A.K. Joshi

Banaras Hindu University, Vārānasi, Uttar Pradesh, India

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Publications (46)63.63 Total impact

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    Proceedings of the International TRIGO (Wheat) Yield Potential WORKSHOP 2015, CENEB, CIMMYT, Cd. Obregón, Sonora, Mexico (24-26th March, 2015); 03/2015
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    ABSTRACT: South Asia, which is already home to more than one-fifth of the world's population and rapidly growing, will require wheat yields to rise annually by 2.0–2.5% to meet demand and maintain food security. To address these challenges, a wheat phenotyping network was established in the region in 2009 to support national breeding programs by applying practical phenotyping techniques to increase selection success using a cooperative multi-location testing network. A number of trials have been grown to introduce new genetic diversity for stress adaptive traits, to establish their genetic bases, and to test a new generation of lines developed using physiological approaches. The 17th Semi-Arid Wheat Yield Trial (SAWYT), consisting of a group of 50 elite spring bread wheat advanced lines, bred in Mexico using both conventional (CON) and physiological trait (PT) approaches, was grown for two seasons 2009/10 and 2010/11. Data showed that PT lines gave superior yields overall, associated with higher grain weight, and with cooler vegetative and grain-filling canopy temperatures (CT); the CT trait is considered indicative of increased gas exchange, a likely consequence in these environments of superior vascular capacity including deeper rooting to access subsoil water. Local check genotypes, which were generally well adapted to the stressed environments tended to be 3–5 days earlier to heading than CIMMYT cultivars. Results demonstrate the potential to integrate physiological breeding approaches into genetic improvement for the region, particularly as future wheat production will take place under increasing water scarcity.
    Field Crops Research 11/2014; 168. DOI:10.1016/j.fcr.2014.07.004 · 2.61 Impact Factor
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    ABSTRACT: A set of 1662 barley accessions from India, ICARDA and CIMMYT were evaluated over three cropping seasons for reaction to spot blotch (causative agent Cochliobolus sativus) infection, along with the four phenotypic traits waxiness, anthocyanin pigmentation, plant height and leaf angle. Only 5% of the entries showed any substantial resistance, while 31% were moderately resistant, 40% moderately susceptible and 24% fully susceptible. The range in mean area under disease progress curve (AUDPC) percent days and days to maturity of the best-performing 25 entries was 250-463 and 88-111, respectively, and most out-performed the best check entry. Four crosses were made between one of the resistant entries (EMBSN-27-4-1, BCU 570, BCU 455 and HMBSN-47-1) and one of the susceptible ones (RD 2503, RD 2624, RD 2614 and CIHO 3510). The F3 and F4 generations were used to test for genetic linkage between spot blotch reaction and the four phenotypic traits. Both waxiness and narrow leaf angle were positively associated with resistance, but neither plant height nor anthocyanin pigmentation was.
    Field Crops Research 12/2013; 154:195-200. DOI:10.1016/j.fcr.2013.08.008 · 2.61 Impact Factor
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    R Prasad, LC Prasad, R Chand, AK Joshi
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    ABSTRACT: Spot blotch is one of the very destructive disease of barley and it is very complicated to know the degree of resistance of the parents because of variable nature of the pathogen and expression of resistance genes of the parents. It is therefore, to know the allelic relationship for resistance total eight resistance barley genotypes namely DWR 39, K 729, BCU 455, ISBCB-03-153, BCU 73, NDB 1180, HUB 20 and DWR 46 were used and crossed in half diallelic fashion and generated 28 cross combitions. F1's were selfed to get F2 and F2 advanced to get F3 follwed by single seed method including all the the crosses. Data of each generation along with parents were recorded. In the F3 generations of 28 crosses 10 crosses showed a narrow range of disease severity and lacked suceptible plants completely. This indicated substantial evedence that these parents carried similar resistance genes conferring resistance and in seven crosses the range od disease deverity/AUDPC was wider but it was lesser than the remaining eleven crosses whic suggesting at leat one gene common in parents of those crosses while remaining crosses showed wide range and indicates absence of common genes for resistance and appearance of transgressive segregants were an indication of non allelic relationship.
