1Aand its APR phenotype was confirmed by the generation of two new APR alleles ofHm1by mutagenesis. The HCTRs encoded by these new APR alleles had undergone relatively conservative missense changes that partially reduced their enzymatic activity similar to HM1A. No difference in accumulation of HCTR was observed between adult and juvenile plants, suggesting that the susceptibility of seedlings derives from a greater need for HCTR activity, not reduced accumulation of the gene product. Conditions and treatments that altered the photosynthetic output of the host had a dramatic effect on resistance imparted by the APR alleles, demonstrating a link between the energetic or metabolic status of the host and disease resistance affected by HC-toxin catabolism by the APR alleles of HCTR.AUTHOR SUMMARYAdult plant resistance (APR) is a phenomenon in which disease resistance genes are able to confer resistance at the adult stages of the plant but somehow fail to do so at the seedling stages. Despite the widespread occurrence of APR in various plant diseases, the mechanism underlying this trait remains obscure. It is not due to the differential transcription of these genes, and here we show that it is also not due to the differential translation or activity of the APR alleles of the maizehm1gene at different stages of development. Using a combination of molecular genetics, biochemistry and physiology, we present multiple lines of evidence that demonstrate that APR is a feature or symptom of weak forms of resistance. While the mature parts of the plant are metabolically robust enough to manifest resistance, seedling tissues are not, leaving them vulnerable to disease. Growth conditions that compromise the photosynthetic output of the plant further deteriorate the ability of the seedlings to protect themselves from pathogens.One sentence summaryCharacterization of adult plant resistance in the maize-CCR1 pathosystem reveals a causal link between weak resistance and APR.

scholarly journals Breeding adult plant resistance to stripe rust in spring bread wheat germplasm adapted to Sichuan Province of China

2011 ◽  
Vol 47 (Special Issue) ◽  
pp. S165-S168 ◽  
Author(s):  
E.N. Yang ◽  
Y.C. Zou ◽  
W.Y. Yang ◽  
Y.L. Tang ◽  
Z.H. He ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Plant Protection ◽  
Stripe Rust Resistance ◽  
Adult Plant ◽  
Spring Bread Wheat ◽  
Breeding Programs ◽  
Wheat Germplasm ◽  
Research Institute

Sichuan is an important wheat producing province of China where severe stripe rust epidemics occur annually. Developing high-yielding wheat varieties with good and stable stripe rust resistance is a foremost breeding objective of all breeding programs. Because minor gene based adult-plant resistance (APR) is considered durable, a shuttle breeding program between Sichuan Academy of Agricultural Sciences (SAAS) and CIMMYT was initiated in 2000 to transfer APR identified in CIMMYT wheats to wheat germplasm adapted in Sichuan. During 2007–2009, a total of 669 advanced generation lines obtained from this shuttle breeding effort were provided to the Plant Protection Research Institute, SAAS for official multi-environment stripe rust tests, and 231 elite lines were characterized for yield performance by the agronomists at the Crop Research Institute, SAAS. Between 11–39% lines were highly resistant depending on the year of testing and 17 (7.3%) lines had 5% or higher yields than the check mean. The adapted resistant lines are being used by various breeding programs to enhance resistance diversity, and three lines are being tested in National or Provincial Yield Trials for possible releases.

scholarly journals Mining and genomic characterization of resistance to tan spot, Stagonospora nodorum blotch (SNB), and Fusarium head blight in Watkins core collection of wheat landraces

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jyotirmoy Halder ◽  
Jinfeng Zhang ◽  
Shaukat Ali ◽  
Jagdeep S. Sidhu ◽  
Harsimardeep S. Gill ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Fusarium Head Blight ◽  
Tan Spot ◽  
Stagonospora Nodorum ◽  
Head Blight ◽  
Sources Of Resistance ◽  
Stagonospora Nodorum Blotch ◽  
Valuable Source ◽  
Race 1 ◽  
Genomic Regions

