Download or read book Studies on Yield Performance of Dwarf X Tall Hybrids in Maize Zea Mays L Involving Line X Tester Design written by K. Neeraja and published by . This book was released on 1989 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on the Comparison of Predicted and Actual Performance of Dwarf and Dwarf X Tall Double Cross Hybrids in Maize Zea Mays L written by I. Swarnalatha Devi and published by . This book was released on 1990 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agronomy Abstracts written by and published by . This book was released on 1993 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes abstracts of the annual meetings of the American Society of Agronomy; Soil Science Society of America; Crop Science Society of America ( - of its Agronomic Education Division).
Download or read book Physiological Basis of Yield Expression in Dwarf and Tall Inbred Lines and Their Single Cross Hybrids in Maize zea Mays L written by Hari Singh and published by . This book was released on 1975 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetics Abstracts written by and published by . This book was released on 1989 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1094 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genotype X Environment Interaction Yield Stability and Adaption Responses of 25 Single cross Maize Zea Mays L Hybrids Grown in Michigan written by Kingstone Mashingaidze and published by . This book was released on 1987 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1992 with total page 1742 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on Live X Tester Analysis for Yield Its Components and Resistance to Charcoal Rot Marcophomina Phaseolina in Maize Zea Mays L written by K. Anuradha and published by . This book was released on 1988 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Study of Yield Traits in Normal and Quality Protein Maize Genotypes Zea Mays L Using Line X Tester Analysis written by Molla Assefa Mengistu and published by . This book was released on 2009 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Maize In The Third World written by Christopher Dowswell and published by CRC Press. This book was released on 2019-04-01 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize is the world's most widely grown cereal and a dietary staple throughout the Third World, but its full potential has only begun to be tapped. This book thoroughly examines the biological and economic issues relevant to improving the productivity of maize in developing countries. The authors explore a wide range of practical problems, from maxi
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1972 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact of Genotype X Environment Interaction and Selection History on Genomic Prediction and Correcting for Non systematic Variability to Increase Efficiency in Maize Zea Mays L Breeding written by Martin Carlos Costa and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developing cultivars with high yield potential and stability across environments is essential to sustain the increasing global population in the context of climate change. Maize (Zea mays L.) is the major crop grown in the United States. Maize breeding processes involve genomic selection and the evaluation of experimental hybrid phenotypes using small plots to estimate genotypic performance. In this dissertation, I work with an extensive multi-environmental trial dataset with the goals to (1) characterize the relative value of the three donor inbreds as sources of useful alleles representing elite, non-elite, and un-selected donor types, (2) understand genomic prediction models that effectively identify new hybrids. Results showed that the parent with additional breeding cycles (elite) produced hybrids with lower genotype by environment interaction (GxE) variance. The reduced GxE variance of the population with the longest history of selection for favorable alleles led to greater prediction accuracy), contributing to greater yield stability. My second study in the dissertation assesses the impact of plant stand (number of plants per plot) and plant spacing variability in contributing non-heritable variation in breeding trials. We evaluated the grain yield performance of five hybrids exhibiting varied ear-flex traits across five manually adjusted plant spacing setups. Results demonstrated that in 36% of the occasions, we found differences that were not a reflection of genotypic effects but rather variations in spacing conditions (significant differences). However, incorporating the plot length, stand count, and plant spacing data into the model corrected for the non-systematic variability in the breeding trial.
Download or read book Physiological Determinants of Nitrogen Dynamics in Response to Genotype by Management Interactions in US Maize Hybrids written by Javier Antonio Fernandez and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In maize (Zea mays L.), the largest staple crop in the world, nitrogen (N) represents a major limiting factor for productivity. However, improving N use efficiency (NUE) is still one of the most critical research issues to achieve food security in a context affected by climate change. This dissertation is structured in six chapters (Chapter 1, Introduction, and Chapter 6, Conclusions) outlining the agronomic and physiological traits associated with a better N utilization in US maize hybrids across Genotype x Environment x Management (G x E x M) conditions, with emphasis on the implications of long-term genetic selection. Chapter 2 presents a comprehensive meta-analysis on a diverse dataset assembled from field studies from 1983 until 2018 to compare early- versus late-season N (applied after tenth-leaf) fertilization effects on yield and N recovery efficiency. Results provided evidence for the lack of a main effect of late N application on yields but suggest the existence of crop growth conditions prone to a greater reproductive N uptake where this practice might be suitable. Throughout multiple field trials, Chapter 3-5 advanced in our understanding of how long-term genetic improvement has modified N dynamics across G x M scenarios. Chapter 3 proposes a novel N by carbon (C) framework to analyze and define key morpho-physiological traits of breeding interest that allow modern maize plants to achieve higher productivity and NUE. Results show both an earlier stem N remobilization and a decline in grain N concentration are key drivers of N utilization efficiency in modern hybrids. Chapter 4 documents the underlying fluxes of post-flowering N allocation and translocation dynamics behind genetic improvement over time in field-grown corn. This research suggests that direct selection for yield has indirectly favored N allocation to leaves in modern genotypes resulting in an improved post-flowering C accumulation. Finally, Chapter 5 explores historical changes in the contribution of grain weight and its physiological characteristics to maize genetic progress. This research evidences a significant contribution of increments in grain weight in US maize but concludes the trade-off between grain number and weight poses a challenge for future yield progress.
Download or read book Bibliography of Agriculture with Subject Index written by and published by . This book was released on 1995 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Full Sib Hybrids and Testcross Progeny Tests for Genomic Prediction and Line X Tester Analysis of Hybrids of Two Multiparental Maize Populations written by Brett Burdo and published by . This book was released on 2018 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this experiment, we compare two progeny tests for unevaluated maize doubled haploids (DH) from two six-line synthetic populations with founders representing the Stiff Stalk and Iodent heterotic patterns. Either testcrossing, where lines are crossed to a common tester of the opposite group, versus information from hybrids produced by randomly crossing pairs of untested inbred lines, deemed Full-Sib (FS) hybrids, in the context of a genomic prediction enabled breeding program. Hybrids were evaluated for grain yield and 6 ancillary traits at two locations in 2014 and 2015, with two replications per location. Marker-based variance component estimates that account for deviations from Hardy-Weinberg equilibrium, suggest that the variance present in this population is predominantly additive. Coincidence of selection of the top 25 lines based on traditional General Combining Ability (GCA) for grain yield within the testcross and random pairs was 48% for the Stiff Stalk and 11% for the Iodent. Coincidence of selection using an additive model for genomic GCA estimation and testcross traditional GCA estimation was higher, at 56% for parental DH lines from either heterotic group. Partitioning dominance variation in the model increased coincidence of selection to 62% for the Stiff Stalk parents but did not increase coincidence beyond 56% for the Iodent. General Combining Ability (GCA)-based prediction accuracy of FS hybrid performance based on midparent of testcross performance was 0.73 and could not be improved with genomic prediction of the hybrid values. 10-fold cross validated prediction of the grain yield of hybrids of untested DH lines was 0.45 and 0.48 under an additive and additive + dominance G-BLUP model trained on the randomly paired lines, respectively, and 0.49 and 0.48 when trained on the testcrosses, none significantly different. Prediction of grain moisture, test weight, plant height and ear height were worse when training on the intercrossed population, but better for prediction of flowering traits. Incorporating marker information does allow for greatly improved GCA estimation from FS hybrids, but this is mostly due to accurate partitioning of additive effects, rather than a significantly enhanced capacity to capture non-additive effects with genomic estimation in the FS hybrids.
Download or read book Genetic Dissection of Yield Component Traits in Zea Mays Using Multiparent Advanced Generation Intercross Populations written by Kathryn Michel and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays L.) yield is a highly quantitative trait controlled by many loci of small effect, the environment, and genotype by environment interactions, which make it a difficult trait to study at the gene level. However, yield may be broken into components such as ear and kernel size and shape, which are more heritable than yield measured in small plots. Multiparent advanced generation intercross (MAGIC) populations and diversity panels are two types of populations that are useful for identifying quantitative trait loci (QTL) that influence phenotypes. This dissertation contains three research projects designed to investigate the control of quantitative traits impacting maize yield. First, we present the genomes of five founders of a Stiff Stalk MAGIC population. Between the reference inbred B73 and the other five inbreds, we found substantial genetic and genomic variation in addition to conservation of haplotypes from the base population from which the inbreds were selected. Second, we describe the Wisconsin-Stiff Stalk-MAGIC population, its associated resources, and demonstrate QTL mapping and genomic prediction for flowering time and plant height. Flowering time and plant height are important characteristics in hybrid maize breeding, so we measured them in both the per se population and two test-crossed hybrid populations. We found that QTL detection depended on the tester used, which was consistent with lower genomic predictive ability when training models with per se data to predict hybrid phenotypes. Third, we used a high throughput image analysis pipeline to measure yield components on four MAGIC populations and a diversity panel. We performed genetic mapping to identify candidate genes underlying ear and kernel size and shape. We found substantial overlap of our results across traits within and between populations and overlap with known metaQTL identified through previous studies. The results from these projects provide new insight into the genetic control of traits including flowering time, plant height, and the size and shape of ears and kernels, all of which impact overall maize yield.
