Agricultural Science Commons^™

Genetic Mapping In Tetraploid Alfalfa: Results And Prospects, E. C. Brummer, J. G. Robins, B. Alarcón Zúñiga, D. Luth

IGC Proceedings (1977-2023)

Among the difficulties of improving forages is their perennial nature, which necessarily requires long selection cycles to fully evaluate genotypes. Further, traits of particular importance—yield and winter hardiness—are difficult to assess on single plants, necessitating evaluation of progeny, which is both time consuming and expensive. Because of this, yield of many forages, and particularly alfalfa, has not improved substantially over the past 25 years (Riday and Brummer, 2002). Winter hardiness often has a negative correlation with autumn growth, although some evidence suggests this is not always true (Brummer et al., 2000). One way to overcome some of these limitations …

Quantitative Trait Locus Analysis Of Morphogenetic And Developmental Traits In An Ssr And Aflp-Based Genetic Map Of White Clover (Trifolium Repens L.), M. T. Abberton, N. O. I. Cogan, K. F. Smith, G. Kearney, A. H. Marshall, A. Williams, T. P. T. Michaelson-Yeates, C. Bowen, E. S. Jones, A. C. Vecchies, J. W. Forster

IGC Proceedings (1977-2023)

Molecular marker-assisted plant breeding is a key target for the temperate legume pasture crop white clover (Trifolium repens L.). The first genetic linkage map of white clover has been constructed using self-fertile mutants to derive an intercross based fourth and fifth generation inbred parental genotypes (F₂[I.4R x I.5J]). The framework map was constructed using simple sequence repeat (TRSSR) and amplified fragment length polymorphism (AFLP) markers. Eighteen linkage groups (LG) corresponding to the anticipated 16 chromosomes of white clover (2n = 4x = 32), with a total map length of 825 cM were derived from a total of …

A Glucanase Gene Cosegregates With A Qtl For Crown Rust Resistance In L. Perenne, H. Muylle, J. Baert, E. Van Bockstaele, I. Roldán-Ruiz

IGC Proceedings (1977-2023)

An important disease in Lolium spp. is crown rust caused by the fungal pathogen Puccinia coronata. In order to study the genetic background of crown rust resistance in L. perenne, a mapping study was carried out and is discussed below. To identify genomic regions or genes involved in resistance, STS markers are extremely useful. This candidate gene approach was applied in the present study.

Qtl Analysis Of Mineral Content And Grass Tetany Potential In Leymus Wildryes, S. R. Larson, H. F. Mayland

IGC Proceedings (1977-2023)

Grass tetany is a metabolic ailment in ruminants, occurring when animals graze rapidly growing C₃ grasses with a K/(Mg+Ca) ratio (KRAT) greater than 2.2. High KRAT values have been documented in several forage grasses including diploid Russian wildrye (Jefferson et al., 2001). The objective of this experiment was to identify quantitative trait loci (QTLs) controlling KRAT in allotetraploid wildryes.

Crown Rust Resistance Of Italian Ryegrass Cultivar ‘Axis’ To An Isolate From Japan, T. Kiyoshi, M. Hirata, T. Takamizo, H. Sato, Y. Mano, M. Fujimori

IGC Proceedings (1977-2023)

Crown rust (Puccinia coronata) is one the most serious diseases of Italian ryegrass. Crown rust resistance genes in Italian ryegrass have been identified from 'Yamaiku130' and ‘Harukaze’. The aim of this study was to identify novel major resistance genes for gene pyramiding in order to develop cultivars with high levels of durable resistance to crown rust

Locating, And Utilising Festuca Pratensis Genes For Winter Hardiness For The Future Development Of More Persistent High Quality Lolium Cultivars, M. W. Humphreys, D. Gasior, A. Kosmala, O. A. Rognli, Z. Zwierzykowski, M. Rapacz

IGC Proceedings (1977-2023)

Genes for freezing-tolerance and winter hardiness were located in Festuca pratensis by QTL analysis and introgression-mapping. QTL for freezing-tolerance on F. pratensis chromosome 4 were orthologous to rice chromosome 3, and Triticeae chromosome 5. Increased energy dissipation during the autumn through a lower maximum quantum yield of photosystem II (PSII) was correlated with improved winter survival. Freezing tolerance in Lolium was achieved by the transfer and subsequent expression of F. pratensis genes from chromosome 4 that govern the expression of a non-photochemical (NPQ) mechanism for the dissipation of excess light energy under low temperature.