Abstract Background In the late 1920s, A. E. Watkins collected about 7000 landrace cultivars (LCs) of bread wheat (Triticum aestivum L.) from 32 different countries around the world. Among which 826 LCs remain viable and could be a valuable source of superior/favorable alleles to enhance disease resistance in wheat. In the present study, a core set of 121 LCs, which captures the majority of the genetic diversity of Watkins collection, was evaluated for identifying novel sources of resistance against tan spot, Stagonospora nodorum blotch (SNB), and Fusarium Head Blight (FHB). Results A diverse response was observed in 121 LCs for all three diseases. The majority of LCs were moderately susceptible to susceptible to tan spot Ptr race 1 (84%) and FHB (96%) whereas a large number of LCs were resistant or moderately resistant against tan spot Ptr race 5 (95%) and SNB (54%). Thirteen LCs were identified in this study could be a valuable source for multiple resistance to tan spot Ptr races 1 and 5, and SNB, and another five LCs could be a potential source for FHB resistance. GWAS analysis was carried out using disease phenotyping score and 8807 SNPs data of 118 LCs, which identified 30 significant marker-trait associations (MTAs) with -log10 (p-value) > 3.0. Ten, five, and five genomic regions were found to be associated with resistance to tan spot Ptr race 1, race 5, and SNB, respectively in this study. In addition to Tsn1, several novel genomic regions Q.Ts1.sdsu-4BS and Q.Ts1.sdsu-5BS (tan spot Ptr race 1) and Q.Ts5.sdsu-1BL, Q.Ts5.sdsu-2DL, Q.Ts5.sdsu-3AL, and Q.Ts5.sdsu-6BL (tan spot Ptr race 5) were also identified. Our results indicate that these putative genomic regions contain several genes that play an important role in plant defense mechanisms. Conclusion Our results suggest the existence of valuable resistant alleles against leaf spot diseases in Watkins LCs. The single-nucleotide polymorphism (SNP) markers linked to the quantitative trait loci (QTLs) for tan spot and SNB resistance along with LCs harboring multiple disease resistance could be useful for future wheat breeding.

scholarly journals Genetic Analysis of Adult Plant Resistance to Yellow Rust and Leaf Rust in Common Spring Wheat Quaiu 3

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 728-736 ◽  
Author(s):  
B. R. Basnet ◽  
R. P. Singh ◽  
S. A. Herrera-Foessel ◽  
A. M. H. Ibrahim ◽  
J. Huerta-Espino ◽  
...  
Keyword(s):  
Spring Wheat ◽  
Resistance Genes ◽  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Molecular Mapping ◽  
Puccinia Striiformis ◽  
Wheat Breeding ◽  
Adult Plant ◽  
Breeding Programs ◽  
Qualitative Approaches

Identifying and utilizing rust resistance genes in wheat has been hampered by the continuous and rapid emergence of new pathogen races. A major focus of many wheat breeding programs is achieving durable adult plant resistance (APR) to yellow (stripe) rust (YR) and leaf (brown) rust (LR), caused by Puccinia striiformis and P. triticina, respectively. This study aimed to determine the genetic basis of resistance to YR and LR in the common spring wheat ‘Quaiu 3’. To that end, we evaluated 198 F5 recombinant inbred lines (RILs), derived from a cross of susceptible ‘Avocet-YrA’ with Quaiu 3, for APR to LR and YR in artificially inoculated field trials conducted in Mexico during the 2009 and 2010 growing seasons. High narrow-sense heritability (h2) estimates, ranging between 0.91 and 0.95, were obtained for both LR and YR disease severities for both years. The quantitative and qualitative approaches used to estimate gene numbers showed that, in addition to known resistance genes, there are at least two to three APR genes associated with LR and YR resistance in the RIL population. The moderately effective race-specific resistance gene Lr42 and the pleiotropic slow-rusting APR gene Lr46/Yr29 were found to interact with additional unidentified APR genes. The unidentified APR genes should be of particular interest for further characterization through molecular mapping, and for utilization by wheat breeding programs.

scholarly journals High-density SNP mapping reveals closely linked QTL for resistance to Stagonospora nodorum blotch (SNB) in flag leaf and glume of hexaploid wheat

