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Full-Text Articles in Molecular Biology

Molecular Genetic Analyses Of Oilseed Brassica Germplasm: Determination Of Life Forms And Germplasm Management Strategies By Using Microsatellite Markers And Flowering Locus-C (Flc1 And Flc3) Gene Sequences , Von Mark V. Cruz Jan 2006

Molecular Genetic Analyses Of Oilseed Brassica Germplasm: Determination Of Life Forms And Germplasm Management Strategies By Using Microsatellite Markers And Flowering Locus-C (Flc1 And Flc3) Gene Sequences , Von Mark V. Cruz

Retrospective Theses and Dissertations

Molecular markers were utilized in conjunction with phenological and morphological information, and statistical methods for diversity analyses to address plant genetic resource conservation issues. The objectives of this study have been categorized into two sets. The first set pertains to exploratory surveys of genetic variation using molecular markers and DNA sequences to determine if microsatellite markers or variation in two copies of the FLOWERING LOCUS C gene (FLC1 and FLC3) can be used in determining life forms of fifty representative accessions of Brassica napus. The second set of objectives addresses good genebank practices and includes: characterization of flowering time of ...


Phenotypic, Biochemical, And Molecular Diversity In Coriander (Coriandrum Sativum L) Germplasm, Pedro Antonio López Jan 2006

Phenotypic, Biochemical, And Molecular Diversity In Coriander (Coriandrum Sativum L) Germplasm, Pedro Antonio López

Retrospective Theses and Dissertations

A study was conducted to assess phenotypic, biochemical, and molecular diversity in coriander accessions from the North Central Regional Plant Introduction Station, in Ames, IA; initially, 139 accessions were characterized for phenological and morphological traits and for fatty-acid composition. A second year of data was collected on those traits from 60 accessions. Fruit essential-oil content and composition were determined, along with a headspace analysis from leaves and an analysis of amplified fragment length polymorphisms (AFLPs). Basic statistics and Pearson correlations were estimated. Matrices of geographical distances (GD), modified Rogers' (MD) distances for molecular data, and Euclidean distances for phenotypic (PD ...


Molecular And Genetic Characterization Of The Inheritance And Expression Of The Synthetic Porcine Alpha-Lactalbumin Transgene In Maize (Zea Mays L) , Earl H. Bicar Jan 2003

Molecular And Genetic Characterization Of The Inheritance And Expression Of The Synthetic Porcine Alpha-Lactalbumin Transgene In Maize (Zea Mays L) , Earl H. Bicar

Retrospective Theses and Dissertations

A codon-adjusted version of a gene encoding the porcine milk protein alpha-lactalbumin was synthesized to create maize with improved nutritional quality. Three expression vectors (P64, P45, P57) containing the synthetic gene were constructed and transformed into maize callus by particle bombardment. The constructs differed in their promoters and subcellular targeting domains. PCR analysis showed that the alpha-La transgene was integrated into the maize genome and transmitted to the F1 generation. Western blot analysis indicated that the transgenes were functional and the alpha-La protein accumulated in the target endosperm. Genomic Southern blot analysis detected no new rearrangements demonstrating stable transgene integration ...


Genetic Basis Of Autumn Growth And Winter Hardiness In Alfalfa , Baldomero Alarcón Zúñiga Jan 2003

Genetic Basis Of Autumn Growth And Winter Hardiness In Alfalfa , Baldomero Alarcón Zúñiga

Retrospective Theses and Dissertations

Alfalfa (Medicago sativa L.) has a broad geographic distribution, with populations adapted to both cold and warm climates. Despite considerable research on winter hardiness, the mechanisms and genetic control of winter survival are poorly understood. We conducted two experiments designed to identify and quantify morphological, physiological, and biochemical traits associated with winter hardiness and to estimate the genetic relationship of these traits with winter hardiness. In Experiment 1, ten alfalfa genotypes were planted in June 2000 and in May 2001 at Ames, IA, and traits were measured in August, November, and the following April in each year. Concentrations of palmitate ...


Molecular Marker Analysis Of Population Genetic Structure And Progress From Reciprocal Recurrent Selection In Two Iowa Maize (Zea Mays L) Populations , Lori Lynn Hinze Jan 2003

Molecular Marker Analysis Of Population Genetic Structure And Progress From Reciprocal Recurrent Selection In Two Iowa Maize (Zea Mays L) Populations , Lori Lynn Hinze

Retrospective Theses and Dissertations

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 ...


Molecular Marker Analysis Of Seed Size In Soybean , Joseph Andrew Hoeck Jan 2002

Molecular Marker Analysis Of Seed Size In Soybean , Joseph Andrew Hoeck

Retrospective Theses and Dissertations

Seed size is an important attribute of soybean [Glycine max (L.) Merr.] for some food uses. The objectives of this study were to identify markers associated with quantitative trait loci for seed size (SSQTL), determine the influence of the environment on expression of the marker-SSQTL associations, and compare the efficiency of phenotypic selection and marker-assisted selection for the trait. Three small-seeded lines were crossed to a line or cultivar with normal seed size to form three two-parent populations. The parents of the populations were screened with 178 simple sequence repeat (SSR) markers to identify polymorphism. Population 1 (Pop 1) had ...


Backcross Introgression And Two-Stage Testing For Conversion Of Improved Tropical Germplasm To Temperate Environments , Freeman Callaway Whitehead Jan 2002

Backcross Introgression And Two-Stage Testing For Conversion Of Improved Tropical Germplasm To Temperate Environments , Freeman Callaway Whitehead

Retrospective Theses and Dissertations

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 ...


Response To S1 Recurrent Selection And Estimation Of Genetic Parameters In Effective Population Sizes Of The Bs11 Maize Population , Kebede Mulatu Ponta Jan 2001

Response To S1 Recurrent Selection And Estimation Of Genetic Parameters In Effective Population Sizes Of The Bs11 Maize Population , Kebede Mulatu Ponta

Retrospective Theses and Dissertations

Recurrent selection is a cyclical breeding technique that has become popular in comprehensive maize improvement strategies. The magnitude of response in recurrent selection depends upon the modes of gene action and their frequencies in effective population sizes. We studied four effective population sizes with the objectives: (1) to estimate response to selection and inbreeding effects, (2) to partition the response to selection into that due to additive and dominance genetic components, and (3) to examine changes in the correlated traits. Four effective population sizes 5, 10, 20, and 30 were developed by S1-progeny selection in the BS11 maize population using ...


Genetic Analysis Of Reproductive Traits In Soybean [Glycine Max (L) Merr] , I. Made Tasma Jan 2001

Genetic Analysis Of Reproductive Traits In Soybean [Glycine Max (L) Merr] , I. Made Tasma

Retrospective Theses and Dissertations

The objectives of this study were to: (1) estimate the number of genes controlling photoperiod insensitivity in soybean; (2) map quantitative trait loci controlling flowering time, maturity, and photoperiod insensitivity in soybean; (3) map homologous and cloned flowering time gene sequences in soybean; (4) correlate these sequences with maturity (E) loci by means of near isogenic lines (NILs). Three populations, two F 6:7 recombinant inbred lines of 101 and 100 progeny and an F2:4 G. max x G. soja population (60 progeny), were used. Forty-one NILs were also included. At least three genes were proposed to control photoperiod ...


The 1dx5 High Molecular Weight Subunit Gene From Wheat In Transgenic Maize , Varaporn Sangtong Jan 2001

The 1dx5 High Molecular Weight Subunit Gene From Wheat In Transgenic Maize , Varaporn Sangtong

Retrospective Theses and Dissertations

We have developed a method for detecting a transgene and its protein product in maize endosperm that allows the kernel to be germinated after analysis. Our method involves first sampling the endosperm with a hand-held rotary grinder. This tissue is then serially extracted for phenotypic analysis by SDS-PAGE with visualization by total protein staining or immuno-blot detection and genotypic analysis by PCR reactions to detect the transgene. This method is useful for screening transgenic kernels in breeding experiments. We have produced transgenic maize plants containing a wheat Glu-1Dx5 gene encoding the high molecular weight glutenin subunit 1Dx5. Analysis by SDS-PAGE ...


