Life Sciences Commons^™

Selection And Agronomic Characterization Of Leucaena Spp. Genotypes For Cold Tolerance. I. Dry Matter Yield., M C. Goldfarb, J F. Casco

IGC Proceedings (1997-2023)

Biotypes of Leucaena spp (56) were evaluated in order to identify those with tolerance to low temperature and with desirable characteristics as a forage crop. Selection was done at two phases. Phase I: 92 days old seedlings (n=2800) were subjected at two temperatures treatments during 14 hours: T1= -8 °C and T2= -3 °C. Selection criteria was established as 50% of live leaves remained after treatments were applied. Phase II: Plants that survived phase I were planted at field conditions and agronomic characteristics were measured. Seventeen plants were selected from eleven different biotypes, resulting one from T1 and the rest …

Response To Drought Of White Clover Lines Selected For Different Stolon Morphologies, H D. Karsten, J R. Caradus, D R. Woodfield

IGC Proceedings (1997-2023)

White clover (Trifolium repens L.) lines were selected from within large and small-leaved cultivars of Grasslands Kopu and Grasslands Tahora, respectively, for long or short internodes, and for high or low branching frequency from plants grown in sun and shade (50% full sunlight). Lines were compared for drought tolerance in a perennial ryegrass (Lolium perenne L.) sward in boxes. Prior to imposing drought branching frequency selections did not differ in branching frequency, although the low branching frequency selection had a higher percentage of rooted nodes. After an imposed drought treatment sun-selected lines grew better than shade-selected lines relative …

Exploring Soil Plant Relationships To Inform Seed Selection For Rangeland Restoration, Mallory Hinton, April Hulet, Matt Madsen, Raechel Hunsaker, Shannon Nelson

Library/Life Sciences Undergraduate Poster Competition 2024

Seeding plants post disturbance on rangelands is a challenge due to unique ecological and environmental conditions such as:

• Limited water availability1

• Invasive species2

• Soil health3

• Native seed supplies4

One of the key factors to address these challenges and have a successful seeding is to understand the relationship between soil properties and the plants that grow within them.

Increased Longevity Of Red Clover Through Selection For Persistence And Disease Resistance, R R. Smith

IGC Proceedings (1997-2023)

Red clover (Trifolium pratense L.), an excellent perennial forage legume, has been considered for many years to be a short-lived, two to three years, forage. Selection for resistance to foliar and root rot diseases and for longevity of stand over the past four decades has improved the persistence of the currently available cultivars. The present studies were conducted to evaluate the progress from selection for longevity and disease resistance. Selection for stand longevity and improved disease resistance has reliably extended the production of red clover into the third and fourth year. Selection for healthy plants in 3- or …

Selection For Herbage Yield And Flowering In Ladino White Clover, J A. Garcia

IGC Proceedings (1997-2023)

A geno-phenotypic recurrent selection program is being carried out on ladino white clover (Trifolium repens L.) aiming to combine good DM and seed yields. Selection criteria includes plant density, vigor, winter growth, flowering and diseases resistance. The performance of selections in terms of DM yields and seed production was evaluated in separate trials. Two cycles of selection increased flowering by 36% and seed yield by 59%. Preliminary data on herbage yields shows a very good performance of the selected material and suggests the feasibility of combining high DM and seed yields.

Selection For Field Survival Increases Freezing Tolerance In Festulolium, M D. Casler, P G. Pitts, P C. Bilkey, C A. Rose-Fricker

IGC Proceedings (1997-2023)

Festulolium (Festulolium braunii K.A.) is marginally adapted to the north central and northeastern USA and southern Canada. The purpose of this study was to evaluate four festulolium populations selected for field survival under harsh winter conditions for their freezing tolerance in controlled environments. Progenies of all four populations showed some improvement in freezing tolerance compared to their parents. Improvements were dependent on the temperature at which measurements were made and varied among germplasms. Improvements were manifested in both decreased plant mortality and decreased injury to surviving plants. Genetic variation for freezing tolerance appears to be a viable mechanism …

Participatory Development Of A Forage Grass Cultivar, Michael D. Casler, P. G. Pitts, P. C. Bilkey, C. A. Rose-Fricker

IGC Proceedings (1997-2023)

Perennial forage grasses exist in both nature and agriculture as a highly heterogeneous mixture of genotypes. Extreme environments, fluctuating environments, and severe managements can impose selection pressures that will result in loss of unadapted genotypes. Mortality of unadapted genotypes leads to dominance of fewer highly adapted genotypes which may be useful as superior germplasm in other similar environments.

