Browsing by Author "Arun K. Joshi"

Now showing 1 - 20 of 34

A new technique for monoconidial culture of the most aggressive isolate in a given population of Bipolaris sorokiniana, cause of foliar spot blotch in wheat and barley
(2007) Dharmendra Kumar; Ramesh Chand; Lal C. Prasad; Arun K. Joshi
We developed a new technique for monoconidial culture of the most aggressive isolate in a given population of Bipolaris sorokiniana, to facilitate the evaluation of spot blotch resistance in wheat and barley. Blotched portions of infected barley leaves were placed on a glass slide in a moist chamber for production of conidia by associated fungal hyphae. Conidia were collected separately and grown on water agar discs. Individual water agar discs having conidium growth were inoculated on barley leaves. The conidium producing the earliest symptom with the largest lesion was considered most aggressive. This lesion was incubated in a moist chamber and the conidial offspring were tested for pathogenicity. When a uniform infection was observed, a small piece of the lesion was cut using a sterilized scalpel, surface sterilized with NaOCl, and inoculated in the centre of Petri dishes containing potato dextrose agar medium. The inoculated Petri dishes were incubated at 25 ± 1°C to yield monoconidial cultures of the most aggressive isolate. Variability in symptom expression caused by the most aggressive isolate of a given population was much less than variability in symptom expression caused by all isolates collectively. The techniques will be useful for plant pathologists and breeders in screening for spot blotch resistance in wheat and barley. © 2007 Springer Science+Business Media B.V.
Association of staygreen trait with canopy temperature depression and yield traits under terminal heat stress in wheat (Triticum aestivum L.)
(Kluwer Academic Publishers, 2013) Maya Kumari; R.N. Pudake; V.P. Singh; Arun K. Joshi
The presence or absence of the staygreen trait was screened for 3 consecutive years in 963 wheat lines from various sources, including Indian and CIMMYT germplasm. Staygreen was assessed at the late dough stage by visual scoring (0-9 scale) and the leaf area under greenness (LAUG) measurement. Around 5. 5 % of the lines were staygreen, 10. 5 % were moderately staygreen, and the remaining lines showed little or no expression of the trait. One hundred lines showing diversity for the staygreen trait were sown under three different sowing dates (timely, late and very late) for 3 consecutive years in three replications to determine the association of staygreen with heat tolerance. There was a decline in yield, biomass, grain filling duration (GFD) and 1,000 grain weight (TGW) under late and very late sowing conditions owing to terminal stress at anthesis and later stages. However, the decline was relatively less in staygreen genotypes compared to the non-staygreen (NSG) ones. The correlation study showed that LAUG and canopy temperature depression (CTD) were strongly correlated. LAUG and CTD were also significantly associated with grain yield, GFD and biomass. To further confirm the association of the staygreen trait with terminal heat stress, individual F2-derived F7 progenies from the cross of the 'staygreen' lines with NSG were evaluated for yield and yield traits at the three sowing dates. In each cross, the staygreen progenies showed a significantly smaller decline in yield and TGW under heat stress than the NSG progenies. These results appear to suggest an association between the staygreen trait and terminal heat stress and, thereby, that the staygreen trait could be used as a morphological marker in wheat to screen for heat tolerance. © 2012 Springer Science+Business Media B.V.
Biochemical and histochemical parameters associated with slow blighting of spot blotch (Bipolaris sorokiniana (Sacc.) Shoem.) in wheat (Triticum spp.); [Kviečių (Triticum spp.) biocheminiai ir histocheminiai rodikliai, susiję su rudadėme dryžlige (Bipolaris sorokiniana (Sacc.) Shoem.)]