    International Conference on Global Scenario of Traditional System of Medicine, Ayurveda, Agriculture and Education., RGSC, Barkachha, BHU; 01/2013
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    ABSTRACT: Leaf rust caused by Puccinia triticina, is a globally important fungal disease of wheat (Triticum aestivum L. em. Thell), resulting in significant yield losses, sometimes up to 40% worldwide. In this study we investigated slow rusting resistance at pathological and molecular level. Fifteen (15) wheat genotypes which also included multiple crosses with the aim to characterize pyramid resistance genes, including slow rusting genes like Lr46 and Lr50 were evaluated for disease severity percent, latent period and incubation period under field conditions. Detached leaf assay was also performed with three virulent pathotypes viz., 21R55 (104-2), 121R63-1 (77-5) and 29R45 (12-5), under controlled laboratory conditions. Genotypes, KIRITATAI//HUW234+LR34/PRINIA, WAXWING*2/TUKURU, WBLLI*2/KIRITATI, KAMBI*2/-BRAMBLING and KAMBI*2/KIRITATI were very close to near immunity and showed comparatively higher level of resistance against all the three pathotypes. Disease severity in resistant genotypes was traced type 5 to 6% in both years, while it was 60 to 80% in the case of susceptible genotypes, that is, 'Agra Local' (S1). Similar pattern was observed for AUDPC, that is, <250.0 in the resistant genotypes, while it was beyond 1000.0 in 'Agra Local'. The shorter mean latent (7.67) and incubation period (6.0) was observed in susceptible genotypes, that is, 'Agra Local' to all the resistant genotypes, that is, LP (10 to 12) and IP (9 to 10); while testing against all the three different pathotypes. Linked microsatellite markers were used to confirm the presence of different rust resistance genes required to achieve near immunity. Out of 10 primers, nine produced gene specific bands with all genotypes except the control, that is, Agra Local. Genotypes which showed slow rusting, had longer latent period and incubation period as well as reduced percent disease severity and confirmed the presence of four to five resistance genes including slow rusting genes, that is, Lr46 and Lr50. This indicates that these genotypes have potential durable resistance and can be used as parental lines in the development of more durable rust resistance.
    AFRICAN JOURNAL OF BIOTECHNOLOGY 11/2012; 11:14956-14966. DOI:10.5897/AJB12.1894 · 0.57 Impact Factor
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    ABSTRACT: Genetic biofortification to improve zinc (Zn) and iron (Fe) concentrations in bread wheat (Triticum aestivum L.) could reduce micronutrient malnutrition-related problems in the developing world. A breeding program on wheat was started to enhance Zn and Fe concentrations and other essential traits needed in a successful commercial variety. The first set of advanced lines derived from crosses of high yielding wheats with genetic resources possessing high Zn and Fe such as Triticum spelta, landraces and synthetic wheat based on Triticum dicoccon were tested at nine locations in South Asia and Mexico for Zn and Fe concentration, grain yield and other traits. Analyses of variance across locations revealed significant genotypic, environmental and genotype × environment (G × E) effects for grain Zn and Fe concentrations and grain yield. Variances associated with environmental effects were larger than the genotypic and G × E effects for all three traits, suggesting that environmental effects have relatively greater influence. Although G × E interaction was significant, high heritabilities were observed for Zn and Fe concentrations at individual sites and across environments, reflecting non-crossover type of interaction. This trend was confirmed by the high genetic correlations between locations that showed similar ranking of entries across locations, indicating that it is possible to select the best adapted entries with high Zn and Fe concentration. Pooled data across locations showed increments of 28% and 25% over the checks for Zn and Fe. A considerable number of entries exceeded intermediate to full breeding target Zn concentrations, indicating that it is possible to develop Zn-biofortified varieties with competitive yields and other farmer preferred agronomic traits. The positive and moderately high correlation between Zn and Fe concentration suggest good prospects of simultaneous improvement for both micronutrients.
    Field Crops Research 10/2012; 137:261–267. DOI:10.1016/j.fcr.2012.07.018 · 2.61 Impact Factor
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    ABSTRACT: Aim Zinc (Zn) fertilization is an effective agronomic tool for Zn biofortification of wheat for overcoming human Zn deficiency. But it still needs to be evaluated across locations with different management practices and wheat cultivars, since grain Zn concentrations may be significantly affected by locations, cultivars and management. Materials Field experiments were conducted over 3 years with the following four Zn treatments: nil Zn, soil Zn application, foliar Zn application and soil + foliar Zn application to explore the impact of Zn fertilization in Zn biofortification of wheat. The experiments were conducted at a total of 23 experimental site-years in China, India, Kazakhstan, Mexico, Pakistan, Turkey and Zambia.