Population Physiology, Demography, And Genetics Of Side-Blotched Lizards (Uta Stansburiana) Residing In Urban And Natural Environments, Spencer B. Hudson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife populations across the globe are poised to lose their natural habitat to urbanization, yet there is limited information on how different species handle living in cities. Animals in urban environments are often susceptible to novel stressors, which can threaten their individual health and population viability. The physiological characteristics of animals, such as those related to metabolic hormones, oxidative stress, and immunity, are expected to be important for survival in this context. If so, animals persisting in urban areas may demonstrate physiological differences from their natural counterparts, perhaps due to evolutionary change. These potential outcomes have been documented in birds …

The Functional Implications Of Anuran Metamorphosis For Survival, Locomotor Performance, And Limb Bone Mechanical Properties, Chase Kinsey

All Dissertations

Many organisms must contend with navigating their environments from birth. An organism could be classified as – and is often studied – in the context of locomotion through a single habitat type. However, many organisms must contend with a wide variety of environmental obstacles and substrates. What’s more, a large group of animals, Lissamphibia, do so while undergoing drastic transformation of their morphology and locomotor appendages. This transformation, term metamorphosis, typically coincides with a movement from water as a tadpole, to land as a frog or salamander. Many studies have associated this transitionary period with decreased locomotor performance and worse …

Effects Of Perennial Ryegrass Cultivars On Traits For Improved Animal Performance, Harm J. Smit, B. M. Tas, Hassan Z. Taweel, J. Dijkstra, Anjo Elgersma, S. Tamminga

IGC Proceedings (1997-2023)

The use of quality parameters in grass breeding is limited. There may be options to improve grass cultivars (cvs) for improved animal performance.

Selection Of Forages For The Tropics (Soft) - A Database And Selection Tool For Identifying Forages Adapted To Local Conditions In The Tropics And Subtropics, B. C. Pengelly, B. G. Cook, I. J. Partridge, D. A. Eagles, M. Peters, J. Hanson, S. D. Brown, J. L. Donnelly, B. F. Mullen, R. Schultze-Kraft, A. Franco, R. O'Brien

IGC Proceedings (1997-2023)

Rising populations and incomes in developing countries are likely to double demand for livestock products by 2020 (Delgado et al. 1999). This strong demand has potential to improve profitability for farmers but will require improved animal feeding in both semi-intensive crop-livestock and more extensive livestock systems. Forages usually are the most cost-effective option to supply feed demands, particularly for ruminant-, but also for pig- and poultry- production. It is critical to select the most suitable forages for the local system and conditions. Small- and even larger-scale farmers depend heavily on advice from extension and development agencies, and from seed …

Mouse Genotyping Array-Based Analysis Of Variation At Single Nucleotide Polymorphic Loci In The Context Of Macro- And Micro-Environments, Freda Qi

Electronic Thesis and Dissertation Repository

Comparing genetic variation between populations can provide insight into selective pressures in the environment. The Mouse Diversity Genotyping Array (MDGA) is a low-cost, high-throughput tool developed to capture and analyze variation at single nucleotide polymorphic (SNP) loci in inbred mouse strains. However, its ability to assess genetic variation in non-inbred mice and associate SNPs with the environment has not been extensively studied. First, SNPs between laboratory inbred and wild-caught mice were compared. No SNPs were associated with either macroenvironment. Instead, SNPs reflected genealogy and inbreeding strategies, consistent with the MDGA’s intended use. Second, mutations at SNP loci were compared between …

Preliminary Performance Of Panicum Maximum Accessions And Hybrids In Brazil, Liana Jank, Rosangela M. S. Resende, S. Calixto, M. M. Gontijo Neto, V. A. Laura, Manuel C. M. Macedo, Cacilda B. Do Valle

