Browsing by Author "Ravi P. Singh"

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Association analysis for yield and quality attributes in Indica rice and screening of hybrids against blast disease (Magnaporthe grisea Barr.)
(Academic Journals Inc., 2013) Mukesh Kumar Singh; Prakash Singh; Ravi P. Singh; Chinmayee Mohapatra
Rice is mostly grown in the Asian subcontinent and known by its good cooking qualities. Its production is, however, often constrained by several biotic factors. The present study may be useful for the development of resistant lines against the blast disease possess high yielding capacity. Thirty nine Indica rice genotypes were used to study the extent of genetic parameter and association analysis for quantitative and qualitative traits. These genotypes were screened against blast disease of rice by artificial inoculation in field. All quantitative and qualitative traits exhibited highly significant difference (p<0.01) among treatments, it indicates the adequate genetic variability among the genotypes under study. Estimates of genotypic and phenotypic coefficient of variation were high for filled grains per plant, total grains per plant, panicle initiation and Grain Yield per Plant (GYPP). Heritability was high (>80%) for all the characters except head rice recovery, hulling percentage and kernel breadth; indicates the roles of additive gene action and a good scope of selection using their phenotypic performance. GYPP showed strong positive association with yield contributing traits while non-significant association with rest of the traits. In blast screening, none of the varieties and F1 hybrids found highly resistant. Among the parental lines, Anjali was resistant, HUR3022, Vandana, HUR105 and BPT5204 were moderately resistant and six lines were moderately to highly susceptible. Among the hybrids, only two hybrids (AnjalixBPT 5204 and AnnadaxBPT 5204) were found resistant to rice blast disease. © 2013 Academic Journals Inc.
Biotic stress management in rice (Oryza sativa L.) through conventional and molecular approaches
(Springer Singapore, 2020) Prakash Singh; Ram Lakhan Verma; Ravi S. Singh; Ravi P. Singh; H.B. Singh; Pandurang Arsode; Manish Kumar; Pawan Kumar Singh
The rice (Oryza sativa L.) productivity is often adversely disturbed by several abiotic and biotic stresses such as drought, submergence, fungal, bacterial, and nematode oriented biotic diseases and pest like brown plant hopper (BPH) and stem borer (SB). The major biotic stresses such as bacterial leaf blight (BLB), sheath blight (ShB), blast, brown spot (BS), false smut (FS), brown plant hopper (BPH), yellow stem borer (YSB), and gall midge (GM) play crucial roles in decreasing the productivity and quality of rice grains. Among the several breeding procedures and various control measures available for mitigating the biotic stresses/factors, the host plant resistance is most effective, economic and eco-friendly which is basically developed by traditional breeding approaches. The related species of rice and wild sources are important for identification of many resistance genes/QTLs, which are successfully introgressed or deployed or pyramided in numerous breeding lines through resistance breeding program and various molecular approaches. In this chapter, an inclusive valuation of the conventional and molecular approaches for mitigating the biotic stresses in rice by imparting major resistance sources has been presented. © Springer Nature Singapore Pte Ltd. 2020. All rights reserved.
Can functional food security decrease the epidemic of obesity and metabolic syndrome? A viewpoint
(Nova Science Publishers, Inc., 2016) Sergey Shastun; Anil K. Chauhan; Ram B. Singh; Meenakshi Singh; Ravi P. Singh; Arunporn Itharat; Sergey Chibisov; Fabien De Meester; Douglas W. Wilson; Ghazi Halabi
The world is still ignorant about the role of functional food security characterized by diversity and adequacy of nutrients that may have been beneficial and abundant in the Paleolithic diet 40,000 years ago because of food diversity. Therefore, the increased prevalence of metabolic syndrome and the resultant type 2 diabetes, hypertension and heart disease throughout the world, are closely linked to food security via westernized dietary patterns, physical inactivity, and rapid increase in the rate of obesity. There is substantial evidence that increased intake of functional foods can bring about a significant decline in the epidemic of obesity and metabolic syndrome, resulting in health promotion. We therefore propose that functional food security can maintain the normal physiology and metabolism of our bodies, resulting in prevention of diseases and improvement of world health. © 2016 Nova Science Publishers, Inc.
