Download or read book Identification of Two Interacting Quantitative Trait Loci Controlling for Condensed Tannin in Sorghum Grain and Grain Quality Analysis of a Sorghum Diverse Collection written by Wenwen Xiang and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Genomic Mapping for Grain Yield Stay Green and Grain Quality Traits in Sorghum written by Sivakumar Sukumaran and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Quantitative Trait Loci Affecting the Agronomic Performance of a Sorghum Bicolor L Moench Recombinant Inbred Restorer Line Population written by Jorge Luis Moran Maradiaga and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Identification of Quantitative Trait Loci for Grain Yield in a Recombinant Inbred B line Population in Sorghum written by Adalberto Sanchez Gomez and published by . This book was released on 2002 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heritability and Quantitative Trait Loci for Popping Characteristics in Sorghum Grain written by Nicholas Ace Pugh and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Restriction Fragment Length Polymorphism in Sorghum Sorghum Bicolor L Moench written by Messias Gonzaga Pereira and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this investigation, restriction fragment length polymorphisms (RFLPs) were used to construct a genetic linkage map for sorghum and to map quantitative trait loci (QTL) controlling morphological characteristics. For both purposes, and F2 population from a cross between Sorghum bicolor subspecies bicolor (CK60) and Sorghum bicolor subspecies drummondii (PI229828) was used. The map consists of 201 loci distributed among ten linkage groups covering a distance of 1530 cm, with and average eight cM between adjancent loci. Maize genomic clones, maize cDNA clones, and sorghum genomic clones were used to identify the loci. Comparison of sorghum and maize maps revealed a high degree of homology, linkage order, and similar genetic distance. Most often a sorghum linkage group contains loci that map to two chromosomes. Frequently, these two maize chromosomes share considerable DNA duplication. For QTL identification, 152 unselected F2 plants were evaluated. Interval mapping identified a total of 43 QTL, four for plant height, four for tillering, three for leaf length, two for leaf width, three for stalk circumference, two for maturity, six for panicle length, five for seed-branch length, two for sterile portion of the seed-branch, six for penducle diameter, three for number of seed-branchs per panicle, and three for seed weight. For each QTL, the most likely map position, magnitude of effects, gene action, and the source (progenitor) of alleles that increased the trait mean were described. Eighty-one percent (...).
Download or read book Physiological Genetic and Genomic Analyses of Herbicide Resistance in Grain Sorghum Sorghum Bicolor written by Balaji Aravindhan Pandian and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Grain sorghum [Sorghum bicolor (L.) Moench ssp. bicolor] is a versatile crop with multiple uses, including for food, feed, and fuel. Postemergence (POST) grass weed control continues to be a major challenge in grain sorghum, primarily due to a lack of herbicide options registered for POST use. The 4- hydroxyphenylpyruvate dioxygenase (HPPD)- (e.g., mesotrione or tembotrione) and acetolactate synthase (ALS)- inhibitor (e.g., chlorsulfuron) herbicides are used for POST control of a broad-spectrum of weeds including grasses in corn and wheat but not in sorghum, due to crop injury. The development of herbicide-resistant sorghum technology to facilitate broad-spectrum POST weed control can be an economical and viable solution. Previously we have identified four sorghum genotypes, two each resistant to mesotrione (G-1 and G-10), tembotrione (G-200 and G-350) and, one susceptible genotype (S-1) from the sorghum association panel. Further, we found that the genotype S-1 is highly resistant to chlorsulfuron. The objectives of this dissertation were to 1) investigate the inheritance, mechanism, and identify genetic loci conferring resistance to mesotrione and tembotrione, 2) characterize, and investigate the inheritance and mechanism of resistance to chlorsulfuron in grain sorghum. To understand the inheritance of the mesotrione and tembotrione resistance, F1 and F2 progeny were generated by performing crosses using S-1 and G-1, G-10, G-200, or G-350. The F1 and F2 progeny were evaluated for their response to various doses of mesotrione and tembotrione treatment. Likewise, chlorsulfuron dose-response experiments were conducted using S-1 along with BTx623, a susceptible check and also F1 and F2 progeny were generated by crossing S-1 and BTx623. The results of genetic analyses of the F1 and F2 progeny demonstrated that the mesotrione resistance in G-1 and G-10 is a single dominant trait, and while the tembotrione resistance in G-200 and G-350 is a partially dominant polygenic trait. Further, sequencing of HPPD gene, the molecular target of mesotrione and tembotrione in the resistant genotypes, revealed no mutations known to bestow resistance. Additionally, the role of cytochrome P450 (CYP) in metabolizing mesotrione and tembotrione, using CYP-inhibitors, malathion and piperonyl butoxide (PBO) was also assessed. The results indicated a significant reduction in biomass accumulation in sorghum plants pre-treated with malathion or PBO, suggesting the involvement of CYPs in the metabolism of mesotrione and tembotrione. Bulk segregation analysis combined with RNA-Seq (BSR-seq) was used to identify the genomic region associated with mesotrione resistance; however, the sequence analyses was unable to map the resistance gene within a smaller interval. Genotype-by-sequencing (GBS) based quantitative trait loci (QTL) mapping revealed three QTLs associated with tembotrione resistance in G-200. The results of the chlorsulfuron dose-response assay indicated that S-1 and F1 progeny were ~20-fold, more resistant to chlorsulfuron relative to BTx623. Segregation of F2 progeny into 3:1 (resistance: susceptibility), suggested that chlorsulfuron resistance in S-1 is a single dominant trait. Sequence analysis of the ALS gene, the molecular target of chlorsulfuron from S-1 revealed no mutations that confer resistance to chlorsulfuron; however, a significant reduction in biomass accumulation was found in plants pre-treated with malathion, indicating that the metabolism of chlorsulfuron contributes to resistance in S-1. Overall, the results of this dissertation provide opportunities to develop herbicide-resistant sorghum hybrids via introgression, which can help effective, POST weed management.