IGC Proceedings (1997-2023)

Due to the lack of high quality forages adapted to the distinct ecosystems in Brazil, a national network to evaluate 14 accessions, 4 hybrids and 5 commercial standards of Panicum maximum was established in 2002, in 5 regions of Brazil (states of Mato Grosso do Sul, Acre, Rondônia, Minas Gerais and in the Federal District). Staff of the Embrapa Beef Cattle group co-ordinated the network and pre-selected the accessions and hybrids (Jank, 1995; Jank et al., 2001; Resende et al., 2004). We present their performance as to leaf dry matter yield (LDMY) and leaf percentage (LP) obtained from …

Agronomic Performance And Genetic Variability Of Panicum Maximum Accessions In The Cerrado Of Federal District, Brazil, F. D. Fernandes, G. B. Martha Jr., Fabio G. Faleiro, Allan K. B. Ramos, R. P. Andrade, Claudio T. Karia, Lourival Vilela, Liana Jank

IGC Proceedings (1997-2023)

In the last three decades, the Brazilian Savanna (locally called "Cerrado") became the most important beef cattle production region in Brazil. Around 90% of all beef produced in the region comes from pasture-based systems. Intensively-managed and fertilised Panicum maximum pastures can be highly productive and economic. As a result, farmers are demanding new P. maximum cultivars for using in well-fertilised pastures or in crop-pasture rotation systems. This study aimed to evaluate the agronomic performance and the genetic variability of P. maximum accessions in the Brazilian Cerrado.

The Feasibility Of Autoclave-Assisted Water Soluble Carbohydrate Extraction To Distinguish Annual Ryegrass Genotypes At The Seedling Stage, L. P. Passos, F. B. De Sousa, A. Mittelmann, M. C. Vidigal, I. G. Perry, L. O. Cruz, J. A. Magalhães

IGC Proceedings (1997-2023)

Annual ryegrass (Lolium multiflorum) swards are being used increasingly in Southern Brazil as animal forage (Carvalho et al., 2001). As observed elsewhere, reduced forage availability and quality during dry or cold seasons often limits the efficacy of pasture utilisation. As reported by Meissner et al. (1992), this demands breeding efforts to improve forage nutritive value. However, lack of concurrent examination of large number of samples for important nutritional parameters, like water-soluble carbohydrate (WSC) levels, which could lead to more precise selection strategies, is a common constraint of those programs. This study aimed to verify the suitability …

Consciousness, Evolution, And The Self-Organizing Brain, Karen Seymour

Journal of Conscious Evolution

While evolution is guided by natural selection, it is internally driven by self-organizing processes. The brain encompasses these complementary forces and dynamics of evolution in both its structure and dynamics by embodying a historical record of the factors that have shaped it throughout its evolutionary past, as well as by being shaped by selective parameters in real time. Self-organization is evident in not only the brain’s structure and form, but also in the processes that support consciousness. From the convergence of complex structure and the novelty-generating dynamics of chaos that both characterize the brain arises the experience of explicit consciousness, …

Grass And Forage Improvement: Temperate Forages, Chris J. Pollock, M. T. Abberton, M. O. Humphreys

IGC Proceedings (1997-2023)

1. Plant breeding has contributed significantly to the development of effective grassland production systems.
2. New technologies offer enhanced precision in breeding and access to wider genetic variation.
3. The requirement for more sustainable production systems will require genetic improvements in complex traits where the use of new technology will be vital.

Grass And Forage Plant Improvement In The Tropics And Sub-Tropics, Liana Jank, C. B. Do Valle, Rosangela M. S. Resende

IGC Proceedings (1997-2023)

1. The majority of tropical and subtropical forage grass genera and/or species have not yet been collected, or need further collection to be representative of their natural distribution.
2. New biotechnological techniques will only result in the release of superior forage cultivars if supported by strong breeding programs.
3. More funding and investment in the formation of strong public research teams in forage conservation and improvement are needed to guarantee the sustainability of tropical and subtropical pasture-based livestock systems in the future.
4. The creation of a permanent international working group on tropical and subtropical forages is essential to assist the International Plant Genetic …

