ORCID Profile
0000-0003-0766-198X
Current Organisation
University of Adelaide
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Publisher: Canadian Science Publishing
Date: 08-2010
DOI: 10.1139/G10-032
Abstract: Septoria speckled leaf blotch (SSLB), caused by Septoria passerinii , is one of the most important foliar diseases of barley ( Hordeum vulgare L.) in North America. The primary problem caused by this disease is substantial yield loss. The objective of this study was to determine the chromosomal location of SSLB resistance genes in the barley accession PI 643302. A recombinant inbred line population was developed from the cross Zhenongda 7/PI 643302. PI 643302 is resistant while Zhenongda 7 is susceptible to SSLB. The population was phenotyped for SSLB resistance in five experiments in the greenhouse. A linkage map comprising 113 molecular markers was constructed and simplified composite interval mapping was performed. Two QTLs, designated QrSp-1H and QrSP-2H, were found. QrSp-1H was found on the short arm of chromosome 1H (1HS) in all five experiments and showed a large effect against SSLB. Based on the location of QrSp-1H, it is likely the SSLB resistance gene Rsp2. The QTL QrSp-2H mapped to the distal region on the long arm of chromosome 2H (2HL), had a smaller effect than QrSp-1H, and was also detected consistently in all five experiments. A QTL for SSLB resistance in the same region on chromosome 2H has not been reported previously in either cultivated or wild barley thus, QrSp-2H is a new QTL for SSLB resistance in barley.
Publisher: Elsevier BV
Date: 03-1993
Publisher: American Chemical Society
Date: 25-09-1990
Publisher: Springer Science and Business Media LLC
Date: 14-09-2017
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.MYCRES.2007.05.008
Abstract: A collection of isolates of Rhizoctonia solani anastomosis group (AG) 2 was examined for genetic ersity and pathogenicity. Anastomosis reactions classified the majority of isolates into the known subgroups of AG 2-1 and AG 2-2 but the classification of several isolates was ambiguous. Morphological characters were consistent with the species, with no discriminating characters existing between subgroups. Vertical PAGE of pectic enzymes enabled the separation of zymogram group (ZG) 5 and 6 within AG 2-1, but not the separation of ZG 4 and 10 within AG 2-2. PCR analysis using inter-simple sequence repeats (ISSR) and the intron-splice junction (ISJ) region supported the separation of ZG 5 and 6, while the AG 2-2 isolates were separated by geographic region. A comparison of distance matrices produced by the zymogram analysis and PCR indicated a strong correlation between the marker types. Pathogenicity studies suggested canola (Brassica napus) cultivars were most severely affected by AG 2-1, while cultivars of two species of medic (Medicago truncatula cv. Caliph and M. littoralis cv. Herald) were susceptible to both AG 2-1 and 2-2. The results indicate that AG 2 is a polyphyletic group in which the classification of subtypes is sometimes difficult. Further investigation of the population structure within Australia is required to determine the extent and origin of the observed ersity.
Publisher: Springer Science and Business Media LLC
Date: 06-1994
DOI: 10.1007/BF00033947
Publisher: Elsevier BV
Date: 04-1996
Publisher: Wiley
Date: 12-1995
Publisher: Public Library of Science (PLoS)
Date: 03-04-2014
Publisher: Wiley
Date: 03-2008
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Elsevier BV
Date: 11-1993
Publisher: American Society for Microbiology
Date: 30-10-2014
Abstract: The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus.
Publisher: Wiley
Date: 03-2006
Publisher: Springer Science and Business Media LLC
Date: 23-01-2007
DOI: 10.1007/S11046-006-0089-7
Abstract: Pectic zymogram, RFLP and PCR analyses were used to characterize Rhizoctonia solani AG 3 isolates collected from diseased potatoes in South Australia. The pectic zymogram data were compared with those obtained for isolates collected from central Iran. Analyses of bands corresponding to pectin esterase and polygalacturonase revealed three zymogram subgroups (ZG) in AG 3. In addition to the previously reported ZG7 (here renamed ZG7-1), two new zymogram subgroups, ZG7-2 and ZG7-3, were identified. Of the 446 isolates tested, 50% of the South Australian and 46% of the Iranian isolates were ZG7-1. The majority of the isolates originating from stem and root cankers were ZG7-1, whereas most of the isolates designated ZG7-2 and ZG7-3 originated from tuber-borne sclerotia. Pathogenicity tests revealed that ZG7-1 generally produced fewer sclerotia and more severe cankers of underground parts of the potato plants than the other two ZGs. Two random DNA clones, one originating from an AG 3 isolate and the other from an AG 4 isolate, were used as probes for RFLP analyses of Australian isolates. The AG 3 probe, previously identified to be specific to this group, detected a high level of genetic ersity, with 11 genotypes identified amongst 50 isolates analysed. The low-copy AG 4 probe resolved three genotypes amongst 24 isolates. For 23 isolates analysed with both markers, the combined data distinguished a total of six genotypes and similarity analysis resolved the isolates into two main groups with 50% homology. PCR, using primers for the plant intron splice junction region (R1), also revealed variation. No obvious relationship among pectic zymogram groups, RFLP and PCR genotypes was observed.
Publisher: Informa UK Limited
Date: 06-1994
Publisher: Wiley
Date: 11-2006
Publisher: Scientific Societies
Date: 08-2007
Abstract: The genetic structure of Septoria passerinii from nine field populations was examined at several scales (within lesions, among lesions in a leaf, among leaves in a field, and among fields in North Dakota and western Minnesota) by using lified fragment length polymorphism (AFLP) markers. A total of 390 isolates were s led from seven barley fields located in North Dakota and two barley fields located nearby in western Minnesota in 2003 and 2004. Based on 57 polymorphic AFLP markers, AFLP DNA fingerprints identified 176 different genotypes among 390 (non-clone-corrected) isolates in nine different fields. In two intensively s led sites, ND16 (Williston, ND) and ND17 (Langdon, ND), only one to four different genotypes were found within a lesion. A higher level of genetic and genotypic ersity was found within a leaf in which six to nine different genotypes were found from lesions on a leaf. The genetic ersity within a leaf was similar to the genetic ersity within a field. The average genetic ersity (H) within a field across all AFLP loci was approximately 0.3, except at site ND12 (Carrington, ND) where it was 0.16. Genotypic ersity was high in all populations, and with the exception of ND15 (Rothsay, MN), very low multilocus linkage disequilibrium values ( r d ) were found in all populations. The population differentiation, G ST , was relatively high (G ST = 0.238) among the nine populations due to the high G ST in ND12, ND14 (Twin Valley, MN), and ND15. Population differentiation without those three populations was 0.09. A lack of correlation between geographical distance and genetic distance was found, suggesting the potential for a high level of gene flow between different geographical regions. The population genetic structure described in this study for S. passerinii in North Dakota and western Minnesota is consistent with that of a sexually reproducing fungus.
Publisher: Springer Netherlands
Date: 1996
Publisher: Wiley
Date: 09-2009
Publisher: Wiley
Date: 05-04-2012
Publisher: Scientific Societies
Date: 06-2011
Abstract: Gibberella zeae, the principal cause of Fusarium head blight (FHB) of barley, contaminates grains with several mycotoxins, which creates a serious problem for the malting barley industry in the United States, China, and Europe. However, limited studies have been conducted on the trichothecene profiles and population genetic structure of G. zeae isolates collected from barley in the United States. Trichothecene biosynthesis gene (TRI)-based polymerase chain reaction (PCR) assays and 10 variable number tandem repeat (VNTR) markers were used to determine the genetic ersity and compare the trichothecene profiles of an older population (n = 115 isolates) of G. zeae collected in 1997 to 2000 with a newer population (n = 147 isolates) collected in 2008. S les were from across the major barley-growing regions in North Dakota and Minnesota. The results of TRI-based PCR assays were further validated using a subset of 32 and 28 isolates of G. zeae by sequence analysis and gas chromatography, respectively. TRI-based PCR assays revealed that all the G. zeae isolates in both populations had markers for deoxynivalenol (DON), and the frequencies of isolates with a 3-acetyldeoxynivalenol (3-ADON) marker in the newer population were ≈11-fold higher than those among isolates in the older population. G. zeae populations from barley in the Midwest of the United States showed no spatial structure, and all the isolates were solidly in clade 7 of G. zeae, which is quite different from other barley-growing areas of world, where multiple species of G. zeae are commonly found in close proximity and display spatial structure. VNTR analysis showed high gene ersity (H = 0.82 to 0.83) and genotypic ersity but low linkage disequilibrium (LD = 0.02 to 0.07) in both populations. Low genetic differentiation (F ST = 0.013) and high gene flow (Nm = 36.84) was observed between the two populations and among subpopulations within the same population (Nm = 12.77 to 29.97), suggesting that temporal and spatial variations had little influence on population differentiation in the Upper Midwest. Similarly, low F ST (0.02) was observed between 3-ADON and 15-acetyldeoxynivalenol populations, indicating minor influence of the chemotype of G. zeae isolates on population sub ision, although there was a rapid increase in the frequencies of isolates with the 3-ADON marker in the Upper Midwest between the older collection made in 1997 to 2000 and the newer collection made in 2008. This study provides information to barley-breeding programs for their selection of isolates of G. zeae for evaluating barley genotypes for resistance to FHB and DON accumulation.
