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Book Genetic Analysis of Grain Yield and Associated Characters in Two Maize Populations Ashwini and Harsha Through Reciprocal Recurrent Selection

Download or read book Genetic Analysis of Grain Yield and Associated Characters in Two Maize Populations Ashwini and Harsha Through Reciprocal Recurrent Selection written by Umakanth U. Akula and published by . This book was released on 1997 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Quantitative Genetics in Maize Breeding

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

Book Response to Full sib Reciprocal Recurrent Selection in a Double cross Maize Population

Download or read book Response to Full sib Reciprocal Recurrent Selection in a Double cross Maize Population written by Eduardo J. Graterol M. and published by . This book was released on 2005 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Molecular Marker Analysis of Population Genetic Structure and Progress from Reciprocal Recurrent Selection in Two Iowa Maize Zea Mays L Populations

Download or read book Molecular Marker Analysis of Population Genetic Structure and Progress from Reciprocal Recurrent Selection in Two Iowa Maize Zea Mays L Populations written by Lori Lynn Hinze and published by . This book was released on 2003 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of the genetic structure of the Iowa Corn Borer Synthetic #1 (CB) and Iowa Stiff Stalk Synthetic (SS) maize populations are of particular significance because they serve as the model on which development of modern commercial hybrids are based. These populations are part of a reciprocal recurrent selection breeding strategy. With this strategy, plants from one population are crossed to plants from the opposite population (i.e. forming hybrids). These hybrids are tested, and the best ones are chosen. The plants crossed to form the chosen hybrids are identified and used to form the next generation in each population. The goal of each successive generation is to improve on the previous generation while maintaining variability within the populations. We measured the progress of this program by testing for between- and within-population level genetic differentiation by analyzing the variation at 86 SSR loci among plants sampled from eight groups (progenitors, Cycle 0, Cycle 1, Cycle 3, Cycle 6, Cycle 9, Cycle 12, and Cycle 15) in each population. The progenitors used to form these populations are highly polymorphic (3.8 alleles/locus and 0.56 expected heterozygosity). This polymorphism decreases through Cycle 15 (1.9 alleles/locus and 0.25 expected heterozygosity). Individual plants within groups have a larger amount of genetic variation (66%) than groups within each population (13%) or between populations (21%). Consistent with theoretical expectations is the repartitioning of variation from within populations (96% in progenitors) to between populations (58% in Cycle 15) over time. When testing for deviations from natural processes, we identified approximately 26 of the 86 SSR loci affected by a non-random process over time. These results implicate genetic drift with a more profound effect than artificial selection in small populations. Through the use of smaller sample sizes, we were able to analyze more intermediate groups than any previous work in these populations. These intermediate time points represent a comprehensive genetic look within CB and SS to evaluate the applied effectiveness of the reciprocal recurrent selection program in relationship to its theoretical framework.

Book Genotype by Environment Interactions and Selection Responses of Two Maize Populations to Reciprocal Recurrent Selection in a High yield Environment

Download or read book Genotype by Environment Interactions and Selection Responses of Two Maize Populations to Reciprocal Recurrent Selection in a High yield Environment written by Hung-shung Lu and published by . This book was released on 1986 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Changes in Physiological Traits Associated with Five Cycles of S1 Recurrent Selection in Two Maize Populations

Download or read book Changes in Physiological Traits Associated with Five Cycles of S1 Recurrent Selection in Two Maize Populations written by Bernard James Hable and published by . This book was released on 1985 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five cycles of S1 recurrent selection for cold tolerance were conducted at Iowa State University in maize population BS13(SCT) and BSSS2(SCT). Previous studies have indicated that improvement in cold tolerance had been realized in these programs and that a correlated improvement in grain yield had taken place. The objective of this study were: 1) to examine the change in ontogenetic development correlated with changes in cold tolerance, 2) to evaluate changes in physiological traits and yield components associated with the previously observed correlated improvements in grain yield, and 3) to relate changes in means to changes in allelic frequencies and genetic drift. The CO, C5, and C0 c C5 intrapopulation cross of both BS13(SCT) and BSSS2(SCT), and the CO xCO and C5 x C5 interpopulation crosses were evaluated in five environments over three years. All experiments were planted in five environments over three years. All experiments were planted after 20 April in central Iowa. To assess the correlated changes, the C0 and C% cycle means were compared and a model proposed by Smith (1979a) was utilized to estimate correlated changes in gene frequency and changes in gne frequency due to restricted population size. The recurrent selection programs for cold tolerance resulted in earlier flowering in both of the population evaluated in this study. The C5 cycels of both BS13(SCT) and BSSS2(SCT) silked in at least 40 fewer growing degree days (GDD) than the CO cycles, and estimated, correlacted for genetic drift, (...).

