Plant Breeding and Genetics Commons^™

Correlation, Regression Analysis Of Seed Oil Contents In Relation To Morphological Characters In Cotton, Hafiz Muhammad Awais, Sarmad Frogh Arshad, Wajad Nazeer, Muhammad Usman, Abdul Latif Khan Tipu, Muqarrab Ali, Asif Saleem, Hasan Junaid Arshad, Asma Shah Rukh

Journal of Bioresource Management

Cotton is the backbone of Pakistan’s economy. More than half of the export of Pakistan depends on cotton and cotton-based products. Morphological quantitative traits are important for estimation of cotton yield. In this regard, a study was conducted to evaluate the morphological responses on cotton crop at experimental farm of MNS-University of Agricultural Multan during the year 2019-2020. Four cotton varieties with different time windows (early, normal and late) were sown in a randomized complete block design (RCBD) in a split plot arrangement. Correlation and regression studies of cultivars of Gossypium and Malvaceae were analyzed for quantitative characters. Result revealed …

Marker-Assisted Selection To Determine The Introgression Of Rpv-3 Mediated Downy Mildew Resistance In 'Chambourcin' X 'Caberenet Sauvignon' Grapevine Population, Kavya Sri Tummala

Graduate Theses/Dissertations

Downy mildew caused by the fungus, Plasmopara viticola in the grapes is one of the major diseases affecting crop yield throughout the world. Breeding grapes via conventional methods for the downy mildew resistance will take approximately 25-30 years to fully evaluate and release new cultivars. Because of the long breeding cycle in woody plant species like grape, developing DNA markers linked to genes or quantitative trait loci (QTLs) for horticultural traits can greatly accelerate the breeding process and allow a much more accurate selection of progeny. This study aims to determine the presence of resistance in the 267 F1 genotypes …

Identification Of Qtls For Berry Acids And Sugar In A Vitis Aestivalis-Derived 'Norton'-Based Population, Karlene Louise Negus

Graduate Theses/Dissertations

Acidity and sugar content are among the grape berry quality traits that influence wine quality. Despite advantageous environmental tolerances of Vitis aestivalis-derived ‘Norton’, its acid and sugar concentrations often deviate from expectations set for V. vinifera. Identification of the genetic determinants of malic acid, tartaric acid, pH, and total soluble solids (TSS) can assist in the improvement of new hybrid cultivars. For this purpose, a ‘Norton’ and V. vinifera ‘Cabernet Sauvignon’ hybrid mapping population containing 223 individuals was used to construct a linkage map containing 384 simple sequence repeat (SSR) and 2084 genotyping-by-sequencing (GBS)-derived single nucleotide polymorphism (SNP) …

B.R. Wells Arkansas Rice Research Studies 2020, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading rice producer in the United States. The state represents 47.5% of total U.S. rice production and 48.1% of the total acres planted to rice in 2020. Rice cultural practices vary across the state and across the U.S. However, these practices are also dynamic and continue to evolve in response to changing political, environmental, and economic times. This survey was initiated in 2002 to monitor and record changes in the way Arkansas rice producers approach their livelihood. The survey was conducted by polling county extension agents in each of the counties in Arkansas that produce rice. Questions …

Understanding Potassium Toxicity Stress Responses Of The Extremophyte Schrenkiella Parvula Using Systems Biology Approaches, Pramod Pantha

LSU Doctoral Dissertations

Schrenkiella parvula is an extremophyte model closely related to Arabidopsis thaliana and Brassica crops. Its natural habitat includes shores of saline lakes in the Irano-Turanian region. It has adapted to grow in soils rich in multiple salts including Na⁺ and K⁺. I have investigated the genetic basis for high K⁺ tolerance in plants using S. parvula as a stress tolerant model compared to the premier plant model, Arabidopsis thaliana which is highly sensitive to salt stresses using physiological, ionomic, transcriptomic, and metabolomic approaches. Under high K⁺ stress, root system architecture changes significantly compared to control …