Comparative analysis on the effect of trimethoprim and bavistin on direct shoot regeneration in Brahmi (Bacopa monniera) in growth regulator free MS medium
(Triveni Enterprises, 2016) Vaibhav Tiwari; Ravi P. Singh; Brahma D. Singh; Prakash Singh; Mukesh K. Singh; Ravish K. Singh
Leaf, node and internode explants of Brahmi Bacopa monniera L. were cultured on growth regulators free (GR free) MS basal medium to assess the effect of an antibiotic (Trimethoprim-TMP) and an antifungal agent (Bavistin-BVN). Direct shoot regeneration without callus formation was induced by culturing different explants on GR free MS medium at lower concentration of TMP. TMP (antibiotic agent) at 50 mg l was found optimum for shoot regeneration from leaf explants, while higher concentration of TMP did not show any improvement on more than 50 mg l for shoot regeneration in node explants. BVN (antifungal agent) at 100 mg l had the optimum effect on regeneration from inter-node and leaf explants, but node explants showed better regeneration on 150 mg l BVN. The adventitious shoot regenerated from vertically placed nodes on medium containing 150 mg l BVN and horizontally placed node segments showed regeneration at 100 mg l . Increasing upto 200 mg l TMP concentrationsignificantly promoted adventitious shoot bud regeneration in inter-modal explants. The combination of TMP and BVN significantly suppressed root regeneration at higher concentration in internodes and leaf explants, whileTMPat lower concentration showed better root regeneration as compared to culture grown on GR-free MS-medium. Trimethoprim and Bavistin exhibited cytokinin-like activity as they promoted axillary shoots from node and adventitious shoot buds regeneration on the surface of all explants. © Triveni Enterprises, Lucknow (India).
Comparative assessment of food-fodder traits in a wide range of wheat germplasm for diverse biophysical target domains in South Asia
(Elsevier B.V., 2019) M. Blümmel; S.R. Updahyay; N. Gautam; N.C.D. Barma; M. Abdul Hakim; Makhdoom Hussain; Muhammad Yaqub Mujahid; R. Chatrath; V.S. Sohu; G. Mavi; V.K. Mishra; I.K. Kalappanavar; Rudra Naik; Suma Biradar; S.V.S. Prasad; Ravi P. Singh; A.K. Joshi
The paper compares food and straw fodder traits in wheat lines of 6 different CIMMYT wheat trials tested across 32 environments of South Asia (India, Nepal, Bangladesh and Pakistan). Experiments were conducted in the main spring wheat season with sowing time of mid-November to mid-December and harvest between March to April. Investigated and compared were grain yield (GY), straw yield (SY), straw nitrogen (N) content, neutral (NDF) and acid (ADF) detergent fiber, acid detergent lignin (ADL), and in vitro organic matter digestibility (IVOMD). Highly significant (P < 0.0001) differences were observed between cultivar types for all traits. The proportional ranges in traits between the cultivar types were high for GY and SY (>60%), considerable (45%) for HI and straw N (40%), moderate for ADL (18%), and minor for NDF, ADF, and IVOMD (<10%). Across cultivar types GY and SY were significantly positive correlated but GY accounted for only 14% of the variation in SY. Positive fodder traits such as N and IVOMD tended to be negatively associated with GY, whereas negative traits such as NDF, ADF and ADL were positively associated with GY, significantly so (P < 0.05) in the cases of ADF and ADL. Except for one case, broad sense h 2 were stronger for GY than for SY. Among straw fodder quality traits, the negative fodder quality traits ADF showed the highest h 2 for all quality traits, with the exception of the two drought trials. Across all cultivar types only ADF was significantly (P < 0.05) positively related to GY. No significant (P > 0.05) relationships were observed between N, ADF and IVOMD and SY. Among cultivars consistent relationships were only observed between N and GY which were significantly (P = 0.03 to 0.009) inversely correlated in five out of the six cultivar types. Within cultivars types ADF varied by at least 2.3% units in HTNM and 1st DRYT and up to 4.9% units in ESWYT. By extrapolation such cultivar-dependent differences will matter at wheat straw trading. © 2019
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.
