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Kleinknecht K.,University of Hohenheim | Mohring J.,University of Hohenheim | Singh K.P.,Directorate of Maize Research | Zaidi P.H.,Indian International Crops Research Institute for the Semi Arid Tropics | And 2 more authors.
Crop Science | Year: 2013

The maize (Zea mays L.) growing area in India is divided into five zones for cultivar testing. During triannual testing of genotypes in official trials within the All-India Coordinated Maize Improvement Program (AICMIP), a large number of entries is rejected each year. Therefore, only a low number of entries is carried forward to the advanced stage of testing. The subdivision of the breeding sites into zones results in limited data per zone. Hence, the question arises how to select the best genotypes per zone and how information can be borrowed across zones to improve the accuracy of selection within zones. We compared the performance of best linear unbiased prediction (BLUP) using the correlation of genetic effects between zones with best linear unbiased estimation (BLUE) based on data per zone. In both cases, data were analyzed using a mixed model. We used simulations to calculate correlations between the true simulated values and the predicted genotype values obtained by BLUE and BLUP using the same models. The data structure and the variance components used in simulations were based on the analysis of 40 triannual series of four different maize maturity groups. Best linear unbiased prediction outperformed BLUE in 38 out of 40 series and on average across all series. An advantage of BLUP was observed for varying genetic correlations between zones. We conclude that the use of BLUP enhanced the estimation accuracy in zoned AICMIP maize testing trials and can be recommended for future use in these trials. © Crop Science Society of America. Source

Saharawat Y.S.,International Rice Research Institute | Singh B.,CCS Haryana Agricultural University | Malik R.K.,CCS Haryana Agricultural University | Ladha J.K.,International Rice Research Institute | And 3 more authors.
Field Crops Research | Year: 2010

The rice-wheat rotation covering 13.5 million ha in the Indo-Gangetic Plains is vital for food security. Its sustainability is at risk as the current production practices are inadequate resulting in high cost of cultivation and inefficient use of inputs (i.e. water, labor and energy). In a field study, we evaluated resource conserving and cost-saving alternative tillage and crop establishment options with an aim to improve system productivity and efficiency. Treatments included transplanting and direct-seeding of rice after reduced and no-tillage, followed by wheat after no-tillage. Conventional-tilled (puddled) transplanted rice followed by conventional-tilled wheat was included as a current practice. Rice yields of transplanted rice were similar irrespective of tillage/puddling. However, both dry and wet direct-seeded rice yielded 0.45-0.61 Mg ha -1 lower than puddled transplanted rice. Wheat yield after no-tillage was either higher or equivalent to conventional practice. Wheat provided more economic return (US $35 ha -1) than rice. No-till wheat was 6% more profitable than the conventional practice (T1). Rice transplanting with or without puddling had similar water application but dry direct-seeded rice had 10-12% lower and wet direct-seeded rice 20-24% higher. Machine labor without tillage was lower by maximum of 51 and 43% in rice and wheat, respectively. Similarly, human labor was also 9-16% lower in no-till rice compared to other practices. Two years results consistently showed $35 more net income when rice was transplanted without puddling than that of conventional practice. Direct-seeded/un-tilled rice had variable response in 2 years; US $16 more in year 1 and similar in year 2 to the puddled transplanted rice. Direct-seeded or transplanted rice after no-tillage can be more efficient and profitable alternatives to current practice (puddled transplanted rice), however, require further refinement in areas of cultivar development for no-till direct-seeding condition, nutrient, water and weed management to harness maximal potential. © 2010 Elsevier B.V. All rights reserved. Source

Ganesan S.K.,Indian Agricultural Research Institute | Singh R.,National Bureau of Plant Genetic Resources | Roy Choudhury D.,National Bureau of Plant Genetic Resources | Bharadwaj J.,National Bureau of Plant Genetic Resources | And 2 more authors.
Industrial Crops and Products | Year: 2014

