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Qtl Analysis And Trait Dissection In Ryegrass (Lolium Spp.), T. Yamada, J. W. Forster

IGC Proceedings (1977-2023)

Key points

1. Molecular marker-based genetic analysis permits the dissection of complex phenotypes through resolution of the locations of pleiotropic and interacting genetic factors.
2. Several QTLs for agronomically important characters such as flowering time, winter hardiness and forage quality have been identified in perennial ryegrass by molecular marker-based map analysis.
3. Some QTLs were putatively orthologous to those for equivalent traits in cereals.
4. The identification of co-location between QTLs and functionally-associated genetic markers is critical for the future implementation of marker-assisted selection programs.

Construction And Exploitation Of A Bacterial Artificial Chromosome (Bac) Library For Lolium Perenne (Perennial Ryegrass), K. Farrar, A. M. Thomas, M. O. Humphreys, I. S. Donnison

IGC Proceedings (1977-2023)

BAC libraries are an important tool in genomics, enabling physical maps, genome sequencing, marker development and map based cloning strategies. A BAC library has therefore been generated for the temperate grass species Lolium perenne (perennial ryegrass) which compliments an existing BAC library of the closely related species, Festuca pratensis also generated by IGER. Moreover the L. perenne BAC library will provide a useful tool for grass comparative genomics to compliment the existing BAC libraries of cereal crops including rice, wheat, barley, Sorghum and maize. In particular it will allow a comparison of micro-synteny between this large genome forage crop species …

Introgression Mapping In The Grasses, I. P. King, J. King, I. P. Armstead, J. A. Harper, L. A. Roberts, H. Thomas, H. J. Ougham, R. N. Jones, A. Thomas, B. J. Moore, L. Huang, I. S. Donnison

IGC Proceedings (1977-2023)

Key points

1. Lolium perenne/Festuca pratensis hybrids and their derivatives provide an ideal system for intergeneric introgression.
2. The Lolium perenne/Festuca pratensis system is being exploited to elucidate genome organisation in the grasses, determination of the genetic control of target traits and the isolation of markers for MAS in breeding programmes.
3. The potential of the system as an aid to contig the Lolium and Festuca genomes and for gene isolation is discussed.

Application Of Molecular Technologies In Forage Plant Breeding, K. F. Smith, J. W. Forster, M. P. Dobrowolski, N. O. I. Cogan, N. R. Bannan, E. Van Zijll De Jong, M Emmerling, G. C. Spangenberg

IGC Proceedings (1977-2023)

Key points

1. A range of molecular breeding technologies have been developed for forage plant species including both transgenic and non-transgenic methodologies.
2. The application of these technologies has the potential to greatly increase the range of genetic variation that is available for incorporation into breeding programs and subsequent delivery to producers in the form of improved germplasm.
3. Further developments in detailing the phenotypic effect of genes and alleles both through research in target species and through inference from results from model species will further refine the delivery of new forage cultivars.

A Computational Pipeline For The Development Of Comparative Anchor Tagged Sequence (Cats) Markers, J. Schauser, J. Fredslund, L. Heegaard Madsen, Niels Sandal, Jens Stougaard

IGC Proceedings (1977-2023)

Key points:

1. Molecular markers that allow the transfer of map information from one species to another are vital in comparative genetics.
2. To identify potential anchor marker sequences more efficiently, we have established a bioinformatic pipeline that combines multi-species EST- and genome- sequence data.
3. Taking advantage of information from a few related species, comparative EST sequence analysis identifies evolutionary conserved sequences in less well-characterised species in the same family.
4. Alignment of evolutionary conserved EST sequences with corresponding genomic sequences defines sets of PCR primer sites flanking introns.
5. Markers identified by this procedure will be readily transferable to other species since they …

Application Of Molecular Markers In Genetic Resources Management Of Perennial Ryegrass, R. Van Treuren

IGC Proceedings (1977-2023)

Key points

1. Molecular markers are effective tools to support traditional approaches in plant genetic resources management.
2. Genetic diversity assessed for perennial ryegrass by AFLP analysis revealed differentiation of populations occurring in traditional Dutch grasslands from commercial varieties, but not from populations occurring in Dutch nature reserves.
3. No specific conservation measures were recommended to maintain the genetic diversity of perennial ryegrass occurring in traditional Dutch grasslands.
4. Pollination rates estimated by microsatellite analysis for a rejuvenated population of a perennial ryegrass genebank accession were very well described by an inverse quadratic function of inter-plant distance between potential mating pairs, while recorded flowering …