Selection For Soybean Seed Yield With Molecular Markers , Joseph Richard Byrum Jan 1999

Selection For Soybean Seed Yield With Molecular Markers , Joseph Richard Byrum

Retrospective Theses and Dissertations

Molecular markers may facilitate the identification of and selection for quantitative trait loci (QTL) that control economically important traits. The objective of the study was to compare the efficiency of selection among soybean [Glycine max (L.) Merrill] lines for seed yield based on single replication progeny-row-yield tests (PRYT), molecular marker loci selected by pedigree analysis, and a combination of PRYT and molecular marker data. A total of 380 random F3-derived lines from three populations were evaluated in the PRYT at Ames, IA, in 1997 and were genotyped for simple sequence repeats (SSRs) that had been chosen by pedigree analysis for ...


Evaluation Of Recurrent Selection In Leaming And Midland Maize Populations , Marcelo Javier Carena Jan 1999

Evaluation Of Recurrent Selection In Leaming And Midland Maize Populations , Marcelo Javier Carena

Retrospective Theses and Dissertations

Rates of maize (Zea mays L.) yield improvement in the United States has been reduced during the 1990's. Double-cycle breeding in a few old inbred lines and limited germplasm evaluation and utilization are possible explanations. Only one heterotic pattern (Iowa Stiff Stalk Synthetic x Lancaster Sure Crop) is being widely exploited in U.S. dent maize breeding programs. Alternative U.S. heterotic patterns have been suggested, but they received limited attention and improvement. The objectives of this research were to evaluate inbred-progeny recurrent selection in Leaming (originated in Ohio), the oldest known U.S. open-pollinated variety, and Midland Yellow ...


Assessment Of Plant Introductions For Increasing The Genetic Variability Of Soybean Populations , James Mark Narvel Jan 1999

Assessment Of Plant Introductions For Increasing The Genetic Variability Of Soybean Populations , James Mark Narvel

Retrospective Theses and Dissertations

Plant introductions (PIs) may increase the genetic variability of soybean populations and lead to greater genetic gains from selection. Five soybean populations containing different percentages of PI parentage were developed at Iowa State University to evaluate the use of PIs for increasing genetic variability for seed yield in a recurrent selection program. The objective of this study was to evaluate the performance and genetic variability of the Cycle 4 (C4) populations of AP 10 (100 % PI), AP 11 (75 % PI), AP12 (50 % PI), AP13 (25 % PI), and AP14 (0 % PI) for agronomic traits and seed composition. Multiplexing technology for simple ...


Genetic Analysis Of Quantitative Trait Loci With The Early Generations Of An Elite, Single-Cross Maize Population , Dwi Asmono Jan 1998

Genetic Analysis Of Quantitative Trait Loci With The Early Generations Of An Elite, Single-Cross Maize Population , Dwi Asmono

Retrospective Theses and Dissertations

The first objective of this study was to detect QTLs affecting agronomically important traits in the F2 plants of an elite, single-cross of maize (Zea mays L.). The second objective was to compare QTL detection in the F2 and F2:3 generations. The third objective was to compare QTL detection in two samples of F2:3 lines derived from the same F2 population;Thirty-eight QTLs affecting five traits were identified in the F2 plants. The QTLs were associated with 6 to 43% of the phenotypic variation. QTLs explaining more than 40% of the variation were observed for plant height and ...


Genetic Analysis Of Quantitative Trait Loci With Inbred And Hybrid Progeny Of Maize , David Frederick Austin Jan 1997

Genetic Analysis Of Quantitative Trait Loci With Inbred And Hybrid Progeny Of Maize , David Frederick Austin

Retrospective Theses and Dissertations

The first objective of this study was to compare quantitative trait loci (QTL) detection in two climatically diverse environments in a population of F6:7 lines of an elite maize (Zea mays L.) single-cross. The second objective was to detect QTL for general (GCA) and specific (SCA) combining ability effects in hybrid progeny of F2:3 and F6:8 lines from the same population. Evaluations of both inbred per se and hybrid progeny from the same population enabled comparisons between QTL controlling the two progeny types;The results from the F6:7 inbred progeny evaluations suggest that QTL detection can ...