Download or read book Quantitative Trait Loci Analysis in Animals written by Joel Ira Weller and published by CABI. This book was released on 2009 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative Trait Loci (QTL) is a topic of major agricultural significance for efficient livestock production. This book covers various statistical methods that have been used or proposed for detection and analysis of QTL and marker-and gene-assisted selection in animal genetics and breeding.
Download or read book Genetic Analysis of the Sorghum Bicolor Stay green Drought Tolerance Trait written by Karen Ruth Harris and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sorghum (Sorghum bicolor [L.] Moench) is the fifth most economically important cereal grown worldwide and is a source of food, feed, fiber and fuel. Sorghum, a C4 grass and a close relative to sugarcane, is adapted to hot, dry adverse environments. Some genotypes of sorghum called stay-green have delayed leaf senescence during grain ripening under drought stress conditions which allows normal grain filling whereas most sorghum lines senesce early under post-anthesis drought. Eight sources of stay-green have been identified in the sorghum germplasm collection, most originating from Sudan and Ethiopia. The diversity of the eight sources of staygreen was analyzed using 55 simple sequence repeats (SSR) markers with genome coverage. This analysis showed that the sources of stay-green are quite diverse and can be divided into five groups based on race or working group. Three sources of stay-green have been used to identify 12 major quantitative trait loci (QTL) that modulate this trait. The origin of favorable alleles for stay-green was traced backward to ancestral lines and forward into breeding materials derived from stay-green germplasm. The analysis of the origin of favorable alleles for stay-green helped explain why subsets of stay-green QTL were identified in different studies and provided evidence that there may be more than one favorable allele in the sorghum germplasm for several of the stay-green QTL. Analysis of stay-green breeding lines from three public sorghum-breeding programs revealed that one of the main QTL identified in mapping studies was not being used in the breeding programs (0/13), most likely due to its association with an allele for lemon yellow seeds. In addition, a subset of the regions containing favorable alleles for staygreen from the genotype BTx642 were over represented in stay-green breeding lines. Nearly isogenic lines containing favorable alleles from BTx642 for Stg1, Stg2, Stg3, and Stg4 in a RTx7000 (senescent) background were characterized and each NIL was shown to exhibit a stay-green phenotype. Based in part on this information, fine-mapping of Stg1 was undertaken by crossing the Stg1 NIL to RTx7000. Overall, these results revealed the origin of favorable alleles for stay-green and the current utilization of alleles for stay-green in public breeding programs. In addition, this study identified additional stay-green sources that could be used for further QTL analysis and highlighted the genetic complexity of the stay-green trait.
Download or read book Condensed Tannin of Sorghum Grain written by Ann E. Hagerman and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integrated Analysis of Phenology Traits and QTL in the Drought Tolerant Sorghum Genotypes BTx642 and RTx7000 written by Brock D. Weers and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth and development of two sorghum drought tolerant genotypes BTx642 (post-flowering drought tolerant, "stay green") and RTx7000 (pre-flowering drought tolerant) were characterized and compared. Differences in phenology and the growth and development of leaves and stalks were identified that could contribute to variation in shoot biomass, grain yield and response to water deficit. An F12 recombinant inbred line (RIL) population derived from the two parents was genotyped using the Illumina Genome Analyzer II platform and the information used to generate a genetic map useful for analysis of quantitative trait loci (QTL). Seventy-two different traits were measured in the RIL population at anthesis and at grain maturity. Plants were grown in well-watered environments in greenhouse conditions and in field conditions near College Station, TX in 2008-2010. QTL mapping was used to analyze the genetic basis of trait variation in the population and to detect associations between traits. A total of 477 QTL were identified that in combination modulate leaf size (length, width, and area), shoot biomass accumulation (shoot, stalk, stem, leaf, and leaf sheath), panicle weight, root size and architecture (length, surface area, and volume, number of tips, forks and nodal roots, and root biomass), stalk and stem length, and flowering time. Six flowering time QTL were identified and variation in time to anthesis affected the expression of several other traits including leaf size and biomass accumulation. However, QTL infrequently had an impact on traits associated with different organs. The specificity observed is consistent with independent genetic control of traits associated with leaves, stems and roots. Nine QTL that modulated shoot biomass accumulation were detected that were not affected by flowering time. Of these, four shoot biomass QTL co-localized with leaf size traits. Eight QTL for panicle biomass were detected with two coincident with QTL for upper leaf size. A QTL for leaf width at anthesis was found to co-localize with a stay green locus.
