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Evaluating Traits Influencing Hybrid Wheat Seed Production Using A Double Haploid Population Derived From Freeman × Camelot, Emre Karahan

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

Hybrid wheat (Triticum aestivum L.) cultivars are preferred for their advanced agronomic traits such as a yield improvement increase up to 20%. However, hybrid cultivars remain difficult to produce on a commercial scale due to inadequate pollen dispersal, the closed nature of the wheat floret and the high cost of inducing sterility or restoring fertility in cleistogamous wheat. Redesigning parent-specific traits and understanding their potential interactions with related agronomic traits are needed to breed improved male lines in hybrid seed production fields. To better understand the genetic control of anther extrusion (AE), 174 double haploid lines derived from Freeman …

Fine Mapping And Cloning Of The Major Seed Protein Quantitative Trait Loci On Soybean Chromosome 20, Christina E. Fliege, Russell A. Ward, Pamela Vogel, Hanh Nguyen, Truyen Quach, Ming Guo, João Paulo Gomes Viana, Lucas Borges Dos Santos, James Specht, Thomas Clemente, Matthew E. Hudson, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is a unique crop species because it has high levels of both protein and oil in its seed. Of the many quantitative trait loci (QTL) controlling soybean seed protein content, alleles of the cqSeed protein-003 QTL on chromosome 20 exert the greatest additive effect. The high-protein allele exists in both cultivated and wild soybean (Glycine soja Siebold & Zucc.) germplasm. Our objective was to fine map this QTL to enable positional-based cloning of its underlying causative gene(s). Fine mapping was achieved by developing and testing a series of populations in which the chromosomal region surrounding …

Microbiome Variation Across Populations Of Desert Halophyte Zygophyllum Qatarensis, Abdul Latif Khan, Lucas Dantas Lopes, Saqib Bilal, Sajjad Asaf, Kerri M. Crawford, Venkatesh Balan, Ahmed Al-Rawahi, Ahmed Al-Harrasi, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Microbial symbionts play a significant role in plant health and stress tolerance. However, few studies exist that address rare species of core-microbiome function during abiotic stress. In the current study, we compared the microbiome composition of succulent dwarf shrub halophyte Zygophyllum qatarensis Hadidi across desert populations. The results showed that rhizospheric and endosphere microbiome greatly varied due to soil texture (sandy and gravel). No specific bacterial amplicon sequence variants were observed in the core-microbiome of bulk soil and rhizosphere, however, bacterial genus Alcaligenes and fungal genus Acidea were abundantly distributed across root and shoot endospheres. We also analyzed major nutrients …

Microbiome Variation Across Populations Of Desert Halophyte Zygophyllum Qatarensis, Abdul Latif Khan, Lucas Dantas Lopes, Saqib Bilal, Sajjad Asaf, Kerri M. Crawford, Venkatesh Balan, Ahmed Al-Rawahi, Ahmed Al-Harrasi, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Microbial symbionts play a significant role in plant health and stress tolerance. However, few studies exist that address rare species of core-microbiome function during abiotic stress. In the current study, we compared the microbiome composition of succulent dwarf shrub halophyte Zygophyllum qatarensis Hadidi across desert populations. The results showed that rhizospheric and endosphere microbiome greatly varied due to soil texture (sandy and gravel). No specific bacterial amplicon sequence variants were observed in the core-microbiome of bulk soil and rhizosphere, however, bacterial genus Alcaligenes and fungal genus Acidea were abundantly distributed across root and shoot endospheres. We also analyzed major nutrients …

Influence Of Roasting On The Proximate, Functional And Sensory Properties Of Jackfruit Seeds And Amaranth Grain Composite Complementary Flours, Agnes Nabubuya, Robert Mugabi, Abraham Kaggwa, Paddy Ainebyona, Rukia Nalugya