Publisher: Scientific Societies
Date: 04-2006
DOI: 10.1094/PD-90-0527C
Abstract: Ergot, caused by Claviceps purpurea (Fr.) Tul., occurs every year on cereals and grasses in North Dakota, but the occurrence on barley (Hordeum vugare L) is generally sporadic with a very low incidence of sclerotia. Disease surveys conducted during the 2005 growing season revealed an unusually widespread occurrence. This is of concern since barley production in North Dakota was estimated at 1.25 million metric tons, 27% of the total 2005 U.S. production. Barley s les (n = 304, ~0.50 kg) collected in all crop-reporting districts of North Dakota, northwestern Minnesota, and northeastern Montana, as part of an annual regional survey of barley crop quality (4), were examined for sclerotia. All barley s les were cleaned for dockage, and ergot (% [w/w]) was estimated on subs les of ~100 g from a s le ider. Of all barley s les collected, 62% contained ergots. The regional average for ergot infested kernels was 0.06%, and s les ranged from .01 to 1.19%. Approximately 15% of all s les were in excess of 0.10% ergots and would have been downgraded to ergoty barley under the Official United States Standards for Grain. Occurrence of ergot was most common in northwestern Minnesota and the three eastern and north-central districts of North Dakota. Ergot was less frequent in the south-central and three western districts of North Dakota and was not detected in s les from northeastern Montana. Floret infection occurs during and up to 15 days after anthesis (2), and in the three eastern and north-central districts of North Dakota that occurred around the last week in June and first week in July. Between 22 June and 4 July, the North Dakota Agricultural Weather Network Stations in that region recorded average daily temperatures of 99% of the 30-year norm, but multiple precipitation events amounted to 227% of the 30-year norm. Rain splash and associated high relative humidity favor conidiation and spread of the fungus (1) and may have contributed to the high disease incidence. Average sclerotia weight for a s le ranged from to 70 mg. However, large sclerotia (37 to 180 mg) often were removed by the no. 6 riddle of the dockage tester and were not counted in the ergot estimates as per U.S. Grading Standards. S les containing 1.19, 0.81, 0.22, 0.14, 0.05, and 0.02% ergots were analyzed for ergopeptine alkaloids (3). These were found to contain 27.9, 25.4, 2.4, 1.1, 1.7, and 5.7 μg/g ergopeptine alkaloids, respectively. The average ratio of ergosine/ergotamine/ergocornine/ergocryptine/ergocristine was approximately 1:2:2:3:9. There also was widespread occurrence of the Fusarium mycotoxin deoxynivalenol (DON) on North Dakota barley in 2005. While there was no apparent relationship between the level of the DON and the amount of ergot in the s les (r = 0.042), more than 90% of s les with ergot had detectable levels (0.1 to 69 μg/g) of DON. While only DON is routinely measured in the crop survey (4), other tricothecenes and zearalenone have also been detected. This should be of concern to livestock producers and grain processors since the potential interactions of multiple mycotoxins are not well known. References: (1) G. M. Marshall. Ann. Appl. Biol. 48:19, 1960. (2) S. B. Puranik and D. E. Mathre. Phytopathology 61:1075, 1971. (3) G. E. Rottinghaus et al. J. Vet. Diag. Invest. 5:242 1993. (4) P. B. Schwarz et al. J. Am. Soc. Brew. Chem. 64:1, 2006.
