Download or read book Genetic Variability for Cold Tolerance in a Maize Zea Mays L Population written by Robin K. Duffy Cowen and published by . This book was released on 1985 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Variation for Chilling Stress and Spectral Reflectance in Short Season Maize written by Wisam Obeidat and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing early season cold tolerance of maize (Zea mays L.) has the potential to lengthen its growing season and enhance yields. We evaluated cold tolerance across 44 inbred and 102 hybrid genotypes in field and controlled environment experiments. Cold tolerance was quantified as the proportion of dry weight (PDW) of plants subjected to cold temperatures or planted early, relative to dry weight of plants grown in control temperatures or planted late. Also, leaf reflectance spectroscopy was used as an alternate indicator of cold stress response. In field experiments, significant effects of genotype, planting date, environment and their interactions were detected for PDW; the mean dry weight per plant for the early planting was considerably lower than for the late planting in five field environments. Cold stress exposure resulted in higher leaf reflectance in the 500 ̶ 680 nm region and lower reflectance between 758 ̶ 1000 nm. We identified novel reflectance predictors, both normalized difference indices and specific wavelengths of first derivative reflectance spectra, that correlated with PDW. In some cases the strongest correlations were found when reflectance data came from unstressed plants. Multiple regression models combining first derivative reflectance at multiple wavelengths, measured on plants not exposed to cold stress, provided the best correlation with PDW; however in general these models were unique to an experiment. Genetic control and heritability of plant dry weight and leaf spectral reflectance under control and early planting conditions was investigated in the field using a North Carolina Design II mating experiment. Consistent general combining ability estimates from early and late planting indicated that additive and dominant gene effects explained hybrid biomass variation across both planting dates. A number of spectral traits were heritable, but parental contributions to hybrid values were moderate. In conclusion, we find that parents explain at most moderate levels of hybrid spectral reflectance variation, across all spectral analysis tools. Thus, selection of traits such as hybrid biomass using spectral reflectance will be inefficient. Nonetheless, we find spectral reflectances stably distinguish maize genotypes within a population irrespective of temperature treatments, so selecting inbred lines using spectral reflectance may advance breeding efforts.
Download or read book Estimates of Genetic Variability and Gene Action in Two Maize Zea Mays L Populations written by Geng-Chen Han and published by . This book was released on 1987 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Variation Within Populations Used in Maize Zea Mays L Breeding written by Myron Ossie Fountain and published by . This book was released on 1993 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inheritance of Cold Tolerance in Maize Zea Mays L written by Melvin Vern Splitter and published by . This book was released on 1972 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimates of Genetic Variability Among Topcrosses of Two Brachytic Maize Zea Mays L Populations written by Roberto de Rissi and published by . This book was released on 1987 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on the Genetics and Breeding of Maize Zea Mays L for Cold Tolerance and Early Maturity written by Obaid Tahir Hassan and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Genetic Variability Using Full sib Families Within and Between the BS10 and BS11 Synthetic Maize Zea Mays L Populations for the Original and Tenth Cycle of Selection written by Todd Eugene Frank and published by . This book was released on 1997 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Variability of Maize Zea Mays L Under Different Tissue Culture Conditions written by Manfred Beckert and published by . This book was released on 1979 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Maize Genome written by Jeffrey Bennetzen and published by Springer. This book was released on 2018-11-24 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses advances in our understanding of the structure and function of the maize genome since publication of the original B73 reference genome in 2009, and the progress in translating this knowledge into basic biology and trait improvement. Maize is an extremely important crop, providing a large proportion of the world’s human caloric intake and animal feed, and serving as a model species for basic and applied research. The exceptionally high level of genetic diversity within maize presents opportunities and challenges in all aspects of maize genetics, from sequencing and genotyping to linking genotypes to phenotypes. Topics covered in this timely book range from (i) genome sequencing and genotyping techniques, (ii) genome features such as centromeres and epigenetic regulation, (iii) tools and resources available for trait genomics, to (iv) applications of allele mining and genomics-assisted breeding. This book is a valuable resource for researchers and students interested in maize genetics and genomics.
Download or read book Genetic Variability and the Inheritance of Aluminum Tolerance in Maize Zea Mays L written by R. Magnavaca and published by . This book was released on 1992 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Genetic Study of Cold Tolerance and Related Traits in an Unselected and a Selected Maize Population written by Kent R. Keim and published by . This book was released on 1979 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Leveraging Genetic Diversity in Maize Breeding written by Alden Perkins and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize (Zea mays L.) cultivars grown in the United States are not closely related to cultivars found in many other parts of the world, and pedigree records suggest that there has been little use of germplasm from other countries in US maize breeding. Exotic germplasm could be a useful source of alleles for improving traits such as grain quality, disease resistance, and abiotic stress tolerance in US populations. Exotic cultivars may also contain alleles that confer adaptation to different climate conditions and management practices, however, which could be detrimental in US growing environments. This dissertation contains a review article about the importance of genetic diversity in breeding and three research projects that involve the incorporation of exotic diversity into US maize germplasm. In the first research project, we investigated the effects of introgressions from open-pollinated populations that originated in Latin America on the performance of maize hybrids in US environments. We compared the phenotypic stability of exotic-derived hybrids and US-adapted hybrids, and we found that the two groups had significantly different stability values for grain yield and flowering time. In the second project, we estimated the effects of exotic introgressions contained in maize populations created by a public-private partnership on grain protein content, kernel vitreousness, and other agronomic traits. One introgression was estimated to increase grain protein content by 0.78%, although it was also associated with detrimental changes in the time of flowering and plant height. Finally, we compared models that could be used to predict the phenotypes of untested hybrids in diverse populations, which could make the process of incorporating new diversity into US germplasm more efficient. We found that models using near-infrared absorbance data collected on inbred seeds as predictors were inferior to models based on genotypic data in most cases, although the difference between the methods was small for traits such as grain moisture and test weight. An alternative to the standard genomic best linear unbiased prediction (GBLUP) method that included additional regularization, called the sparse selection index method, was superior to GBLUP models when large training populations were available. Collectively, the results from these projects provide new insights into how exotic germplasm can be used in US maize breeding most effectively.
Download or read book Molecular and Genetic Perspectives of Cold Tolerance in Plants written by Yingfang Zhu and published by Frontiers Media SA. This book was released on 2022-11-25 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Variation of Heat Tolerance and Correlation with Other Agronomic Traits in a Maize Z e a M a y s L Recombinant Inbred Line Population written by Jiangping Bai and published by . This book was released on 2003 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Variability in Germinating Ability of Zea Mays L at Low Temperatures written by Johng Ki Lim and published by . This book was released on 1960 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Quantitative Genetics of a Non stiff stalk Maize Zea Mays L Population written by Brandon M. Wardyn and published by . This book was released on 2006 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The genetic relationship among individuals is at the core of nearly all quantitative genetic theory. Dominant gene action has long been either ignored or disregarded as insignificant in many previous genetic models. For grain yield in maize (Zea mays L.), dominance has consistently accounted for a large proportion of genetic variance. We have used previously developed genetic theory that accounts for dominance variance during inbreeding and applied it to a unique breeding design. Our breeding design allowed us to estimate five genetic covariance parameters for six traits. In addition, we developed genetic gain equations that accounted for both dominance and inbreeding. We found that the genetic covariance parameters introduced via inbreeding were significant for five traits. Our estimates of the genetic covariance parameters allowed us to predict genetic gain over a range of selection units and response units. Half-sib selection proved superior to inbred progeny selection when the response was measured in the outbred progeny. In addition, the relative proportions of additive and dominance variance influenced the effectiveness of inbred progeny selection. We also showed that even when dominance constitutes a larger proportion of the total genetic variance than additive variance, the loss of additive effects has a greater influence on the decline associated with inbreeding than the addition of homozygous dominance deviations. Our results also indicated that the reason realized gain often falls short of predicted gain is due to the negative covariance between additive effects and homozygous dominance effects. The effect of a negative covariance is that positive gain via additive effects is offset by negative gain via homozygous dominance deviations.