Rice From Paddy To Pantry To Plate: Mitigating Rice Blast Disease With Saponins Of Medicago, Improving Shelf Life With Crispr, And Exploring Global Cuisine Through Text Analysis, Kathryn Haydon

Graduate Theses and Dissertations

Rice is the staple food for more than half the world’s population, with nearly 500 million metric tons of rice consumed globally every year. Any risk of loss due to disease, waste, or spoilage is therefore noteworthy. This dissertation explores the passage of rice from paddy to pantry to plate, with special attention given to disease and storage life. The most important disease of rice is blast, caused by the ascomycete Magnaporthe oryzae, which can cause losses of ~30% every year. This study found that saponin-enriched root extracts of Medicago truncatula effectively kill fungal spores in vitro and reduce moderate …

Genetic Resistance To The Downy Mildew Pathogen And Breeding Towards Durable Disease Management In Spinach, Bazgha Zia

Graduate Theses and Dissertations

Spinach (Spinacia oleracea) is a self-pollinated, dioecious winter crop. Prevalent challenges to the production of spinach include disease pressure imposed by downy mildew, which is caused by Peronospora effusa (=P. farinosa f. sp. spinaciae [Pfs]). A total of 19 new races of P. effusa have emerged, imposing serious challenges to the disease management in spinach production. Accordingly, this study was designed to explore the genetic components for establishing the basis of durable disease resistance development against the downy mildew pathogen (P. effusa 13) in spinach, through the use of various genome engineering approaches.

Our results have led (Chapter 2) to …

Arkansas Corn And Grain Sorghum Research Studies 2020, Victor Ford, Jason Kelley, Nathan Mckinney Ii

Arkansas Agricultural Experiment Station Research Series

The 2021 edition of the Arkansas Corn and Grain Sorghum Research Studies Series includes research results on topics pertaining to corn and grain sorghum production, including weed, disease, and insect management; economics; sustainability; irrigation; post-harvest drying; soil fertility; mycotoxins; cover crop management; feral hog control; and research verification program results. Our objective is to capture and broadly distribute the results of research projects funded by the Arkansas Corn and Grain Sorghum Board. The intended audience includes producers and their advisors, current investigators, and future researchers. The Series serves as a citable archive of research results. Reports in this publication are …

Summaries Of Arkansas Cotton Research 2020, Fred Bourland

Arkansas Agricultural Experiment Station Research Series

In the five years before 2020, cotton acreage in Arkansas had steadily increased from an all-time low of 210,000 acres in 2015 to 610,000 planted acres in 2019. One reason for the increase can be attributed to a downturn in prices received by producers for commodities such as corn and soybean, which compete for acres with cotton. With the worldwide COVID-19 pandemic, cotton mill use dropped significantly during the first half of 2020 https://www.cottongrower.com/market-analysis/ncc-cotton-demand-returning-as-u-s-and-world-economies-rebound/. This disruption of the cotton supply chain was felt across the entire cotton industry. The resulting downturn of cotton prices prior to planting impacted producers planting …

Effect Of Harvest Time On The Incidence Of Red Drupelet Reversion And Development Of Tetraploid Linkage Maps In Blackberry, Mitchell E. Armour

Graduate Theses and Dissertations

The cultivated eastern U.S. blackberry (Rubus L. subgenus Rubus Watson) has gone through tremendous strides in both trait improvement and market outreach at the University of Arkansas System Division of Agriculture (UA System). What began as primarily a pick-your-own local fruit found mostly in the wild, has become a commercialized year-round product in most major U.S. grocery retailers. This could not have been achieved without decades of diligent breeding efforts. Although the genetic improvement of fresh-market blackberries has advanced, there are still issues that need to be addressed. One issue is the prevalence of red drupelet reversion (RDR), a physiological …

Weedy Rice Conserved Ex Situ Characterized Using Morphological And Simple Sequence Repeat (Ssr) Markers, Rubylyn Mijan Infante, Maria Elizabeth B. Naredo, Merlyn S. Mendioro