Publisher: Wiley
Date: 05-2007
Publisher: Wiley
Date: 07-08-2012
Publisher: Scientific Societies
Date: 09-2005
Abstract: Recent reports have shown induction of resistance to Rhizoctonia root rot using nonpathogenic strains of binucleate Rhizoctonia spp. (np-BNR). This study evaluates the biocontrol ability of several np-BNR isolates against root and foliar diseases of cotton in greenhouse trials, provides evidence for induced systemic resistance (ISR) as a mechanism in this biocontrol, and compares the disease control provided by np-BNR with that provided by the chemical inducer benzothiadiazole (BTH). Pretreatment of cotton seedlings with np-BNR isolates provided good protection against pre- and post-emergence d ing-off caused by a virulent strain of Rhizoctonia solani (AG-4). Seedling stand of protected cotton was significantly higher (P 0.05) than that of nonprotected seedlings. Several np-BNR isolates significantly reduced disease severity. The combination of BTH and np-BNR provided significant protection against seedling rot and leaf spot in cotton however, the degree of disease reduction was comparable to that obtained with np-BNR treatment alone. Significant reduction in leaf spot symptoms caused by Alternaria macrospora occurred on cotyledons pretreated with np-BNR or sprayed with BTH, and the np- BNR-treated seedlings had significantly less leaf spot than BTH-treated seedlings. The results demonstrate that np-BNR isolates can protect cotton from infections caused by both root and leaf pathogens and that disease control was superior to that observed with a chemical inducer.
Publisher: Oxford University Press (OUP)
Date: 02-2004
Publisher: Scientific Societies
Date: 09-2008
Abstract: Gibberella zeae, a causal agent of Fusarium head blight (FHB) in wheat and barley, is one of the most economically harmful pathogens of cereals in the United States. In recent years, the known host range of G. zeae has also expanded to noncereal crops. However, there is a lack of information on the population genetic structure of G. zeae associated with noncereal crops and across wheat cultivars. To test the hypothesis that G. zeae populations s led from barley, wheat, potato, and sugar beet in the Upper Midwest of the United States are not mixtures of species or G. zeae clades, we analyzed sequence data of G. zeae, and confirmed that all populations studied were present in the same clade of G. zeae. Ten variable number tandem repeat (VNTR) markers were used to determine the genetic structure of G. zeae from the four crop populations. To examine the effect of wheat cultivars on the pathogen populations, 227 strains were s led from 10 subpopulations according to wheat cultivar types. The VNTR markers also were used to analyze the genetic structure of these subpopulations. In all populations, gene (H = 0.453 to 0.612) and genotype ersity (GD = .984) were high. There was little or no indication of linkage disequilibrium (LD) in all G. zeae populations and subpopulations. In addition, high gene flow (Nm) values were observed between cereal and noncereal populations (Nm = 10.69) and between FHB resistant and susceptible wheat cultivar subpopulations (Nm = 16.072), suggesting low population differentiation of G. zeae in this region. Analysis of molecular variance also revealed high genetic variation ( %) among in iduals within populations and subpopulations. However, low genetic variation ( %) was observed between cereal and noncereal populations and between resistant and susceptible wheat subpopulations. Overall, these results suggest that the populations or subpopulations are likely a single large population of G. zeae affecting crops in the upper Midwest of the United States.