(Lithuanian Research Centre for Agriculture and Forestry; Vytautas Magnus University, 2013) Musaed Eisa; Ramesh Chand; Arun K. Joshi
Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat (Triticum spp.) in warm and humid wheat growing regions of the world. Area under the disease progress curve (AUDPC) in field experiment was used to find out the role of total phenol content (TPC), phenylalanine ammonia-lyase (PAL) activity and lignin deposition in the development of slow blight. Ten recombinant inbred lines (RILs) of spring wheat obtained from the cross between the susceptible parent 'Sonalika' and the resistant parent 'Yangmai 6' along with their parental genotypes were scored for disease severity (DS), AUDPC and lesion size in a field experiment on spot blotch. These lines were also evaluated for TPC, PAL and lignin deposition. The minimum DS, AUDPC and lesion size were recorded in the resistant parent 'Yangmai 6' (13%, 116.04 and 0.23 cm2, respectively) and RILs (18%, 113.3 and 0.27 cm2, respectively in RIL83 and RIL89) which associated with an elevated level of phenol content (395 mg g-1 fresh weight (wt) at 48 hours after inoculation (hai), PAL (928.41 μmoles cinnamic acid (cna) mg-1 fresh wt) and higher quantity of lignin (84%). While DS, AUDPC and lesion size were comparatively higher in the susceptible parent 'Sonalika' as well as susceptible RILs (100%, 938.27 and 3.43 cm2, respectively). Mean TPC (133.5 mg g-1 fresh wt 24 hai, respectively), PAL (248.8 μmoles cna mg-1 fresh wt) and lignin (10%) were significantly lower in the susceptible genotype 'Sonalika' and suscptible RILs. The study indicated that enhanced level of TPC, PAL and higher lignin deposition led to the development of slow blighting of spot blotch in terms of lower AUDPC and smaller lesion size in resistant RILs of wheat.
Biochemical and histochemical traits: A promising way to screen resistance against spot blotch (Bipolaris sorokiniana) of wheat
(2013) Musaed Eisa; Ramesh Chand; Arun K. Joshi
Spot blotch caused by Bipolaris sorokiniana is a serious disease of wheat in warmer and humid regions of the world. Three blighting components, area under disease progress curve (AUDPC), disease severity (DS) and lesion size along with four biochemical and histochemical factors viz., total phenol content (TPC), chlorophyll content (CHC), phenylalanine ammonia-lyase (PAL) activity and lignin deposition were studied in a recombinant inbred lines (RILs) population involving parents "Sonalika" (susceptible) and "Yangmai 6" (resistant). The objective was to identify one or more robust and reliable tools of resistance, physical, biochemical or histochemical, to facilitate selection against spot blotch. The DS, AUDPC and lesion size were higher in the susceptible parent and RILs compared to the resistant. The mean TPC (246 mg Gallic acid g-1 fresh weight) of the most resistant RIL was significantly higher than the most susceptible (181.5 mg Gallic acid g-1 fresh weight) at 48 h after inoculation (hai). The mean SPAD value for CHC varied between 48.8 in the most resistant RILs to 8.8 in the most susceptible, while the mean PAL varied between 928.4 and 96.0 μmoles Cinnamic acid mg-1 fresh weight at 48 hai in resistant and susceptible RILs, respectively. Likewise, lignin deposition was significantly higher in resistant RILs compared to the susceptible. The biochemical and histochemical parameters were significantly correlated with resistance and appeared robust for facilitating screening of breeding material and for increased precision in phenotyping against spot blotch. © 2013 KNPV.
CHALLENGES and PROSPECTS of WHEAT PRODUCTION in Bhutan: A REVIEW
(Cambridge University Press, 2018) Sangay Tshewang; Robert F. Park; Bhagirath S. Chauhan; Arun K. Joshi
Bhutan is a small country in the Himalayan mountains where subsistence agriculture is practiced due to small land holdings and undulating mountainous terrains. Due to diverse altitudinal and agro-ecological environments, many food crops are cultivated. Wheat is currently a secondary cereal, grown over an area of 1,964 ha with a total production of 3,465 Mg. While there are enormous opportunities to increase wheat production in Bhutan, it is challenged by numerous biotic and socio-economic factors such as labour shortage and low economic return. Among the biotic constraints, stripe rust and leaf rust are the most important diseases. Stem rust has not yet been reported. Poor crop nutrition, both through low soil fertility and inadequate external supply, also results in low productivity. In addition, better remunerative crops and affordable-imported products discourage wheat production. However, the availability and accessibility to higher yielding disease-resistant varieties, fertilization (both organic and inorganic), appropriate seed rate, optimum planting time, mechanization, rotation with legumes and expansion of wheat area are some measures that will play a crucial role in managing sustainable wheat production in Bhutan. In this paper, we provide a brief overview of the current scenario of wheat production, discuss the constraints and provide strategic guidance to improve wheat production in Bhutan. Copyright © Cambridge University Press 2017.
