Backcross Introgression and Two-stage Testing for Conversion of Improved Tropical Germplasm to Temperate Environments

Backcross Introgression and Two-stage Testing for Conversion of Improved Tropical Germplasm to Temperate Environments PDF Author: Freeman Callaway Whitehead
Publisher:
ISBN:
Category :
Languages : en
Pages : 254

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Book Description
The use of exotic maize (Zea mays L.) germplasm, particularly of tropical and subtropical adaptation, has been suggested to increase genetic variability and grain yield of maize breeding material in temperate environments. Lack of adaptation to temperate areas and photoperiod sensitivity may mask desirable traits and reduce breeding progress. The objectives of this study included two-stage evaluation and selection of segregating families in the central U.S. Corn Belt derived from the backcross introgression of previously improved tropical CIMMYT germplasm into adapted, elite U.S. Corn Belt germplasm. The U.S. Corn Belt heterotic patterns of Stiff Stalk and non-Stiff Stalk were combined with germplasm of primarily Tuxpeno and non-Tuxpeño racial origin, respectively. Per se evaluation of 891 backcross (BClF1) families from 33 different backcrosses, component Fl crosses, and adapted recurrent populations were conducted in Iowa in 1997. Backcross populations displayed grain yields either similar to or greater than the respective Fl crosses but with significantly less grain moisture and days to mid-pollen, suggesting 25% tropical germplasm to be the preferred starting point to initiate selection. Stalk lodging of backcross populations was similar to and sometimes less than the respective adapted recurrent population check while yield was greater in more than 50% of the crosses. BC1F1 families were selected from within Stiff Stalk and non-Stiff Stalk oriented materials and testcrossed to an elite inbred of the opposite heterotic pool. Testcrosses of backcross families and testcrosses of adapted parental populations were evaluated at seven locations in Iowa and Nebraska in 1999. Grain yield, percent root and stalk lodging, and plant and ear heights of selected testcrosses were generally similar (p[Less than or equal to symbol]0.05) to their respective checks. Harvest grain moisture and days to mid-silk and mid-pollen were either similar to or greater than the checks, averaging early zone 8 for maturity. Results support backcrossing to introduce previously improved tropical germplasm to the central U.S. Corn Belt. The alignment of established U.S. Corn Belt heterotic pools with tropical racial or heterotic pools during introgression will serve to enhance genetic variation within and among pools. Previously selected tropical germplasm of known heterotic affinity may be considered a significant resource for introduction of tropical germplasm into temperate breeding programs.

Backcross Introgression and Two-stage Testing for Conversion of Improved Tropical Germplasm to Temperate Environments

Backcross Introgression and Two-stage Testing for Conversion of Improved Tropical Germplasm to Temperate Environments PDF Author: Freeman Callaway Whitehead
Publisher:
ISBN:
Category :
Languages : en
Pages : 254

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Book Description
The use of exotic maize (Zea mays L.) germplasm, particularly of tropical and subtropical adaptation, has been suggested to increase genetic variability and grain yield of maize breeding material in temperate environments. Lack of adaptation to temperate areas and photoperiod sensitivity may mask desirable traits and reduce breeding progress. The objectives of this study included two-stage evaluation and selection of segregating families in the central U.S. Corn Belt derived from the backcross introgression of previously improved tropical CIMMYT germplasm into adapted, elite U.S. Corn Belt germplasm. The U.S. Corn Belt heterotic patterns of Stiff Stalk and non-Stiff Stalk were combined with germplasm of primarily Tuxpeno and non-Tuxpeño racial origin, respectively. Per se evaluation of 891 backcross (BClF1) families from 33 different backcrosses, component Fl crosses, and adapted recurrent populations were conducted in Iowa in 1997. Backcross populations displayed grain yields either similar to or greater than the respective Fl crosses but with significantly less grain moisture and days to mid-pollen, suggesting 25% tropical germplasm to be the preferred starting point to initiate selection. Stalk lodging of backcross populations was similar to and sometimes less than the respective adapted recurrent population check while yield was greater in more than 50% of the crosses. BC1F1 families were selected from within Stiff Stalk and non-Stiff Stalk oriented materials and testcrossed to an elite inbred of the opposite heterotic pool. Testcrosses of backcross families and testcrosses of adapted parental populations were evaluated at seven locations in Iowa and Nebraska in 1999. Grain yield, percent root and stalk lodging, and plant and ear heights of selected testcrosses were generally similar (p[Less than or equal to symbol]0.05) to their respective checks. Harvest grain moisture and days to mid-silk and mid-pollen were either similar to or greater than the checks, averaging early zone 8 for maturity. Results support backcrossing to introduce previously improved tropical germplasm to the central U.S. Corn Belt. The alignment of established U.S. Corn Belt heterotic pools with tropical racial or heterotic pools during introgression will serve to enhance genetic variation within and among pools. Previously selected tropical germplasm of known heterotic affinity may be considered a significant resource for introduction of tropical germplasm into temperate breeding programs.