Leaves Of High Yielding Perennial Ryegrass Contain Less Aggregated Rubisco Than S23, A. Kingston-Smith, P. W. Wilkins

IGC Proceedings (1977-2023)

Breeding diploid perennial ryegrass for improved dry matter yield under nitrogen-limiting conditions has reduced the nitrogen (N) concentration of the herbage (Wilkins et al., 2003). Reduced N concentration in the ruminant diet is one potential way to reduce losses of N to the environment by reducing the amount of N that animals excrete. The underlying physiological basis of this increased N-use efficiency in ryegrass was investigated.

Variability In Quantity And Composition Of Water Soluble Carbohydrates Among Irish Accessions And European Varieties Of Perennial Ryegrass, S. Mcgrath, S. Barth, A. Frohlich, M. Francioso, S. A. Lamorte, T. R. Hodkinson

IGC Proceedings (1977-2023)

The objective of this study was to identify perennial ryegrass accessions displaying high fructose and glucose contents and an improved ratio between fructose and glucose fractions across different time points throughout the year. Fructose and glucose are the main constituents of the water soluble carbohydrate (WSC) fraction in perennial ryegrass. For animal nutrition the amount of WSC is crucial as it is the primary energy source available to metabolise the intake of plant protein. The ratio between fructose and glucose fractions is important since fructosan chains, which are an excellent energy source for ruminants, are built from fructose. Furthermore the …

Introgression Breeding For Improvement Of Winter Hardiness In Lolium /Festuca Complex Using Androgenenesis, T. Yamada, Y. D. Guo, Y. Mizukami

IGC Proceedings (1977-2023)

Intergeneric hybrids between closely related Lolium and Festuca species are used to broaden the gene pool and provide plant breeders with options to combine complementary traits to develop robust but high quality grass varieties. Androgenesis was found to be an effective procedure for selecting Lolium-Festuca genotypes comprising gene combinations rarely or never recovered by conventional backcross breeding programs. Here we describe the optimisation of androgenesis in Lolium perenne x Festuca pratensis. The male fertility and freezing tolerance of the Festulolium microspore-derived progenies were analysed and these progenies were also analysed by using genomic in situ hybridisation (GISH). The object …

A New Napier Grass Stunting Disease In Kenya Associated With Phytoplasma, A. B. Orodho, S. I. Ajanga, P. Jones, P. O. Mudavadi

IGC Proceedings (1977-2023)

Napier grass (Pennisetum purpureum Schum) is a cultivated elephant grass native to Eastern and Central Africa forming the major livestock feed on East African smallholder dairy farms (Valk, 1990) as it is suitable for cut and carry zero-grazing management systems. Although several plant pathogens have been described historically they were seldom severe. However, in the 1970s there was an outbreak of snow mould fungal disease caused by Beniowskia spheroidea that attacked most varieties of napier grass. A napier grass variety (clone 13) was bred which is resistant to the disease. In the 1990s two major outbreaks of napier grass …

Studies Of Seed Characteristics Of Ecotypes Of Lucerne, Bromus And Agropyron In Response To Fusarium Oxysporum And F. Solani, M. A. Alizadeh

IGC Proceedings (1977-2023)

Vigorous seeds and seedlings are more resistant to pathogens than non-vigorous seeds and seedlings (Kim, 1994). Therefore, it is necessary to assess seed and seedling performance in response to seed borne fungi.

Genetic Analysis Of The Interaction Between The Host Perennial Ryegrass And The Crown Rust Pathogen (Puccinia Coronata F.Sp. Lolii), P. M. Dracatos, J. L. Dumsday, R. S. Olle, N. O. I. Cogan, M. P. Dobrowolski, K. F. Smith, J. W. Forster

IGC Proceedings (1977-2023)

Crown rust (Puccinia coronata f.sp lolii) is the most important fungal pathogen of perennial ryegrass (L.perenne L.). The physiological effects associated with infection include reduction of water soluble carbohydrate (WSC) reserves, causing decreased dry matter yield, digestibility and palatability for herbivores reared for meat, milk and wool production. Phenotypic variability of rust-infection in perennial ryegrass is likely to be due to environmental effects, as well as the interaction of defence and resistance genes in the grass and virulence genes in the pathogen. Classical and molecular genetic marker-based studies have previously detected both qualitative and quantitative resistance, due respectively …