Esterase Mediated Insecticide Resistance In The Southern House Mosquito, Culex Quinquefasciatus, Vivek Pokhrel

LSU Doctoral Dissertations

Much is known about the development of insecticide resistance associated with targeted application against insect populations. However, off-target selection by applications of insecticides in agricultural and residential sites also impacts development of insecticide resistance and is understudied. Similarly, the impact of selecting one life stage of mosquitoes on the insecticide susceptibility of different life stages is largely unknown. The first part of this study shows that susceptibility to chlorantraniliprole, which is applied in rice and sugarcane fields in LA, decreased (5.7 to12-fold) in populations of Culex quinquefasciatus collected from near these fields compared to a reference field strain. In addition, …

Grass And Forage Plant Improvement In The Tropics And Sub-Tropics, Liana Jank, Cacilda B. Do Valle, Rosangela M. S. Resende

IGC Proceedings (1997-2023)

Key points

1. The majority of tropical and subtropical forage grass genera and/or species have not yet been collected, or need further collection to be representative of their natural distribution.

2. New biotechnological techniques will only result in the release of superior forage cultivars if supported by strong breeding programs.

3. More funding and investment in the formation of strong public research teams in forage conservation and improvement are needed to guarantee the sustainability of tropical and subtropical pasture-based livestock systems in the future.

4. The creation of a permanent international working group on tropical and subtropical forages is essential …

Grass And Forage Improvement: Temperate Forages, Chris J. Pollock, M. T. Abberton, M. O. Humphreys

IGC Proceedings (1997-2023)

Key points

1. Plant breeding has contributed significantly to the development of effective grassland production systems.

2. New technologies offer enhanced precision in breeding and access to wider genetic variation.

3. The requirement for more sustainable production systems will require genetic improvements in complex traits where the use of new technology will be vital.

Using Genetic Approaches To Study Local Adaptation And Reproductive Success In Snow Buntings (Plectrophenax Nivalis), Keta K. Patel

Electronic Theses and Dissertations

Genetic analyses can facilitate effective and timely conservation and management actions. Arctic-migratory species in particular are in need of conservation genetic insights as they are experiencing substantial population pressures due to the impact of climate change (and other anthropogenic effects) on processes that affect their survival and reproduction. Therefore, identification of genetic mechanisms driving population divergence and variation in reproductive fitness in such species is critical. The goal of this thesis is to examine reproductive isolation among breeding populations of an Arctic-migratory passerine, the snow bunting (Plectrophenax nivalis) and determine factors that drive local adaptation and variation in …

A Game Theoretic Approach To Design Mating Programs For Livestock, Ebru Ergüneş Berki̇n, Hasan Önder, Özgür Hakan Aydoğmuş

Turkish Journal of Veterinary & Animal Sciences

In this study, we proposed a new game theoretic method to design a mating program. The index and game theoretic methods were applied with calculated breeding values using pedigree on two different data sets whose economic traits consist of negative (milk yield and fat percentage) and positive (birth and weaning weight) genetic correlated data. For the negative genetic correlated data set, even if total expected benefits were equal for two methods, mating programs were changed, and the coefficient of variation obtained using the game theoretic method was smaller than that of the index method. This result showed that the expected …

Productive Performance, Egg Quality, And Hatching Traits Of Japanese Quail Lines Selectedfor Higher Body Weight And Egg Number, Abdur Rehman, Jibran Hussain, Athar Mahmud, Khalid Javed, Abdul Ghayas, Sohail Ahmad

Turkish Journal of Veterinary & Animal Sciences

The present study evaluated the effect of selection for higher body weight (weight based selection = WBS) and egg numbers (egg based selection = EBS) on productivity, egg quality, and hatching traits of Japanese quail for three generations. From a base population of 1125 day-old chicks of Japanese quail, best performing families were allowed to propagate for getting next generation. WBS in G3 presented higher values of feed intake, egg weight, hatching weight. However, egg production and feed conversion ratio were better in EBS during G3. The incidence of embryonic mortality was also lower in the WBS line. In the …

Display Site Selection By Male Ruffed Grouse In The Upper Great Lakes Region, Seth Finkel