Development of a Functional Food Security for Parents for Transgenerational Epigenetic Health Promotion and Disease Prevention Among Offspring
(Elsevier, 2018) Ram B. Singh; Anil K. Chauhan; Ravi P. Singh; Meenakshi Singh; Sanjay Mishra; Fabien De Meester; Krasimira Hristova; Toru Takahashi; Jan Fedacko; Anna Gvozdjakova; Arunporn Itharat; Ekasit Onsaard; Douglas W. Wilson
Background: Noncommunicable diseases (NCDs) have become a worldwide problem due food security and lack of physical activity. The rapid increase may be due to interaction of genes/memes and environment, having adverse effects on the epigenome. A new package of nutrient-rich functional foods (FFs) or a package of micronutrients (based on healthy foods) and egg or soy bean milk, may protect against epigenetic inheritance, which is probably a safe strategy for protection from diseases. Methods: Discussion with colleagues in this field and website search. Results: Recent studies indicate that Mediterranean-style foods and multiple micronutrients are inversely associated with risk of NCDs; cardiovascular diseases, type 2 diabetes, and obesity later in adult life. Recommendations by UNICEF/WHO/UNU for pregnant women include 15 micronutrients likely to be administered during the antenatal period. Micronutrients supplementation is required in three different conditions, namely, nonpregnant, pregnant, and lactating women. As Mediterranean-style diets are rich in FFs, administration of these foods during pregnancy provides most of the aforementioned nutrients, which may be beneficial to mothers, as well as the fetus and offspring. A significant increase in body length was observed on administering a high-fat diet to pregnant mice, which remained across two generations of offspring. It could be an epigenetic inheritance of a growth-related factor in the offspring, reflecting reduced insulin sensitivity across two generations, and also providing a proof of epigenetic alterations in gene expression via altered tertiary structure of a DNA strand, without altering the DNA sequence. Conclusions: This approach may cause health promotion and disease prevention in the next generation. The idea of FF security for global health is important and practical. © 2018 Elsevier Inc. All rights reserved.
Dietary Fiber and Risk of Cardiovascular Diseases
(Elsevier Inc., 2017) Divya R. Gunashekar; Ram B. Singh; Mohammad A. Niaz; Anand R. Shewale; Toru Takahashi; Anil K. Chauhan; Ravi P. Singh
Mortality and morbidity due to heart diseases is decreasing in developed countries due to healthy diet and lifestyle, whereas in developing countries, it is rapidly increasing due to unhealthy diets and lifestyle. Healthy diets are rich in plant foods and majority of the plant foods are rich in fiber. Vegetables, whole grains, fruits, and legumes are rich sources of fibers. Soluble fibers have been considered more useful compared to insoluble fibers. Dietary fibers are known to have hypoglycemic, hypocholesterolemic, antioxidant, antiinflammatory, and antihypertensive effects indicating that fiber intake may be protective against cardiovascular diseases (CVDs), coronary artery disease (CAD), stroke, and hypertension, as well as diabetes. In a meta-analysis, 22 cohort study publications met inclusion criteria. Total dietary fiber intake, fiber subtypes, or fiber from food sources and primary events of CVDs or CAD were considered important. Total dietary fiber intake was inversely associated with risk of CVD including CAD. Observed heterogeneity between pooled studies for CVD and CAD were apparent. Insoluble fiber and fiber from cereal and vegetable sources were inversely associated with risk of CAD and CVD. Fruit fiber intake as part of Mediterranean style diet was also inversely associated with risk of CVD. It is possible that increased consumption of dietary fiber may be associated with a lower risk of both CVD and CAD. These results support the general recommendations to increase fiber intake for prevention of CVDs. The mechanism could be that fiber inhibit the absorption of fat from the gut but recently dietary fiber has been demonstrated to be beneficial for gut microbiome. The differing strengths of association by fiber type or source highlight the need for a better understanding of the mode of action of fiber components and the effects of fiber on other targets, which indirectly control CVDs. © 2017 Elsevier Inc. All rights reserved.