The Philippine Agricultural Scientist

A clear understanding of genetic diversity in weedy rice is important in improving protocols for its conservation, ex situ. To this end, Asian collections of weedy rice together with accessions of the wild AA genome species Oryza nivara Sharma et Shastry and Oryza rufipogon Griffith, and the cultivated species, Oryza sativa L. were characterized using 16 qualitative morphological traits and 18 SSR markers. The Shannon-Weaver index (H’) revealed higher diversity in the weedy (mean H’ = 0.76) and wild O. nivara (mean H’ = 0.79) and O. rufipogon samples (mean H’ = 0.69) compared to the cultivated …

Grain Yield Variations In Rice Genotypes Under Different Growing Environments In The Philippines, Kim Nyka C. Perdiguerra, Shiro Mitsuya, Akira Yamauchi, Felino P. Lansigan, Maria Victoria O. Espaldon, Jose E. Hernandez, Pompe C. Sta. Cruz

The Philippine Agricultural Scientist

Grain yield variations in PSB Rc18, NSIC Rc222 (inbreds) and NSIC Rc202H (hybrid) were determined across growing environments as a function of cropping seasons and locations in rice producing areas in the Philippines. Contribution of location to variation in grain yield is 61.0%, while 12.7% for the season, and 6.1% for the genotype and this must be due location by season by genotype interactions. Dry season cropping in Nueva Ecija produced the highest mean grain yield. On the other hand, wet season cropping in Davao del Sur produced the least mean grain yield. The genotypes differed in their response to …

Toward Sustainable Production Of Value-Added Bioenergy And Industrial Oils In Oilseed And Biomass Feedstocks, Kiyoul Park, Sanju A. Sanjaya, Truyen Quach, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Plant fatty acids are used forfood, feed, fuel, and industrial materials. Structurally and chemically diverse fatty acids, referred to as unusual or specialized fatty acids, are found in the seed oils of diverse plant species. Many unusual fatty acids have potential use as alternative and renewable sources of biofuels and biobased industrial feedstocks due to their variant structures' physical or functional properties. Oils enriched in these fatty acids can increase the value of oilseed crops and provide co-products that can be readily extracted from lignocellulosic materials in biomass crops. Here, we describe recent progress in strategies for enhancement of oil …

Disruption Of Long-Chain Base Hydroxylation Alters Growth And Impacts Sphingolipid Synthesis In Physcomitrella Patens, Abraham R. Steinberger, William Oscar Merino, Rebecca E. Cahoon, Edgar B. Cahoon, Daniel V. Lynch

Center for Plant Science Innovation: Faculty Publications

Sphingolipids have roles as membrane structural components and as bioactive molecules in plants. In Physcomitrella patens, 4-hydroxysphinganine (phytosphingosine, t18:0) is the predominant sphingolipid long-chain base (LCB). To assess the functional significance of t18:0, CRISPR-Cas9 mutagenesis was used to generate mutant lines lacking the sole SPHINGOID BASE HYDROXYLASE (SBH) gene encoding the hydroxylase responsible for converting sphinganine (d18:0) to t18:0. Total sphingolipid content in sbh protonemata was 2.4-fold higher than in wild-type. Modest changes in glycosyl inositolphosphorylceramide (GIPC) glycosylation patterns occurred. Sphingolipidomic analyses of mutants lacking t18:0 indicated modest alterations in acyl-chain pairing with d18:0 in GIPCs and ceramides, but dramatic …

Next Generation Sequencing Identifies Population Structure And Signatures Of Local Adaptation In Red Alder (Alnus Rubra Bong.), Jacob Brent Loveless

Dissertations and Theses

Red alder (Alnus rubra Bong.) is the dominant hardwood tree species in the Pacific Northwest. Red alders are only found in western North America, generally within 200 km of the coast and below 1000 m in elevation--although there are several disjunct populations in the northern Rocky Mountains in Idaho. Commonly a riparian species, the shade intolerant red alder generates most of the leaf litter in the streams and rivers it occupies which has been shown to greatly influence the decomposer communities. This, in turn, has a cascading effect throughout the entire riparian ecosystem greatly influencing multiple levels of the …

Evaluation Of Masculinization Treatments To Produce Feminized Hemp Seed (Cannabis Sativa L.), Ted Fitzgerald, J. Wyatt Brown

