The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
S. P. Jefferies - One of the best experts on this subject based on the ideXlab platform.
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Genetic dissection of Grain Yield in bread wheat. I. QTL analysis
Theoretical and Applied Genetics, 2007Co-Authors: H. Kuchel, K. J. Williams, P. Langridge, H. A. Eagles, S. P. JefferiesAbstract:Grain Yield forms one of the key economic drivers behind a successful wheat ( Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of Grain Yield. A doubled-haploid population, comprising 182 individuals, produced from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative Grain Yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to moderate Grain Yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, Grain Yield data were recorded for the population at 18 site-year combinations. Grain Yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence Grain Yield and Grain Yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated with Grain Yield. A QTL associated with Grain Yield on chromosome 1B, with no significant relationship with plant height, ear-emergence or rust resistance, was detected (LOD ≥2) at eight of the 18 environments. The mean Yield, across 18 environments, of individuals carrying the ‘Molineux’ allele at the 1B locus was 4.8% higher than the mean Grain Yield of those lines carrying the ‘Trident’ allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain Yield at six of the 18 environments. Of the nine Grain Yield QTL not shown to be associated with plant height, phenology or rust resistance, two were located near QTL associated with Grain Yield components. A third QTL, associated with Grain Yield components at each of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with Grain Yield at any of the environments. The implications of these findings on marker-assisted selection for Grain Yield are discussed.
S. J. Wall - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of a divergent set of SSR markers to predict F1 Grain Yield performance and Grain Yield heterosis in maize
Maydica, 2020Co-Authors: O. S. Smith, H. Sullivan, B. Hobart, S. J. WallAbstract:Previous work showed that many of the loci polymorphic between the Stiff Stalk Synthetic and Lancaster Sure Crop heterotic group had allele frequency differences of 0.5 or more. These loci were also located in regions where large quantitative trait loci (QTL) have been detected for Yield heterosis in the cross between the widely used genetically divergent inbred lines B73 and Mo17. B73 and Mo17 represent one of the widely used heterotic maize groups in the U.S Corn Belt. It was hypothesized that perhaps those markers responsible for distinguishing heterotic groups are linked to loci that are responsible, in part, for heterosis.' The objectives of this study were to test this hypothesis for maize hybrids with unrelated parents from widely used U.S. Corn Belt heterotic groups. In this study loci that were polymorphic between the two heterotic groups and had allele frequency differences of 0.40 or more were examined. F1 Grain Yield and Grain Yield heterosis were determined in a set of 59 crosses between unrelated parents that had been grown in a set of replicated experiments. The loci polymorphic with allele frequency differences in these two heterotic groups were located in almost all of the regions identified previously as being polymorphic with allele frequency differences of 0.5 or greater between the Stiff Stalk Synthetic and Lancaster Sure Crop lines, The Stiff Stalk Synthetic heterotic group was common to both studies but the Lancaster group was not. However, the selected loci in this study did not explain significantly more of the variation for F1 Grain Yield or Grain Yield heterosis than that explained using all of the loci studied.
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Similarities among a group of elite maize inbreds as measured by pedigree, F1 Grain Yield, Grain Yield, heterosis, and RFLPs
Theoretical and Applied Genetics, 1990Co-Authors: O. S. Smith, J. S. C. Smith, S. L. Bowen, R. A. Tenborg, S. J. WallAbstract:Genetic distances were calculated among 37 inbred lines representing a wide range of related and unrelated elite Corn Belt germ plasm of maize (Zea Mays L.), using 257 probe restriction enzyme combinations. Genetic distances based on RFLP data were highly correlated with coefficients of parentage among pairs of lines. The RFLP-based distance had a higher correlation with single-cross Grain Yield performance and Grain Yield heterosis than any of the other measures of similarity we calculated using these same lines. The coefficients of determination (r2) from regressing the coefficient of parentage, Grain Yield, and Grain Yield heterosis on Nei's measure of genetic similarity based on RFLP data were 0.81, 0.87 and 0.77, respectively. A cluster diagram based upon the RFLP data grouped the lines into families consistent with the breeding history and heterotic response of these lines. We believe that measures of similarity calculated from RFLP data, coupled with pedigree knowledge and using molecular markers to locate quantitative trait loci (QTL), could allow maize breeders to predict combinations of lines that result in high-Yielding, single-cross hybrids.
H. Kuchel - One of the best experts on this subject based on the ideXlab platform.
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Genetic dissection of Grain Yield in bread wheat. I. QTL analysis
Theoretical and Applied Genetics, 2007Co-Authors: H. Kuchel, K. J. Williams, P. Langridge, H. A. Eagles, S. P. JefferiesAbstract:Grain Yield forms one of the key economic drivers behind a successful wheat ( Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of Grain Yield. A doubled-haploid population, comprising 182 individuals, produced from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative Grain Yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to moderate Grain Yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, Grain Yield data were recorded for the population at 18 site-year combinations. Grain Yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence Grain Yield and Grain Yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated with Grain Yield. A QTL associated with Grain Yield on chromosome 1B, with no significant relationship with plant height, ear-emergence or rust resistance, was detected (LOD ≥2) at eight of the 18 environments. The mean Yield, across 18 environments, of individuals carrying the ‘Molineux’ allele at the 1B locus was 4.8% higher than the mean Grain Yield of those lines carrying the ‘Trident’ allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain Yield at six of the 18 environments. Of the nine Grain Yield QTL not shown to be associated with plant height, phenology or rust resistance, two were located near QTL associated with Grain Yield components. A third QTL, associated with Grain Yield components at each of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with Grain Yield at any of the environments. The implications of these findings on marker-assisted selection for Grain Yield are discussed.
