scholarly journals New Sources of Eastern Filbert Blight Resistance and Simple Sequence Repeat Markers on Linkage Group 6 in Hazelnut (Corylus avellana L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Golnaz Komaei Koma ◽  
Merve Şekerli ◽  
Jacob W. Snelling ◽  
Shawn A. Mehlenbacher
Keyword(s):  
Linkage Group ◽  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Corylus Avellana ◽  
Sequence Repeat ◽  
Disease Response ◽  
Resistance Sources ◽  
Group 6 ◽  
Eastern Filbert Blight ◽  
Simple Sequence

Commercial production of hazelnut (Corylus avellana) in Oregon’s Willamette Valley is threatened by eastern filbert blight (EFB), a serious canker disease caused by the pyrenomycete Anisogramma anomala (Peck) E. Müller. The fungus also prevents the establishment of hazelnut orchards in eastern North America. Genetic resistance is considered the most effective way to control the disease. A high level of EFB resistance was first discovered in ’Gasaway’. This resistance is conferred by a dominant allele at a single locus on linkage group 6 (LG6). Resistance from several additional sources has been assigned to the same chromosomal region. In this study, new simple sequence repeat (SSR) markers were developed for the resistance region on LG6 and new sources of resistance were investigated. Forty-two new SSR markers were developed from four contigs in the genome sequence of ‘Jefferson’ hazelnut, characterized, and nine of them were placed on LG6 of the genetic map. Accessions representing 12 new sources of EFB resistance were crossed with susceptible selections resulting in 18 seedling populations. Segregation ratios in the seedling populations fit the expected 1:1 ratio for 10 sources, while one source showed an excess of resistant seedlings and another showed an excess of susceptible seedlings. Based on correlation of disease response and scores of SSR markers in the ‘Gasaway’ resistance region in the seedlings, eight resistance sources were assigned to LG6. Linkage maps were constructed for each progeny using SSR markers. The LG6 resistance sources include two selections (#23 and #26) from the Russian Research Institute of Forestry and Mechanization near Moscow, four selections from southern Russia, one selection (OSU 1185.126) from Crimea, one selection (OSU 533.129) from Michigan, Corylus heterophylla ‘Ogyoo’ from the South Korea, and the interspecific hybrid ’Estrella #1’. These new LG6 resistance sources and SSR markers should be useful in breeding new cultivars, including the pyramiding of resistance genes. For the other four resistance sources (Moscow #37, hybrid selection OSU 401.014, C. americana ‘Winkler’ and C. americana OSU 366.060), SSR marker scores on linkage groups 6, 7 and 2 were not correlated with disease response and merit further investigation.

A genetic linkage map for hazelnut (Corylus avellana L.) based on RAPD and SSR markers

Genome ◽  
2006 ◽  
Vol 49 (2) ◽  
pp. 122-133 ◽  
Author(s):  
Shawn A Mehlenbacher ◽  
Rebecca N Brown ◽  
Eduardo R Nouhra ◽  
Tufan Gökirmak ◽  
Nahla V Bassil ◽  
...  
Keyword(s):  
Linkage Map ◽  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Random Amplified Polymorphic Dna ◽  
Corylus Avellana ◽  
Sequence Repeat ◽  
Starting Point ◽  
Ssr Loci ◽  
Corylus Avellana L ◽  
Simple Sequence

A linkage map for European hazelnut (Corylus avellana L.) was constructed using random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers and the 2-way pseudotestcross approach. A full-sib population of 144 seedlings from the cross OSU 252.146 × OSU 414.062 was used. RAPD markers in testcross configuration, segregating 1:1, were used to construct separate maps for each parent. Fifty additional RAPD loci were assigned to linkage groups as accessory markers whose exact location could not be determined. Markers in intercross configuration, segregating 3:1, were used to pair groups in one parent with their homologues in the other. Eleven groups were identified for each parent, corresponding to the haploid chromosome number of hazelnut (n = x = 11). Thirty of the 31 SSR loci were able to be assigned to a linkage group. The maternal map included 249 RAPD and 20 SSR markers and spanned a distance of 661 cM. The paternal map included 271 RAPD and 28 SSR markers and spanned a distance of 812 cM. The maps are quite dense, with an average of 2.6 cM between adjacent markers. The S-locus, which controls pollen-stigma incompatibility, was placed on chromosome 5S where 6 markers linked within a distance of 10 cM were identified. A locus for resistance to eastern filbert blight, caused by Anisogramma anomala, was placed on chromosome 6R for which two additional markers tightly linked to the dominant allele were identified and sequenced. These maps will serve as a starting point for future studies of the hazelnut genome, including map-based cloning of important genes. The inclusion of SSR loci on the map will make it useful in other populations.Key words: Corylus avellana, hazelnut, filbert, linkage map, pseudotestcross, pollen-stigma incompatibility, random amplified polymorphic DNA, simple sequence repeat, microsatellite.