Dissertations, Master's Theses and Master's Reports

The Ruffed Grouse (Bonasa umbellus) is widely known for its characteristic territorial drumming display. In this study, I used ruffed grouse drumming survey data from Minnesota and Michigan, in a series of mixed logistic models, to identify drivers of drumming log selection by reproductive male ruffed grouse. I collected drumming stage data utilizing a paired-random sampling structure. I used information theoretic model selection to examine three sets of a priori mixed logistic models: one for the entirety of my Minnesota dataset, one consisting of stages identified in aspen stands in Minnesota, and one for my Michigan dataset. In …

Improvement Of Rose Clover Winter Forage Production, Gerald R. Smith, F. M. Rouquette Jr.

IGC Proceedings (1997-2023)

Rose clover (Trifolium hirtum All.) is a winter annual forage legume that has potential for increased use in the U.S. southern region. New cultivars of rose clover are needed with the combination of cold tolerance, winter forage production and full bloom date of late April. Crosses were made between two early flowering cultivars and one late flowering rose clover cultivar. The F₂ and F₃ generations from these crosses were evaluated in northeast Texas for winter growth, cold damage and date of flowering. Fourteen F₃ lines, out of 37 selected F2 parents, showed large increases (>100%) …

Genetic Resources For Tropical Areas: Achievements And Perspectives, Cacilda B. Do Valle

IGC Proceedings (1997-2023)

This paper analyses the present status of tropical forage resources and their utilization in the development of novel cultivars based on the accumulated information from past decades of collecting, evaluation and whatever little breeding has been pursued. The situation of world collections of tropical forages is presented and discussed in the light of limited investment and dwindling resources. A cause for concern is the lesser priority assigned to conservation and manipulation of official tropical germplasm banks, such as CSIRO’S and CIAT’s. In order to assure the availability of tropical genetic resources for the future it is imperative that international efforts …

Response Of Contrasting Cocksfoot Varieties To Summer Moisture Availability In A Mediterranean Environment, E. Piano, M. Romani, A. M. Carroni, L. Pecetti

IGC Proceedings (1997-2023)

The responsiveness to water availability in summer and the effect of summer drought were assessed in a Mediterranean environment on both temperate and Mediterranean cocksfoot (Dactylis glomerata L.) materials. Three consecutive evaluation phases were contemplated: i) under rainfed conditions from autumn to spring; ii) under contrasting moisture conditions in the following summer; and iii) under rainfed conditions in the subsequent autumn-spring season to assess the effect of the previous summer treatments. The ability to become summer dormant under conducive conditions, such as in Mediterranean germplasm, proved a plant pre-requisite for survival under drought. All the “summer-active”, temperate varieties did …

Evolutionary Mechanisms For Host Resistance To Tumor Growth And Subsequent Cancer Cell Counter-Adaptations, Arig Ibrahim Hashim

USF Tampa Graduate Theses and Dissertations

Cancer is well-recognized as an evolutionary system, as first proposed by Cairns and Nowell more than 60 years ago. In an evolutionary context, cancers growing in vivo typically consist of heterogeneous subpopulations of cells that interact with each other and with host cells through selection forces operating at many temporal and spatial scales. Moreover, the tumor environment comprises more than just cancer cells; it includes a rich cancer stroma and cancer-driving molecules such as cytokines and metabolites. The tumor’s environment comprises intratumoral heterogeneity that often leads to therapy resistance attributed to the essential roles of many genetic and nongenetic mechanisms. …

Effects Of Selection On Morphological Characteristics In Setaria Sphacelata (Schumach.) Moss, Liana Jank, Kenneth H. Quesenberry, P. Mislevy

IGC Proceedings (1997-2023)

Cattle production in Florida is limited by the lack of available warm-season forages adapted to the cool winters of the region. Setaria (S. sphacelata) has demonstrated green growth during cool conditions in subtropical climates around the world, and has the potential to fill this niche in cattle production in Florida. Four populations were selected in Gainesville and Ona, Florida: two cycles of selection for increased head number, one cycle for increased leaf width and one cycle for grazing tolerance. The objectives of this research were to compare these populations morphologically to determine changes due to selection. Selection for …