Genetic diversity assessment is prerequisite for future crop improvement programme therefore in the present study, morphological and molecular diversity among the 12 Indian drumstick (Moringa oleifera Lam.) populations were assessed. A total of 300 genotypes belonging to 12 populations of drumstick (M. oleifera Lam.) were collected from northern (Himachal Pradesh) and southern (Tamil Nadu) parts of India. Under field condition 14 qualitative and 11 quantitative morphological characters were recorded to assess the diversity at morphological level. Correlation studies showed significant correlation between the quantitative characters. At molecular level, 19 SSR primers that produced clear and reproducible bands were selected for diversity study. A total of 35 bands were amplified of which 29 (82.86%) were polymorphic with an average of 1.84 bands per primer. Polymorphic information content (PIC) value for SSR primers ranged from 0.01 for primer MO64 to 0.37 for primer MO1 with an average of 0.15. The gene diversity ranged from 0.01 to 0.49 with an average of 0.18. Cluster analysis based on morphological characters (qualitative and quantitative) divided populations into two groups whereas; SSR makers divided it into three groups. Population MO9 (PKM1) form Periyakulum, Tamil Nadu was ungrouped based on quantitative characters. Principal coordinate analysis (PCoA) with SSR markers showed that large diversity existed in Indian drumsticks collection. The percentage of variation explained by the first 3 axes was 31.69% (axis1 - 14.35%, axis2 - 9.39% and axis3 - 7.95%). Analysis of molecular variance (AMOVA) indicated that 2% diversity was attributed to differences among regions, 3% at the level of populations and 95% contributed by the genotypes within the populations. Model based population structure were tested using K values from 1 to 20, but there was no clear population structure, therefore Ln(PD) derived δ. k was plotted against the K to determine the number of populations. Based on population structure analysis five clear populations were obtained instead of 12 natural populations. Cluster analysis and structure based population study showed that, no geographical isolation exists between genotypes collected from northern and southern part of India. Principal coordinate analysis showed large genetic diversity exists in Indian drumstick collection which can be utilised for crop improvement programme particularly traits related to oil yield. © 2014 Elsevier B.V. Source

Gupta H.S.,Vivekananda Parvatiya Krishi Anusandhan Sansthan VPKAS | Gupta H.S.,Indian Agricultural Research Institute | Raman B.,Vivekananda Parvatiya Krishi Anusandhan Sansthan VPKAS | Raman B.,International Maize and Wheat Improvement Center | And 5 more authors.
Plant Breeding | Year: 2013

Vivek Maize Hybrid 9- a popular single-cross hybrid developed by crossing CM 212 and CM 145 was released for commercial cultivation in India. The parental lines, being deficient in lysine and tryptophan, were selected for introgression of opaque-2 allele using CML 180 and CML 170 as donor lines through marker-assisted backcross breeding. The opaque-2 homozygous recessive genotypes with >90% recovery of the recurrent parent genome were selected in BC2F2, and the seeds with <25% opaqueness in BC2F3 were forwarded for seed multiplication. Vivek Quality Protein Maize (QPM) 9, the improved QPM hybrid, showed 41% increase in tryptophan and 30% increase in lysine over the original hybrid. The grain yield of the improved hybrid was on par with the original hybrid. The newly improved QPM maize hybrid released in 2008 will help in reducing the protein malnutrition because its biological value is superior over the normal maize hybrids. This short duration QPM maize hybrid has been adopted in several hill states of North Western and North Eastern Himalayan regions. © 2012 Blackwell Verlag GmbH. Source

Nepolean T.,Indian Agricultural Research Institute | Singh I.,Directorate of Maize Research | Hossain F.,Indian Agricultural Research Institute | Pandey N.,Indian Agricultural Research Institute | Gupta H.S.,Indian Agricultural Research Institute
Journal of Plant Biochemistry and Biotechnology | Year: 2013

A set of 24 genotypes bred at different centres in India as well as in CIMMYT showing variability for drought tolerance were selected for molecular and morpho-physiological characterization. A set of 35 SSR markers, having genome-wide coverage, was chosen for genotyping the inbreds. These markers generated a total of 111 polymorphic alleles with an average of 3. 17 alleles per locus. The minimum and maximum PIC value was 0. 27 and 0. 77 with a mean of 0. 5. A total of 13 unique alleles were found in the 24 inbred lines. The coefficient of genetic dissimilarity ranged from 0. 192 to 0. 803. NJ-based tree suggested the presence of three major clusters of which, two of them had subgroups. Phenotyping of inbreds by morpho-physiological traits revealed that there was a positive relationship among root length, chlorophyll content, relative water content while anthesis-silking interval was negative relationship with all these traits. Genotyping data complemented by morpho-physiological parameters were used to identify a number of pair-wise combinations for the development of mapping population segregating for drought tolerance and potential heterotic pairs for the development of drought tolerant hybrids. © 2012 Society for Plant Biochemistry and Biotechnology. Source

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