Genome ◽  
2018 ◽  
Vol 61 (2) ◽  
pp. 145-149 ◽  
Author(s):  
Michael G. Francki ◽  
Esther Walker ◽  
Dora A. Li ◽  
Kerrie Forrest
Keyword(s):  
Average Distance ◽  
Flag Leaf ◽  
Snp Markers ◽  
Genetic Maps ◽  
Stagonospora Nodorum ◽  
Adult Plant ◽  
Stagonospora Nodorum Blotch ◽  
Snp Mapping ◽  
Marker Loci ◽  
Genomic Regions

The genetic control of adult plant resistance to Stagonospora nodorum blotch (SNB) is complex, consisting of genes with minor effects interacting in an additive manner. Earlier studies detected quantitative trait loci (QTL) for flag leaf resistance in successive years on chromosomes 1B, 2A, 2D, and 5B using SSR- and DArT-based genetic maps of progeny from the crosses EGA Blanco/Millewa, 6HRWSN125/WAWHT2074, and P92201D5/P91193D1. Similarly, QTL for glume resistance detected in successive years and multiple environments were identified on chromosomes 2D and 4B from genetic maps of P92201D5/P91193D1 and 6HRWSN125/WAWHT2074, respectively. The SSR- and DArT-based genetic maps had an average distance of 6.5, 7.8, and 9.7 cM between marker loci for populations EGA/Millewa, P92201D5/P91193D1, and 6HRWSN125/WAWHT2074, respectively. This study used single nucleotide polymorphism (SNP) markers from the iSelect Infinium 90K genotyping array to fine-map genomic regions harbouring QTL for flag leaf and glume SNB resistance, reducing the average distance between markers to 2.9, 3.3, and 3.4 cM for populations P92201D5/P91193D1, EGA/Millewa, and 6HRWSN125/WAWHT2074, respectively. Increasing the marker density of the genetic maps with SNPs did not identify any new QTL for SNB resistance but discriminated previously identified co-located QTL into separate but closely linked QTL.

scholarly journals Genome-wide association analysis permits characterization of Stagonospora nodorum blotch (SNB) resistance in hard winter wheat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rami AlTameemi ◽  
Harsimardeep S. Gill ◽  
Shaukat Ali ◽  
Girma Ayana ◽  
Jyotirmoy Halder ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Genome Wide Association Study ◽  
Seedling Stage ◽  
Genome Wide Association ◽  
Stagonospora Nodorum ◽  
Complex Nature ◽  
Breeding Programs ◽  
Stagonospora Nodorum Blotch ◽  
Genome Wide ◽  
A Genome

AbstractStagonospora nodorum blotch (SNB) is an economically important wheat disease caused by the necrotrophic fungus Parastagonospora nodorum. SNB resistance in wheat is controlled by several quantitative trait loci (QTLs). Thus, identifying novel resistance/susceptibility QTLs is crucial for continuous improvement of the SNB resistance. Here, the hard winter wheat association mapping panel (HWWAMP) comprising accessions from breeding programs in the Great Plains region of the US, was evaluated for SNB resistance and necrotrophic effectors (NEs) sensitivity at the seedling stage. A genome-wide association study (GWAS) was performed to identify single‐nucleotide polymorphism (SNP) markers associated with SNB resistance and effectors sensitivity. We found seven significant associations for SNB resistance/susceptibility distributed over chromosomes 1B, 2AL, 2DS, 4AL, 5BL, 6BS, and 7AL. Two new QTLs for SNB resistance/susceptibility at the seedling stage were identified on chromosomes 6BS and 7AL, whereas five QTLs previously reported in diverse germplasms were validated. Allele stacking analysis at seven QTLs explained the additive and complex nature of SNB resistance. We identified accessions (‘Pioneer-2180’ and ‘Shocker’) with favorable alleles at five of the seven identified loci, exhibiting a high level of resistance against SNB. Further, GWAS for sensitivity to NEs uncovered significant associations for SnToxA and SnTox3, co-locating with previously identified host sensitivity genes (Tsn1 and Snn3). Candidate region analysis for SNB resistance revealed 35 genes of putative interest with plant defense response-related functions. The QTLs identified and validated in this study could be easily employed in breeding programs using the associated markers to enhance the SNB resistance in hard winter wheat.

scholarly journals Quantitative Trait Loci for Seedling and Adult Plant Resistance to Stagonospora nodorum in Wheat