scholarly journals New Simple Sequence Repeat Markers on Linkage Groups 2 and 7, and Investigation of New Sources of Eastern Filbert Blight Resistance in Hazelnut

2021 ◽  
pp. 1-18
Author(s):  
Merve Şekerli ◽  
Golnaz Komaei Koma ◽  
Jacob W. Snelling ◽  
Shawn A. Mehlenbacher
Keyword(s):  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
The Other ◽  
Single Locus ◽  
Null Alleles ◽  
Dominant Allele ◽  
Sequence Repeat ◽  
Sources Of Resistance ◽  
Eastern Filbert Blight ◽  
Simple Sequence

Eastern filbert blight (EFB), caused by Anisogramma anomala, is a fungal disease threatening the european hazelnut (Corylus avellana) industry in the Willamette Valley of Oregon. The pathogen is endemic to the eastern United States where it causes little damage to the wild Corylus americana but causes severe cankers on most cultivars of the commercially important european hazelnut. The host genetic resistance in ‘Gasaway’ is conferred by a dominant allele at a single locus on linkage group 6 (LG6), and resistance from several other sources has been mapped to the same region. Some fungal isolates can overcome ‘Gasaway’ resistance, prompting a search for other sources of resistance. Resistance from other sources has been mapped to LG2 and LG7, for which additional simple sequence repeat (SSR) markers would facilitate marker-assisted selection (MAS). In this study, an in silico approach was used to develop new polymorphic SSR markers in the EFB resistance regions on LG2 and LG7. Starting with a search of 17 contigs of the ‘Jefferson’ genome sequence, 45 new polymorphic SSR markers were developed, characterized, and placed on the linkage map. The new SSR markers had an average of 10.18 alleles per locus, and average values for expected heterozygosity, observed heterozygosity, polymorphism information content, and frequency of null alleles of 0.72, 0.65, 0.68, and 0.068, respectively. Of the 42 new polymorphic SSRs segregating in the mapping population, 24 were on LG2, 12 were on LG7, and six were placed on other LGs. The new and previously developed SSR markers were used to study six new sources of EFB resistance, four from Russia and two from Crimea. Six resistant selections were crossed with susceptible selections, resulting in 7 progenies. Phenotyping for disease response revealed that segregation in progenies of the two Moscow selections (#2 and #27), one Russian selection (OSU 1187.101), and one Crimean selection (H3R12P62) fit the 1:1 segregation ratio expected for control of resistance by a dominant allele at a single locus; but in progenies of the other Russian selection (OSU 1166.123) and the other Crimean selection (H3R07P11), there was an excess of resistant seedlings. Correlation of disease scores and alleles at SSR loci indicated that resistance from three Russian selections (Moscow selections #2 and #27 and OSU 1166.123) and the Crimean selection H3R12P62 was on LG7, while resistance from Russian selection OSU 1187.101 was on LG2. Resistance from Crimean selection H3R07P11 was not correlated with markers on LG6, or LG2, or LG7. These sources and new SSR markers will be useful in MAS and the pyramiding of resistance genes in the breeding of new EFB-resistant cultivars.

scholarly journals Genotyping of Peach and Nectarine Cultivars with SSR and SRAP Molecular Markers

2004 ◽  
Vol 129 (2) ◽  
pp. 204-210 ◽  
Author(s):  
Riaz Ahmad ◽  
Dan Potter ◽  
Stephen M. Southwick
Keyword(s):  
Molecular Markers ◽  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Sweet Cherry ◽  
Prunus Persica ◽  
Sequence Repeat ◽  
Srap Markers ◽  
Upgma Cluster Analysis ◽  
Commercially Important ◽  
Simple Sequence