Tanzania Journal of Science

This study evaluated the effects of roasting on jackfruit seeds (JFS) and amaranth grain composite complementary flours. Eleven formulations were used for the study. The moisture, crude protein, crude fat, crude fibre, crude ash and carbohydrate contents varied from 6.5 to 8.7%, 10.66 to 20.9%, 0.93 to 5.98%, 4.46 to 10.2%, 2.6 to 3.76% and 51.3 to 71.7%, respectively. The water absorption capacity (WAC), water solubility index (WSI), oil absorption capacity, swelling power (SP) and bulk density (BD) ranged from 238.9 to 360.5%, 3.9 to 12%, 107.4 to 200.6%, 13.3 to 45.9%, and 0.5 to 0.7 g/mL, respectively. Increasing amaranth …

Evaluation Of Pasting Properties Of Plantain, Cooking Banana, Selected Cereals And Their Composites As Indicators For Their Food Values, Wasiu B. Agbaje, Oluseye O. Abiona, Shola H. Awojide, Luqman A. Azeez, Adeniyi S. Tayo

Tanzania Journal of Science

The pasting properties of unripe plantain, unripe cooking banana, some selected cereals and their composite flours were investigated in relation to their food values. Each of the samples was cleaned, air–dried and pulverized to form the native flours which were mixed in different proportions to form the composite flours. Soft doughs were prepared from the flours and subjected to textural evaluation. The adjudged best from each set was analysed using Rapid Visco–Analyser followed by determination of their proximate composition and functional properties. The results showed that the breakdown viscosity (cP) of each of the composite flours was less than 920.50 …

Effects Of Neem Aqueous Extract (Azadirachta Indica) Against Aphids And Aphid-Borne Virus In Cowpea (Vigna Unguiculata L. Walp), Kehinde T. Kareem, Rachael B. Olayinka, Juliana A. Ugwu, Olubusola F. Oduwaye

Tanzania Journal of Science

Pests and diseases are among the major factors limiting plant growth and yields. Pests are known vectors of pathogens including viruses. Proper management of plant pests is an indirect means of controlling viral diseases in plants. This study aimed at comparing the potential of neem extract and a synthetic insecticide (lambda cyhalothrin) for the management of aphids and Cowpea aphid-borne mosaic virus (CABMV) in five different cowpea (Vigna unguiculata) genotypes and to determine the residual effects of the insecticide in the cowpea grains. The experimental field was laid out in randomized complete block design with three replicates. Treatments included; spraying …

Effect Of Solitary And Combined Use Of Cover Crops On Soilborne Disease Suppressiveness In Woody Ornamental Nursery Production Systems, Madhav Parajuli, Fulya Baysal-Gurel, Milan Panth

Student Research

Cover crops are known to be effective in reducing soilborne diseases in woody ornamentals. However, it remains unknown how solitary and combined uses of cover crops influence soilborne disease, and whether these effects differ with seed rate. The objective of this study was to explore the impacts of cover crops, in solitary and combined use, on soilborne disease suppressiveness in woody ornamental nursery production systems. Soils were sampled from the established red maple (Acer rubrum L.) plantation grown with and without cover crops [crimson clover (Trifolium incarnatum L.)] or triticale (× Triticosecale W.) or (their mixture)] following the cover crop …

A Comparison Of Natural, Living, And Hardened Shorelines Ability To Prevent Coastal Erosion And Maintain A Healthy Ecosystem, Gabrielle Spellmann

Master's Theses

It is important to find a suitable method to protect the U.S. Gulf Coast shoreline, since its’ low elevation and the Loop current make it vulnerable to sea level rise. I focused on two manmade methods, hardened, and living shorelines, of coastal protection for when the natural marsh suffers excess erosion rates. Living shorelines are a suite of shoreline conservation and restoration techniques that usually involve some sort of hardened structure that dampens wave energy so that the native vegetation behind it can take root and stabilize the shoreline. This study looked at six different sites, all containing a natural, …

A Global Soil Spectral Calibration Library And Estimation Service, Keith D. Sheperd, Rich Ferguson, David Hoover, Fenny Van Egmond, Jonathan Sanderman, Yufeng Ge

Department of Agronomy and Horticulture: Faculty Publications

There is growing global interest in the potential for soil reflectance spectroscopy to fill an urgent need for more data on soil properties for improved decision-making on soil security at local to global scales. This is driven by the capability of soil spectroscopy to estimate a wide range of soil properties from a rapid, inexpensive, and highly reproducible measurement using only light. However, several obstacles are preventing wider adoption of soil spectroscopy. The biggest obstacles are the large variation in the soil analytical methods and operating procedures used in different laboratories, poor reproducibility of analyses within and amongst laboratories and …

Substrate Type Affects The Drying Speed And Desiccation Tolerance Of Fern Gametophytes, Jordyn D. Regier, Mayra J. Hernandez, Camille K. Sicangco, Stephen D. Davis, Helen I. Holmlund

Seaver College Research And Scholarly Achievement Symposium

Although most ferns require abundant water to thrive, some ferns can survive in habitats with limited water. Previous studies have examined the adaptations that allow xeric ferns to thrive in mediterranean-type ecosystems such as southern California. However, the large fern sporophyte only represents one stage of the fern life cycle; the independent gametophyte phase must also survive water stress, including the six-month summer drought periods of the Santa Monica Mountains. Some fern gametophytes have been reported to be desiccation tolerant (capable of recovery from near-complete drying), and this trait is believed to be dependent on the plant’s drying speed. In …

Southeast Asia Must Narrow Down The Yield Gap To Continue To Be A Major Rice Bowl, Shen Yuan, Alexander M. Stuart, Alice G. Laborte, Juan I. Rattalino Edreira, Achim Dobermann, Le Vu Ngoc Kien, Lưu Thị Thúy, Kritkamol Paothong, Prachya Traesang, Khin Myo Tint, Su Su San, Marcelino Q. Villafuerte Ii, Emma D. Quicho, Anny Ruth P. Pame, Rathmuny Then, Rica Joy Flor, Neak Thon, Fahmuddin Agus, Nurwulan Agustiani, Nanyan Deng, Tao Li, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Southeast Asia is a major rice-producing region with a high level of internal consumption and accounting for 40% of global rice exports. Limited land resources, climate change and yield stagnation during recent years have once again raised concerns about the capacity of the region to remain as a large net exporter. Here we use a modelling approach to map rice yield gaps and assess production potential and net exports by 2040. We find that the average yield gap represents 48% of the yield potential estimate for the region, but there are substantial differences among countries. Exploitable yield gaps are relatively …

Western Prairie Fringed Orchid Management, Ecology, And Decline At Mormon Island, Andrew J. Caven

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The western prairie fringed orchid (Platanthera praeclara Sheviak & M. L. Bowles; WPFO) was first detected in a vegetative state on Mormon Island in 1978 and identification was confirmed following a mass flowering event in 1982. From a high count of ~60 plants the WPFO slowly declined and has not been observed since 2000 despite flowering season surveys conducted in 15 of the last 20 years. We explore the natural history of the WPFO in the contexts of Mormon Island to establish potential causes for its apparent disappearance and evaluate the possibility it persists in some capacity. Our investigation …

Editorial: Genomics-Enabled Triticeae Improvement, Xue-Feng Ma, Xianchun Xia, Shuyu Liu, P. Stephen Baenziger, Hakan Özkan

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Quantifying And Manipulating The Angles Of Light In Experimental Measurements Of Plant Gas Exchange, Z. Carter Berry, Jerry Larue, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Diffuse light has been shown to alter plant leaf photosynthesis, transpiration and water-use efficiency. Despite this, the angular distribution of light for the artificial light sources used with common gas exchange systems is unknown. Here, we quantify the angular distribution of light from common gas exchange systems and demonstrate the use of an integrating sphere for manipulating those light distributions. Among three different systems, light from a 90° angle perpendicular to the leaf surface (±5.75°) was <25% of the total light reaching the leaf surface. The integrating sphere resulted in a greater range of possible distributions from predominantly direct light (i.e., >40% of light from a 90 ± 5.75° angle perpendicular to the leaf surface) to almost entirely diffuse (i.e., light from an even distribution …

Building Sustainable Rangeland Management Systems Through A One System Innovative Approach, Benedict C. Irwin, T. A. Ameha, M. Mangano, B. W. Solomon, T. Wood

IGC Proceedings (1977-2023)

Working through a collaborative working partnership between the USAID Feed the Future Resilience in Pastoralist Areas (RiPA)1 program and Land Governance Activity (LGA)2 and selected technical partners, these new rangeland programs aim to build on significant breakthrough successes in rangeland management from their previous lowland programs3. These new lowlands pastoralist development programs have been purposely positioned by USAID to coordinate, collaborate and combine working activities focused on the continued improvement and strengthening of rangeland management systems in the lowlands of Ethiopia. In light of this positioning, it is proposed that the programs work together to build a comprehensive sustainable rangeland …

Sustainable Development And The Transformation Of Female Rural Labor: The Case Of Woman Cattle Ranchers In Uruguay, Virginia Courdin

IGC Proceedings (1977-2023)

Internationally, rural women are considered key to sustainable development. However, in the Uruguayan livestock sector, women’s work is largely unrecognized by public policy makers, causing younger women to migrate, and resulting in the "masculinization" of livestock husbandry. In Uruguay, extensive livestock production (range livestock) analysis has historically ignored the genuinely productive role that women play in rangelands, limiting the visibility of their action to reproductive activities while ignoring their importance in terms of income generation, herd management, networking, strategic planning, etc. Although family production integrates women, their work is often invisible, subsumed within domestic chores or seen as "helping" the …

Ruminant Livestock Production Systems And Imperatives For Sustainable Development, J. W. Smith

IGC Proceedings (1977-2023)

No abstract provided.

Biodiversity Conservation And Sustainable Livelihoods In Rangelands: Trends, Challenges And Opportunities, J. Waithaka

IGC Proceedings (1977-2023)

Rangelands cover about 54% of the earth’s surface and are essential for agricultural and livestock production, environmental protection and the in-situ conservation of genetic resources. Despite providing services that support life on earth, rangelands have been neglected to a large extent when compared to other types of ecosystems. This paper provides an overview of the importance of rangelands in conserving biodiversity and supporting the livelihoods of millions of people globally. Rangelands have lost ecological integrity due to unsustainable anthropogenic land-use changes and impacts. It is estimated that over 80% of Key Biodiversity Areas (KBAs) are either not adequately protected or …

Feasibility Of Organic Certification Of Sheep And Goats Produced In Pastoral Systems In Northern Kenya, F. Von Steimker, H. T. Wario, B. Kaufmann

IGC Proceedings (1977-2023)

In pastoral systems of Kenya, sale of small ruminants is the main regular income source for most households. Although the meat of small ruminants produced in Marsabit county is preferred in the domestic market, no mechanisms are in place that allow for a respective price differentiation. Establishing value chains for labelled sheep and goat meat would be an option to allow pastoralists to profit from their high process and product quality. The aim of the current study is to assess the requirements and feasibility to establish a value chain for labelled products (e.g. origin labelled, organic certified) together with the …

Uses Of Native Plant Species Of A Communal Rangeland Within ‘Sierra De Huautla’ Protected Area, México, E. Cortés-Díaz, T. González-Bonilla, L. López-Aguilar, Pedro A. Martínez-Hernández, A. Hernández-Tapia

IGC Proceedings (1977-2023)