Book Comparative Response to Selection of Two Reciprocal Recurrent Procedures in BS21 and BS22 Maize Populations

Download or read book Comparative Response to Selection of Two Reciprocal Recurrent Procedures in BS21 and BS22 Maize Populations written by Mónica A. Menz Rademacher and published by . This book was released on 1997 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Realized heritability and response to selection for yield were 25 to 50% of their predicted values. In this study there was no evidence that the genetic variance among testcrosses for yield was greater when using inbred lines as testers than when using populations as tester. The traditional RRS procedure was more effective than MRRS to improve grain yield in the cross population BS2lxBS22.

Book Direct and Correlated Response to Recurrent Selection for Grain Yield in Maize Breeding Populations

Download or read book Direct and Correlated Response to Recurrent Selection for Grain Yield in Maize Breeding Populations written by M.A.B. Fakorede and published by . This book was released on 1977 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr. G. F. Sprague initiated recurrent selection programs during the 1940' and 1950' to improve the grain-yield performance of several maize (Zea mays L.) population at the Iowa Agriculture and Home Economics Experiments Station. Seven cycles of reciprocal recurrent selections (RRS) in Iowa Stiff Stalk Synthetic (BSSS) and Iowa Corn Borer Synthetic #1 (BSCB1), and six cycles of recurrent half-sib selection (HS) in the open-pollinated variety 'Alph'(i.e., BS12) have been completed. Inbred B14 was the tester in the HS program. My objectives were to (1) evaluate progress that resulted from the RRS and HS programs and (2) evaluate changes in several other traits associated with recurrent selection for grain yield. I evaluated the CO x CO, C5, and C7 x C7 of the RRS program, and CO and C6 of the HS program, each testcrossed to B14A. Estimated gain from seven cycles of RRS was 2.06 q/ha (or 5.21%) per cycle and observed difference in mean yield between CO and C6 of the program was 2.25 q/ha (or 6.00%) per cycle. Improved hybrids outyield their unimproved counterparts at all levels of nitrogen (0, 90, 180, and 270 kg N/ha) and plant density (39,000; 59,300; 79,000; and 98,800 plants/ha) investigated. Each hybrid displayed a positive, curvilinear response to nitrogen and a negative, linear response to plant density. Stability and adaptation-reaction analysis revealed that improved hybrids consistently demonstrated greater adaptation to high-nitrogen environments, but their unimproved counterparts did not take (...).

Book Evaluation of Reciprocal Recurrent Selection for Grain Yield in Maize Z Mays L

Download or read book Evaluation of Reciprocal Recurrent Selection for Grain Yield in Maize Z Mays L written by Seme Debela and published by . This book was released on 1972 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Evaluation of Progress from Full sib Family Selection for Potential Yield Improvement in Two Tropical Maize Populations

Download or read book Evaluation of Progress from Full sib Family Selection for Potential Yield Improvement in Two Tropical Maize Populations written by Samuel Cephas Muchena and published by . This book was released on 1977 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Genetic Analysis and Stability Performance for Grain Yield and Its Contributing Characters in Newly Developed Hybrids of Maize Zea Mays L

Download or read book Genetic Analysis and Stability Performance for Grain Yield and Its Contributing Characters in Newly Developed Hybrids of Maize Zea Mays L written by Puttaramanaik and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: