Identification of Quantitative Trait Loci for Grain Yield in a Recombinant Inbred B-line Population in Sorghum PDF Download

Author: Adalberto Sanchez Gomez
Publisher:
ISBN:
Category :
Languages : en
Pages : 186

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Author: Jorge Luis Moran Maradiaga
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Lately the rate of genetic gain in most agronomic crop species has been reduced due to several factors that limit breeding efficiency and genetic gain. New genetic tools and more powerful statistical analyses provide an alternative approach to enhance genetic improvements through the identification of molecular markers linked to genomic regions or QTLs controlling quantitative traits. The main objective of this research was to identify genomic regions associated with enhanced agronomic performance in lines per se and hybrid combination in Sorghum bicolor (L.) Moench. A population composed of 187 F5:6 recombinant inbred lines (RIL) was derived from the cross of restorer lines RTx430 and RTx7000. Also, a testcross hybrid population (TCH) was developed by using each RIL as a pollinator onto ATx2752. A linkage map was constructed using 174 marker loci generated from AFLP and SSR primer combinations. These markers were assigned to 12 different linkage groups. The linkage map covers 1573 cM with marker loci spaced at an averaged 9.04 cM. In this study, 89 QTL that control variation in seven different morphological traits were identified in the recombinant inbred line population, while in the testcross hybrid population, 79 QTL were identified. These traits included grain yield, plant height, days to mid-anthesis, panicle number, panicle length, panicle exsertion and panicle weight. These putative QTL explained from 4 to 42% of the phenotypic variation observed for each trait. Many of the QTL were not consistent across populations and across environments. Nevertheless, a few key QTL were identified and the source of the positive additive genetics isolated. RTx7000 was consistently associated with better agronomic performance in RIL, while in testcrosses, RTx430 was. Some genomic regions from RTx7000 may be utilized to improve RTx430 as a line per se. However, it is very unlikely that such regions will have a positive effect on the combining ability of RTx430 since testcross results did not reveal any transgressive segregants from the RIL population.

Author: Michael Phillip Jines
Publisher:
ISBN:
Category :
Languages : en
Pages : 153

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Keywords: qtl, maturity, gls resistance.

Author: Nicholas Ace Pugh
Publisher:
ISBN:
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Languages : en
Pages :

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Popped sorghum (Sorghum bicolor, L. Moench) is becoming increasingly popular with niche consumers. However, sorghum has not undergone the years of intensive selective breeding that popcorn has. This study measured popping characteristics and grain traits to estimate heritability, the relative effect of environment and genotype x environment interactions on these traits and to identify quantitative trait loci (QTL) for popping quality. Using a heated-air popping methodology, a recombinant inbred line population was phenotyped for popping characteristics in grain from three environments in Texas. Entry-mean heritability of popping efficiency (PE) ranged from 0.595 - 0.755 and the heritability of expansion ratio (ER) ranged from 0.617 - 0.769 across environments. ANOVA indicate that both environment and genotype x environment interactions were significant sources of variation. Using genome sequence mapping technology, five QTL were identified for popping efficiency and four were identified for expansion ratio. Additionally QTL for endosperm color, kernel diameter, kernel weight, and kernel hardness were found, and several of those were consistent across multiple production environments. These results indicate that popping quality a complex quantitative trait in sorghum, but improvement of popping efficiency, expansion ratio, and other kernel characteristics via marker-assisted selection is possible. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155661

Author:
Publisher: Academic Press
ISBN: 0080524354
Category : Technology & Engineering
Languages : en
Pages : 303

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Advances in Agronomy continues to be recognized as a leading reference and a first-rate source of the latest research in agronomy. Major reviews deal with the current topics of interest to agronomists, as well as crop and soil scientists. As always, the subjects covered are varied and exemplary of the myriad subject matter dealt with by this long-running serial. Editor Donald Sparks, former president of the Soil Science Society of America and current president of the International Union of Soil Science, is the S. Hallock du Pont Chair of Plant and Soil Sciences at The University of Delaware. Volume 83 contains five excellent reviews that discuss topics critical to agricultural and environmental sustainability. - Maintains the highest impact factor among serial publications in Agriculture - Presents timely reviews on important agronomy issues - Enjoys a long-standing reputation for excellence in the field

