Quantitative trait locus analysis of late maturity a-amylase in wheat using the doubled haploid population Cranbrook Halberd

2001 ◽  
Vol 52 (12) ◽  
pp. 1267 ◽  
Author(s):  
K. Mrva ◽  
D. J. Mares
Keyword(s):  
Quantitative Trait Locus ◽  
Doubled Haploid ◽  
Quantitative Trait ◽  
Triticum Aestivum L ◽  
Temperature Treatment ◽  
Doubled Haploid Population ◽  
Cool Temperature ◽  
Haploid Population ◽  
Late Maturity ◽  
Trait Locus

Mapping of the late maturity α-amylase (LMA) gene using quantitative trait locus (QTL) analysis represents an important step in identification of potential molecular markers that would greatly improve efficiency and accuracy of screening for LMA. QTL controlling the expression of LMA in wheat were detected in a doubled haploid (DH) cross/population derived from wheat (Triticum aestivum L. em. Thell) cultivars Cranbrook (LMA source) and Halberd (non-LMA). The DH population and parents were sown in replicated trials at Narrabri with sowing times differing by 2 weeks. Cool temperature treatment of detached tillers was used to induce expression of LMA in lines carrying the defect. The number of grains in ripe, treated tillers that contained high pI (malt, germination type) α-amylase isozymes was measured using an ELISA antibody kit highly specific for high pI isozymes. QTL analyses were conducted separately for each sowing, but results from both sowings were consistent and indicated that there was a highly significant (P < 0.001) QTL on the long arm of chromosome 7B (accounting for 31% of the variation in the first experiment), with Cranbrook contributing the higher value allele. A second QTL that accounted for 13% of the variation was found close to the centromere on chromosome 3B. Although it was less important than the QTL on 7B it was nevertheless still significant (P < 0.05).

Induction of late maturity a-amylase in wheat by cool temperature

2001 ◽  
Vol 52 (4) ◽  
pp. 477 ◽  
Author(s):  
K. Mrva ◽  
D. J. Mares
Keyword(s):  
Doubled Haploid ◽  
Single Gene ◽  
Temperature Treatment ◽  
Screening Tests ◽  
Doubled Haploid Population ◽  
Cool Temperature ◽  
Grain Development ◽  
Haploid Population ◽  
Late Maturity ◽  
Days After Anthesis

Wheat genotypes prone to late maturity α-amylase (LMA) produced high levels of germination-type (high pI isozymes) α-amylase following exposure to cool temperature during grain development. Plants grown in the glasshouse, plants grown in the field and transplanted to the glasshouse after flowering, and tillers taken from field or glasshouse grown plants all responded in a similar manner. Plants or detached tillers can therefore be used in screening tests to identify germplasm with the LMA genotype. The cool temperature treatment was effective when applied continuously from shortly after flowering until near-ripeness, or when limited to the phase of grain development (26–35 days after anthesis) in LMA-prone genotypes that appears to be most sensitive to cool temperature. Based on these observations, guidelines for screening wheat germplasm are proposed and the advantages of using detached tillers discussed. The detached tiller method was successfully applied to a range of genotypes, some of which were known to be prone to LMA, and to a doubled haploid population derived from the cross Janz (low amylase) BD159 (LMA genotype). The preliminary data from this population were consistent with control by a single gene and similar therefore to the model proposed previously for cv. Spica.

scholarly journals Mapping Quantitative Trait Loci for 1000-Grain Weight in a Double Haploid Population of Common Wheat

2020 ◽  
Vol 21 (11) ◽  
pp. 3960 ◽  
Author(s):  
Tao Liu ◽  
Lijun Wu ◽  
Xiaolong Gan ◽  
Wenjie Chen ◽  
Baolong Liu ◽  
...  
Keyword(s):  
Quantitative Trait ◽  
Genetic Distances ◽  
Snp Markers ◽  
Grain Weight ◽  
High Yield ◽  
Doubled Haploid Population ◽  
Phenotypic Variance ◽  
Yield Trait ◽  
Haploid Population ◽  
Trait Locus

Thousand-grain weight (TGW) is a very important yield trait of crops. In the present study, we performed quantitative trait locus (QTL) analysis of TGW in a doubled haploid population obtained from a cross between the bread wheat cultivar “Superb” and the breeding line “M321” using the wheat 55-k single-nucleotide polymorphism (SNP) genotyping assay. A genetic map containing 15,001 SNP markers spanning 2209.64 cM was constructed, and 9 QTLs were mapped to chromosomes 1A, 2D, 4B, 4D, 5A, 5D, 6A, and 6D based on analyses conducted in six experimental environments during 2015–2017. The effects of the QTLs qTgw.nwipb-4DS and qTgw.nwipb-6AL were shown to be strong and stable in different environments, explaining 15.31–32.43% and 21.34–29.46% of the observed phenotypic variance, and they were mapped within genetic distances of 2.609 cM and 5.256 cM, respectively. These novel QTLs may be used in marker-assisted selection in wheat high-yield breeding.

Localisation of quantitative trait loci for quality attributes in a doubled haploid population of wheat (Triticum aestivum L.)

Genome ◽  
2009 ◽  
Vol 52 (8) ◽  
pp. 701-715 ◽  
Author(s):  
R. Raman ◽  
H. Allen ◽  
S. Diffey ◽  
H. Raman ◽  
P. Martin ◽  
...  
Keyword(s):  
Doubled Haploid ◽  
Quantitative Trait ◽  
Development Time ◽  
Doubled Haploid Population ◽  
Whole Genome ◽  
Quality Traits ◽  
Dough Strength ◽  
Haploid Population ◽  
Dough Extensibility ◽  
Dough Development Time

Selection of wheat germplasm for a range of quality traits has been a challenging exercise because of the cost of testing, the variation within testing data, and a poor understanding of the underlying genetics. The objective of this study was to identify quantitative trait loci (QTLs) underlying quality traits in wheat. A doubled haploid population comprising 190 lines from Chara/WW2449 was grown in two different environments and evaluated for various quality traits. A molecular map comprising 362 markers based upon simple sequence repeat, sequence tagged microsatellite, glutenin, and DArT loci was constructed and subsequently exploited to identify QTLs using a whole-genome approach. Fifteen QTLs that were consistent in the two different environments were identified for thousand kernel mass, grain protein content, milling yield, flour protein content, flour colour, flour water absorption, dough development time, dough strength (extensograph height and resistance at 5 cm), and dough extensibility (extensograph length) using the whole genome average interval mapping approach. The amount of genetic variation explained by individual QTLs ranged from 3% to 49%. A number of QTLs associated with dough strength, dough extensibility, dough development time, and flour water absorption were located close to the glutenin Glu-B1 locus on chromosome 1B. Identification of the chromosomal location and effect of the QTLs influencing wheat quality may hasten the development of superior wheats for target markets via marker-assisted selection.

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