2008 ◽  
Vol 98 (8) ◽  
pp. 886-893 ◽  
Author(s):  
M. Shankar ◽  
E. Walker ◽  
H. Golzar ◽  
R. Loughman ◽  
R. E. Wilson ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Grain Yield ◽  
Plant Resistance ◽  
Qtl Analysis ◽  
Quantitative Trait ◽  
Adult Plant Resistance ◽  
Flag Leaf ◽  
Grain Weight ◽  
Stagonospora Nodorum ◽  
Adult Plant

Stagonospora nodorum blotch (SNB) caused by Stagonospora nodorum is a severe disease of wheat (Triticum aestivum) in many areas of the world. S. nodorum affects both seedling and adult plants causing necrosis of leaf and glume tissue, inhibiting photosynthetic capabilities, and reducing grain yield. The aims of this study were to evaluate disease response of 280 doubled haploid (DH) individuals derived from a cross between resistant (6HRWSN125) and susceptible (WAWHT2074) genotypes, compare quantitative trait loci (QTL) for seedling and adult plant resistance in two consecutive years, and assess the contribution of QTL on grain weight. Flag leaves and glumes of individuals from the DH population were inoculated with mixed isolates of S. nodorum at similar maturity time to provide accurate disease evaluation independent of morphological traits and identify true resistance for QTL analysis. Fungicide protected and inoculated plots were used to measure relative grain weight (RGW) as a yield-related trait under pathogen infection. The lack of similar QTL and little or no correlation in disease scores indicate different genes control seedling and adult plant disease and independent genes control flag leaf and glume resistance. This study consistently identified a QTL on chromosome 2DL for flag leaf resistance (QSnl.daw-2D) and 4BL for glume resistance (QSng.daw-4B) from the resistant parent, 6HRWSN125, explaining 4 to 19% of the phenotypic variation at each locus. A total of 5 QTL for RGW were consistently detected, where two were in the same marker interval for QSnl.daw-2D and QSng.daw-4B indicating the contribution of these QTL to yield related traits. Therefore, RGW measurement in QTL analysis could be used as a reliable indicator of grain yield affected by S. nodorum infection.

Transfer of leaf and stripe rust resistance genes Lr19 and Yr15 in to a susceptible wheat cultivar HS295

2019 ◽  
Vol 79 (3) ◽  
Author(s):  
Pratima Sharma ◽  
Madhu Patial ◽  
Dharam Pal ◽  
S. C. Bhardwaj ◽  
Subodh . Kumar ◽  
...  
Keyword(s):  
Rust Resistance ◽  
Ssr Marker ◽  
Scar Marker ◽  
Adult Plant Resistance ◽  
Wheat Cultivar ◽  
Stripe Rust Resistance ◽  
Adult Plant ◽  
Potential Donor ◽  
Seedling Resistance ◽  
Breeding Lines

The present study was conducted to transfer multiple rust resistance in a popular but rust susceptible wheat cultivar HS295. Selected derivatives WBM3632 and WBM3635 have been developed from a cross, HS295*2/FLW20//HS295*2/ FLW13 using bulk-pedigree method of breeding. Advance line WBM3697 selected from a breeding line WBM3532 was named as HS661. This line was evaluated for seedling resistance to a wide array of rust pathotypes and found to possess resistance to all the three rusts. HS661 was also tested under field conditions and showed adult plant resistance to leaf rust (AC1=0.6), stem rust (ACI=2.7) and strpe rust (AC1=3.8). Among 34 F3 lines, 28 were tested positive for SSR marker Xwmc221 indicating the presence of Lr19/Sr25. Out of 14 selected F4 lines from F3, nine were homozygous positive for Lr19/Sr25. The advanced breeding lines viz., WBM3632 (WBM3697) and WBM3635 were also positive for Lr19/Sr25 with SCAR marker SCS265512. SSR marker Xgwm1 producing 215 bp band in Avst-15, FLW13 and HS661 confirmed the presence of Yr15 . Agronomically, HS661 was comparable with recipient variety HS295 and superior to a standard check HS490 under late sown restricted irrigation production conditions of NHZ. HS661 may serve as a potential donor for creating new usable variability against all the three rusts.

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