Combining ability analysis for grain filling duration and yield traits in spring wheat (Triticum aestivum L. em. Thell.)
(Brazilian Journal of Genetics, 2007) Kamaluddin; Rishi M. Singh; Lal C. Prasad; Malik Z. Abdin; Arun K. Joshi
A diallel analysis of wheat (Triticum aestivum L. em. Thell) parents (n = 11) and their F1 (n = 55) and F2 (n = 55) offspring was carried out for the following four traits: grain filling duration (GFD), GFD for growing degree days (GDD), 1000 seed weight and seed yield per plant. Analysis of variance for general combining ability (GCA) and specific combining ability (SCA) displayed significant F1 and F2 general and specific combining ability effects for the four traits studied. For all the traits the GCA effects were relatively more important than the SCA effects, indicating that additive genetic effects were predominant. Crosses displaying high SCA effects for grain filling duration, seed weight and yield were observed to be derived from parents having various types of GCA effects (high x high, high x low, low x low and medium x low). The single seed descent method can be applied to exploit additive gene effects whereas dominance gene effects could be valuable in hybrid wheat breeding programs. Among the parents, genotypes from the International Maize and Wheat Improvement Center (Centro Internacional de Mejoramiento de Maíz y Trigo, CIMMYT) as well as South Asia were found to be superior general combiners for grain filling duration. Likewise, crosses involving diverse parents from CIMMYT and South Asia showed significant SCA effects for grain filling duration and other traits. Copyright by the Brazilian Society of Genetics.
Correction to: Strategic crossing of biomass and harvest index—source and sink—achieves genetic gains in wheat (Euphytica, (2017), 213, 257, 10.1007/s10681-017-2040-z)
(Springer Netherlands, 2018) Matthew P. Reynolds; Alistair J. D. Pask; William J. E. Hoppitt; Kai Sonder; Sivakumar Sukumaran; Gemma Molero; Carolina Saint Pierre; Thomas Payne; Ravi P. Singh; Hans J. Braun; Fernanda G. Gonzalez; Ignacio I. Terrile; Naresh C. D. Barma; Abdul Hakim; Zhonghu He; Zheru Fan; Dario Novoselovic; Maher Maghraby; Khaled I. M. Gad; ElHusseiny G. Galal; Adel Hagras; Mohamed M. Mohamed; Abdul Fatah A. Morad; Uttam Kumar; Gyanendra P. Singh; Rudra Naik; Ishwar K. Kalappanavar; Suma Biradar; Sakuru V. Sai Prasad; Ravish Chatrath; Indu Sharma; Kishor Panchabhai; Virinder S. Sohu; Gurvinder S. Mavi; Vinod K. Mishra; Arun Balasubramaniam; Mohammad R. Jalal-Kamali; Manoochehr Khodarahmi; Manoochehr Dastfal; Seyed M. Tabib-Ghaffari; Jabbar Jafarby; Ahmad R. Nikzad; Hossein Akbari Moghaddam; Hassan Ghojogh; Asghar Mehraban; Ernesto Solís-Moya; Miguel A. Camacho-Casas; Pedro Figueroa-López; Javier Ireta-Moreno; Jorge I. Alvarado-Padilla; Alberto Borbón-Gracia; Araceli Torres; Yei Nayeli Quiche; Shesh R. Upadhyay; Deepak Pandey; Muhammad Imtiaz; Monsif U. Rehman; Manzoor Hussain; Makhdoom Hussain; Riaz Ud-Din; Maqsood Qamar; Muhammad Sohail; Muhammad Y. Mujahid; Gulzar Ahmad; Abdul J. Khan; Mahboob A. Sial; Pompiliu Mustatea; Eben von Well; Moses Ncala; Stephan de Groot; Abdelraheem H. A. Hussein; Izzat S. A. Tahir; Amani A. M. Idris; Hala M. M. Elamein; Yann Manes; Arun K. Joshi
The original article was corrected. Author Muhammad Kundi should instead read: Muhammad Sohail. © 2017, Springer Science+Business Media B.V., part of Springer Nature.
