Browsing by Author "Hugh Wallwork"

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Exploring the possibility of obtaining terminal heat tolerance in a doubled haploid population of spring wheat (Triticum aestivum L.) in the eastern Gangetic plains of India
(2012) Chhavi Tiwari; Hugh Wallwork; Ram Dhari; B. Arun; V.K. Mishra; Arun K. Joshi
High temperature during grain filling stage causes significant yield losses to wheat in south Asia and many other parts of the world. One hundred and forty doubled haploid (DH) wheat lines (including parents), derived from the cross Berkut (heat susceptible) × Krichauff (heat tolerant), were grown in six environments comprising two dates of sowing in three consecutive years (2007-2008, 2008-2009, and 2009-2010) at Banaras Hindu University, Varanasi, India. The objective was to assess DH lines for heat tolerance and to identify superior lines under hot humid environments of the eastern Gangetic plains (EGP) of India. Considerable variation was observed for grain yield (GY), thousand grain weight (TGW), grain fill duration (GFD), and canopy temperature (CT). Likewise, considerable variation was also observed for heat susceptibility index (HSI) of GY, TGW, and GFD. The DH lines were grouped into four categories based on the HSI and around 5-10% lines were categorized as heat tolerant. A few lines yielded significantly more than the better parent and possessed good expression of other traits. The most promising 20 lines have been listed as sources of heat tolerance, with 3 lines better yielding than the superior parent Krichauff. The results demonstrated that it is possible to obtain lines that perform better for yield and yield related traits in heat stressed environments of the EGP of India. © 2012 Elsevier B.V.
Molecular mapping of high temperature tolerance in bread wheat adapted to the Eastern Gangetic Plain region of India
(Elsevier B.V., 2013) Chhavi Tiwari; Hugh Wallwork; Uttam Kumar; Ram Dhari; B. Arun; V.K. Mishra; M.P. Reynolds; Arun K. Joshi
The inheritance of tolerance to high temperature stress during the grain filling period was investigated via a QTL analysis based on 138 doubled haploid progeny of a cross between the wheat cultivars Berkut and Krichauff. Performance data were collected from three seasons, in each of which the material was planted both at the conventional time and a month later. A heat sensitivity index (HSI) was also used to monitor the effect of high temperature on grain yield, thousand grain weight, grain filling duration and canopy temperature. Using composite interval mapping, seven stable QTL were identified for HSI of traits, mapping to chromosomes 1D, 6B, 2D and 7A. Three of the QTL related to HSI of grain filling duration, two to thousand grain weight and one each to grain yield and canopy temperature. A region of chromosome 1D harbored a QTL determining HSI of both thousand grain weight and canopy temperature. The QTL analysis for the direct traits GY, TGW, GFD and CT led to detection of 22 QTLs spread over to 17 chromosomal regions. Of these 13 QTLs were shown under normal sown, while 9 under the heat stress. A QTL for TGW on chromosome 6B under normal sown co-located with HSI(TGW) QTL QHTgw.bhu-6BL. QTL. ×. environment interactions were not observed for any of the grain filling duration associated loci. © 2013 Elsevier B.V.
Molecular mapping of quantitative trait loci for zinc, iron and protein content in the grains of hexaploid wheat
(Springer Netherlands, 2016) Chhavi Tiwari; Hugh Wallwork; Balasubramaniam Arun; Vinod Kumar Mishra; Govindan Velu; James Stangoulis; Uttam Kumar; Arun Kumar Joshi
Understanding the genetic basis of micronutrient concentration in wheat grain may provide useful information to breed for biofortified varieties through marker assisted selection (MAS). One hundred and thirty eight doubled haploid progeny of a cross between the wheat cultivars ‘Berkut’ and ‘Krichauff’ were evaluated for 2 years at two locations on the eastern Gangetic plains of India under timely (November) sown conditions. Grains were evaluated for Zn and Fe concentrations by energy-dispersive X-ray fluorescence. Using composite interval mapping, three QTLs were identified; two for Zn (1B and 2B) with a QTL (2B) co-located for Fe and the third (1A), for protein. The QTL located on chromosome 1B (flanked by wmc036–cfa2129) and 2B (flanked by gwm120–wpt2430) for Zn explained up to 23.1 and 35.9 % of mean phenotypic variation respectively, whereas up to 22.2 % was explained by the Fe QTL co-located with the Zn QTL on chromosome 2B. A QTL for grain protein was detected on chromosome 1A and flanked by the markers, wpt9592 and GBM1153 which explained up to 17.7 % of the total phenotypic variation. With their detection over consecutive seasons, the detected QTLs appeared robust and useful for MAS. © 2015, Springer Science+Business Media Dordrecht.