Master's Theses

Cannabis sativa L. (hemp) develops plants with either male or female flowers, and growers of hemp greatly prefer female flowers which bear the glandular trichomes that contain cannabinoids. Feminized (all female) seeds are highly desired, which are produced by crossing a female plant with a masculinized female plant. Masculinization is achieved through the inhibition of ethylene and/or addition of gibberellins before flower initiation in female plants. The hemp industry uses silver thiosulfate (STS) to masculinize hemp, but spraying silver poses environmental concerns. This study compared STS to three other ethylene-inhibiting agents: aminoethoxyvinylglycine (AVG), cobalt nitrate (CBN), and 1-methylcyclopropene (1-MCP). Treatments …

Quantitative Trait Loci Controlling Agronomic And Biochemical Traits In Cannabis Sativa, Patrick Woods, Brian J. Campbell, Timothy J. Nicodemus, Edgar B. Cahoon, Jack L. Mullen, John K. Mckay

Center for Plant Science Innovation: Faculty Publications

Understanding the genetic basis of complex traits is a fundamental goal of evolutionary genetics. Yet, the genetics controlling complex traits in many important species such as hemp (Cannabis sativa) remain poorly investigated. Because hemp’s change in legal status with the 2014 and 2018 U.S. Federal Farm Bills, interest in the genetics controlling its numerous agriculturally important traits has steadily increased. To better understand the genetics of agriculturally important traits in hemp, we developed an F2 population by crossing two phenotypically distinct hemp cultivars (Carmagnola and USO31). Using whole-genome sequencing, we mapped quantitative trait loci (QTL) associated with variation …

The Influence Of Singlet Oxygen And Loss Of Function Of Fatty Acid Desaturase 7 In The Chloroplast On Aphid Resistance In Arabidopsis Thaliana, Hillary Donna Fischer

Graduate Theses and Dissertations

Fatty Acid Desaturase 7 (FAD7) is a chloroplast-localized enzyme that alters the fatty acid content of photosynthetic membranes, and that negatively regulates plant defenses against aphids. Previous studies in the model organism Arabidopsis (Arabidopsis thaliana) have shown that loss-of-function mutations in FAD7 decrease population growth of the green peach aphid (GPA; Myzus persicae Sulzer). This study further characterized the effects of a fad7 null mutant on aphids, and investigated the role of reactive oxygen species (ROS), including singlet oxygen (1O2), in plant responses to aphid resistance in fad7 as well as in wild type plants and a mutant with heightened …

Evaluation Of Irrigation And Nutrient Management Strategies In Rice Using Alternative Irrigation Methods, Justin Lee Chlapecka

Graduate Theses and Dissertations

As water resources gain value across the Mid-South, alternative irrigation strategies of rice (Oryza sativa L.) have garnered increasing attention. In 2015, an estimated 1.7% of Arkansas rice hectarage used alternate wetting and drying (AWD) irrigation and 0.9% used furrow irrigation. As of 2020, 2.5% used AWD and 16.9% used furrow irrigation, the latter accounting for near 99,000 ha in Arkansas. Little information exists in the scientific literature in relation to management of rice grown in the Mid-South without a conventional flood. This fact coupled with the rapid adoption rate, especially for furrow-irrigated rice (FIR), during the last five years …

Production, Evaluation, And Selection Of Elite Quality Protein Popcorn (Qpp) Hybrids, Leandra Marshall Parsons

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

In 2017, twelve Quality Protein Popcorn (QPP) inbred lines were developed and selected as premier dent by popcorn crosses fit for hybridization and testing. These QPP inbred lines were derived from specific Quality Protein dent Maize (QPM) by ConAgra Brands® popcorn line crosses to produce high lysine, vitreous popcorn lines capable of near-equal popping characteristics compared to the original popcorn parents. The QPP hybridization project commenced in the summer of 2018 utilizing these 12 inbred QPP lines and crossing them in a full diallel. Since then, the production of QPP hybrids has employed a diverse set of selection factors evaluating …