    Plant and Soil 10/2012; online(1-2). DOI:10.1007/s11104-012-1369-2 · 3.24 Impact Factor
  • Acta Phytopathologica et Entomologica Hungarica 06/2011; 46(1):49-57. DOI:10.1556/APhyt.46.2011.1.6
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    ABSTRACT: An important step towards reducing the vulnerability of wheat in Africa and Asia to the Ug99 race of the stem rust pathogen is the substitution of current susceptible varieties with superior resistant varieties. In the 2008–2009 cropping season both seed multiplication and dissemination of Ug99 resistant varieties were initiated in Afghanistan, Bangladesh, Egypt, Ethiopia, Iran, India, Nepal and Pakistan. Ug99 resistant varieties must occupy about 5% of the area sown to wheat in each country to ensure sufficient seed to displace current popular varieties. Because of the underdeveloped seed industry and small farm sizes in most of these countries, various strategies are being applied for rapid multiplication and dissemination of resistant varieties. Approaches being used include pre-release seed multiplication while candidate resistant lines are being tested in national evaluation trials and farmer participatory selection. Resistant varieties are already released in Afghanistan, Bangladesh, Egypt and Pakistan and more varieties are expected to be released in 2010 in these and other countries. Our results show that some new Ug99 resistant lines have yield superiority over dominant local varieties. Activities and progress in seed multiplication using existing and new Ug99 resistant varieties are discussed. Keywords Puccinia graminis f. sp. tritici –Farmer participation–Seed distribution systems–Stem rust– Triticum aestivum –Participatory varietal selection–Ug99
    Euphytica 01/2011; 179(1):187-196. DOI:10.1007/s10681-010-0314-9 · 1.69 Impact Factor
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    R Prasad, LC Prasad, B Arun, AK Joshi
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    ABSTRACT: The North East Plains Zone of India (predominantly rice-wheat cropping system area) is lagging behind other developed regions such as North West Plains Zone in production and productivity of cereals especially wheat, barley growing zone. The major problems of the zone are terminal heat stress, poor irrigation facilities, sometimes mid-season drought, spot blotch and significant yield gap. There is need for the development and dissemination of appropriate technology taking care of the specific need of the location and the farmer. This work can get augmented following an appropriate scientist-farmers interaction. Through participatory research we can improve the average yield of barley and wheat. This work needs to be extended to all the nearby districts of Varanasi, including the adjoining states of Bihar and Madhya Pradesh. By this approach the time lag between agricultural research and its dissemination could be reduced by active participation of the farmers and we would be able to attain food target of the coming decades.
    National Seminar on Emerging Trands in Education & Research in Ayurveda, RGSC, Barkachha, BHU; 01/2011
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    ABSTRACT: Farmers' preference study and informal seed dissemination was carried out through farmer participa-tory variety selection (PVS) during 2006–2007 to 2008–2009 by the Wheat Research Centre (WRC), Bangladesh Agricultural Research Institute (BARI), Dinajpur, Bangladesh, in collaboration with CIMMYT. Four varieties including widely grown Shatabdi and four advance lines including Ug99 tolerant BAW 1064 were tested in mother-baby trial approach in 8 villages in each year. Mother trials were researcher designed but farmer managed. However, baby trials were designed and managed by farmers themselves. Preference scores of 30 farmers for varieties were recorded two times viz., pre and post-harvest stages. Farmers' preferred BAW 1064 owing to its 10% yield superiority over the widely grown Shatabdi variety, bolder white grains, larger grains/spike, non-lodging behaviour, earliness and resistance to diseases. This variety was found moderately resistant to Ug99 in Kenya. BAW 1064 was released as BARI Gom 26 in March 2010. After three years of PVS work, 19.4 t seeds reached informally to 969 farmers of 24 PVS villages from only 252 kg source seeds supplied for trials. In 2009–2010, seed production of this variety was done in 44 ha; 33.8 ha in 111 farmers' fields and 10.2 ha in research stations. Around 150 t seeds were produced that are being used for further testing and multiplication in 2010–2011. Seed dissemination through PVS was much faster than official approach of Bangladesh Agriculture Development Corporation (BADC). Hence, for selection and dissemination of CIMMYT developed Ug99 tolerant lines, farmer-participatory approach is being deployed.