Gene action analysis and identification of combiners for yield traits in maize
(Society for Plant Research, 2017) Ravish Kumar Singh; Erappa Gangappa; Prakash Singh; Ravi P. Singh; Ashish Kumar Pandey; Mukesh K. Singh
Field experiment was conducted using half diallel analysis involving 14 high yielding drought tolerant inbreds to generate 91 F1 hybrids of maize (Zea mays L.) to study the gene action and identify the best combiners for grain yield and its associated traits. The analysis of variances represents significant amounts of variability present among inbreeds for most of the traits studied. The estimates of general combining ability (GCA) and specific combining ability (SCA) variances were found significant, it indicated the preponderance of both additive and non-additive gene actions for the expression of yield controlling traits in maize. The parent CML-359 and CML-41 were found best general combiners, showing significant GCA effect for grain yield and its associated traits, and also simultaneously possessed high per se performance. However, the hybrids, CML-326 × DMR-N-21, HKI 26-24 (1-2) × CM-500, HKI-26-24(1-2) × CML-411, CML-41 × HKI-164-4(1-3)-2 and CML-41 × CM-500 were found best specific combiners for grain yield and its associated traits. The present study revealed that 5 best identified hybrids among 91 hybrids, may be used directly as hybrids for development of synthetics or composites or high yielding hybrids of maize (Zea mays L.). © 2017, SPR, All Rights Reserved.
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).
Identification of good combiners in early maturing × high yielding cultivars of Indica rice (Oryza sativa L.)
(Bangladesh Botanical Society, 2013) Mukesh Kumar Singh; Ravi P. Singh; Prakash Singh
Line × tester analysis involving seven early maturing lines and four high yielding testers, made to produce 28 F1s hybrids. The F1 data revealed that both additive and non-additive gene were important in controlling yield contribution in Indica rice. Variances were significant for GCA and SCA effects for all the characters indicating the significance of both additive and non-additive genes. There was high proportion of non-additive genes for the expression of different traits. Cultivars Anjali, MTU-7029 and BPT-5204 were identified as best general combiners for yield and yield traits among the parents. The most promising specific combiners for grain yield and its contributing traits were Govind × HUR 105, NDR 97 × HUR 4-3, Anjali × HUR 4-3, NDR 97 × MTU 7029, Vandana × BPT 5204, Shanthi × HUR 105, Anjali × MTU 7029 and Shanthi × BPT 5204.
Mapping of spot blotch disease resistance using NDVI as a substitute to visual observation in wheat (Triticum aestivum L.)
(Springer Science and Business Media B.V., 2016) Suneel Kumar; Marion S. Röder; Ravi P. Singh; Sundeep Kumar; Ramesh Chand; Arun K. Joshi; Uttam Kumar
Evaluation of wheat for spot blotch disease resistance relies on various visual observation methods. The person evaluating the lines needs to be experienced in scoring disease severity. To facilitate high-throughput phenotyping, a hand-held green seeker NDVI sensor was used to map spot blotch disease resistance QTLs. A total of 108 germplasm lines along with 335 SSD-derived lines (F4 and F5 generations) originating from the cross ‘YS116 × Sonalika’ were used. The population was evaluated at BISA, Pusa Bihar, a hot spot for spot blotch, for 2 consecutive years. Data were recorded using the NDVI as well as by visual observation as % disease severity. The correlation coefficient was calculated between two scoring methods (NDVI and % DS) recorded at different growth stages. High negative correlation was observed between the NDVI and % DS at GS69 and GS77 on Zadoks' scale. With both methods, the QTL was mapped in the same chromosomal region on 5BL. Using the NDVI value, the detected QTL explained up to 54.9 % of phenotypic variation while up to 56.1 % using the % DS. The Sb2 gene was mapped between the markers Xgwm639 and Xgwm1043 with an interval of 0.62 cM. The markers linked to the Tsn1 gene (Xfcp1 and Xfcp623) were mapped 1.1 cM apart from the sb2 gene. It is concluded that the NDVI the can be used as an alternative to visual scoring of spot blotch disease in wheat and create a new avenue for high-throughput phenotyping. © 2016, Springer Science+Business Media Dordrecht.
