Diagnostic KASP Markers of Wheat Broad-spectrum Powdery Mildew Resistance Genes Pm21, PmV and Pm12 Developed for High Throughput Marker-assisted Selection

Plant Disease ◽  
2021 ◽  
Author(s):  
Xu Zhang ◽  
Wenrui Wang ◽  
Cheng Liu ◽  
Shanying Zhu ◽  
Huiming Gao ◽  
...  

Wheat powdery mildew is a devastating disease that seriously threatens yield worldwide. Utilization of host resistance is considered an effective strategy to minimize powdery mildew damage. Pm21, PmV, and Pm12 confer broad-spectrum resistance to wheat powdery mildew in China, of which Pm21 and PmV are allelic genes derived from the 6VS chromosome of Dasypyrum villosum, and Pm12 is derived from the 6SS chromosome of Aegilops speltoides and most likely orthologous to the former two genes. To accurately and efficiently transfer and pyramid these genes using marker-assisted selection (MAS), distinctive single nucleotide polymorphisms (SNPs) among the exon sequences of Pm21, PmV, and Pm12 and their homologous sequences in the common wheat genome were identified and used for developing diagnostic Kompetitive Allele-Specific PCR (KASP) markers. The markers were validated in different genotypes including transgenic vectors, transgenic lines, translocation lines, resistance stocks with documented Pm genes, and in multiple susceptible cultivars without Pm genes. As a result, we initially developed a KASP marker that can simultaneously diagnose Pm21, Pm12, and PmV. Subsequently, we obtained a highly diagnostic KASP marker for each of the three genes that could distinguish among the three genes and also accurately distinguish them from other resistant stocks with documented Pm genes and from multiple susceptible genotypes. Compared with previously reported markers, the highly diagnostic KASP markers developed in this study have the advantages of low cost, easy assay, accuracy, and potentially high throughput for MAS.

Genome ◽  
2006 ◽  
Vol 49 (8) ◽  
pp. 864-872 ◽  
Author(s):  
G Tacconi ◽  
V Baldassarre ◽  
N C Collins ◽  
D Bulgarelli ◽  
A M Stanca ◽  
...  

Recessive mlo alleles of the barley Mlo gene confer resistance to almost all known isolates of the powdery mildew fungal pathogen targeting barley (Hordeum vulgare). To characterize haplotypes present in the Mlo chromosomal region of cultivated Mlo and mlo barley genotypes, weconducted a polymorphism search in 3 predicted low-copy sequence regions adjacent to the Mlo gene by examining a sample of 4 Mlo and 3 mlo cultivars. Eight single-nucleotide polymorphisms (SNPs) and 1 insertion–deletion (indel) were detected, and easy to use PCR-based markers were developed for typing the SNPs. The PCR markers were used to characterize a collection of 46 Mlo and 25 mlo barley cultivars, identifying 3 distinct mlo-11 haplotypes, 1 mlo-9 haplotype, and 4 Mlo haplotypes. We summarized the haplotype and marker information obtained here and in a previous study to help breeders identify strategies for mlo marker-assisted selection. The ability of the markers to identify mlo-resistant genotypes in segregating populations was demonstrated using 2 resistance-characterized F2 populations derived by 3-way crosses.Key words: barley, powdery mildew resistance, mlo, SNPs, marker-assisted selection.


2020 ◽  
Author(s):  
R. Rebecca Love ◽  
Marco Pombi ◽  
Moussa W. Guelbeogo ◽  
Nathan R. Campbell ◽  
Melissa T. Stephens ◽  
...  

ABSTRACTChromosomal inversion polymorphisms have special importance in the Anopheles gambiae complex of malaria vector mosquitoes, due to their role in local adaptation and range expansion. The study of inversions in natural populations is reliant on polytene chromosome analysis by expert cytogeneticists, a process that is limited by the rarity of trained specialists, low throughput, and restrictive sampling requirements. To overcome this barrier, we ascertained tag single nucleotide polymorphisms (SNPs) that are highly correlated with inversion status (inverted or standard orientation). We compared the performance of the tag SNPs using two alternative high throughput molecular genotyping approaches versus traditional cytogenetic karyotyping of the same 960 individual An. gambiae and An. coluzzii mosquitoes sampled from Burkina Faso, West Africa. We show that both molecular approaches yield comparable results, and that either one performs as well or better than cytogenetics in terms of genotyping accuracy. Given the ability of molecular genotyping approaches to be conducted at scale and at relatively low cost without restriction on mosquito sex or developmental stage, molecular genotyping via tag SNPs has the potential to revitalize research into the role of chromosomal inversions in the behavior and ongoing adaptation of An. gambiae and An. coluzzii to environmental heterogeneities.


2018 ◽  
Vol 11 (6) ◽  
pp. 879-882 ◽  
Author(s):  
Huagang He ◽  
Shanying Zhu ◽  
Renhui Zhao ◽  
Zhengning Jiang ◽  
Yaoyong Ji ◽  
...  