    Czech Journal of Genetics and Plant Breeding 11/2010; 47(Special Issue). · 0.49 Impact Factor
  • J. Crossa, M. Vargas, A K Joshi
    Canadian Journal of Plant Science 09/2010; 90(5):561-574. DOI:10.4141/CJPS10003 · 0.92 Impact Factor
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    ABSTRACT: Zinc and iron are important micronutrients for human health for which widespread deficiency occurs in many regions of the world including South Asia. Breeding efforts for enriching wheat grains with more zinc and iron are in progress in India, Pakistan and CIMMYT (International Maize and Wheat Improvement Centre). Further knowledge on genotype × environment interaction of these nutrients in the grain is expected to contribute to better understand the magnitude of this interaction and the potential identification of more stable genotypes for this trait. Elite lines from CIMMYT were evaluated in a multilocation trial in the eastern Gangetic plains (EGP) of India to determine genotype × environment (GE) interactions for agronomic and nutrient traits. Agronomic (yield and days to heading) data were available for 14 environments, while zinc and iron concentration of grains for 10 environments. Soil and meteorological data of each of the locations were also used. GE was significant for all the four traits. Locations showed contrasting response to grain iron and zinc. Compared to iron, zinc showed greater variation across locations. Maximum temperature was the major determinant for the four traits. Zinc content in 30–60 cm soil depth was also a significant determinant for grain zinc as well as iron concentration. The results suggest that the GE was substantial for grain iron and zinc and established varieties of eastern Gangetic plains India are not inferior to the CIMMYT germplasm tested. Hence, greater efforts taking care of GE interactions are needed to breed iron and zinc rich wheat lines.
    Field Crops Research 04/2010; 116(3):268–277. DOI:10.1016/j.fcr.2010.01.004 · 2.61 Impact Factor
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    ABSTRACT: Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat growing regions of the world. To identify quantitative trait loci (QTLs) for spot blotch resistance, two mapping populations were developed by making the crosses between common susceptible cultivar ‘Sonalika’ with the resistant breeding lines ‘Ning 8201’ and ‘Chirya 3’. Single seed descent derived F6, F7, F8 lines of the first cross ‘Ning 8201’ × ‘Sonalika’ were evaluated for resistance to spot blotch in three blocks in each of the 3 years. After screening of 388 pairs of simple sequence repeat primers between the two parents, 119 polymorphic markers were used to genotype the mapping population. Four QTLs were identified on the chromosomes 2AS, 2BS, 5BL and 7DS and explained 62.9% of phenotypic variation in a simultaneous fit. The QTL on chromosome 2A was detected only in 1 year and explained 22.7% of phenotypic variation. In the second cross (‘Chirya 3’ × ‘Sonalika’), F7 and F8 population were evaluated in three blocks in each of the 2 years. In this population, five QTLs were identified on chromosomes 2BS, 2DS, 3BS, 7BS and 7DS. The QTLs identified in the ‘Chirya 3’ × ‘Sonalika’ population explained 43.4% of phenotypic variation in a simultaneous fit. The alleles for reduced disease severity in both the populations were derived from the respective resistant parent. The QTLs QSb.bhu-2B and QSb.bhu-7D from both populations were placed in the same deletion bins, 2BS1-0.53-0.75 and 7DS5-0.36-0.61, respectively. The closely linked markers Xgwm148 to the QTL on chromosome 2B and Xgwm111 to the QTL on chromosome 7D are potentially diagnostic markers for spot blotch resistance.