Development and characterization of the 4th CSISA-spot blotch nursery of bread wheat
(Kluwer Academic Publishers, 2015) Pawan K. Singh; Yong Zhang; Xinyao He; Ravi P. Singh; Ramesh Chand; Vinod K. Mishra; Paritosh K. Malaker; Mostofa A. Reza; Mokhlesur M. Rahman; Rabiul Islam; Apurba K. Chowdhury; Prateek M. Bhattacharya; Ishwar K. Kalappanavar; José Crossa; Arun K. Joshi
Spot blotch (SB) caused by Cochliobolus sativus is a serious biotic stress to wheat in warm and humid areas, particularly South Asia (SA). In order to support South Asian farmers to combat SB, International Maize and Wheat Improvement Center (CIMMYT) established an efficient SB screening system at Agua Fria, Mexico and developed a nursery under the project - Cereal Systems Initiative for South Asia (CSISA). The materials used to form CSISA-SB nursery were selected from advanced breeding lines from different wheat breeding programs at CIMMYT. Seed of CSISA-SB nursery was produced at disease-free plots at El Batan and Mexicali, and distributed to SA after rigorous seed health checks. The 4th CSISA-SB, made available in 2012, comprised 50 entries including two resistant and two susceptible checks. The nursery was evaluated in seven locations in Mexico, India, and Bangladesh in the 2012–13 cropping season. The results indicated that although few lines exhibited stable resistance across locations due to strong G × E interaction, promising lines with SB resistance and good agronomy can still be identified in each location. The two most promising lines showing consistent spot blotch resistance across the regions were CHUKUI#1 (CIMMYT germplasm bank identification number, GID 6178575) and VAYI#1 (GID 6279248). These lines could be promoted as sources of SB resistance or directly released as cultivars in SA. © 2015, Koninklijke Nederlandse Planteziektenkundige Vereniging.
Dissecting Quantitative Trait Loci for Spot Blotch Resistance in South Asia Using Two Wheat Recombinant Inbred Line Populations
(Frontiers Media S.A., 2021) Chandan Roy; Navin C. Gahtyari; Xinyao He; Vinod K. Mishra; Ramesh Chand; Arun K. Joshi; Pawan K. Singh
Spot blotch (SB) disease causes significant yield loss in wheat production in the warm and humid regions of the eastern Gangetic plains (EGP) of South Asia (SA). Most of the cultivated varieties in the eastern part of SA are affected by SB under favorable climatic conditions. To understand the nature of SB resistance and map the underlying resistant loci effective in SA, two bi-parental mapping populations were evaluated for 3 years, i.e., 2013–2015 for the BARTAI × CIANO T79 population (denoted as BC) and 2014–2016 for the CASCABEL × CIANO T79 population (CC), at Varanasi, Uttar Pradesh, India. DArTSeq genotyping-by-sequencing (GBS) platform was used for genotyping of the populations. Distribution of disease reaction of genotypes in both populations was continuous, revealing the quantitative nature of resistance. Significant “genotype,” “year,” and “genotype × year” interactions for SB were observed. Linkage map with the genome coverage of 8,598.3 and 9,024.7 cM in the BC and CC population, respectively, was observed. Two quantitative trait loci (QTLs) were detected on chromosomes 1A and 4D in the BC population with an average contribution of 4.01 and 12.23% of the total phenotypic variation (PV), respectively. Seven stable QTLs were detected on chromosomes 1B, 5A, 5B, 6A, 7A, and 7B in the CC population explaining 2.89–10.32% of PV and collectively 39.91% of the total PV. The QTL detected at the distal end of 5A chromosome contributed 10.32% of the total PV. The QTLs on 6A and 7B in CC could be new, and the one on 5B may represent the Sb2 gene. These QTLs could be used in SB resistance cultivar development for SA. © Copyright © 2021 Roy, Gahtyari, He, Mishra, Chand, Joshi and Singh.
