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Okechukwu E.C.,University of Nigeria | Agbo C.U.,University of Nigeria | Uguru M.I.,University of Nigeria | Ogbonnaya F.C.,Grains Research and Development Corporation GRDC
Chilean Journal of Agricultural Research | Year: 2016

Breeding for heat tolerance in bread wheat (Triticum aestivum L.) is a serious global concern due to the increasing threats of high temperature. Thus, 189 wheat genotypes coded from 1 to 189 were evaluated for heat tolerance in normal and late seasons in the International Centre for Agricultural Research in Dry Areas (ICARDA), Tel Hadya, Syria, from 2010 to 2012. The experiments were laid out in alpha lattice designs with two replicates. Data collected on the grain yield, days to heading and maturity, grain filling duration and plant height were subjected to restricted maximum likelihood (REML) analysis for generation of the best linear unbiased estimates (BLUEs). Very highly significant effects (p ≤ 0.001) of genotype, season, and genotype by season interaction on grain yield and other traits were obtained. The grain yield and other traits performance of the wheat genotypes were significantly (p ≤ 0.05) higher in the normal season than in the late season. Genotype 148 was among the 30 top grain yielding genotypes in all the environments, while genotypes 172 and 124 were among the top yielding genotypes in all the environments except in late season 2. The relative heat tolerance of the genotypes ranged from -33.69% to -77.95% in late season 1 vs. normal season 1 and -65.28% to -95.83% in late season 2 vs. normal season 2. The high variability obtained in the germplasm underlies sufficient genetic variability for improving heat tolerance in bread wheat. © 2016, Instituto de Investigaciones Agropecuarias, INIA. All rights reserved. Source


Tan M.-K.,Australian Department of Primary Industries and Fisheries | El-Bouhssini M.,Rabat Institute | Emebiri L.,Australian Department of Primary Industries and Fisheries | Wildman O.,Australian Department of Primary Industries and Fisheries | And 3 more authors.
Molecular Breeding | Year: 2015

The HfrDrd gene has been reported to be induced specifically in the wheat’s defence response to Hessian fly larvae and is not a general stress-responsive gene. The gene is located on chromosome 7DS with a homeologue on 7AS. In this study, two SNPs in the gene that result in amino acid substitutions in the dirigent-like protein have been identified. Both are C/T polymorphisms at nt position 86 and 143 in exon 1 of the gene. The first SNP (from 5′ end) causes an alanine-to-valine substitution. The second is a serine-to-leucine change and is located in the conserved dirigent domain. Both ‘T’ nucleotide SNPs are characteristic of the Hessian fly-resistant genotype, Iris (JX501668, JX501669). Only SNP 143 has been found to be significantly associated with Hessian fly resistance. One hundred and seventy-one Australian cultivars screened were susceptible and have the ‘C’ nucleotide at SNP 143. The ‘T’ SNP at nt 143 was found in thirteen resistant cultivars, and the heterozygous state was identified in four other resistant cultivars. This study has identified other resistant genotypes which do not carry the ‘T’ nucleotide at nt 143 in the gene. Their resistance mechanism possibly involves other Hessian fly-response (Hfr) genes. SNP 143 will be useful for deployment in developing varieties with the resistant HfrDrd allele. © 2015, Springer Science+Business Media Dordrecht. Source


Tadesse W.,International Center for Agricultural Research in the Dry Areas | Ogbonnaya F.C.,International Center for Agricultural Research in the Dry Areas | Ogbonnaya F.C.,Grains Research and Development Corporation GRDC | Jighly A.,International Center for Agricultural Research in the Dry Areas | And 4 more authors.
PLoS ONE | Year: 2015

The main goal of this study was to investigate the genetic basis of yield and grain quality traits in winter wheat genotypes using association mapping approach, and identify linked molecular markers for marker assisted selection. A total of 120 elite facultative/winter wheat genotypes were evaluated for yield, quality and other agronomic traits under rain-fed and irrigated conditions for two years (2011-2012) at the Tel Hadya station of ICARDA, Syria. The same genotypes were genotyped using 3,051 Diversity Array Technologies (DArT) markers, of which 1,586 were of known chromosome positions. The grain yield performance of the genotypes was highly significant both in rain-fed and irrigated sites. Average yield of the genotypes ranged from 2295 to 4038 kg/ha and 4268 to 7102 kg/ha under rain-fed and irrigated conditions, respectively. Protein content and alveograph strength (W) ranged from 13.6-16.1% and 217.6-375 Jx10-4, respectively. DArT markers wPt731910 (3B), wPt4680 (4A), wPt3509 (5A), wPt8183 (6B), and wPt0298 (2D) were significantly associated with yield under rain-fed conditions. Under irrigated condition, tPt4125 on chromosome 2B was significantly associated with yield explaining about 13% of the variation. Markers wPt2607 and wPt1482 on 5B were highly associated with protein content and alveograph strength explaining 16 and 14% of the variations, respectively. The elite genotypes have been distributed to many countries using ICARDA's International system for potential direct release and/or use as parents after local adaptation trials by the NARSs of respective countries. The QTLs identified in this study are recommended to be used for marker assisted selection after through validation using bi-parental populations. © 2015 Tadesse et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source


Abberton M.,International Institute Of Tropical Agriculture | Batley J.,University of Western Australia | Batley J.,University of Queensland | Bentley A.,The John Bingham Laboratory | And 29 more authors.
Plant Biotechnology Journal | Year: 2016

Summary: Agriculture is now facing the 'perfect storm' of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic-assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change. > © 2016 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd. Source


Joukhadar R.,University of Aleppo | El-Bouhssini M.,The International Center for Agricultural Research in Dry Areas | Jighly A.,The International Center for Agricultural Research in Dry Areas | Ogbonnaya F.C.,Grains Research and Development Corporation GRDC
Molecular Breeding | Year: 2013

Insect pests cause substantial damage to wheat production in many wheat-producing areas of the world. Amongst these, Hessian fly (HF), Russian wheat aphid (RWA), Sunn pest (SP), wheat stem saw fly (WSSF) and cereal leaf beetle (CLB) are the most damaging in the areas where they occur. Historically, the use of resistance genes in wheat has been the most effective, environmentally friendly, and cost-efficient approach to controlling pest infestations. In this study, we carried out a genome-wide association study with 2518 Diversity Arrays Technology markers which were polymorphic on 134 wheat genotypes with varying degrees of resistance to the five most destructive pests (HF, RWA, SP, WSSF and CLB) of wheat, using mixed linear model (MLM) analysis with population structure as a covariate. We identified 26 loci across the wheat genome linked to genes conferring resistance to these pests, of which 20 are potentially novel quantitative trait loci with significance values which ranged between 5 × 10-3 and 10-11. We used an in silico approach to identify probable candidate genes at some of the genomic regions and found that their functions varied from defense response with transferase activity to several genes of unknown function. Identification of potentially new loci associated with resistances to pests would contribute to more rapid marker-aided incorporation of new and diverse genes to develop new varieties with improved resistance against these pests. © 2013 Springer Science+Business Media Dordrecht. Source

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