scholarly journals Identification of quantitative trait loci for resistance to two species of root-lesion nematode (Pratylenchus thornei and P. neglectus) in wheat

2005 ◽  
Vol 56 (4) ◽  
pp. 345 ◽  
Author(s):  
R. S. Zwart ◽  
J. P. Thompson ◽  
I. D. Godwin
Keyword(s):  
Quantitative Trait Loci ◽  
Microsatellite Markers ◽  
Phenotypic Variation ◽  
Quantitative Trait ◽  
Nematode Resistance ◽  
Root Lesion Nematode ◽  
Pratylenchus Thornei ◽  
Lesion Nematode ◽  
Chromosome Regions ◽  
Major Qtl

Pratylenchus thornei and P. neglectus are two species of root-lesion nematode that cause substantial yield losses in wheat. No commercially available wheat variety has resistance to both species. A doubled-haploid population developed from a cross between the synthetic hexaploid wheat line CPI133872 and the bread wheat Janz was used to locate and tag quantitative trait loci (QTLs) associated with resistance to both P. thornei and P. neglectus. Wheat plants were inoculated with both species of nematode in independent replicated glasshouse trials repeated over 2 years. Known locations of wheat microsatellite markers were used to construct a framework map. After an initial single-marker analysis to detect marker-trait linkages, chromosome regions associated with putative QTLs were targetted with microsatellite markers to increase map density in the chromosome regions of interest. In total, 148 wheat microsatellite markers and 21 amplified fragment length polymorphism markers were mapped. The codominant microsatellite marker Xbarc183 on the distal end of chromosome 6DS was allelic for resistance to both P. thornei and P. neglectus. The QTL were designated QRlnt.lrc-6D.1 and QRlnn.lrc-6D.1, for the 2 traits, respectively. The allele inherited from CPI133872 explained 22.0–24.2% of the phenotypic variation for P. thornei resistance, and the allele inherited from Janz accounted for 11.3–14.0% of the phenotypic variation for P. neglectus resistance. Composite interval mapping identified markers that flank a second major QTL on chromosome 6DL (QRlnt.lrc-6D.2) that explained 8.3–13.4% of the phenotypic variation for P. thornei resistance. An additional major QTL associated with P. neglectus resistance was detected on chromosome 4DS (QRlnn.lrc-4D.1) and explained a further 10.3–15.4% of the phenotypic variation. The identification and tagging of nematode resistance genes with molecular markers will allow appropriate allele combinations to be selected, which will aid the successful breeding of wheat with dual nematode resistance.

scholarly journals Quantitative trait loci for root lesion nematode (Pratylenchus thornei) resistance in Middle-Eastern landraces and their potential for introgression into Australian bread wheat

2005 ◽  
Vol 56 (10) ◽  
pp. 1059 ◽  
Author(s):  
A. L. Schmidt ◽  
C. L. McIntyre ◽  
J. Thompson ◽  
N. P. Seymour ◽  
C. J. Liu
Keyword(s):  
Quantitative Trait Loci ◽  
Phenotypic Variation ◽  
Quantitative Trait ◽  
Middle Eastern ◽  
Susceptibility Locus ◽  
Root Lesion Nematode ◽  
Pratylenchus Thornei ◽  
Single Marker ◽  
Marker Regression ◽  
Lesion Nematode

Plant parasitic nematodes are a major biotic cause of wheat yield loss in temperate wheat-growing regions. Previous studies using Australian germplasm and/or synthetic hexaploid lines have identified quantitative trait loci (QTLs) for root lesion nematode resistance on chromosomes 2B, 6D, and 7A. This study examines Pratylenchus thornei resistance in 2 Middle-Eastern landraces (AUS13124 and AUS4926), using doubled haploid populations generated by crossing with the susceptible Australian cultivar Janz. Single marker regression and QTL analysis identified resistance loci on chromosomes 2B, 3B, 6D, and 7A, and a susceptibility locus on chromosome 1B. The 2B and 6D loci, which have been reported to explain up to 19% and 24% of variation, respectively, in previous studies, made smaller contributions in the Middle-Eastern varieties, explaining 2–13% (2B) and 1–6% (6D) of phenotypic variation in these populations. The previously reported 7A locus (P. neglectus resistance) was detected through single marker regression only (AUS13124 × Janz – LRS = 4.1, P = 0.04292; AUS4926 × Janz – LRS = 9.6, P = 0.00195), with genotype at the microsatellite marker Xgwm350.3 accounting for 3–23% of phenotypic variation. The previously unreported resistance QTL, located on chromosome 3B, explained up to 24% of phenotypic variation, and the susceptibility locus on chromosome 1B explained up to 21%. The 3B locus was detected in both the AUS13124 × Janz (max. LRS = 20.13) and AUS4926 × Janz (max. LRS = 11.19) populations, and the 1B locus was detected in the AUS4926 × Janz population (max. LRS = 18.82) only.

A triumph of tolerance: managing the threat to wheat production by the root lesion nematode Pratylenchus thornei in the subtropical grain region of eastern Australia.