Diversity in Indian barley (Hordeum vulgare) cultivars and identification of genotype-specific fingerprints using microsatellite markers
(Springer India, 2013) S.K. Jaiswal; Shree P. Pandey; S. Sharma; R. Prasad; L.C. Prasad; R.P.S. Verma; Arun K. Joshi
[No abstract available]
Elucidation of defense-related signaling responses to spot blotch infection in bread wheat (Triticum aestivum L.)
(Blackwell Publishing Ltd, 2016) Ranabir Sahu; Murali Sharaff; Maitree Pradhan; Avinash Sethi; Tirthankar Bandyopadhyay; Vinod K. Mishra; Ramesh Chand; Apurba K. Chowdhury; Arun K. Joshi; Shree P. Pandey
Spot blotch disease, caused by Bipolaris sorokiniana, is an important threat to wheat, causing an annual loss of ~17%. Under epidemic conditions, these losses may be 100%, yet the molecular responses of wheat to spot blotch remain almost uncharacterized. Moreover, defense-related phytohormone signaling genes have been poorly characterized in wheat. Here, we have identified 18 central components of salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and enhanced disease susceptibility 1 (EDS1) signaling pathways as well as the genes of the phenylpropanoid pathway in wheat. In time-course experiments, we characterized the reprogramming of expression of these pathways in two contrasting genotypes: Yangmai #6 (resistant to spot blotch) and Sonalika (susceptible to spot blotch). We further evaluated the performance of a population of recombinant inbred lines (RILs) by crossing Yangmai#6 and Sonalika (parents) and subsequent selfing to F10 under field conditions in trials at multiple locations. We characterized the reprogramming of defense-related signaling in these RILs as a consequence of spot blotch attack. During resistance to spot blotch attack, wheat strongly elicits SA signaling (SA biogenesis as well as the NPR1-dependent signaling pathway), along with WRKY33 transcription factor, followed by an enhanced expression of phenylpropanoid pathway genes. These may lead to accumulation of phenolics-based defense metabolites that may render resistance against spot blotch. JA signaling may synergistically contribute to the resistance. Failure to elicit SA (and possibly JA) signaling may lead to susceptibility against spot blotch infection in wheat. © 2016 The Authors. © 2016 John Wiley & Sons Ltd.
Enhanced resistance in wheat against stem rust achieved by marker assisted backcrossing involving three independent Sr genes
(Elsevier, 2015) Punam S. Yadav; V.K. Mishra; B. Arun; R. Chand; M.K. Vishwakarma; N.K. Vasistha; A.N. Mishra; I.K. Kalappanavar; Arun K. Joshi
Marker assisted backcrossing (MABC) was used to transfer the three stem rust (Puccinia graminis tritici) resistant genes Sr25, SrWeb and Sr50 into the popular Indian wheat cv. HUW234. The donor was the CIMMYT breeding line PMBWIR4, and each of the target genes was marked by a simple PCR assay. A three step screening strategy was adopted: the first screen comprised foreground selection, the second used markers lying close to the introgression borders to reduce the extent of linkage drag, and the last was background selection based on 149 informative microsatellite assays. Based on the background selection outcomes, at the BC1F1 generation the proportion of the genome fixed for cv. HUW234 alleles ranged from 55% to 67%. Three BC1F1 individuals were crossed a second time with cv. HUW234, resulting in the identification of six BC2F3 families carrying all three target Sr genes; the proportion of their genome inherited from cv. HUW234 ranged from 86% to 92%. BC2F4 and BC2F5 material was planted at three different locations under both disease-free and artificially induced epiphytotic conditions. Compared to recurrent parent, the improved versions of cv. HUW234 displayed significantly superior resistance to stem rust, and their agronomic performance was as good as, or even marginally better than that of the source cultivar. © 2015.