Publisher: Springer Japan
Date: 2015
Publisher: Informa UK Limited
Date: 03-2007
Publisher: Elsevier BV
Date: 12-2006
Publisher: Elsevier BV
Date: 1994
Publisher: Scientific Societies
Date: 08-2018
Publisher: Scientific Societies
Date: 02-2007
Abstract: Five random lified polymorphic DNA markers, two in coupling (OPAH5 545C , and OPBA12 314C ) and three in repulsion phase (UBC285 158R , OPC2 441R , and OPB17 451R ), closely linked to Rsp genes conferring resistance to Septoria speckled leaf blotch (SSLB), were identified using bulked segregant analysis in three F 2 populations, each containing a Rsp gene. These markers were converted into the sequence tagged site (STS) markers SUBC285, SOPC2, SOPAH5, and SOPBA12. Another STS marker (MWG938) linked to Rsp2 in coupling phase was also identified in an F 2 population from the cross Robust/CIho 4780. The STS markers were tested on a set of 42 resistant and susceptible barley germplasm lines and 98 landraces. The expected sizes of marker fragments associated with each allele at Rsp loci were present in resistant or susceptible accessions. Efficiency of marker-assisted selection (MAS) for Rsp1, Rsp2, and Rsp3 using STS markers were evaluated in three F 2–3 populations in the greenhouse and the field. Results of testing F 2–3 progeny demonstrated that the accuracy of MAS was, with one exception, greater than 97% in the greenhouse and in two field locations (90% in the Osnabrock, ND trial for Rsp2). The STS markers closely linked to Rsp genes also identified the SSLB resistance corresponding to Rsp1, Rsp2, or Rsp3 in gene pyramiding F 2 populations. The STS markers tightly linked to Rsp genes may be useful for M and for pyramiding with other genes in barley breeding for SSLB resistance.
Publisher: American Society for Microbiology
Date: 11-2008
DOI: 10.1128/AEM.01580-08
Abstract: Gibberella zeae is one of the most devastating pathogens of barley and wheat in the United States. The fungus also infects noncereal crops, such as potatoes and sugar beets, and the genetic relationships among barley, wheat, potato, and sugar beet isolates indicate high levels of similarity. However, little is known about the toxigenic potential of G. zeae isolates from potatoes and sugar beets. A total of 336 isolates of G. zeae from barley, wheat, potatoes, and sugar beets were collected and analyzed by TRI (trichothecene biosynthesis gene)-based PCR assays. To verify the TRI -based PCR detection of genetic markers by chemical analysis, 45 representative isolates were grown in rice cultures for 28 days and 15 trichothecenes and 2 zearalenone (ZEA) analogs were quantified using gas chromatography-mass spectrometry. TRI -based PCR assays revealed that all isolates had the deoxynivalenol (DON) marker. The frequencies of isolates with the 15-acetyl-deoxynivalenol (15-ADON) marker were higher than those of isolates with the 3-acetyl-deoxynivalenol (3-ADON) marker among isolates from all four crops. Fusarium head blight (FHB)-resistant wheat cultivars had little or no influence on the ersity of isolates associated with the 3-ADON and 15-ADON markers. However, the frequency of isolates with the 3-ADON marker among isolates from the Langdon, ND, s ling site was higher than those among isolates from the Carrington and Minot, ND, sites. In chemical analyses, DON, 3-ADON, 15-ADON, b-ZEA, and ZEA were detected. All isolates produced DON (1 to 782 μg/g) and ZEA (1 to 623 μg/g). These findings may be useful for monitoring mycotoxin contamination and for formulating FHB management strategies for these crops.
Publisher: Naturalis Biodiversity Center
Date: 31-12-2011
Publisher: Wiley
Date: 07-2008
Publisher: Scientific Societies
Date: 05-2012
Abstract: The associations between Fusarium head blight (FHB), caused by Gibberella zeae, and deoxynivalenol (DON) accumulation in spring malting barley (Hordeum vulgare) and hourly weather conditions predictive of DON accumulation were examined using data from six growing seasons in the U.S. Northern Great Plains. Three commonly grown cultivars were planted throughout the region, and FHB disease and DON concentration were recorded. Nine predictor variables were calculated using hourly temperature and relative humidity during the 10 days preceding full head spike emergence. Simple logistic regression models were developed using these predictor variables based on a binary threshold for DON of 0.5 mg/kg. Four of the nine models had sensitivity greater than 80%, and specificity of these models ranged from 67 to 84% (n = 150). The most useful predictor was the joint effect of average hourly temperature and a weighted duration of uninterrupted hours (h) with relative humidity greater than or equal to 90%. The results of this study confirm that FHB incidence is significantly associated with DON accumulation in the grain and that weather conditions prior to full head emergence could be used to accurately predict the risk of economically significant DON accumulation for spring malting barley.