2021 ◽  
pp. 13-19
Author(s):  
Kirsty Owen
Keyword(s):  
Management Practices ◽  
Resistance Breeding ◽  
Nematode Resistance ◽  
Future Research ◽  
Root Lesion Nematode ◽  
Wheat Production ◽  
Production Region ◽  
Pratylenchus Thornei ◽  
Eastern Australia ◽  
Lesion Nematode

Abstract This chapter provides information on the economic importance, host range, geographical distribution, damage symptoms, biology and life cycle and interactions with other nematodes and pathogens of the root lesion nematode, Pratylenchus thornei, a severe and widespread threat to wheat production in the subtropical grain production region of eastern Australia. Some recommended integrated nematode management practices and future research for nematode resistance breeding are also presented.

scholarly journals Genomic Dissection of Peduncle Morphology in Barley through Nested Association Mapping

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Sebastian Zahn ◽  
Thomas Schmutzer ◽  
Klaus Pillen ◽  
Andreas Maurer
Keyword(s):  
Quantitative Trait Loci ◽  
Association Mapping ◽  
Cross Section ◽  
Quantitative Trait ◽  
Spring Barley ◽  
Raw Material ◽  
Total Thickness ◽  
Nested Association Mapping ◽  
Elite Cultivar ◽  
Major Qtl

Straw biomass and stability are crucial for stable yields. Moreover, straw harbors the potential to serve as a valuable raw material for bio-economic processes. The peduncle is the top part of the last shoot internode and carries the spike. This study investigates the genetic control of barley peduncle morphology. Therefore, 1411 BC1S3 lines of the nested association mapping (NAM) population “Halle Exotic Barley 25” (HEB-25), generated by crossing the spring barley elite cultivar Barke with an assortment of 25 exotic barley accessions, were used. Applying 50k Illumina Infinium iSelect SNP genotyping yielded new insights and a better understanding of the quantitative trait loci (QTL) involved in controlling the peduncle diameter traits, we found the total thickness of peduncle tissues and the area of the peduncle cross-section. We identified three major QTL regions on chromosomes 2H and 3H mainly impacting the traits. Remarkably, the exotic allele at the QTL on chromosome 3H improved all three traits investigated in this work. Introgressing this QTL in elite cultivars might facilitate to adjust peduncle morphology for improved plant stability or enlarged straw biomass production independent of flowering time and without detrimental effects on grain yield.

Identification of quantitative trait loci underlying lutein content in soybean seeds across multiple environments

2017 ◽  
Vol 155 (8) ◽  
pp. 1263-1271 ◽  
Author(s):  
W. L. TENG ◽  
W. J. FENG ◽  
J. Y. ZHANG ◽  
N. XIA ◽  
J. GUO ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Phenotypic Variation ◽  
Quantitative Trait ◽  
Average Distance ◽  
Recombinant Inbred Lines ◽  
Chromosome 9 ◽  
Soybean Seeds ◽  
Trait Loci ◽  
Breeding Programmes ◽  
Lutein Content

SUMMARYLutein benefits human health significantly, including that of the eyes, skin and heart. Therefore, increasing lutein content in soybean seeds is an important objective for breeding programmes. However, no information about soybean lutein-related quantitative trait loci (QTL) has been reported, as of 2016. The aim of the present study was to identify QTLs underlying the lutein content in soybean seeds. A population including 129 recombinant inbred lines was developed from the cross between ‘Dongnong46’ (lutein 13·10 µg/g) and ‘L-100’ (lutein 23·96 µg/g), which significantly differed in seed lutein contents. This population was grown in ten environments including Harbin in 2012, 2013, 2014 and 2015; Hulan in 2013, 2014 and 2015; and Acheng in 2013, 2014 and 2015. A total of 213 simple sequence repeat markers were used to construct the genetic linkage map, which covered approximately 3623·39 cM, with an average distance of 17·01 cM between markers. In the present study, eight QTLs associated with lutein content were found initially, which could explain 1·01–19·66% of the observed phenotypic variation in ten different tested environments. The phenotypic contribution of qLU-1 (located near BARC-Satt588 on chromosome 9 (Chr 9; linkage group (LG) K)) was >10% across seven tested environments, while qLU-2 (located near Satt192 of Chr 12 (LG H)) and qLU-3 (located near Satt353 of Chr12 (LGH)) could explain 5–10% of the observed phenotypic variation in more than seven environments, respectively. qLU-5, qLU-6, qLU-7 and qLU-8 could be detected in more than four environments. These eight QTLs were novel, and have considerable potential value for marker-assistant selection of higher lutein content in soybean lines.