Enhancing spot blotch resistance in wheat by marker-aided backcross breeding
(Springer Netherlands, 2016) Neeraj K. Vasistha; Arun Balasubramaniam; Vinod K. Mishra; Ramesh Chand; Jayasudha Srinivasa; Punam S. Yadav; Arun K. Joshi
The cultivar HUW234 is well adapted and widely grown throughout the Eastern Gangetic plains (EGP) of India. However, popular cultivars of EGP are highly susceptible to the spot blotch disease caused by Bipolaris sorokiniana. The production is highly affected, thereby exerting pressure on the livelihood of the poor and marginal farmers of this region. Two parallel backcross programs were conducted to transfer resistance against spot blotch in the susceptible cultivar HUW 234. The two donor parents were Chirya 3 and Ning 8201. One program targeted the locus QSb.bhu-2A, while the second focused on the two loci Qsb.bhu-2A and Qsb.bhu-5B. Foreground selection was achieved using SSR markers linked to the target(s), and background selection was based on a set of well distributed SSRs. Ten resistant BC3F3 selections were made in Chirya 3 × HUW 234 and 15 in the Ning 8201 × HUW 234. Based on background selection marker genotype, the genetic similarity of the selected BC3F3individuals with the recipient parent reached as high as 94.3 %. The BC3F3selections and those made in BC3F4 and BC3F5showed improved spot blotch resistance in the field, and also yielded better than the recipient parent in presence of the disease. © 2015, Springer Science+Business Media Dordrecht.
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.
Expression analysis of hormonal pathways and defense associated genes in gamma-rays mutagenized wheat genotypes against combined stresses of spot blotch and terminal heat
(Elsevier B.V., 2022) G Mahendra Singh; SrinathaReddy S; Gaurav Sharma; Suman Bakshi; Uttam Kumar; Pradeep Bhati; Sanjay J. Jambhulkar; Ramesh Chand; Arun K. Joshi; Vinod K. Mishra; Sandeep Sharma
Wheat (Tritium aestivum L.) productivity is severely hampered by various pathogens and changing climatic conditions. Spot blotch and terminal heat stress are the major constraints of wheat production in the eastern Gangetic plains of India. To identify novel breeding sources and to understand underlying resistance mechanisms, forty-four gamma rays mutagenized wheat genotypes, derived from three different parents were screened under favourable agro-ecological conditions for spot blotch and terminal heat stress. Ten mutants showed reduced spot blotch infection calculated based on Area Under Disease Progress Curve (AUDPC), than their respective parents. The mutant TAW41 had the least infection (AUDPC: 354.32), significantly lower than its parent HD2967 (AUDPC: 675.51) and other checks. TAW41 also had a higher Normalized Difference Vegetation Index (NDVI) and chlorophyll content than the parent. Gene expression analysis of TAW41 showed differential accumulation of transcripts involved in hormonal pathways (Salicylic acid, Jasmonic acid, and ethylene) and other defense-associated genes, indicating that TAW41 might have unique resistance mechanism that facilitates this genotype to perform better against the combined stress of spot blotch and terminal heat. Hence, mutant TAW41 has been identified as a novel source of resistance that could be exploited in wheat improvement programmes to enhance tolerance to spot blotch and terminal heat stress. © 2021 The Authors
Genomic prediction for grain zinc and iron concentrations in spring wheat
(Springer Verlag, 2016) Govindan Velu; Jose Crossa; Ravi P. Singh; Yuanfeng Hao; Susanne Dreisigacker; Paulino Perez-Rodriguez; Arun K. Joshi; Ravish Chatrath; Vikas Gupta; Arun Balasubramaniam; Chhavi Tiwari; Vinod K. Mishra; Virinder Singh Sohu; Gurvinder Singh Mavi
