The analysis of quantitative traits in wheat mapping populations

2001 ◽  
Vol 52 (12) ◽  
pp. 1195 ◽  
Author(s):  
P. J. Eckermann ◽  
A. P. Verbyla ◽  
B. R. Cullis ◽  
R. Thompson
Keyword(s):  
Doubled Haploid ◽  
Qtl Analysis ◽  
Field Trials ◽  
Major Effect ◽  
Field Variation ◽  
Percent Protein ◽  
Maturity Class ◽  
Highly Correlated ◽  
Standard Situation ◽  
Mapping Populations

This paper discusses the analysis of quantitative trait loci (QTLs) using molecular markers from a doubled haploid wheat mapping population arising from the Cranbrook Halberd cross. Two field trials are used to provide phenotypic information on the trait of interest, which is grain percentage protein. Methods for QTL analysis are reviewed together with methods for the analysis of field trials. The aim of the paper is to examine different approaches for QTL analysis, namely the conventional approach available in standard software, which ignores field variation, a 2-stage approach that provides adjusted phenotypic effects for a subsequent QTL analysis, and a joint marker and spatial analysis. The major effect, however, is the maturity class of the doubled haploid lines. Maturity and percent protein appear highly correlated genetically so QTL analysis shows marked changes if maturity is included as a covariate. More subtle changes occur due to field variation but this may not be the standard situation.

scholarly journals Salinity tolerance and Na+ exclusion in wheat: variability, genetics, mapping populations and QTL analysis

2011 ◽  
Vol 47 (Special Issue) ◽  
pp. S85-S93 ◽  
Author(s):  
Y. Shavrukov ◽  
N. Shamaya ◽  
M. Baho ◽  
J. Edwards ◽  
C. Ramsey ◽  
...  
Keyword(s):  
Bread Wheat ◽  
Salinity Tolerance ◽  
Qtl Analysis ◽  
Triticum Dicoccoides ◽  
Field Trials ◽  
Wide Range ◽  
Growing Conditions ◽  
Tolerance Gene ◽  
Tolerance To Salinity ◽  
Mapping Populations

A wide range of variability in both Na<sup>+</sup> exclusion and salinity tolerance was shown in Triticum dicoccoides and the best performing genotype, from Getit, was identified for further study and for crossing. In bread wheat, plants BC<sub>6</sub>F<sub>1</sub> from the cross Chinese Spring/line SQ1 showed less variability, but the line 1868 was identified as a potential source of tissue tolerance to salinity. Two Afghani durum landraces were identified among 179 screened, with approximately 50% lower Na<sup>+</sup> accumulation in shoots. Genetic analysis of F<sub>2</sub> progenies between landraces and durum wheat showed clear segregation indicating on the single, major salinity tolerance gene in the landraces. Further genetic and molecular analysis of the candidate gene and its localization is in the progress. QTL analysis of two non-pedigree related mapping populations of bread wheat, Cranbrook &times;&nbsp;Halberd and Excalibur &times; Kukri, showed one QTL in each population on the same region of chromosome 7AS, independent of year or growing conditions (both supported hydroponics and field trials), and a novel gene is expected to be associated with this QTL.

scholarly journals Assessment of Somaclonal Variation in Chrysan-themum (Dendranthema grandiflora Kitam.) using RAPD and Morphological Analysis

1970 ◽  
Vol 18 (2) ◽  
pp. 139-149 ◽  
Author(s):  
P. Kengkarj ◽  
P. Smitamana ◽  
Y. Fujime
Keyword(s):  
Somaclonal Variation ◽  
Morphological Changes ◽  
Field Trials ◽  
Plant Production ◽  
Dendranthema Grandiflora ◽  
Shape Deviation ◽  
Floral Color ◽  
Rapd Pattern ◽  
Morphological Differences ◽  
Highly Correlated