Sustainability of communal rangelands has become a major concern at national and international levels because land use conflicts and associated social conflicts allows for over-utilization of selected species making a high pressure on them and given away their places to species with no use at all becoming lands degraded and unproductive. The objective of the study was to determine floristic composition and native plant uses by local peasants. The range surface is of 4262 ha, belongs to the communal land ‘El Limon’, in Tepalcingo, Morelos, Mexico, and it is within the Natural Reserve Area “Sierra de Huautla”. Native vegetation is …

Beta Macrophyta Diversity Analysis In The Temporary Pond Habitats Of Vettangudi Birds Sanctuary, Kannan Dorai Pandian, Mahesh Mony

IGC Proceedings (1977-2023)

Three temporary ponds of Vettangudi birds sanctuary situate in very close proximity, located in Sivaganga District, Tamil Nadu state of India. However similar eco-climatic conditions prevailing at these pond habitat, those ponds experience the varying nature of biotic interactions. Since the habitat conditions and their land-use pattern have the major role on the vegetation diversity. Temporary ponds of Vettangudi Birds Sanctuary has the characteristic alternate drying and inundation at varying levels and this environmental condition in addition to the biotic influence over the habitat ecology and its vegetation diversity. Understanding this specific relationship is pivotal in the development of management …

Sustainable Intensification In Crop-Livestock Systems, P. Rovira, Paulo C. De F. Carvalho, J. Terra, F. Lattanzi, R. Pizzio, W. Ayala

IGC Proceedings (1977-2023)

Extensive livestock production is the main animal source food system in the Pampas and Campos sub-regions in South America. Beef cattle and sheep convert forage biomass that humans cannot eat into nutrient-dense human-edible foods (meat and milk) and valuable co-products (wool). However, diverse global pressures are acting on Pampas systems including increasing demand for protein sources (food security), climate change, environmental footprint, and competition for land. The integration of small areas of pasture-crop rotations is an alternative for increasing efficiency and sustainable intensification of agroecosystems based on natural grasslands. Rotations led by improved pastures increase the carrying capacity and productivity …

Nutritional Sensitivity Per Morphological Component In Urochloa Hybrid Under Tropical Environments, Bernal-Flores Alvaro, E. A. Pizarro, Adrián R. Quero-Carrillo, Paulino Pérez-Rodríguez, Ramon Rodolfo Ruíz, Thiago Da Cruz Madeira

IGC Proceedings (1977-2023)

Camello^® (GP 3025) is a tolerant to drought Urochloa hybrid grass showing good forage production, early flowering with high regrowth rates. The objective was to define nutrient concentration changes by morphological component and, their differences for two tropical contrasting environments. Nutrient concentrations differences (P≤0.05) were observed among morphological components over time. In environments (Aw₁) the morphological components showed higher average protein content in comparison to that from hostile conditions (Aw₀); lamina (12.2% vs 10.4%), pseudostem (9.5% vs 6.6%) and sheath (9.8% vs 6.8%). Hostile environments (Aw0) promoted increases for FAD (47.9%, 46.9%, pseudostem …

The Comparative Effects Of Short Duration, High Density And Conventional, Rotational Grazing On Different Soil, Vegetation And Animal Parameters In Dry And Mesic Grasslands Of South Africa, Jamie Paulse, Paul Malan, Nico Smit

IGC Proceedings (1977-2023)

Short duration, high density grazing is a grazing management strategy that incorporates the rotation of large livestock herds, often at double or triple the normal prescribed stocking densities of the specific area. It is claimed that this type of grazing management can improve rangeland health by improving soil and vegetation condition, and subsequently influencing animal performance. Regardless of the scarcity of scientific evidence validating these claims, the change from conventional rotational grazing systems to short duration, high density grazing systems is on the increase in South Africa. This study aims to assess these claims, through the quantification of various rangeland …