Key message: Predictability estimated through cross-validation approach showed moderate to high level; hence, genomic selection approach holds great potential for biofortification breeding to enhance grain zinc and iron concentrations in wheat. Abstract: Wheat (Triticum aestivum L.) is a major staple crop, providing 20 % of dietary energy and protein consumption worldwide. It is an important source of mineral micronutrients such as zinc (Zn) and iron (Fe) for resource poor consumers. Genomic selection (GS) approaches have great potential to accelerate development of Fe- and Zn-enriched wheat. Here, we present the results of large-scale genomic and phenotypic data from the HarvestPlus Association Mapping (HPAM) panel consisting of 330 diverse wheat lines to perform genomic predictions for grain Zn (GZnC) and Fe (GFeC) concentrations, thousand-kernel weight (TKW) and days to maturity (DTM) in wheat. The HPAM lines were phenotyped in three different locations in India and Mexico in two successive crop seasons (2011–12 and 2012–13) for GZnC, GFeC, TKW and DTM. The genomic prediction models revealed that the estimated prediction abilities ranged from 0.331 to 0.694 for Zn and from 0.324 to 0.734 for Fe according to different environments, whereas prediction abilities for TKW and DTM were as high as 0.76 and 0.64, respectively, suggesting that GS holds great potential in biofortification breeding to enhance grain Zn and Fe concentrations in bread wheat germplasm. © 2016, Springer-Verlag Berlin Heidelberg.
Genomic selection for spot blotch in bread wheat breeding panels, full-sibs and half-sibs and index-based selection for spot blotch, heading and plant height
(Springer Science and Business Media Deutschland GmbH, 2022) Philomin Juliana; Xinyao He; Jesse Poland; Krishna K. Roy; Paritosh K. Malaker; Vinod K. Mishra; Ramesh Chand; Sandesh Shrestha; Uttam Kumar; Chandan Roy; Navin C. Gahtyari; Arun K. Joshi; Ravi P. Singh; Pawan K. Singh
Key message: Genomic selection is a promising tool to select for spot blotch resistance and index-based selection can simultaneously select for spot blotch resistance, heading and plant height. Abstract: A major biotic stress challenging bread wheat production in regions characterized by humid and warm weather is spot blotch caused by the fungus Bipolaris sorokiniana. Since genomic selection (GS) is a promising selection tool, we evaluated its potential for spot blotch in seven breeding panels comprising 6736 advanced lines from the International Maize and Wheat Improvement Center. Our results indicated moderately high mean genomic prediction accuracies of 0.53 and 0.40 within and across breeding panels, respectively which were on average 177.6% and 60.4% higher than the mean accuracies from fixed effects models using selected spot blotch loci. Genomic prediction was also evaluated in full-sibs and half-sibs panels and sibs were predicted with the highest mean accuracy (0.63) from a composite training population with random full-sibs and half-sibs. The mean accuracies when full-sibs were predicted from other full-sibs within families and when full-sibs panels were predicted from other half-sibs panels were 0.47 and 0.44, respectively. Comparison of GS with phenotypic selection (PS) of the top 10% of resistant lines suggested that GS could be an ideal tool to discard susceptible lines, as greater than 90% of the susceptible lines discarded by PS were also discarded by GS. We have also reported the evaluation of selection indices to simultaneously select non-late and non-tall genotypes with low spot blotch phenotypic values and genomic-estimated breeding values. Overall, this study demonstrates the potential of integrating GS and index-based selection for improving spot blotch resistance in bread wheat. © 2022, The Author(s).