Novel chrysanthemum (Dendranthema grandiflora Kitam.) somaclones from seven commercial cultivars were obtained through the petal segments culture. Morphological variation of the derived clones observed from the field trials was found to be cultivar specific. The major variants within the same cultivar were found only color and inflorescence shape deviation, whereby leaf and stem characters remained unchanged. Distinct variations were found in the 'Pinkgin' cultivar that color changed from magenta to red. The morphological differences of the tested somaclones showed high correlation with the RAPD patterns analysis.  The morphological differences of the tested somaclones were shown to be highly correlated using RAPD pattern analysis. RAPD markers, using ten primers could better separate each cultivar at 80% similarity value. All the somaclones could be singly separated at 90% similarity. However, the higher level of variability of RAPD patterns in chrysanthemum rendered these RAPD fragments as good candidates for somaclonal and cultivar identification. The results from this study revealed the potential increase in range of floral color and morphological changes of petal segment culture, thus this technique would be effectively used for novel plant production. Key words:  Petal culture, Dendranthema grandiflora, Somaclonal variation, RAPD, Identification D.O.I. 10.3329/ptcb.v18i2.3396 Plant Tissue Cult. & Biotech. 18(2): 139-149, 2008 (December)

Improving Evaluation of Potato Resistance to Rhizoctonia solani infection by Optimizing Inoculum Method Combined with Toxin-based Assay

2020 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Xing Xing ◽  
Yayan Feng ◽  
Zhuo Yu ◽  
Jianjun Hao ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Seed Piece ◽  
Wheat Bran ◽  
Agar Medium ◽  
Stem Canker ◽  
Field Trials ◽  
Potato Seed ◽  
Potato Resistance ◽  
Highly Correlated ◽  
Potato Seedlings

Abstract Background: Rhizoctonia solani causes stem canker and significantly impacts the production of potato. Conventional assay to evaluate potato resistance using R. solani inoculum is time consuming. To establish an effective and fast assay, 20 potato germplasms were examined using both R. solani inoculum and R. solani-derived toxin (RS toxin). Results: In field trials of 2009 and 2010, wheat-bran-based inoculum of R. solani was incorporated at either 0, 2, 3, 4 or 5 g per seed piece in the soil followed by sowing potato seed pieces in the furrow. Stem canker was evaluated in the growing season. Inoculum of wheat-bran-based 2, 3, or 4 g could well distinguish resistance of potato germplasms. For a quick assay of resistance screening, a toxin-based method was established by treating potato seedlings with the toxin of R. solani (RS toxin). RS toxin was prepared by heating R. solani culture. Potato seedlings were obtained through tissue culture and grown in Murashige and Skoog medium. Seedlings at the stage of 12 cm in height were transferred into agar medium amended with RS toxin and incubated for eight days. The inhibition caused by RS toxin was positively correlated with toxin concentration. By evaluating various potato cultivars that have different sensitivities to toxin, the inhibition of potato stems sections and seedlings was from 33% to 100% and from 32% to 148%, respectively. Results of toxin-based evaluation were highly correlated with the field data using pathogen inoculum (r = 0.731, P < 0.01). Conclusions: Inoculation with wheat bran-mediated R. solani of 2, 3 or 4 g per seed piece was an effective method for the evaluation of potato resistance in field trials. The toxin-based assay could improve efficiency and speed of disease resistance evaluation of potato germplasms. Both assays showed that none of the 20 potato materials was completely resistant to R. solani. However, cultivar ‘Desiree’ had the lowest level of disease, whereas ‘Atlantic’, ‘Favorita’, and ‘Shepody’ showed the high susceptibility.

Yield response of barley germplasm to field variation in salinity quantified using the EM-38

1990 ◽  
Vol 30 (4) ◽  
pp. 551 ◽  
Author(s):  
PG Slavich ◽  
BJ Read ◽  
BR Cullis
Keyword(s):  
Soil Salinity ◽  
Field Trials ◽  
Yield Response ◽  
Soil Conditions ◽  
Yield Reduction ◽  
Field Variation ◽  
Secondary Salinisation ◽  
Salinity Response ◽  
Unit Increase ◽  
Barley Germplasm

Five field trials to screen a range of barley germplasm for tolerance to saline soil conditions were conducted on irrigation farms in southern New South Wales, in areas affected by secondary salinisation from shallow watertables. Three trials were located on heavy grey clay soils and 2 on red-brown earth soils. An electromagnetic soil conductivity meter (EM-38) was used to quantify the salinity of individual field plots. Cultivars were compared in terms of their grain yield response to soil salinity. Yields were significantly reduced by soil salinity at all sites except 1 on red-brown earth. Both genetic and site differences in salinity response were identified. The reduction in yield per unit increase in electrical conductivity of the saturated paste (EC,), averaged across sites, varied from 4.7% for Forrest to 6.6% for Schooner. However, the yield reduction per unit increase in EC,, averaged across cultivars, varied from 4.1% in a red-brown earth to 6.4% in heavy clays.