Principal component analysis of morpho-floral traits in Oryza sativa × Oryza longistaminata advanced backcross lines of rice
(Editorial board of Journal of Experimental Biology and Agricultural Sciences, 2024) Madhu Choudhary; Ravi P. Singh; P.K. Singh; S. Jayasudha
Hybrid rice technology substantially improves the food security of South Asian countries where rice (Oryza sativa L.) is a staple food. Several traits contribute to hybrid seed production efficiency, among which stigma exsertion is crucial for enhancing production by facilitating out-crossing pollination. This study evaluated the variation patterns and relative impact of 12 morpho-floral traits on overall variability in advanced backcross lines derived from crosses CRMS 32B cv. Oryza sativa and Oryza longistaminata. For this study, 290 BC4F2 lines were grown during Kharif 2019 in 3 replications using a randomized complete block design (RCBD). Principle component analysis (PCA) was performed on all traits, and the findings revealed 11 principal components (PCs). Out of 11 PCs, the first five displayed eigenvalues exceeding 1, collectively explaining 78.78% of the total variability. PC1, PC2, PC3, PC4, and PC5 contributed 26.36%, 19.94%, 14.22%, 9.81%, and 8.44% of the variation, with eigenvalues of 3.16, 2.39, 1.71, 1.18 and 1.01, respectively. PC1 was predominantly associated with yield-related traits such as panicle length, plant height, grain yield per plant, grains per panicle, and effective tillers per plant. On the other hand, PC2 was mainly associated with outcrossing-related floral traits such as total stigma exsertion percentage, dual stigma exsertion percentage, and single stigma exsertion percentage. However, PC3 and PC4 were associated with both floral and yield-related traits, i.e., days to 50% flowering (DF), days to maturity (DM), plant height (PH), effective tillers per plant (ETPP), spikelet fertility percentage (SFP), grain yield per plant (GYPP) and grains per panicle (GPP). Therefore, PC1, PC2, PC3, and PC4 were major contributors to rice hybrid seed production. © 2024, Editorial board of Journal of Experimental Biology and Agricultural Sciences. All rights reserved.
QTL for spot blotch resistance in bread wheat line Saar co-locate to the biotrophic disease resistance loci Lr34 and Lr46
(Springer Verlag, 2013) Morten Lillemo; Arun K. Joshi; Ravindra Prasad; Ramesh Chand; Ravi P. Singh
Spot blotch caused by Bipolaris sorokiniana is a major disease of wheat in warm and humid wheat growing regions of the world including south Asian countries such as India, Nepal and Bangladesh. The CIMMYT bread wheat line Saar which carries the leaf tip necrosis (LTN)-associated rust resistance genes Lr34 and Lr46 has exhibited a low level of spot blotch disease in field trials conducted in Asia and South America. One hundred and fourteen recombinant inbred lines (RILs) of Avocet (Susceptible) × Saar, were evaluated along with parents in two dates of sowing in India for 3 years (2007-2008 to 2009-2010) to identify quantitative trait loci (QTL) associated with spot blotch resistance, and to determine the potential association of Lr34 and Lr46 with resistance to this disease. Lr34 was found to constitute the main locus for spot blotch resistance, and explained as much as 55 % of the phenotypic variation in the mean disease data across the six environments. Based on the large effect, the spot blotch resistance at this locus has been given the gene designation Sb1. Two further, minor QTL were detected in the sub-population of RILs not containing Lr34. The first of these was located about 40 cM distal to Lr34 on 7DS, and the other corresponded to Lr46 on 1BL. A major implication for wheat breeding is that Lr34 and Lr46, which are widely used in wheat breeding to improve resistance to rust diseases and powdery mildew, also have a beneficial effect on spot blotch. © 2012 Springer-Verlag Berlin Heidelberg.