Simple sequence repeat (SSR) and sequence related amplified polymorphism (SRAP) molecular markers were evaluated for detecting intraspecific variation in 38 commercially important peach and nectarine (Prunus persica) cultivars. Out of the 20 SSR primer pairs 17 were previously developed in sweet cherry and three in peach. The number of putative alleles revealed by SSR primer pairs ranged from one to five showing a low level of genetic variability among these cultivars. The average number of alleles per locus was 2.2. About 76% of cherry primers produced amplification products in peach and nectarine, showing a congeneric relationship within Prunus species. Only nine cultivars out of the 38 cultivars could be uniquely identified by the SSR markers. For SRAP, the number of fragments produced was highly variable, ranging from 10 to 33 with an average of 21.8 per primer combination. Ten primer combinations resulted in 49 polymorphic fragments in this closely related set of peaches and nectarines. Thirty out of the 38 peach and nectarine cultivars were identified by unique SRAP fingerprints. UPGMA Cluster analysis based on the SSR and SRAP polymorphic fragments was performed; the relationships inferred are discussed with reference to the pomological characteristics and pedigree of these cultivars. The results indicated that SSR and SRAP markers can be used to distinguish the genetically very close peach and nectarine cultivars as a complement to traditional pomological studies. However, for fingerprinting, SRAP markers appear to be much more effective, quicker and less expensive to develop than are SSR markers.

scholarly journals Assessment of the Genetic Diversity of Rice Germplasms Characterized by Black-Purple and Red Pericarp Color Using Simple Sequence Repeat Markers

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 471
Author(s):  
Jae-Ryoung Park ◽  
Won-Tae Yang ◽  
Yong-Sham Kwon ◽  
Hyeon-Nam Kim ◽  
Kyung-Min Kim ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Germplasm Collection ◽  
Group Method ◽  
Sequence Repeat ◽  
Rice Varieties ◽  
Red Pericarp ◽  
Simple Sequence ◽  
Colored Rice

The assessment of the genetic diversity within germplasm collections can be accomplished using simple sequence repeat (SSR) markers and association mapping techniques. The present study was conducted to evaluate the genetic diversity of a colored rice germplasm collection containing 376 black-purple rice samples and 172 red pericarp samples, conserved by Dong-A University. There were 600 pairs of SSR primers screened against 11 rice varieties. Sixteen informative primer pairs were selected, having high polymorphism information content (PIC) values, which were then used to assess the genetic diversity within the collection. A total of 409 polymorphic amplified fragments were obtained using the 16 SSR markers. The number of alleles per locus ranged from 11 to 47, with an average of 25.6. The average PIC value was 0.913, ranging from 0.855 to 0.964. Four hundred and nine SSR loci were used to calculate Jaccard’s distance coefficients, using the unweighted pair-group method with arithmetic mean cluster analysis. These accessions were separated into several distinctive groups corresponding to their morphology. The results provided valuable information for the colored rice breeding program and showed the importance of protecting germplasm resources and the molecular markers that can be derived from them.

scholarly journals Grass Hosts Harbor More Diverse Isolates of Puccinia striiformis Than Cereal Crops

2016 ◽  
Vol 106 (4) ◽  
pp. 362-371 ◽  
Author(s):  
P. Cheng ◽  
X. M. Chen ◽  
D. R. See
Keyword(s):  
Ssr Markers ◽  
Stripe Rust ◽  
Simple Sequence Repeat ◽  
Puccinia Striiformis ◽  
The United States ◽  
Grass Species ◽  
Cereal Crops ◽  
Sequence Repeat ◽  
Grass Hosts ◽  
Simple Sequence

Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals.

scholarly journals Use of simple sequence repeat (SSR) markers for screening blue disease resistance in cotton germplasm exchange

2015 ◽  
Vol 14 (41) ◽  
pp. 2871-2875 ◽  
Author(s):  
Faustine Christopher ◽  
Vieira Hoffmann Lucia ◽  
Ismail Tibazarwa Flora ◽  
Lukonge Everina
Keyword(s):  
Disease Resistance ◽  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Sequence Repeat ◽  
Germplasm Exchange ◽  
Simple Sequence
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