Sustainable Management Of Rangelands: An Assessment Of Invasion Cover Trajectories And Their Contribution To Invasion Management In Marigat Sub-County, Kenya, Beatrice Adoyo, Albrecht Ehrensperger, Mikalitsa S. Mukhovi, Boniface Kiteme, Purity Mbaabu Rima, Sandra Eckert, Simon Choge, Urs Schaffner

IGC Proceedings (1977-2023)

Invasive alien species have complex spatiotemporal patterns of spread beyond geographical and jurisdictional boundaries. This calls for a coordinated management approach that is spatially explicit, extends beyond individual plot levels, and incorporates land users’ perceptions and decisions. This study, therefore, aims at assessing spatiotemporal invasion trajectories of the invasive tree Prosopis juliflora in Baringo County, Kenya, and evaluating their possible relation to land users’ management decisions. Pre-classified land cover data over a seven-year time period (1988–2016) were reclassified based on the presence or absence of P. juliflora and integrated into ArcGIS to produce P. juliflora cover trajectories for analysis. The …

Enhancing Grassland Biodiversity And Its Consequences For Grassland Management And Utilisation, Johannes Isselstein

IGC Proceedings (1977-2023)

Key points

1. Grasslands make an important contribution to the biodiversity of rural landscapes.

2. Biodiversity has the potential to support the production function of grassland. The conditions for this are largely unexplored.

3. The enhancement of biodiversity on agriculturally improved, species-poor grasslands is difficult to achieve due to seed limitation and high residual soil fertility.

4. Measures to overcome constraints are addition of propagules, depletion of soil nutrients, and the use of specific sward treatments.

5. Agri-environmental schemes will play an increasing role in achieving the biodiversity targets in the future, however, the efficiency of such schemes needs improvement.

Understanding Common Perceptions Of The Drylands, C. Bedelian, D. Pertaub, F. Ngarachu, C. Hesse, S. Krätli, J. Obando, C. Shisanya, J. Maraigua

IGC Proceedings (1977-2023)

Drylands occupy over 40% of the earth’s surface and are home to more than 2 billion people. Drylands are key to the food and nutritional security of the planet and vital to the economies and livelihoods of dryland inhabitants. Yet, drylands are commonly perceived as unproductive, economically inefficient and marginal lands where small-scale farmers and pastoralists practice environmentally degrading activities. Driven by inadequate understanding and misconceptions of the drylands, policy-makers devise inappropriate policies and interventions. The BRECcIA project developed an online Drylands Perceptions Survey to understand the perceptions of researchers, practitioners and policy makers working in the drylands of Kenya, …

Relationships Between Biodiversity And Production In Grasslands At Local And Regional Scales, A. Hector, M. Loreau

IGC Proceedings (1977-2023)

Key points

1. Experimental manipulations of plant species diversity in unfertilised prairies and meadows has revealed that increasing diversity often leads to increased productivity (range of observed relationships varies from flat to log-linearly positive); driven by a combination of facilitation, niche-partitioning and sampling/selection effects.

2. The longer-term effects of diversity on ecosystem stability are not as clear and in need of further work.

3. Recent applied work, and a new review of the grassland literature, both show the potential for biodiversity to increase productivity under realistic field conditions.

4. The longer-term feedback of grazers on biodiversity gradients is unknown, and …

Methane And Nitrous Oxide Emissions From Grazed Grasslands, Harry Clark, C. Pinares-Patiño, C. De Klein

IGC Proceedings (1977-2023)

Key points

1. Emissions of methane (CH₄) and nitrous oxide (N₂O) from grasslands make a substantial contribution to total agricultural emissions of these two gases.

2. At present practical mitigation options that relate to grazing ruminants and grazed pastures are limited.

3. Research into agricultural greenhouse gas emissions is of low priority in most developed countries.

4. Direct manipulation of the rumen ecosystem provides the best opportunity for large reductions in CH₄ in the long term.

5. Reducing the amount of nitrogen (N) excreted by grazing animals is a priority in N₂O research, …