Gluten index compared with SDS-sedimentation volume for early generation selection for gluten strength in durum wheat

2010 ◽  
Vol 90 (1) ◽  
pp. 1-11 ◽  
Author(s):  
F R Clarke ◽  
J M Clarke ◽  
N A Ames ◽  
R E Knox ◽  
R J Ross
Keyword(s):  
Durum Wheat ◽  
Protein Concentration ◽  
Triticum Turgidum ◽  
Sodium Dodecyl ◽  
Field Trials ◽  
Gluten Strength ◽  
Sedimentation Volume ◽  
Selection For ◽  
Highly Correlated ◽  
Gluten Index

Gluten strength is an important end-use quality factor in durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.], affecting pasta manufacture and cooking quality. The objective of this research was to determine the inheritance and heritability of gluten index in comparison with the widely used SDS-sedimentation (sodium dodecyl sulphate) technique for selection for gluten strength. Seven durum populations were grown in replicated, multi-location, multi-year field trials in Saskatchewan, Canada, during the period 1995 to 2002. Gluten index and SDS-sedimentation volume were determined on all plots after harvest. Both traits were affected by genotype, and to a lesser extent by year or location. Genotype environmental interactions were generally minor. The majority of genotypes in each population had similar relative ranking for gluten index and SDS-sedimentation volume in each environment. Both traits were highly heritable, ranging from 0.80 to 0.97, and both were complexly inherited with estimates of effective factors ranging from 3 to 21. Gluten index and SDS-sedimentation volume were highly correlated, indicating that they are measuring similar aspects of gluten strength. SDS-sedimentation volume was positively associated with protein concentration (r2 = 0.52), but gluten index was not. Therefore, gluten index would be more desirable than SDS-sedimentation volume for use in selection where there are within-trial protein concentration trends.Key words: Gluten strength, SDS-sedimentation, gluten index, heritability, inheritance

QTL analysis of malting quality in barley based on the doubled-haploid progeny of two elite North American varieties representing different germplasm groups

2000 ◽  
Vol 101 (1-2) ◽  
pp. 173-184 ◽  
Author(s):  
L. A. Marquez-Cedillo ◽  
P. M. Hayes ◽  
B. L. Jones ◽  
A. Kleinhofs ◽  
W. G. Legge ◽  
...  
Keyword(s):  
Doubled Haploid ◽  
North American ◽  
Qtl Analysis ◽  
Malting Quality

scholarly journals Soil Calcium Status Unrelated to Tipburn of Romaine Lettuce

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1681-1684 ◽  
Author(s):  
Timothy K. Hartz ◽  
Paul R. Johnstone ◽  
Richard F. Smith ◽  
Michael D. Cahn
Keyword(s):  
Soil Solution ◽  
Calcium Nitrate ◽  
Field Capacity ◽  
Field Trials ◽  
Romaine Lettuce ◽  
Soil Calcium ◽  
Exchangeable Ca ◽  
Salinas Valley ◽  
Highly Correlated ◽  
A Charge