Molecular Characterisation Of Bacterial Wilt Resistance In Lolium Multiflorum Lam., B. Studer, B. Boller, F. Windmer, U. K. Posselt, E. Bauer, R. Kölliker

IGC Proceedings (1977-2023)

Italian ryegrass (Lolium multiflorum Lam.), a forage grass of prime importance throughout the world, is adversely affected by the pathogen Xanthomonas translucens pv graminis. Breeding for resistant cultivars is the only practicable means of disease control. However, the inheritance of bacterial wilt resistance is largely unknown. The aim of our research is to elucidate genetic control of bacterial wilt resistance using molecular technologies such as genetic linkage mapping and the analysis of quantitative trait loci (QTL).

Ear Emergence Of Different Grass Species Under Finnish Growing Conditions, M. Niskanen, O. Niemeläinen, L. Jauhiainen

IGC Proceedings (1977-2023)

Timothy is the most commonly cultivated grass species in Finland. Swards cultivated for silage of hay are of pure timothy or timothy is the dominant species of the mixture. Successful timing of harvesting of the primary growth is very critical in Northern latitudes where the stand develops very rapidly at daylengths of above 18 hours with a daily mean temperature close to 20 °C. The primary growth has to be harvested within a very short period to obtain a yield of high and uniform quality. Short harvesting periods require high capacity harvest machinery which lead to high costs. If it …

The Effect Of Harvest Management On Forage Production And Self-Reseeding Potential Of Italian Ryegrass (Lolium Multiflorum L.), P. W. Bartholomew, R. D. Williams

IGC Proceedings (1977-2023)

Italian ryegrass (Lolium multiflorum L.) (IRG) can be managed to produce a seed output sufficient for effective re-establishment, without compromising forage yield, it may provide an alternative to perennial cool-season grasses in the Southern Great Plains of the U.S.A. The reduction in cost of replanting and avoidance of cultivation offered by a self-seeding crop may be particularly useful in low-input production systems. We examined the effect of dates of initial harvest in spring and of partial harvests on forage yield, seed output and re-establishment of Italian ryegrass.

The Influence Of Fertiliser Application To Strip-Sown Grasslands On Herbage Production And Quality, A. Kohoutek, P. Komárek, V. Odstrčilová, P. Nerušil

IGC Proceedings (1977-2023)

To increase the productivity of dairy cattle in the Czech Republic requires an improvement in herbage quality and an increase in the net energy of herbage. The decrease in cattle numbers by 50 % and the expansion of the grassland area both result in a surplus of feedstuffs of low quality. Introduction of strip-seeding of legumes and grasses into grasslands in interaction with fertilisation provides a possible solution to this problem.

Constraints On Dairy Cattle Production From Locally Available Forages In Bangladesh, M. A. S. Khan

IGC Proceedings (1977-2023)

The productivity of milk producing animals in Bangladesh is low because of low individual yield and poor fertility. The reasons for the low productivity are complex but, in order of priority, appear to be (a) the imbalanced nature of the nutrients that arise from the digestion of the forage resources, (b) the incidence of disease/parasitism, and (c) the often harsh climatic circumstances. Thus, the purpose of this study was to find out the practical constraints on dairy cattle production from locally available forages under small holding village conditions of Bangladesh.

Pasture Management In Deer Farms In Mauritius, P. Grimaud, P. Thomas, J. Sauzier

IGC Proceedings (1977-2023)

Rusa deer (Cervus timorensis russa) were introduced into Mauritius in 1639, and with a population of 65,000 deer now provide the first source of red meat in the island. From June to September, the hunting period, extensive ranches ensure the venison market, while intensive farms provide it for the rest of the year. A pasture survey was carried out over 3 years to advise deer farmers on their sward management.