Metabolomic profiling of wheat genotypes resistant and susceptible to root-lesion nematode Pratylenchus thornei

2021 ◽  
Author(s):  
Md Motiur Rahaman ◽  
Rebecca S. Zwart ◽  
Thusitha W. T. Rupasinghe ◽  
Helen L. Hayden ◽  
John P. Thompson
Keyword(s):  
Root Lesion Nematode ◽  
Wheat Genotypes ◽  
Metabolomic Profiling ◽  
Pratylenchus Thornei ◽  
Lesion Nematode

Fine mapping of root lesion nematode (Pratylenchus thornei) resistance loci on chromosomes 6D and 2B of wheat

2019 ◽  
Vol 133 (2) ◽  
pp. 635-652 ◽  
Author(s):  
Muhammad Shefatur Rahman ◽  
Katherine J. Linsell ◽  
Julian D. Taylor ◽  
Matthew J. Hayden ◽  
Nicholas C. Collins ◽  
...  
Keyword(s):  
Fine Mapping ◽  
Root Lesion Nematode ◽  
Pratylenchus Thornei ◽  
Lesion Nematode

scholarly journals Identification of quantitative trait loci associated with canopy temperature in soybean

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sumandeep K. Bazzer ◽  
Larry C. Purcell
Keyword(s):  
Quantitative Trait Loci ◽  
Phenotypic Variation ◽  
Quantitative Trait ◽  
Recombinant Inbred Lines ◽  
Canopy Temperature ◽  
Growth And Yield ◽  
Indirect Measure ◽  
Trait Loci ◽  
Genomic Regions ◽  
The Impact

Abstract A consistent risk for soybean (Glycine max L.) production is the impact of drought on growth and yield. Canopy temperature (CT) is an indirect measure of transpiration rate and stomatal conductance and may be valuable in distinguishing differences among genotypes in response to drought. The objective of this study was to map quantitative trait loci (QTLs) associated with CT using thermal infrared imaging in a population of recombinant inbred lines developed from a cross between KS4895 and Jackson. Heritability of CT was 35% when estimated across environments. QTL analysis identified 11 loci for CT distributed on eight chromosomes that individually explained between 4.6 and 12.3% of the phenotypic variation. The locus on Gm11 was identified in two individual environments and across environments and explained the highest proportion of phenotypic variation (9.3% to 11.5%) in CT. Several of these CT loci coincided with the genomic regions from previous studies associated with canopy wilting, canopy temperature, water use efficiency, and other morpho-physiological traits related with drought tolerance. Candidate genes with biological function related to transpiration, root development, and signal transduction underlie these putative CT loci. These genomic regions may be important resources in soybean breeding programs to improve tolerance to drought.

scholarly journals Mapping Quantitative Trait Loci for Resistance to Rice Blast

2011 ◽  
Vol 101 (2) ◽  
pp. 176-181 ◽  
Author(s):  
Y. Jia ◽  
G. Liu
Keyword(s):  
Quantitative Trait Loci ◽  
Phenotypic Variation ◽  
Quantitative Trait ◽  
Composite Interval Mapping ◽  
Rice Blast ◽  
Ssr Marker ◽  
Interval Mapping ◽  
Chromosome 8 ◽  
Chromosome 12 ◽  
Trait Loci

Quantitative trait loci (QTLs) conferring resistance to rice blast, caused by Magnaporthe oryzae, have been under-explored. In the present study, composite interval mapping was used to identify the QTLs that condition resistance to the 6 out of the 12 common races (IB1, IB45, IB49, IB54, IC17, and ID1) of M. oryzae using a recombinant inbred line (RIL) population derived from a cross of the moderately susceptible japonica cultivar Lemont with the moderately resistant indica cultivar Jasmine 85. Disease reactions of 227 F7 RILs were determined using a category scale of ratings from 0, representing the most resistant, to 5, representing the most susceptible. A total of nine QTLs responsive to different degrees of phenotypic variation ranging from 5.17 to 26.53% were mapped on chromosomes 3, 8, 9, 11, and 12: qBLAST3 at 1.9 centimorgans (cM) to simple sequence repeat (SSR) marker RM282 on chromosome 3 to IB45 accounting for 5.17%; qBLAST8.1 co-segregated with SSR marker RM1148 to IB49 accounting for 6.69%, qBLAST8.2 at 0.1 cM to SSR marker RM72 to IC17 on chromosome 8 accounting for 7.22%; qBLAST9.1 at 0.1 cM to SSR marker RM257 to IB54, qBLAST9.2 at 2.1 cM to SSR marker RM108, and qBLAST9.3 at 0.1 cM to SSR marker RM215 to IC17 on chromosome 9 accounting for 4.64, 7.62, and 4.49%; qBLAST11 at 2.2 cM to SSR marker RM244 to IB45 and IB54 on chromosome 11 accounting for 26.53 and 19.60%; qBLAST12.1 at 0.3 cM to SSR marker OSM89 to IB1 on chromosome 12 accounting for 5.44%; and qBLAST12.2 at 0.3 and 0.1 cM to SSR marker OSM89 to IB49 and ID1 on chromosome 12 accounting for 9.7 and 10.18% of phenotypic variation, respectively. This study demonstrates the usefulness of tagging blast QTLs using physiological races by composite interval mapping.

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