Molecular Marker Analysis Of Iron Efficiency In Soybean (Glycine Max (L.) Merr.) , Shun-Fu Lin Jan 1996

Molecular Marker Analysis Of Iron Efficiency In Soybean (Glycine Max (L.) Merr.) , Shun-Fu Lin

Retrospective Theses and Dissertations

The objectives of the studies were to map genes affecting iron deficiency chlorosis in soybean, to test the hypothesis that two genetic mechanisms control iron deficiency chlorosis in soybean, and to determine the effectiveness of nutrient solution evaluation for iron deficiency chlorosis in soybean. Chlorosis symptoms of one hundred and twenty F2:4 lines from a Pride B216 x A15 population, and 92 F2:4 lines from an Anoka x A7 population grown in a field of calcareous soil in 1993 and 1994 were evaluated by visual scores and spectrometric chlorophyll determinations. Each population also was evaluated separately with two ...


Restriction Fragment Length Polymorphism In Sorghum (Sorghum Bicolor (L.) Moench): Characterization Of Genetic Diversity And Quantitative Trait Loci , Dario Ahnert Jan 1995

Restriction Fragment Length Polymorphism In Sorghum (Sorghum Bicolor (L.) Moench): Characterization Of Genetic Diversity And Quantitative Trait Loci , Dario Ahnert

Retrospective Theses and Dissertations

Restriction fragment length polymorphisms (RFLPs) were employed to investigate genetic diversity and quantitative trait loci (QTL) for morphological characters on sorghum (Sorghum bicolor (L.) Moench). The objectives of this research were accomplished by studying two different sets of genotypes. One set was composed of 105 elite inbred lines (47 B- and 58 R-lines) and the other of 152 F[subscript]2:3 lines. In the R- and B-lines set, the objectives were to define the level of genetic similarity (GS) and relationships within these lines. In the 152 F[subscript]2:3 lines set, the objectives were to characterize QTL ...


Rflp Mapping Of Quantitative Trait Loci For Reproductive, Morphological, And Seed Traits Of Soybean (Glycine Max L.) Across Environments , Heike Kross Jan 1995

Rflp Mapping Of Quantitative Trait Loci For Reproductive, Morphological, And Seed Traits Of Soybean (Glycine Max L.) Across Environments , Heike Kross

Retrospective Theses and Dissertations

Quantitative trait loci (QTL) and QTL x environment interaction were identified for 11 agronomic traits in soybean, when measured at two locations in each of two years in Iowa. The segregating population consisted of 76 F[subscript]2:5/F[subscript]2:6 families derived from the cross between the two soybean (Glycine max (L.) Merr.) cultivars 'Minsoy' (PI27.890) and 'Noir 1' (PI 290.136). A genetic linkage map consisting of 81 markers in 25 linkage groups was used to locate QTL by interval mapping. Analyses of variance was performed on 72 linked and unlinked markers to test for ...


Parent Selection To Maximize Heterosis Expression In Soybean (Glycine Max L. [Merr.]) , Francisco Jonathan Cerna Jan 1992

Parent Selection To Maximize Heterosis Expression In Soybean (Glycine Max L. [Merr.]) , Francisco Jonathan Cerna

Retrospective Theses and Dissertations

Utilization of heterosis effects in breeding soybean (Glycine max (L.) Merr) cultivars for commercial production is still a possibility. One objective of this research was to determine heterosis expression in soybean germplasms obtained from the crossing of parents selected on the basis of restriction fragment length polymorphism (RFLP) diversity and isozyme loci (ISO) constitution compared to parents selected for high-yielding (HY) ability and differences in geographic origin (GO). The second objective was to compare mean heterotic performance of F[subscript]1 hybrids and F[subscript]2 bulks evaluated in hill- and row-plots;Twenty-one genotypes of each of Maturity Groups (MG ...


The Combining Ability Of Selected Alfalfa Clones As Related To The Self-Fertility Of The Clones, Their F1 And F2 Progenies , Devere Richard Mcallister Jan 1950

The Combining Ability Of Selected Alfalfa Clones As Related To The Self-Fertility Of The Clones, Their F1 And F2 Progenies , Devere Richard Mcallister

Retrospective Theses and Dissertations

No abstract provided.