Cereals

Cereals PDF Author: Marcelo J. Carena
Publisher: Springer Science & Business Media
ISBN: 0387722971
Category : Technology & Engineering
Languages : en
Pages : 432

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Book Description
Agriculture depends on improved cultivars, and cultivars are developed through proper plant breeding. Unfortunately, applied plant breeding programs that are focused on cereal commodity crops are under serious erosion because of lack of funding. This loss of public support affects breeding continuity, objectivity, and, perhaps equally important, the training of future plant breeders and the utilization and improvement of plant genetic resources currently available. Breeding programs should focus not only on short-term research goals but also on long-term genetic improvement of germplasm. The research products of breeding programs are important not only for food security but also for commodity-oriented public and private programs, especially in the fringes of crop production. Breeding strategies used for long-term selection are often neglected but the reality is that long-term research is needed for the success of short-term products. An excellent example is that genetically broad-based public germplasm has significantly been utilized and recycled by industry, producing billions of dollars for industry and farmers before intellectual property rights were available. Successful examples of breeding continuity have served the sustainable cereal crop production that we currently have. The fact that farmers rely on public and private breeding institutions for solving long-term challenges should influence policy makers to reverse this trend of reduced funding. Joint cooperation between industry and public institutions would be a good example to follow. The objective of this volume is to increase the utilization of useful genetic resources and increase awareness of the relative value and impact of plant breeding and biotechnology. That should lead to a more sustainable crop production and ultimately food security. Applied plant breeding will continue to be the foundation to which molecular markers are applied. Focusing useful molecular techniques on the right traits will build a strong linkage between genomics and plant breeding and lead to new and better cultivars. Therefore, more than ever there is a need for better communication and cooperation among scientists in the plant breeding and biotechnology areas. We have an opportunity to greatly enhance agricultural production by applying the results of this research to meet the growing demands for food security and environmental conservation. Ensuring strong applied plant breeding programs with successful application of molecular markers will be essential in ensuring such sustainable use of plant genetic resources.

Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 712

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Commencement

Commencement PDF Author: Iowa State University
Publisher:
ISBN:
Category : Commencement ceremonies
Languages : en
Pages : 562

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THE STATE OF THE WORLD’s FOREST GENETIC RESOURCES

THE STATE OF THE WORLD’s FOREST GENETIC RESOURCES PDF Author: Food and Agriculture Organization of the United Nations
Publisher: Food & Agriculture Org.
ISBN: 9251084025
Category : Technology & Engineering
Languages : en
Pages : 304

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Book Description
The publication was prepared based on information provided by 86 countries, outcomes from regional and subregional consultations and commissioned thematic studies. It includes: •an overview of definitions and concepts related to Forest Genetic Resources (FGR) and a review of their value; •a description of the main drivers of changes; •the presentation of key emerging technologies; •an analysis of the current status of FGR conservation, use and related developments; •recommendations addressing the challenges and needs. By the FAO Commission on Genetic Resources for Food and Agriculture.

Broadening the Genetic Base of Crop Production

Broadening the Genetic Base of Crop Production PDF Author: H. David Cooper
Publisher:
ISBN:
Category : Crops
Languages : en
Pages : 484

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Book Description
This book focuses on the previously neglected interface between the conservation of plant genetic resources and their utilization. Only through utilization can the potential value of conserved genetic resources be realized. However, as this book shows, much conserved germplasm has to be subjected to long-term pre-breeding and genetic enhancement before it can be used in plant breeding programs.The authors explore the rationale and approaches for such pre-breeding efforts as the basis for broadening the genetic bases of crop production. Examples from a range of major food crops are presented and issues analyzed by leading authorities from around the world.

Plant Breeding in the Omics Era

Plant Breeding in the Omics Era PDF Author: Rodomiro Ortiz Ríos
Publisher: Springer
ISBN: 3319205323
Category : Science
Languages : en
Pages : 250

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Book Description
​The field of plant breeding has grown rapidly in the last decade with breakthrough research in genetics and genomics, inbred development, population improvement, hybrids, clones, self-pollinated crops, polyploidy, transgenic breeding and more. This book discusses the latest developments in all these areas but explores the next generation of needs and discoveries including omics beyond genomics, cultivar seeds and intellectual and property rights. This book is a leading-edge publication of the latest results and forecasts important areas of future needs and applications.​

Manual on MUTATION BREEDING THIRD EDITION

Manual on MUTATION BREEDING THIRD EDITION PDF Author: Food and Agriculture Organization of the United Nations
Publisher: Food & Agriculture Org.
ISBN: 9251305269
Category : Technology & Engineering
Languages : en
Pages : 319

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Book Description
This paper provides guidelines for new high-throughput screening methods – both phenotypic and genotypic – to enable the detection of rare mutant traits, and reviews techniques for increasing the efficiency of crop mutation breeding.

Handbook of Maize

Handbook of Maize PDF Author: Jeff L. Bennetzen
Publisher: Springer Science & Business Media
ISBN: 0387778632
Category : Technology & Engineering
Languages : en
Pages : 785

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Book Description
Maize is one of the world’s highest value crops, with a multibillion dollar annual contribution to agriculture. The great adaptability and high yields available for maize as a food, feed and forage crop have led to its current production on over 140 million hectares worldwide, with acreage continuing to grow at the expense of other crops. In terms of tons of cereal grain produced worldwide, maize has been number one for many years. Moreover, maize is expanding its contribution to non-food uses, including as a major source of ethanol as a fuel additive or fuel alternative in the US. In addition, maize has been at the center of the transgenic plant controversy, serving as the first food crop with released transgenic varieties. By 2008, maize will have its genome sequence released, providing the sequence of the first average-size plant genome (the four plant genomes that are now sequenced come from unusually tiny genomes) and of the most complex genome sequenced from any organism. Among plant science researchers, maize has the second largest and most productive research community, trailing only the Arabidopsis community in scale and significance. At the applied research and commercial improvement levels, maize has no peers in agriculture, and consists of thousands of contributors worthwhile. A comprehensive book on the biology of maize has not been published. The "Handbook of Maize: the Genetics and Genomics" center on the past, present and future of maize as a model for plant science research and crop improvement. The books include brief, focused chapters from the foremost maize experts and feature a succinct collection of informative images representing the maize germplasm collection.

A Guide to Sorghum Breeding

A Guide to Sorghum Breeding PDF Author: Leland R. House
Publisher:
ISBN:
Category :
Languages : en
Pages : 238

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Book Description