Download or read book Gene Action and Heterosis with Particular Reference to Single Cross Hybrids of Maize Zea Mays L written by SHAREW A. A and published by . This book was released on 2001 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Genetics in Maize Breeding written by Arnel R. Hallauer and published by Springer Science & Business Media. This book was released on 2010-09-28 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize is used in an endless list of products that are directly or indirectly related to human nutrition and food security. Maize is grown in producer farms, farmers depend on genetically improved cultivars, and maize breeders develop improved maize cultivars for farmers. Nikolai I. Vavilov defined plant breeding as plant evolution directed by man. Among crops, maize is one of the most successful examples for breeder-directed evolution. Maize is a cross-pollinated species with unique and separate male and female organs allowing techniques from both self and cross-pollinated crops to be utilized. As a consequence, a diverse set of breeding methods can be utilized for the development of various maize cultivar types for all economic conditions (e.g., improved populations, inbred lines, and their hybrids for different types of markets). Maize breeding is the science of maize cultivar development. Public investment in maize breeding from 1865 to 1996 was $3 billion (Crosbie et al., 2004) and the return on investment was $260 billion as a consequence of applied maize breeding, even without full understanding of the genetic basis of heterosis. The principles of quantitative genetics have been successfully applied by maize breeders worldwide to adapt and improve germplasm sources of cultivars for very simple traits (e.g. maize flowering) and very complex ones (e.g., grain yield). For instance, genomic efforts have isolated early-maturing genes and QTL for potential MAS but very simple and low cost phenotypic efforts have caused significant and fast genetic progress across genotypes moving elite tropical and late temperate maize northward with minimal investment. Quantitative genetics has allowed the integration of pre-breeding with cultivar development by characterizing populations genetically, adapting them to places never thought of (e.g., tropical to short-seasons), improving them by all sorts of intra- and inter-population recurrent selection methods, extracting lines with more probability of success, and exploiting inbreeding and heterosis. Quantitative genetics in maize breeding has improved the odds of developing outstanding maize cultivars from genetically broad based improved populations such as B73. The inbred-hybrid concept in maize was a public sector invention 100 years ago and it is still considered one of the greatest achievements in plant breeding. Maize hybrids grown by farmers today are still produced following this methodology and there is still no limit to genetic improvement when most genes are targeted in the breeding process. Heterotic effects are unique for each hybrid and exotic genetic materials (e.g., tropical, early maturing) carry useful alleles for complex traits not present in the B73 genome just sequenced while increasing the genetic diversity of U.S. hybrids. Breeding programs based on classical quantitative genetics and selection methods will be the basis for proving theoretical approaches on breeding plans based on molecular markers. Mating designs still offer large sample sizes when compared to QTL approaches and there is still a need to successful integration of these methods. There is a need to increase the genetic diversity of maize hybrids available in the market (e.g., there is a need to increase the number of early maturing testers in the northern U.S.). Public programs can still develop new and genetically diverse products not available in industry. However, public U.S. maize breeding programs have either been discontinued or are eroding because of decreasing state and federal funding toward basic science. Future significant genetic gains in maize are dependent on the incorporation of useful and unique genetic diversity not available in industry (e.g., NDSU EarlyGEM lines). The integration of pre-breeding methods with cultivar development should enhance future breeding efforts to maintain active public breeding programs not only adapting and improving genetically broad-based germplasm but also developing unique products and training the next generation of maize breeders producing research dissertations directly linked to breeding programs. This is especially important in areas where commercial hybrids are not locally bred. More than ever public and private institutions are encouraged to cooperate in order to share breeding rights, research goals, winter nurseries, managed stress environments, and latest technology for the benefit of producing the best possible hybrids for farmers with the least cost. We have the opportunity to link both classical and modern technology for the benefit of breeding in close cooperation with industry without the need for investing in academic labs and time (e.g., industry labs take a week vs months/years in academic labs for the same work). This volume, as part of the Handbook of Plant Breeding series, aims to increase awareness of the relative value and impact of maize breeding for food, feed, and fuel security. Without breeding programs continuously developing improved germplasm, no technology can develop improved cultivars. Quantitative Genetics in Maize Breeding presents principles and data that can be applied to maximize genetic improvement of germplasm and develop superior genotypes in different crops. The topics included should be of interest of graduate students and breeders conducting research not only on breeding and selection methods but also developing pure lines and hybrid cultivars in crop species. This volume is a unique and permanent contribution to breeders, geneticists, students, policy makers, and land-grant institutions still promoting quality research in applied plant breeding as opposed to promoting grant monies and indirect costs at any short-term cost. The book is dedicated to those who envision the development of the next generation of cultivars with less need of water and inputs, with better nutrition; and with higher percentages of exotic germplasm as well as those that pursue independent research goals before searching for funding. Scientists are encouraged to use all possible breeding methodologies available (e.g., transgenics, classical breeding, MAS, and all possible combinations could be used with specific sound long and short-term goals on mind) once germplasm is chosen making wise decisions with proven and scientifically sound technologies for assisting current breeding efforts depending on the particular trait under selection. Arnel R. Hallauer is C. F. Curtiss Distinguished Professor in Agriculture (Emeritus) at Iowa State University (ISU). Dr. Hallauer has led maize-breeding research for mid-season maturity at ISU since 1958. His work has had a worldwide impact on plant-breeding programs, industry, and students and was named a member of the National Academy of Sciences. Hallauer is a native of Kansas, USA. José B. Miranda Filho is full-professor in the Department of Genetics, Escola Superior de Agricultura Luiz de Queiroz - University of São Paulo located at Piracicaba, Brazil. His research interests have emphasized development of quantitative genetic theory and its application to maize breeding. Miranda Filho is native of Pirassununga, São Paulo, Brazil. M.J. Carena is professor of plant sciences at North Dakota State University (NDSU). Dr. Carena has led maize-breeding research for short-season maturity at NDSU since 1999. This program is currently one the of the few public U.S. programs left integrating pre-breeding with cultivar development and training in applied maize breeding. He teaches Quantitative Genetics and Crop Breeding Techniques at NDSU. Carena is a native of Buenos Aires, Argentina. http://www.ag.ndsu.nodak.edu/plantsci/faculty/Carena.htm
Download or read book Gene Action in Single Cross Hybrids of Maize written by Pavan R. and published by LAP Lambert Academic Publishing. This book was released on 2012-07 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize is an important cereal crop belonging to family, Poaceae. It is one of the staple food crop and widely cultivated crop throughout the world. It is the only cereal which can be used as food at various stages of its plant development. The potential of heterosis is just beginning to be exploited in developing countries through expansion of hybrid seeds. It has the highest potential of per day carbohydrate productivity. Thus, the father of green revolution, the renowned Nobel Laureate, Dr. Norman E. Borlaug, believes that "after the last two decades saw the revolution in rice and wheat, the next few decades will be known as maize era." Shull (1908 and 1911) gave the original concept for production and growing of single cross hybrids. The recent trends even in the developing and under developed countries single cross hybrids are more popular due to their higher yield under favourable environment and uniformity in expression. Hence, there is a greater scope for the exploitation of heterosis through single cross hybrids, than double cross hybrids.
Download or read book Heterosis and Combining Ability in Maize Zea Mays L A Research written by T. Sandeep Kumar and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maize Breeding Research........This book is purely based on maize breeding research which deals with selection of elite parents, generating crosses and understanding the gene action involved in the expression of traits. Further, association among various yield components in final expression of yield is explained. It is helpful for a new breeder to get a preliminary understanding on plant breeding research in developing new promising hybrids. Thank you my beloved Parents
Download or read book Effects of Hybridization on Heterochromatic Small Interfering RNA and Gene Expression in Zea Mays written by Travis Korry Coleman and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterosis for quantitative traits in maize (Zea mays L.) is generally controlled by the cumulative effects of multiple genes and regulatory elements. In particular, 24-nt heterochromatic small interfering RNAs (hetsiRNAs) may affect heterosis of gene expression by mediating trans-genomic interactions when two genomes come into contact in an F1 nucleus. Previous research has suggested that hetsiRNAs exhibit non-additive expression upon hybridization, with the majority of hetsiRNAs being downregulated compared to parental levels. This could have implications for the regulation of nearby genes, thus influencing heterosis of gene expression in a non-Mendelian and epigenetic manner. This research sought to examine trends in hetsiRNA expression and hetsiRNA/gene co-expression resulting from hybridization of commercial maize germplasm. Small RNA and mRNA were isolated and deep sequenced from two inbred lines and their F1 hybrid. Results confirmed that mean hetsiRNA expression was significantly reduced in the F1 hybrid relative to its parents. The F1 hybrid also demonstrated a marked reduction in hetsiRNA diversity, with 41% of hetsiRNA clusters being expressed in one or both parents but not the hybrid. Similarly, classifying hetsiRNA expression in the hybrid relative to the expected midparent value demonstrated that the vast majority of hetsiRNA clusters were expressed below the midparent level, with many transgressive below the low parent. Localization of hetsiRNA clusters within the boundaries of a genic frame showed a strong enrichment of hetsiRNA clusters in the +/- 1 kb flanks of genic regions. Expression level analyses indicated a mean downregulation of both hetsiRNA and mRNA expression relative to expected midparent values for a small but significant number of genes with co-located hetsiRNA clusters. Furthermore, knockout of hetsiRNA production in the mediator of paramutation 1 mutant mop1-1 demonstrated a trend toward upregulation of genes relative to the wildtype. These results suggest that hetsiRNA may play a limited role in non-additive, epigenetic regulation of gene expression in hybrids. These findings have implications for the development of hybrid crop species and the notion of an epigenome that may not exhibit traditional patterns of Mendelian inheritance and may therefore affect phenotype in an unpredictable manner.
Download or read book Heterosis written by Iowa State College and published by . This book was released on 1952 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combining Ability Gene Action and Heterosis for Some Seed Quality and Yield Parameters in Maize zea Mays L written by Gopal Katna and published by . This book was released on 2000 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetics and Exploitation of Heterosis in Crops written by J. G. Coors and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore the momentous contributions of hybrid crop varieties with worldwide experts. Topics include an overview, quantitative genetics, genetic diversity, biochemistry and molecular biology, methodologies, commercial strategies, and examples from numerous crops.
Download or read book Molecular Basis of Heterosis in Maize written by Hui Zhi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterosis, or hybrid vigor, refers to the superiority of F1 hybrid performance over the mean of its parents (mid-parent heterosis) theoretically, or the performance of better parents. It has been discovered in many species of plants and animals as well as in humans, and played an important role in enhanced agricultural production, especially in maize, rice and sorghum although the mechanism have not been elucidated. We studied the molecular basis of heterosis with a combined genomics and systems biology approach using model organism maize. We profiled the expression of 39 genes that were most differentially expressed (DG) between the mid-parents and their F1 hybrid (Mo17 x B73) in the 13V-satged, developed whole ear shoots of 13 inbred lines and their 22 F1 hybrids grown in the field trails and phenotyped their 13 traits significant for grain yield. The results showed that gene expression varies significantly among inbreds, among hybrids and in heterosis. The gene clustering heat map and gene action networks in inbreds and hybrids were constructed respectively based on their gene expression profile. According to these pattern analyses, we find dramatically difference between inbreds and their hybrids, although the differential expression varies across different hybrids. Our results also suggest that gene networks are altered from inbreds to hybrids, including their gene contents and wire structures. Last but not least, we have determined the genetic variation correlations between the gene expression and trait performance and constructed the gene networks for the development of 12 of the 13 traits that varied significantly among genotypes. This has led to identification of genes significantly contributing to the performances of the traits, with 1-16 genes per trait. These results have indicated that heterosis results not only from altered expression level of corresponding genes between inbreds and their hybrids, importantly, also from the altered gene action networks and expression patterns. These alternations could be derived from gene actions in a manner of additivity, dominance, over dominance, pseudo-overdominance, epistasis and/or their combinations. Therefore, our findings provide a better understanding of the underlying molecular basis of heterosis. The genes identified for the traits will provide tools for advanced studies of the trait heterosis and could be used as tools for their heterosis breeding in maize. The strategy developed in this study will provide an effective tool for studies of other complicated, quantitative traits in maize and other species.