Author: Malay C. Saha
Publisher: John Wiley & Sons
ISBN: 111860945X
Category : Technology & Engineering
Languages : en
Pages : 308

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Bioenergy and biofuels are generated from a wide variety of feedstock. Fuels have been converted from a wide range of sources from vegetable oils to grains and sugarcane. Second generation biofuels are being developed around dedicated, non-food energy crops, such as switchgrass and Miscanthus, with an eye toward bioenergy sustainability. Bioenergy Feedstocks: Breeding and Genetics looks at advances in our understanding of the genetics and breeding practices across this diverse range of crops and provides readers with a valuable tool to improve cultivars and increase energy crop yields. Bioenergy Feedstocks: Breeding and Genetics opens with chapters focusing primarily on advances in the genetics and molecular biology of dedicated energy crops. These chapters provide in-depth coverage of new, high-potential feedstocks. The remaining chapters provide valuable overview of breeding efforts of current feedstocks with specific attention paid to the development of bioenergy traits. Coverage in these chapters includes crops such as sorghum, energy canes, corn, and other grasses and forages. The final chapters explore the role of transgenics in bioenergy feedstock production and the development of low-input strategies for producing bioenergy crops. A timely collection of work from a global team of bioenergy researchers and crop scientists, Bioenergy Feedstocks: Breeding and Genetics is an essential reference on cultivar improvement of biomass feedstock crops.

Author: Wenwen Xiang
Publisher:
ISBN:
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Languages : en
Pages :

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Tannin, a second metabolic product in sorghum, has been directly related to resistance to insects and birds. Tannin also impacts sorghum nutritional value. Previous studies have shown tannin content has a positive correlation with early season cold tolerance, an important agronomic trait. Sorghum contains condensed tannins in testa layer below the pericarp. The testa layer tannin is controlled by two complementary genes B1 and B2: tannins are present when both genes are dominant but absent when only one or none of these two is dominant. The purpose of this research is to identify and map QTLs associated with the presence of condensed tannins, analyze interaction of QTLs, and provide a potential path to dissect the more complex trait of early season cold tolerance in future studies. A population of 109 F6:7 recombinant inbred lines (RILs) developed from the cross of a high tannin sorghum Shan Qui Red (SQR) and non-tannin line Tx430 was used in the mapping study. Two QTLs related to condense tannin presence in testa layer were mapped to chromosome 2 and 4, respectively. Strong epistatic interaction of these two QTLs was detected. The two QTLs together with their interaction explained 74% of the phenotypic variation. Sorghum grain quality traits, including kernel size, kernel hardness, protein and starch content, are complex traits which are directly related to sorghum nutritional value and market value. Association mapping is a promising method for complex quantitative traits analysis and dissection in plant science. Sorghum grain quality trait association analysis research is purposed to analyze large amount of grain quality data based on a diversity panel. A sorghum bicolor panel of 300 lines including germplasm derived from sorghum conversion program and elite commercial lines were established and served as diversity population for the association study. Phenotypic data of grain quality traits were collected by single kernel characterization system (SKCS) and near infrared reflectance spectroscopy (NIRS). Data analysis proved high diversity within the SB panel. A correlation between tannin presence and kernel hardness was also observed. Quality traits showed high consistence across years and environments.