Strategies For Achieving Agriculture Carbon Peak And Carbon Neutrality In China Based On View Of Biogeochemical Cycle, Shiqi Yang, Xin Yan

Bulletin of Chinese Academy of Sciences (Chinese Version)

Biogeochemical cycle is the basic theory of matter (elements) flow among atmosphere, hydrosphere, biosphere and lithosphere, which provides important guidance to achieving the national goal of agriculture carbon peak (ACP) and agriculture carbon neutrality (ACN). As a basic industry, agriculture has large-scale temporal and spatial influence on the greenhouse effect, hence great importance should be attached to ACP and ACN in order to assist the overall strategy of achieving national carbon peak and neutrality. Based on the view of biogeochemical cycle and connotations of ACP and ACN, this article analyzes the paths to achieve ACP and ACN, and discusses the …

Port-Of-Entry Simulation Model For Potential Wait Time Reduction And Air Quality Improvement: A Case Study At The Gateway International Bridge In Brownsville, Texas, Usa, Benjamin Stewart, Hiram Moya, Amit U. Raysoni, Esmeralda Mendez, Matthew Vechione

School of Earth, Environmental, & Marine Sciences Faculty Publications

The mathematical study known as queueing theory has recently become a major point of interest for many government agencies and private companies for increasing efficiency. One such application is vehicle queueing at an international port-of-entry (POE). When queueing, fumes from idling vehicles negatively affect the overall health and well-being of the community, especially the U.S. Customs and Border Protection (CBP) agents that work at the POEs. As such, there is a need to analyze and optimize the border crossing queuing operations to minimize wait times and number of vehicles in the queue and, thus, reduce the vehicle emissions. For this …

Land Use/Land Cover Uncertainty Analysis Using Hydrological Modeling In The Northern Watershed Of Lake Okeechobee, Andres Lora Santos

USF Tampa Graduate Theses and Dissertations

Over the past 150 years, Florida has undergone a major land-form transformation, transitioning from a natural to a primarily built environment. The state's population has grown exponentially, from less than 50,000 residents in the 1850s to approximately 22 million residents today. This population growth has led to significant changes in land use, including urbanization, mining, and agriculture. This trend is expected to continue, with projections indicating an increase in urbanization across the state. 2070 land use/land cover projections were used as input for the Watershed Assessment Model (WAM) to analyze the potential impact of these changes on flow, total nitrogen …

A Multiscale Linkage Between Riverscape And Fish Community Coevolution, Loren W. Stearman

Dissertations

Sediment dynamics are foundational to stream and watershed morphology. Yet aquatic ecologists have relied on an oversimplified model of sediment dynamics characterizing sediments as agents of stream bed burial, and which fails to describe many types of aquatic habitat evolution. In this dissertation I employ both fluvial geomorphic and ecological frameworks to gain a deeper understanding of how sediment dynamics shape stream morphology and fish community evolution at multiple scales. Using a paired historic and contemporary approach, I analyzed geomorphic evolution and fish community change in the Bayou Pierre, Mississippi, from the 1980s to recent. Patterns of erosion due to …

A Review Of Literature On The Usage Of Low-Cost Sensors To Measure Particulate Matter, Amit U. Raysoni, Sai Deepak Pinakana, Esmeralda Mendez, Dawid K. Wladyka, Katarzyna Sepielak, Owen Temby

School of Earth, Environmental, & Marine Sciences Faculty Publications

With advances in technological sciences, individuals can utilize low-cost air monitoring sensors to record air quality at homes, schools, and businesses. Air quality data collected from LCSs are publicly accessible, informing the community of the air quality around them. It is important to measure local and regional particulate matter (PM) concentrations to keep the public involved, especially those with specific health concerns, such as asthma, wheezing, and seasonal allergies. The number of studies involving the use of LCSs to evaluate PM levels is increasing with more manufacturers producing ‘easy to use’ LCSs targeting the public. The goal of this review …

New Surficial Geologic Mapping In Kentucky (2021-2022), Matthew Massey, Antonia Bottoms, Max Hammond Iii, Ann Hislop, Meredith Swallom, Michele M. Mchugh

Research Data--KGS

New surficial geologic mapping was performed in nine new 7.5-minute quadrangles in Hardin, Meade, Breckinridge, Grayson, Hart, and Larue Counties, Kentucky.

Quadrangles include Big Clifty, Big Spring (Hardin county only), Custer (Hardin County only), Flaherty, Madrid (Hardin county only), Millerstown, Summit, Tonieville (Hardin county only), and Upton.

Mapping data for each of the nine quadrangles is captured in a ZIP file that contains an ESRI geodatabase and associated FGDC-compliant metadata files (.xml).