Application of calcium (Ca) fertilizers is a common practice of California lettuce growers to minimize the occurrence and severity of tipburn, particularly in romaine lettuce (Lactuca sativa L. var. longifolia Lam.). An evaluation of the effect of soil Ca availability on the severity of tipburn in romaine lettuce was conducted in the Salinas Valley of central California in 2005 to 2006. Twenty representative soils from this region were evaluated for Ca availability by ammonium acetate extraction, saturated paste extraction, and extraction of soil solution through centrifugation of soil at field-capacity moisture content. Soil solution Ca in these soils was generally high, ranging from 5 to 80 mmolc·L−1, representing 44% to 71% of cations on a charge basis. Soil solution Ca was highly correlated with saturated paste Ca (r 2 = 0.70) but not with exchangeable Ca (r 2 = 0.01). However, saturated paste extraction significantly underestimated soil solution Ca concentration (regression slope = 0.19). A survey of 15 commercial romaine lettuce fields showed tipburn severity to be unrelated to either leaf Ca concentration or soil Ca availability. The most severe tipburn was observed in fields in which transpiration was reduced by foggy weather during the final 2 weeks of growth. Ca fertilizers (calcium nitrate, calcium thiosulfate, and calcium chloride) applied through drip irrigation during the final weeks of lettuce growth were ineffective in increasing romaine leaf Ca concentration in three field trials; tipburn was present in only one trial, and Ca fertigation had no effect on tipburn severity. We conclude that under typical field conditions in this region, tipburn severity is primarily a function of environmental conditions. Soil Ca availability plays no substantive role in tipburn severity, and Ca fertigation does not improve lettuce Ca uptake or reduce tipburn.

scholarly journals Limited genetic parallels underlie convergent evolution of quantitative pattern variation in mimetic butterflies

2020 ◽  
Author(s):  
Hannah E. Bainbridge ◽  
Melanie N. Brien ◽  
Carlos Morochz ◽  
Patricio A. Salazar ◽  
Pasi Rastas ◽  
...  
Keyword(s):  
Quantitative Trait Locus ◽  
Qtl Analysis ◽  
Quantitative Trait ◽  
Convergent Evolution ◽  
Genetic Basis ◽  
Major Effect ◽  
Multivariate Approach ◽  
Trait Variation ◽  
Heliconius Melpomene ◽  
Trait Locus

AbstractMimetic systems allow us to address the question of whether the same genes control similar phenotypes in different species. Although widespread parallels have been found for major effect loci, much less is known about genes that control quantitative trait variation. In this study, we identify and compare the loci that control subtle changes in the size and shape of forewing pattern elements in two Heliconius butterfly co-mimics. We use quantitative trait locus (QTL) analysis with a multivariate phenotyping approach to map the variation in red pattern elements across the whole forewing surface of Heliconius erato and Heliconius melpomene. These results are compared to a QTL analysis of univariate trait changes, and show that our resolution for identifying small effect loci is improved with the multivariate approach. QTL likely corresponding to the known patterning gene optix were found in both species but otherwise, a remarkably low level of genetic parallelism was found. This lack of similarity indicates that the genetic basis of convergent traits may not be as predictable as assumed from studies that focus solely on Mendelian traits.

scholarly journals Effect of superphosphate, lime, and cocksfoot on summer dry hill country pasture production

1990 ◽  
pp. 131-134
Author(s):  
A.D. Mackay ◽  
R.W. Tillmanz ◽  
W.J. Parker ◽  
D.J. Barker
Keyword(s):  
Factorial Design ◽  
Field Trials ◽  
Major Effect ◽  
Pasture Production ◽  
Hill Country ◽  
Autumn And Winter ◽  
Term Field

Two long-term field trials were carried out in the Wairarapa. One, established on a resident ryegrass/browntop pasture in 1981, compared the effect of lime (0, 1.25, 2.50 and 5.00 t/ha) and superphosphate (0,125,250 and 500 kg/ha) in a 4 x 4 factorial design. The second, started in 1985, compared the response of a similar pasture with that of au oversowu 'Grasslands Wana' cocksfoot pasture to 4 rates of lime (0, 1.25, 2.5 and 5.0 t/ha). The major effect of the traditional fertiliser policy was increased spring and, under favourable conditions, increased summer and autumn production. The introduction of cocksfoot guaranteed a more predictable summer supply of feed and improved autumn and winter production. An assessment of 3 methods of designating fertiliser expenditure suggests that continuation with maintenance fertiliser inputs, or a 2.3: 1 substitution of fertiliser expenditure for cocksfoot establishment, would provide greater benefits than discontinuing fertiliser inputs. Keywords 'Grasslands Wana', cocksfoot, lime, superphosphate, ferthser, strategies, hill country

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