Hydrogen peroxide prompted lignification affects pathogenicity of hemi-bio-trophic pathogen bipolaris sorokiniana to wheat
(Korean Society of Plant Pathology, 2019) Ajit Poudel; Sudhir Navathe; Ramesh Chand; Vinod K. Mishra; Pawan K. Singh; Arun K. Joshi
Spot blotch caused by Bipolaris sorokiniana has spread to more than 9 million ha of wheat in the warm, humid areas of the Eastern Gangetic Plains (EGP) of South Asia and is a disease of major concern in other similar wheat growing regions worldwide. Differential lignin content in resistant and susceptible genotypes and its association with free radicals such as hydrogen peroxide (H2O2), superoxide (O2 -) and hydroxyl radical (OH-) were studied after inoculation under field conditions for two consecutive years. H2O2 significantly influenced lignin content in flag leaves, whereas there was a negative correlation among lignin and H2O2 to the Area Under Disease Progress Curve (AUDPC). The production of H2O2 was higher in the resistant genotypes than susceptible ones. The O2 - and OH- positively correlated with AUDPC but negatively with lignin content. This study illustrates that H2O2 has a vital role in prompting lignification and thereby resistance to spot blotch in wheat. We used cluster analysis to separate the resistant and susceptible genotypes by phenotypic and biochemical traits. H2O2 associated lignin production significantly reduced the number of appressoria and penetration pegs. We visualized the effect of lignin in disease resistance using differential histochemical staining of tissue from resistant and susceptible genotypes, which shows the variable accumulation of hydrogen peroxide and lignin around penetration sites. © The Korean Society of Plant Pathology.
Identification of QTLs for stay green trait in wheat (Triticum aestivum L.) in the 'Chirya 3' × 'Sonalika' population
(2010) Uttam Kumar; Arun K. Joshi; Maya Kumari; Rajneesh Paliwal; Sundeep Kumar; Marion S. Röder
Stay green or delayed senescence is considered to play a crucial role in grain development in wheat when assimilates are limited. We identified three QTLs for stay green on the chromosomes 1AS, 3BS and 7DS using a recombinant inbred (RI) population developed by making crosses between the stay green parent 'Chirya 3' and non-stay green 'Sonalika'. The RI lines were evaluated in natural field conditions for 2 years in replicated trial. The QTL on chromosome 1A was identified in both the years, while the QTLs on 3BS and 7DS were identified only in 1st and 2nd year, respectively. The QTLs explained up to 38.7% of phenotypic variation in a final simultaneous fit. The alleles for higher stay green values derived from the stay green parent 'Chirya 3'. The QTLs were named as QSg.bhu-1A, QSg.bhu-3B and QSg.bhu-7D. The QTL QSg.bhu-3B and QSg.bhu-7D were placed in the 3BS9-0.57-0.78 and 7DS5-0.36-0.61 deletion bins, respectively. © 2010 Springer Science+Business Media B.V.
Introgression of the high grain protein gene Gpc-B1 in an elite wheat variety of Indo-Gangetic Plains through marker assisted backcross breeding
(Elsevier B.V., 2014) Manish K. Vishwakarma; V.K. Mishra; P.K. Gupta; P.S. Yadav; H. Kumar; Arun K. Joshi
Grain protein content (GPC) in wheat has been a major trait of interest for breeders since it has enormous end use potential. In the present study, marker-assisted backcrossing (MABC) was successfully used to improve GPC in wheat cultivar HUW468. The genotype Glu269 was used as the donor parent for introgression of the gene Gpc-B1 that confers high GPC. In a segregating population, SSR marker Xucw108, with its locus linked to Gpc-B1 was used for foreground selection to select plants carrying Gpc-B1. Background selection, involving 86 polymorphic SSR markers dispersed throughout the genome, was exercised to recover the genome of HUW468. For eliminating linkage drag, markers spanning a 10. cM region around the gene Gpc-B1 were employed to select lines with a donor segment of the minimum size carrying the gene of interest. Improved lines had significantly higher GPC and displayed 88.4-92.3 per cent of the recurrent parent genome (RPG). For grain yield, selected lines were at par with the recurrent parent HUW468, suggesting that there was no yield penalty. The whole exercise of transfer of Gpc-B1 and reconstitution of the genome of HUW468 was completed within a period of two and half years (five crop cycles) demonstrating practical utility of MABC for developing high GPC lines in the background of any elite and popular wheat cultivar with relatively higher speed and precision.(. http://creativecommons.org/licenses/by-nc-nd/3.0/). © 2014 The Authors.