2009 ◽  
Vol 99 (7) ◽  
pp. 840-849 ◽  
Author(s):  
Ryan Parks ◽  
Ignazio Carbone ◽  
J. Paul Murphy ◽  
Christina Cowger

The structure of the U.S. wheat powdery mildew population (Blumeria graminis f. sp. tritici) has not been previously investigated, and the global evolutionary history of B. graminis f. sp. tritici is largely unknown. After gathering 141 single-ascosporic B. graminis f. sp. tritici isolates from 10 eastern U.S. locations, 34 isolates from the United Kingdom, and 28 isolates from Israel, we analyzed pathogen population structure using presumptively neutral markers. DNA was extracted from conidia, primers for 12 “housekeeping” genes were designed, and amplicons were examined for polymorphism. Four genes were found to contain a total of 12 single-nucleotide polymorphisms in the U.S. population and were also analyzed in the U.K. and Israeli populations. In total, 25 haplotypes were inferred from the four concatenated genes, with 2 haplotypes comprising over 70% of the U.S. population. Using Hudson's tests and analysis of molecular variance, we found the wheat mildew isolates subdivided into four groups corresponding to distinct regions: the mid-Atlantic United States, the southern United States, the United Kingdom, and Israel. Genotypic diversity was greatest in samples from the United Kingdom, Israel, Virginia, and Kinston, NC. Using rarefaction, a procedure that compensates for differing sample sizes when estimating population richness and diversity, we found that cooler locations with greater conduciveness to regular powdery mildew epidemics had the greatest haplotype richness. Our results suggest that the eastern U.S. B. graminis f. sp. tritici population is young, descended recently from Old World populations with isolation and genetic drift, and is currently subdivided into northern and southern subpopulations.


2019 ◽  
pp. 05-09

The presence study deals with powdery mildews in various cucurbits in Katsina city (Barhim Estate, Kofar Durbi, Kofar Sauri, Kofar Marusa and Low Cost), Nigeria. The finding shows that the areas infested with powdery mildew is one of the important disease of cucurbits. The Sphaerotheca fuliginea was identified to be the causal organism present on all observed cucurbits in the study. Highest frequency of disease was found in Kofar Sauri(79%) fallowed by Kofar Marusa (68%), Kofar Durbi (66%), Barhim Estate (65%) and the lowest frequency of occurrence of disease was found in Low Cost (55%).The intensity of the disease was moderate to severe in general but it was high in many fields, the area-wise variation was also noticed. On vegetables, the highest frequency of occurrence of powdery mildew disease was observed on L. cylindrica (76.4%) followed by C. moschata (60%), C. sativus (59.3%), C. vulgaris (53.9%) and lowest was found on C. melo (44.4%). The highest intensity of disease was found on C. moschata, followed by L. cylindrica, C. sativus, C. vulgaris and C. melo.


2020 ◽  
Vol 16 (4) ◽  
pp. 455-461
Author(s):  
Gabriela M. Baia ◽  
Otniel Freitas-Silva ◽  
Murillo F. Junior

Fruits and vegetables are foods that come into contact with various types of microorganisms from planting to their consumption. A lack or poor sanitation of these products after harvest can cause high losses due to deterioration and/ or pathogenic microorganisms. There are practically no post-harvest fungicides or bactericides with a broad spectrum of action that have no toxic residual effects and are safe. However, to minimize such problems, the use of sanitizers is an efficient device against these microorganisms. Chlorine is the most prevalent sanitizing agent because of its broad spectrum, low cost and well-established practices. However, the inevitable formation of disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), is considered one of the main threats to food safety. Alternative sanitizers, such as chlorine dioxide (ClO2) and ozone, are becoming popular as a substitute for traditional post-harvest treatments. Thus, this review addresses the use of chlorine, chlorine dioxide and ozone emphasizing aspects, such as usage, safe application, spectrum of action and legislation. In order to ensure the quality and safety of final products, the adoption of well-prepared sanitation and sanitation programs for post-harvest fruits and vegetables is essential.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  

AbstractThe vagus nerve supports diverse autonomic functions and behaviors important for health and survival. To understand how specific components of the vagus contribute to behaviors and long-term physiological effects, it is critical to modulate their activity with anatomical specificity in awake, freely behaving conditions using reliable methods. Here, we introduce an organ-specific scalable, multimodal, wireless optoelectronic device for precise and chronic optogenetic manipulations in vivo. When combined with an advanced, coil-antenna system and a multiplexing strategy for powering 8 individual homecages using a single RF transmitter, the proposed wireless telemetry enables low cost, high-throughput, and precise functional mapping of peripheral neural circuits, including long-term behavioral and physiological measurements. Deployment of these technologies reveals an unexpected role for stomach, non-stretch vagal sensory fibers in suppressing appetite and demonstrates the durability of the miniature wireless device inside harsh gastric conditions.


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