Publisher: Wiley
Date: 12-1989
Publisher: Springer Science and Business Media LLC
Date: 09-06-2018
Publisher: Springer Netherlands
Date: 1996
Publisher: Springer Science and Business Media LLC
Date: 29-04-2010
Publisher: Springer Netherlands
Date: 1996
Publisher: Springer Science and Business Media LLC
Date: 06-1993
DOI: 10.1007/BF00012994
Publisher: Informa UK Limited
Date: 09-2007
Publisher: Scientific Societies
Date: 02-2007
Abstract: Septoria speckled leaf blotch (SSLB) caused by Septoria passerinii is a common disease in barley. SSLB resistance genes Rsp1, Rsp2, and Rsp3 have previously been identified in the United States Department of Agriculture National Small Grains collection accessions CIho 14300, CIho 4780, and CIho 10644, respectively. Populations of 100 to 120 F 2 in iduals were evaluated for SSLB resistance in the greenhouse. Inheritance was evaluated in F 2:3 -derived families in the field. Partial molecular maps for three Rsp genes were constructed on F 2 and F 2:3 families derived from crosses between Robust and the resistant accessions CIho 14300, CIho 4780, and CIho 10644. The resistant locus Rsp1 was mapped to the short arm of chromosome 3H with two flanking ersity arrays technology (DArT) markers, bPb-6978 (8.9 cM) and bPb-9945 (16.3 cM), and two random lified polymorphic DNA (RAPD) markers, OPC2 441R (3.0 cM) and UBC285 158R (4.3 cM). The genes Rsp2 and Rsp3 were positioned on the short arm of barley chromosome 1H with two restriction fragment length polymorphism (RFLP), six DArT, and three RAPD markers. An RFLP marker, MWG938, and an RAPD marker, OPAH5 545C , were tightly associated with Rsp2 at a distance of 0 cM. Five DArT markers spanning the short arm of 1H surrounded Rsp3 at a distance of 2.3 and 5.8 cM, while two RAPD markers—OPBA12 314C (2.4 cM) in coupling and OPB17 451R (3.5 cM) in repulsion—flanked Rsp3. Molecular marker data associated with Rsp2 and Rsp3 indicated that the two genes are closely linked on chromosome 1HS. A total of 17 of 154 simple sequence repeats (SSRs) tested were associated with Rsp genes on chromosome 1H and 3H, and they were also integrated into genetic linkage maps of the three F 2 Robust populations. Knowledge about the map position of Rsp genes on barley chromosomes will be useful for breeding for SSLB resistance in barley and eventual gene cloning.
Publisher: Springer Science and Business Media LLC
Date: 04-12-2015
DOI: 10.1007/S00122-014-2437-1
Abstract: QTL identified for seedling and adult plant crown rot resistance in four partially resistant hexaploid wheat sources. PCR-based markers identified for use in marker-assisted selection. Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in many wheat-growing regions globally. Complete resistance to infection by F. pseudograminearum has not been observed in a wheat host, but germplasm with partial resistance to this pathogen has been identified. The partially resistant wheat hexaploid germplasm sources 2-49, Sunco, IRN497 and CPI133817 were investigated in both seedling and adult plant field trials to identify markers associated with the resistance which could be used in marker-assisted selection programs. Thirteen different quantitative trait loci (QTL) conditioning crown rot resistance were identified in the four different sources. Some QTL were only observed in seedling trials whereas others appeared to be adult plant specific. For ex le while the QTL on chromosomes 1AS, 1BS, and 4BS contributed by 2-49 and on 2BS contributed by Sunco were detected in both seedling and field trials, the QTL on 1DL present in 2-49 and the QTL on 3BL in IRN497 were only detected in seedling trials. Genetic correlations between field trials of the same population were strong, as were correlations between seedling trials of the same population. Low to moderate correlations were observed between seedling and field trials. Flanking markers, most of which are less than 10 cM apart, have now been identified for each of the regions associated with crown rot resistance.