Strategic crossing of biomass and harvest index—source and sink—achieves genetic gains in wheat
(Springer Netherlands, 2017) 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; El.Husseiny.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 Kundi; 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
To accelerate genetic gains in breeding, physiological trait (PT) characterization of candidate parents can help make more strategic crosses, increasing the probability of accumulating favorable alleles compared to crossing relatively uncharacterized lines. In this study, crosses were designed to complement “source” with “sink” traits, where at least one parent was selected for favorable expression of biomass and/or radiation use efficiency—source—and the other for sink-related traits like harvest-index, kernel weight and grains per spike. Female parents were selected from among genetic resources—including landraces and products of wide-crossing (i.e. synthetic wheat)—that had been evaluated in Mexico at high yield potential or under heat stress, while elite lines were used as males. Progeny of crosses were advanced to the F4 generation within Mexico, and F4-derived F5 and F6 generations were yield tested to populate four international nurseries, targeted to high yield environments (2nd and 3rd WYCYT) for yield potential, and heat stressed environments (2nd and 4th SATYN) for climate resilience, respectively. Each nursery was grown as multi-location yield trials. Genetic gains were achieved in both temperate and hot environments, with most new PT-derived lines expressing superior yield and biomass compared to local checks at almost all international sites. Furthermore, the tendency across all four nurseries indicated either the superiority of the best new PT lines compared with the CIMMYT elite checks, or the superiority of all new PT lines as a group compared with all checks, and in some cases, both. Results support—in a realistic breeding context—the hypothesis that yield and radiation use efficiency can be increased by improving source:sink balance, and validate the feasibility of incorporating exotic germplasm into mainstream breeding efforts to accelerate genetic gains for yield potential and climate resilience. © 2017, The Author(s).
Variations in straw fodder quality and grain–Straw relationships in a mapping population of 287 diverse spring wheat lines
(Elsevier B.V., 2019) Arun K. Joshi; Uttam Kumar; V.K. Mishra; Ramesh Chand; R. Chatrath; Rudra Naik; Suma Biradar; Ravi P. Singh; Neeraj Budhlakoti; Ravi Devulapalli; Michael Blümmel
A wheat association mapping population consisting of 287 diverse spring wheat lines were evaluated for three years in one location (Varanasi) and out of these for one year across three locations (Karnal, Dharwad and Varanasi) in India. Straw fodder quality traits analyzed were nitrogen (N) content, neutral (NDF) and acid (ADF) detergent fiber, acid detergent lignin (ADL), ash (ASH), in vitro organic matter digestibility (IVOMD) and metabolizable energy (ME) content. Grain yield (GY) and straw yield (SY) were also recorded. Highly significant (P < 0.0001) differences among lines were observed for all traits except for ADF and ADL in the three years trials conducted at Varanasi. However, year and location had strong (P < 0.0001) effects on all traits. Compared to line-dependent variations in GY and SY variation in straw fodder quality traits were small. Proportionally greatest variations between lines were observed for straw N where lowest and highest N varied by about 30%. Difference for NDF and ADF between lines were at most 4% units and below 3% units for IVOMD. Grain yield and straw yield were positively correlated (P < 0.0001) with GY accounting for 26% of the variation in SY. Straw N, IVOMD and ME were weakly but significantly (P < 0.05) negatively associated with GY and SY. Straw NDF and ADF were significantly (P < 0.05) positively correlated with GY but the association was again weak. Straw NDF, ADF and ADL were also weakly but significantly positively correlated with SY. Genome-wide association studies (GWAS) were applied to detect significant marker- straw fodder quality trait associations. Five genomic regions contributed for six traits (ADF, ADL, ASH, IVOMD, ME and NDF). ADF and ADL mapped in the common QTL region on chromosome 2B. Similarly, for the IVOMD and ME QTLs on chromosome 5B were associated with SNP marker, wsnp_Ku_c35090_44349517. While some associations were detected for ADF, ALD, ASH, IVOMD, ME and NDF on chromosomes 1A, 2B, 3A, 5A and 5B, the phenotypic variation explained was low to medium by individual QTL. A likely contributing factor was the comparatively small difference in straw fodder quality traits among the lines. It is interesting to note that line dependent variations in GY and SY were about two-fold. In other words, strong genotypic variations of GY and SY do exist. The lack of any similar variations in straw fodder quality traits is intriguing and requires further research. © 2019 The Authors