Download or read book Restriction Fragment Length Polymorphism in Sorghum Sorghum Bicolor L Moench written by Dario Ahnert and published by . This book was released on 1995 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Genomic Analysis of Agroclimatic Traits in Sorghum written by Olalere Marcus Olatoye and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change has been anticipated to affect agriculture, with most the profound effect in regions where low input agriculture is being practiced. Understanding of how plants evolved in adaptation to diverse climatic conditions in the presence of local stressors (biotic and abiotic) can be beneficial for improved crop adaptation and yield to ensure food security. Great genetic diversity exists for agroclimatic adaptation in sorghum (Sorghum bicolor L. Moench) but much of it has not been characterized. Thus, limiting its utilization in crop improvement. The application of next-generation sequencing has opened the plant genome for analysis to identify patterns of genome-wide nucleotide variations underlying agroclimatic adaptation. To understand the genetic basis of adaptive traits in sorghum, the genetic architecture of sorghum inflorescence traits was characterized in the first study. Phenotypic data were obtained from multi-environment experiments and used to perform joint linkage and genome-wide association mapping. Mapping results identified previously mapped and novel genetic loci underlying inflorescence morphology in sorghum. Inflorescence traits were found to be under the control of a few large and many moderate and minor effect loci. To demonstrate how our understanding of the genetic basis of adaptive traits can facilitate genomic enabled breeding, genomic prediction analysis was performed with results showing high prediction accuracies for inflorescence traits. In the second study, the sorghum-nested association mapping (NAM) population was used to characterize the genetic architecture of leaf erectness, leaf width, and stem diameter. About 2200 recombinant inbred lines were phenotyped in multiple environments. The obtained phenotypic data was used to perform joint linkage mapping using ~93,000 markers. The proportion of phenotypic variation explained by QTL and their allele frequencies were estimated. Common and moderate effects QTL were found to underlie marker-trait associations. Furthermore, identified QTL co-localized with genes involved in both vegetative and inflorescence development. Our results provide insights into the genetic basis of leaf erectness and stem diameter in sorghum. The identified QTL will also facilitate the development of genomic-enable breeding tools for crop improvement and molecular characterization of the underlying genes Finally, in a third study, 607 Nigerian accessions were genotyped and the resulting genomic data [about 190,000 single nucleotide polymorphisms (SNPs)] was used for downstream analysis. Genome-wide scans of selection and genome-wide association studies (GWAS) were performed and alongside estimates of levels of genetic differentiation and genetic diversity. Results showed that phenotypic variation in the diverse germplasm had been shaped by local adaptation across climatic gradient and can provide plant genetic resources for crop improvement.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1998 with total page 1960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry and Significance of Condensed Tannins written by Richard W. Hemingway and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was developed from the proceedings of the first North American Tannin Conference held in Port. Angeles, Washington, August 1988. The objective of the conference was to bring together people with a common interest in condensed tannins and to promote interdisciplinary interactions that will lead to a better understanding of these important substances. Anot. her objective was the publicat. ion of this book because there has not been a monograph devoted to the chemistry and significance of tannins for several decades. The book is organized into sections dealing with the biosynthesis, structure, re actions, complexation with other biopolymers, biological significance, and use of tannins as specialty chemicals. The authors made a special attempt to focus on what we don't know as well as to provide a summary of what we do know in an effort to assist in planning future research. Our thanks go to the authors who so kindly contributed chapters and so pa tiently responded to our requests. We also thank Rylee Geboski and the Conference Assist. ance Staff, College of Forestry, Oregon State University, for their assistance in planning and conducting t. he conference, and Julia Wilson, Debbie Wolfe, Helen Coletka, and Nancy Greene of the Southern Forest Experiment Station, Pineville, Louisiana, who typed the chapt. ers. Linda Chalker-Scott was especially helpful in assisting us wit. h editing. Dick Hemingway is indebted t. o the staff of the Alexandria Forest.
Download or read book Genetic Mapping of Quantitative Trait Loci Associated with Bioenergy Traits and the Assessment of Genetic Variability in Sweet Sorghum Sorghum Bicolor L Moench written by Lekgari Aatshwaelwe Lekgari and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Dissection of Complex Traits written by Andrew H. Paterson and published by CRC Press. This book was released on 2019-09-17 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past 10 years, contemporary geneticists using new molecular tools have been able to resolve complex traits into individual genetic components and describe each such component in detail. Molecular Dissection of Complex Traits summarizes the state of the art in molecular analysis of complex traits (QTL mapping), placing new developments in thi