Timothy J Arkebauer - One of the best experts on this subject based on the ideXlab platform.
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modis based corn Grain Yield estimation model incorporating crop phenology information
Remote Sensing of Environment, 2013Co-Authors: Toshihiro Sakamoto, Anatoly A Gitelson, Timothy J ArkebauerAbstract:Abstract A crop Yield estimation model using time-series MODIS WDRVI was developed. The main feature of the proposed model is the incorporation of crop phenology detection using MODIS data, called the “Shape-Model Fitting Method”. MODIS WDRVI taken 7–10 days before the corn silking stage had strong linear correlation with corn final Grain Yield at both field and regional scales. The model revealed spatial patterns of corn final Grain Yield all over the U.S. from 2000 to 2011. State-level corn Yield was estimated accurately with coefficient of variation below 10% especially for the 18 major corn producing states including Iowa, Illinois, Delaware, Minnesota, Ohio, West Virginia, Wisconsin, Michigan, Indiana, Nebraska, Kentucky, New York, South Dakota, Missouri, Pennsylvania, Tennessee, New Jersey and Maryland. The results corresponded well with the spatial pattern of high-Yield regions derived from the USDA/NASS data. However, the model tended to underestimate corn Grain Yield in three irrigated regions: the Midwestern region depending on the Ogallala Aquifer, the downstream basin of the Mississippi, and the southwestern region of Georgia. In contrast, it tended to overestimate corn Grain Yield around the outlying regions of the U.S. Corn Belt, specifically, the East Coast, North Dakota, Minnesota, Wisconsin, and Missouri. The estimation accuracy of the proposed model differed depending on the region. However, the annual variation of state level corn Grain Yield could be detected with high accuracy, especially in the major corn producing states.
O. S. Smith - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of a divergent set of SSR markers to predict F1 Grain Yield performance and Grain Yield heterosis in maize
Maydica, 2020Co-Authors: O. S. Smith, H. Sullivan, B. Hobart, S. J. WallAbstract:Previous work showed that many of the loci polymorphic between the Stiff Stalk Synthetic and Lancaster Sure Crop heterotic group had allele frequency differences of 0.5 or more. These loci were also located in regions where large quantitative trait loci (QTL) have been detected for Yield heterosis in the cross between the widely used genetically divergent inbred lines B73 and Mo17. B73 and Mo17 represent one of the widely used heterotic maize groups in the U.S Corn Belt. It was hypothesized that perhaps those markers responsible for distinguishing heterotic groups are linked to loci that are responsible, in part, for heterosis.' The objectives of this study were to test this hypothesis for maize hybrids with unrelated parents from widely used U.S. Corn Belt heterotic groups. In this study loci that were polymorphic between the two heterotic groups and had allele frequency differences of 0.40 or more were examined. F1 Grain Yield and Grain Yield heterosis were determined in a set of 59 crosses between unrelated parents that had been grown in a set of replicated experiments. The loci polymorphic with allele frequency differences in these two heterotic groups were located in almost all of the regions identified previously as being polymorphic with allele frequency differences of 0.5 or greater between the Stiff Stalk Synthetic and Lancaster Sure Crop lines, The Stiff Stalk Synthetic heterotic group was common to both studies but the Lancaster group was not. However, the selected loci in this study did not explain significantly more of the variation for F1 Grain Yield or Grain Yield heterosis than that explained using all of the loci studied.
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Similarities among a group of elite maize inbreds as measured by pedigree, F1 Grain Yield, Grain Yield, heterosis, and RFLPs
Theoretical and Applied Genetics, 1990Co-Authors: O. S. Smith, J. S. C. Smith, S. L. Bowen, R. A. Tenborg, S. J. WallAbstract:Genetic distances were calculated among 37 inbred lines representing a wide range of related and unrelated elite Corn Belt germ plasm of maize (Zea Mays L.), using 257 probe restriction enzyme combinations. Genetic distances based on RFLP data were highly correlated with coefficients of parentage among pairs of lines. The RFLP-based distance had a higher correlation with single-cross Grain Yield performance and Grain Yield heterosis than any of the other measures of similarity we calculated using these same lines. The coefficients of determination (r2) from regressing the coefficient of parentage, Grain Yield, and Grain Yield heterosis on Nei's measure of genetic similarity based on RFLP data were 0.81, 0.87 and 0.77, respectively. A cluster diagram based upon the RFLP data grouped the lines into families consistent with the breeding history and heterotic response of these lines. We believe that measures of similarity calculated from RFLP data, coupled with pedigree knowledge and using molecular markers to locate quantitative trait loci (QTL), could allow maize breeders to predict combinations of lines that result in high-Yielding, single-cross hybrids.