Wheat genetic resources enhancement by the International Maize and Wheat Improvement Center (CIMMYT)
(2008) Rodomiro Ortiz; Hans-Joachim Braun; José Crossa; Jonathan H. Crouch; Guy Davenport; John Dixon; Susanne Dreisigacker; Etienne Duveiller; Zhonghu He; Julio Huerta; Arun K. Joshi; Masahiro Kishii; Petr Kosina; Yann Manes; Monica Mezzalama; Alexei Morgounov; Jiro Murakami; Julie Nicol; Guillermo Ortiz Ferrara; J. Iván Ortiz-Monasterio; Thomas S. Payne; R. Javier Peña; Matthew P. Reynolds; Kenneth D. Sayre; Ram C. Sharma; Ravi P. Singh; Jiankang Wang; Marilyn Warburton; Huixia Wu; Masa Iwanaga
The International Maize and Wheat Improvement Center (CIMMYT) acts as a catalyst and leader in a global maize and wheat innovation network that serves the poor in the developing world. Drawing on strong science and effective partnerships, CIMMYT researchers create, share, and use knowledge and technology to increase food security, improve the productivity and profitability of farming systems and sustain natural resources. This people-centered mission does not ignore the fact that CIMMYT's unique niche is as a genetic resources enhancement center for the developing world, as shown by this review article focusing on wheat. CIMMYT's value proposition resides therefore in its use of crop genetic diversity: conserving it, studying it, adding value to it, and sharing it in enhanced form with clients worldwide. The main undertakings include: long-term safe conservation of world heritage of both crop resources for future generations, in line with formal agreements under the 2004 International Treaty on Plant Genetic Resources for Food and Agriculture, understanding the rich genetic diversity of two of the most important staples worldwide, exploiting the untapped value of crop genetic resources through discovery of specific, strategically-important traits required for current and future generations of target beneficiaries, and development of strategic germplasm through innovative genetic enhancement. Finally, the Center needs to ensure that its main products reach end-users and improve their livelihoods. In this regard, CIMMYT is the main international, public source of wheat seed-embedded technology to reduce vulnerability and alleviate poverty, helping farmers move from subsistence to income-generating production systems. Beyond a focus on higher grain yields and value-added germplasm, CIMMYT plays an "integrative" role in crop and natural resource management research, promoting the efficient use of water and other inputs, lower production costs, better management of biotic stresses, and enhanced system diversity and resilience. © 2008 Springer Science+Business Media B.V.
Wheat improvement in India: Present status, emerging challenges and future prospects
(2007) A.K. Joshi; B. Mishra; R. Chatrath; G. Ortiz Ferrara; Ravi P. Singh
India is the second largest producer of wheat in the world, with production hovering around 68-75 million tons for past few years. The latest estimated demand for wheat production for the year 2020 is approximately 87.5 million tons, or about 13 million tons more than the record production of 75 million tons harvested in crop season 1999-2000. Since 2000, India has struggled to match that record production figure and thus faces a critical challenge in maintaining food security in the face of its growing population. The current major challenges facing future wheat production in India are increasing heat stress; dwindling water supplies for irrigation; a growing threat of new virulence of diseases such as wheat rusts (yellow, brown, and black) and leaf blight; continuous adoption of rice-wheat systems on around 11 million hectares; changes in urbanization patterns, and demand for better quality wheat. In addition, the threat posed by the new stem rust race Ug99 can not be underestimated. The wide gap (around 2.5 t/ha) between the potential and harvested yield in the eastern Gangetic Plains also cries out for solutions. Addressing issues related to different stresses will require harnessing genes discovered in landraces and wild relatives following conventional as well as non-conventional approaches. For effective technology delivery in areas that suffer from poor linkages with farmers, participatory research needs to be strengthened. The future germplasm requirements from a dependable collaborator such as CIMMYT are largely being dictated by the above factors. © 2007 Springer Science+Business Media B.V.