    Molecular Breeding 01/2010; 3(26):477-491. DOI:10.1007/s11032-009-9388-2 · 2.28 Impact Factor
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    ABSTRACT: Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat growing regions of the world. To identify quantitative trait loci (QTLs) for spot blotch resistance, two mapping populations were developed by making the crosses between common susceptible cultivar ‘Sonalika’ with the resistant breeding lines ‘Ning 8201’ and ‘Chirya 3’. Single seed descent derived F6, F7, F8 lines of the first cross ‘Ning 8201’בSonalika’ were evaluated for resistance to spot blotch in three blocks in each of the 3years. After screening of 388 pairs of simple sequence repeat primers between the two parents, 119 polymorphic markers were used to genotype the mapping population. Four QTLs were identified on the chromosomes 2AS, 2BS, 5BL and 7DS and explained 62.9% of phenotypic variation in a simultaneous fit. The QTL on chromosome 2A was detected only in 1year and explained 22.7% of phenotypic variation. In the second cross (‘Chirya 3’בSonalika’), F7 and F8 population were evaluated in three blocks in each of the 2years. In this population, five QTLs were identified on chromosomes 2BS, 2DS, 3BS, 7BS and 7DS. The QTLs identified in the ‘Chirya 3’בSonalika’ population explained 43.4% of phenotypic variation in a simultaneous fit. The alleles for reduced disease severity in both the populations were derived from the respective resistant parent. The QTLs QSb.bhu-2B and QSb.bhu-7D from both populations were placed in the same deletion bins, 2BS1-0.53-0.75 and 7DS5-0.36-0.61, respectively. The closely linked markers Xgwm148 to the QTL on chromosome 2B and Xgwm111 to the QTL on chromosome 7D are potentially diagnostic markers for spot blotch resistance. Keywords Bipolaris sorokiniana -QTL mapping-Diagnostic marker-Spot blotch- Triticum aestivum L
    Molecular Breeding 01/2010; 26(3):477-491. · 2.28 Impact Factor
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    ABSTRACT: Sixty-seven isolates of Bipolaris sorokiniana of barley, belonging to three groups (black, white and mixed) were studied to find an association of melanin with the spore production of the fungus. Conidiogenesis in black, white and mixed subpopulation of B. sorokiniana was positively correlated with melanin content/g of mycelium. Primary hyphae of black and mixed subpopulation differentiated into secondary hyphal structures which subsequently produced conidiophores and conidia. Primary hyphae could not differentiate into secondary hyphae and subsequently conidiophores and conidia in white subpopulation. A melanin containing mutant developed from white subpopulation regained its ability to differentiate into secondary hyphae, conidiophores and conidia. Results showed that melanization of mycelia B. sorokiniana mycelia is an important factor for conidia production.
    World Journal of Microbiology and Biotechnology 01/2010; 26(2):309-316. DOI:10.1007/s11274-009-0177-1 · 1.35 Impact Factor
  • Indian Journal of Agricultural Sciences 01/2009; 79:562-564. · 0.18 Impact Factor
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    ABSTRACT: Three F1 progenies and their families in the segregating generations (F3, F4, F5 and F6), obtained after crossing resistant × susceptible wheat genotypes were studied in the field to determine the genetics of resistance to spot blotch caused by Bipolaris sorokiniana. Spot blotch scores in the F1 generation showed absence of dominance. Individually threshed F2 plants were used to advance the generations. Progenies (200-250) of resistant genotypes Acc. No. 8226, Mon/Ald, Suzhoe#8 crossed with susceptible ‘Sonalika’ were evaluated in the F3, F4, F5 and F6 generations under induced epiphytotic conditions. Based on disease score distribution in individual progeny rows, F3 progenies were grouped into four classes: homozygous resistant, homozygous susceptible, segregating resistant and segregating susceptible. Resistance appeared to be under the control of three additive genes. The presence of three genes was also noted in the distribution of F4 and F5 lines. In the case of F6 progeny rows, both quantitative and qualitative models were used to estimate the number of segregating genes based on a 2-year trial. It appeared that resistance to spot blotch was controlled by the additive interaction of more than two genes, possibly only three.
    Plant Breeding 06/2008; 123(3):213 - 219. DOI:10.1111/j.1439-0523.2004.00954.x · 1.34 Impact Factor
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    ABSTRACT: Helminthosporium leaf blight (HLB) is the most important disease constraint to wheat (Triticum aestivum L.) cultivation in the eastern Gangetic Plains of South Asia. A Helminthosporium Monitoring Nursery (HMN) including potential adapted and exotic sources of HLB resistance was developed in Bangladesh, India and Nepal to assess the stability of genetic resistance across locations. The 8th, 9th and 10th HMN assessed the HLB resistance and agronomic traits of 17 wheat genotypes across 20 environments of Bangladesh, India and Nepal in the 1999-2000, 2000-2001 and 2001-2002 cropping seasons, respectively. The area under the disease progress curve (AUDPC) for HLB, grain yield, thousand-kernel weight (TKW), days to heading, days to maturity, and plant height were examined. The 17 genotypes showed a range of variability for disease and agronomic characters. Disease severity (AUDPC) differed in the 3 years and showed the highest values in 2002. The increase in AUDPC in 2002 caused the lowest grain yield, with an average 18% reduction due to HLB. A few genotypes (SW 89-5422, Yangmai-6 and Ning 8201) appeared to have stable HLB resistance across environments. However, most of the higher-yielding genotypes, except BL 1883, were unstable. The results suggest that careful selection of HLB resistance with acceptable grain yield, TKW and plant height may be possible using the wheat genotypes included in the HMN.
    Plant Breeding 06/2008; 123(6):520 - 524. DOI:10.1111/j.1439-0523.2004.01006.x · 1.34 Impact Factor