Author: Sivakumar Sukumaran
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Knowledge of the genetic bases of grain quality traits will complement plant breeding efforts to improve the end use value of sorghum (Sorghum bicolor (L.) Moench). The objective of the first experiment was to assess marker-trait associations for 10 grain quality traits through candidate gene association mapping on a diverse panel of 300 sorghum accessions. The 10 grain quality traits were measured using the single kernel characterization system (SKCS) and near-infrared reflectance spectroscopy (NIRS). The analysis of the accessions through 1,290 genome-wide single nucleotide polymorphisms (SNPs) separated the panel into five subpopulations that corresponded to three major sorghum races (durra, kafir, and caudatum), one intermediate race (guinea-caudatum), and one working group (zerazera/caudatum). Association analysis between 333 SNPs in candidate genes/loci and grain quality traits resulted in eight significant marker-trait associations. A SNP in starch synthase IIa (SSIIa) gene was associated with kernel hardness (KH) with a likelihood ratio-based R2 (R[subscript]L[subscript]R2) value of 0.08. SNPs in starch synthase (SSIIb) gene (R[subscript]L[subscript]R2 = 0.10) and loci pSB1120 (R[subscript]L[subscript]R2 = 0.09) was associated with starch content. Sorghum is a crop well adapted to the semi arid regions of the world and my harbor genes for drought tolerance. The objective of second experiment was to identify quantitative trait loci (QTLs) for yield potential and drought tolerance. From a cross between Tx436 (food grain type) and 00MN7645 (drought tolerant) 248 recombinant inbred lines (RILs) was developed. Multi-location trials were conducted in 8 environments to evaluate agronomic performance of the RILs under favorable and drought stress conditions. The 248 RILs and their parents were genotyped by genotyping-by-sequencing (GBS). A subset of 800 SNPs was used for linkage map construction and QTL detection. Composite interval mapping identified a major QTLs for grain yield in chromosome 8 and QTL for flowering time in chromosome 9 under favorable conditions. Three major QTLs were detected for grain yield in chromosomes 1, 6, and 8 and two flowering time QTLs on chromosome 1 under drought conditions. Six QTLs were identified for stay green: two on chromosome 4; one each on chromosome 5, 6, 7, and 10 under drought conditions.

Author: Yi-Hong Wang
Publisher: CRC Press
ISBN: 1482210088
Category : Science
Languages : en
Pages : 368

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Sorghum is one of the hardiest crop plants in modern agriculture and also one of the most versatile. Its seeds provide calorie for food and feed, stalks for building and industrial materials and its juice for syrup. This book provides an in-depth review of the cutting-edge knowledge in sorghum genetics and its applications in sorghum breeding. Each chapter is authored by specialists in their fields to report the latest trends and findings. The book showcases the definitive value of sorghum as a model system to study the genetic basis of crop productivity and stress tolerance and will provide a foundation for future studies in sorghum genetics, genomics, and breeding.

Author: R. Madhusudhana
Publisher: Springer
ISBN: 8132224221
Category : Technology & Engineering
Languages : en
Pages : 231

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This book provides an up-to-date overview of international research work on sorghum. Its comprehensive coverage of our current understanding of transgenic development in sorghum and the strategies that are being applied in molecular breeding make this book unique. Important areas such as genetic diversity, QTL mapping, heterosis prediction, genomic and bioinformatics resources, post-genome sequencing developments, molecular markers development using bioinformatics tools, genetic transformation and transgenic research are also addressed. The availability of the genome sequence along with other recent developments in sequencing and genotyping technologies has resulted in considerable advances in the area of sorghum genomics. These in turn have led to the generation of a large number of DNA-based markers and resulted in the identification and fine mapping of QTL associated with grain yield, its component traits, biotic and abiotic stress tolerance as well as grain quality traits in sorghum. Though a large volume of information has accumulated over the years, especially following the sequencing of the sorghum genome, until now it was not available in a single reference resource. This book fills that gap by documenting advances in the genomics and transgenic research in sorghum and presenting critical reviews and future prospects. “Sorghum Molecular Breeding” is an essential guide for students, researchers and managers who are involved in the area of molecular breeding and transgenic research in sorghum and plant biologists in general.