Download or read book Genetic Studies and Identification of Favourable Alleles for the Improvment of Single Cross Hybrids of Maize Zea Mays L written by D. M. Reddy and published by . This book was released on 1998 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Progress in Recurrent Selection for Specific Combining Ability in Two Open pollinated Maize Zea Mays L Varieties written by Ronald N. Walejko and published by . This book was released on 1976 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: To decide upon the most efficient breeding and testing procedures to improve maize populations, the plant breeder must have adequate knowledge of the type of gene action involved in yield heterosis. Two types of gene action have been postulated to account for yield heterosis in maize: dominance and overdominance. Recurrent selection of specific combining ability and for general combining ability have been proposed as methods to improve maize populations. Recurrent selection for specific combining ability uses a narow genetic base tester and originally was proposed on the assumption that overdominance is the main type of gene action responsible for yield heterosis. Conversely, selection for general combining ability uses a broad genetic base tester and assumes that dominant, favorable factors are concerned in yield heterosis. A procedure was proposed to compare the relative importance of dominance and overdominance in yield heterosis. This procedure involved recurrent relection for specific combining ability in two heterozygous source populations with a common inbred line tester. The purpose of this study was to evaluate progress in 5 cycles of recurrent slection for specific combining ability in two open-pollinated maize varieties and to determine the type of gene action involved in yield heterosis. The two source populations were the open-pollinated varieties, Kolkmeier and Lancaster, and the inbred line, Hy, was used as the common tester. After 5 cycles of recurrent selection, 6 population (C0 to C5) from (...).
Download or read book Heterosis written by J. W. GOWEN (ed) and published by . This book was released on 1952 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early ideas on inbreeding and crossbreeding; Beginings of the heterosis concept; Preferencial segregation in maize; Inbreedding and crossbreeding in seed development; Physiology of gene action in hybrids; Origin of corn belt maize and its genetics significance; Heterosis in population genetics; Fixing transgressive vigor in nicotina rustica; Hybridization in the evolution of maize; Biochemical models of heterosis in Neurospora; Nature and origin of heterosis; Specificity of gene effects; Genetics and citology of Sacchoromyces; Genetic implications of mutation in S. Typhirmurium; Dominance and overdominance; Gene recombination and heterosis; Inbred lines for heterosis tests?; Specific and general combining ability; Rotational crossbreeding and heterosis; Gamete selection for specific combining ability; Monoploids in maize; Early testing and recurrent selection; Heterosis in a new population; Recurrrent selection and overdominance; Hybrid vigor in Drosophila; Estimation of average dominance of genes.
Download or read book Heterosis Combining Ability and Gene Action in Maize Zea Mays L written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specialty Corns written by Arnel R. Hallauer and published by CRC Press. This book was released on 2000-08-23 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely revised and updated, the Second Edition of Specialty Corns includes everything in the first edition and more. Considered the standard in this field, significant changes have been made to keep all the information current and bring the references up-to-date. Two new chapters have been added to keep up with the latest trends: Blue Corn and
Download or read book Heterosis written by R. Frankel and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: When trying to solicit authors for this book it became apparent that the causal factors for heterosis at the physiological and biochemical level are today almost as obscure as they were 30 years ago. Though biometrical-genetical analyses point to dispersion of complementary genes - not overdominance - as the major cause of the phenomenon, plant breeders' experience still suggests a cautious, pragmatic approach to the dominance-overdominance controversy in breeding hybrid cultivars. Thus we are faced with a striking discordance between our limited comprehension of the causal factors and mechanism of heter osis on the one hand, and the extensive agricultural practice of utiliza tion of hybrid vigor on the other. Such utilization is the result of the economic value of hybrid combinations displaying superior yields and qualities as well as stability of performance, of benefits derived in breeding programs, and of the enhanced varietal protection of proprietary rights. No comprehensive and critical analysis of the phenomenon of heterosis in economic plants has been published for the last three decades since the now classical book Heterosis, edited by J . W. Gowen (Iowa State College Press, Ames, Iowa, 1952). The present book attempts to fill the gap and to assess the status of our present knowl edge of the concept, the basis, the extent, and the application of heterosis in economic plants.
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin written by and published by . This book was released on 2010 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