Publisher: Canadian Science Publishing
Date: 02-2010
DOI: 10.1139/G09-091
Abstract: Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe (teleomorph Gibberella zeae (Schwein.) Petch), is one of the major diseases of barley (Hordeum vulgare L.) in eastern China, the Upper Midwest of the USA, and the eastern Prairie Provinces of Canada. To identify quantitative trait loci (QTL) controlling FHB resistance, a recombinant inbred line population (F 6:7 ) was developed from the cross Zhenongda 7/PI 643302. The population was phenotyped for resistance to FHB in two experiments in China and four experiments in North Dakota. Accumulation of the mycotoxin deoxynivalenol was determined in one experiment in China and two in North Dakota. Simplified composite interval mapping was performed on the whole genome level using the software MQTL. The QTL FHB-2 from PI 643302 for FHB resistance was found on the distal portion of chromosome 2HL in all six FHB screening environments. This QTL accounted for 14% of phenotypic variation over six environments and was not associated with heading date or plant height. The FHB resistance QTL FHB-2 detected near the end of chromosome 2HL is in a different location from those found previously and is therefore probably unique. Because the QTL was not contributed by the Chinese cultivar Zhenongda 7, it is likely a native QTL present in North American barley. The QTL FHB-2 represents the first reported QTL for native FHB resistance in North American germ plasm and has been given the provisional name Qrgz-2H-14. This QTL should be considered for pyramiding with other FHB QTL previously mapped.
Publisher: Elsevier BV
Date: 06-1996
Publisher: Naturalis Biodiversity Center
Date: 23-12-2015
Publisher: Elsevier BV
Date: 02-1994
Publisher: Elsevier BV
Date: 06-1994
Publisher: Elsevier BV
Date: 1994
Publisher: Scientific Societies
Date: 2017
DOI: 10.1094/PHYTO-03-16-0136-R
Abstract: Pyrenophora teres f. maculata, the causal agent of spot form of net blotch (SFNB), is an emerging pathogen of barley in the United States and Australia. Compared with net form of net blotch (NFNB), less is known in the U.S. Upper Midwest barley breeding programs about host resistance and quantitative trait loci (QTL) associated with SFNB in breeding lines. The main objective of this study was to identify QTL associated with SFNB resistance in the Upper Midwest two-rowed and six-rowed barley breeding programs using a genome-wide association study approach. A total of 376 breeding lines of barley were evaluated for SFNB resistance at the seedling stage in the greenhouse in Fargo in 2009. The lines were genotyped with 3,072 single nucleotide polymorphism (SNP) markers. Phenotypic evaluation showed a wide range of variability among populations from the four breeding programs and the two barley-row types. The two-rowed barley lines were more susceptible to SFNB than the six-rowed lines. Continuous distributions of SFNB severity indicate the quantitative nature of SFNB resistance. The mixed linear model (MLM) analysis, which included both population structure and kinship matrices, was used to identify significant SNP-SFNB associations. Principal component analysis was used to control false marker-trait association. The linkage disequilibrium (LD) estimates varied among chromosomes (10 to 20 cM). The MLM analysis identified 10 potential QTL in barley: SFNB-2H-8-10, SFNB-2H-38.03, SFNB-3H-58.64, SFNB-3H-78.53, SFNB-3H-91.88, SFNB-3H-117.1, SFNB-5H-155.3, SFNB-6H-5.4, SFNB-6H-33.74, and SFNB-7H-34.82. Among them, four QTL (SFNB-2H-8-10, SFNB-2H-38.03 SFNB-3H-78.53, and SFNB-3H-117.1) have not previously been published. Identification of SFNB resistant lines and QTL associated with SFNB resistance in this study will be useful in the development of barley genotypes with better SFNB resistance.
Publisher: Springer Science and Business Media LLC
Date: 2004
DOI: 10.1071/AP04012
Publisher: Elsevier BV
Date: 12-1995
Publisher: Springer Science and Business Media LLC
Date: 29-07-2015
Location: No location found
Location: Australia
No related grants have been discovered for Stephen Neate.