The geodatabase is a relational geodatabase of spatial and non-spatial data that conforms to "GeMS (Geologic Map Schema)--a standard format for digital publication of geologic maps", available at …

Tectonic Evolution Of The Northern Margin Of North America, Karol Faehnrich

Dartmouth College Ph.D Dissertations

The northern margin of North America records a protracted history of Neoproterozoic–early Paleozoic rifting and passive margin development, followed by the middle Paleozoic accretion of continental fragments. Contrasting tectonic models have been proposed for the history of continent separation, the role of strike-slip displacement during terrane accretion, and the Mesozoic opening of the Arctic Ocean. Here, I explore several of these models by investigating Neoproterozoic–early Paleozoic sedimentary and volcanic rocks across the northern margin of North American, as well as the main faulted boundaries between displaced terranes and autochthonous rocks of North America. First, I present a new tectonic model …

Discriminating Stay-Green Grasses Using Hyperspectral Imaging And Chemometrics, J. Taylor, B. Moore, J. J. Rowland, H. Thomas, H. J. Ougham

IGC Proceedings (1977-2023)

Screening of plant collections for traits can be expensive, in terms of the number of plants to be screened, the duration of the plant lifecycle and the required observations. This study describes the application of a non-invasive method, hyperspectral imaging, combined with multivariate analysis, to distinguish between homozygous wild-type (YY) Lolium multiflorum and Lolium multiflorum F2 back cross plants heterozygous for y, a recessive Festuca pratensis stay-green gene (Thomas et al., 1997).

Non-Destructive Assessment Of Quality And Yield For Grass-Breeding, A. G. T. Schut, M. J. J. Pustjens, P. W. Wilkins, J. Meuleman, P. Reyns, A. Lovatt, G. W. A. M. Van Der Heijden

IGC Proceedings (1977-2023)

Selection of cultivars has, until now, been based mainly on dry matter (DM) yields because of the high costs of sampling and chemical analysis. Imaging spectroscopy could reduce costs by limiting sampling and harvesting of individual plots to reference samples (Schut et al., accepted). In this study, the prediction accuracy of DM yields and chemical composition with imaging spectroscopy is evaluated for cultivar selection purposes.

Root Senescence In Red Clover (Trifolium Pratense L.), K. J. Webb, E. Tuck, S. Heywood

IGC Proceedings (1977-2023)

Legume root systems form a mosaic of living, ageing and dead roots and nodules. The balance between these stages alters during plant development. Stressful events (drought, temperature change, reduced carbon supply, etc.) disturb the balance (Butler et al., 1959). Effects of root and nodule death on soil structure, composition and leaching and on plant persistency are understood poorly. Plants with differing senescence patterns are useful tools to study these effects. Molecular studies of root senescence need detailed knowledge of the process and timing of root senescence and death. Biochemical and histochemical markers of senescence were used to generate preliminary …

Development Of Simple Sequence Repeat (Ssr) Markers And Their Use To Assess Genetic Diversity In Apomictic Guineagrass (Panicum Maximum Jacq.), M. Ebina, Kaori Kouki, S. Tsuruta, M. Takahara, M. Kobayashi, T. Yamamoto, K. Nakajima, H. Nakagawa

IGC Proceedings (1977-2023)

Guineagrass is an important and widely grown tropical forage grass. Despite its importance and increasing popularity, only little is known about its genetic diversity (Ebina et al., 2001). Such information is useful for the selection of diverse parents in breeding programmes. Moreover, no simple sequence repeat (SSR) markers have been reported in any apomixis species. In this study SSR markers were developed and used to investigate genetic diversity in germplasm of apomictic guineagrass.

Construction Of Microsatellite-Enriched Libraries For Tropical Forage Species And Characterization Of The Repetitive Sequences Found In Brachiaria Brizantha, Letícia Jungmann, C. B. Do Valle, P. R. Laborda, Rosangela M. S. Resende, Liana Jank, A. P. De Souza

IGC Proceedings (1977-2023)

The Brazilian cattle herd comprises 185 million animals fed with about 177 million hectares of native and cultivated pastures (IBGE, 2002). Of the grass species used for forage in Brazil, the African genus Brachiaria is the most widely planted, followed by Panicum, which also has an African origin. Legumes of the Stylosanthes genus, native to the South America, have emerged in the last few years as potential forage species for use with the grasses. These forage species have been bred at Embrapa Beef Cattle and the breeding programs have shown the need for more genetic information including the use …