Qtl Analysis Of Vernalisation Requirement And Heading Traits In Festuca Pratensis Huds., Å Ergon, C. Fang, Ø. Jørgensen, T. S. Amalid, O. A. Rognli

IGC Proceedings (1977-2023)

The transition from the vegetative phase to the reproductive phase occurs as a result of environmental and endogenous stimuli. In Festuca pratensis, low temperature and/or short days over a certain period (primary induction) followed by long days (secondary induction) will lead to heading and flowering (Heide, 1988). We present results from QTL mapping of vernalisation requirement and heading traits and mapping of the Vrn-1 ortholog in F. pratensis.

Consistency Of Qtl For Dollar Spot Resistance Between Greenhouse And Field Inoculations, Multiple Locations, And Different Population Sizes In Creeping Bentgrass, N. Chakraborty, J. Bae, J. Curley, S. Warnke, M. Casler, S. Bughrara, G. Jung

IGC Proceedings (1977-2023)

Dollar spot caused by Sclerotinia homoeocarpa F. T. Bennett is the most economically important turf disease in North America. Previous work indicated differences among cultivars in their susceptibility to dollar spot (Bonos et al., 2003). Studies have indicated that dollar spot resistance might be quantitatively inherited (Bonos et al., 2003) but the number, location and effect of genomic regions conferring resistance is still not known. Therefore the objective of this research is to understand the effect of population size, inoculation assays, and field locations on QTL for dollar spot resistance in creeping bentgrass.

Structural And Functional Genomic Research In Model Legume Plants: The National Bioresource Project (Nbrp) In Japan, S. Tsuruta, M. Hashiguchi, Ryo Akashi

IGC Proceedings (1977-2023)

Lotus japonicus is a wild perennial plant with a small genome and a short life cycle. This plant is expected to play a role as the model organism of leguminous plants, which include important crop plants such as soybean (Glycine max). Legume Base, a resource centre for Lotus japonicus and Glycine max, was established in April 2004. The scope of Legume Base is the collection, development and conservation of the genetic resources of L. japonicus and G. max and the distribution of the material for utilization by the research community. DNA resources including genomic DNA clones will …

Detecting Fauna Habitat In Semi-Arid Grasslands Using Satellite Imagery, N. A. Bruce, Ian D. Lunt, M. Abuzar, M. Mitchell

IGC Proceedings (1977-2023)

Managing grasslands for biodiversity conservation is a relatively recent phenomenon and there is uncertainty over the most effective strategy. Past research has found that intermediate levels of disturbance (e.g. burning or grazing) may be required to maintain the natural mosaic of small-scale patterning required for a diverse range of flora and fauna species. For sustainable grassland management, appropriate methods of spatial assessment and temporal monitoring are required, to facilitate understanding of how past and present climate, land management and landscape features influence vegetation structure. Due to the expense and time-consuming nature of conventional ground-based monitoring, satellite remote-sensing techniques offer a …

The Milk Yield By Cinisara Cows In Different Management Systems: 2. Effect Of Season Of Production, M. Alabiso, C. Giosuè, M. L. Alicata, G. Parrino

IGC Proceedings (1977-2023)

Cinisara is a Sicilian autochthonous breed of dairy cow. Qualitative characteristics of milk yield are influenced by composition of pasture and its changes over the seasons (Di Grigoli et al., 2000). The grazing resource is characterized by notable variability, even in adjacent areas, because of different environmental conditions, such as aspect, the nature of soil and altitude. The aim of this research is to study the effect of season of production on qualitative characteristics of Cinisara cow milk in farms located at different altitudes.

A New Perennial Legume To Combat Dryland Salinity In South-Western Australia, L. W. Bell, M. A. Ewing, M. Ryan, S. J. Bennett, G. A. Moore

IGC Proceedings (1977-2023)

Dryland salinity has devastated large tracts of productive land in Australia. This has resulted from the clearing of native perennial vegetation and its replacement with annual crops and pastures. As annual plants are shallow rooted and only use water during their winter-spring growing season, unutilised rainwater leaks into groundwater tables which rise and bring stored salt to the soil surface. The adoption of deep rooted perennial pasture plants that increase the water use can help to manage dryland salinity whilst maintaining productivity. However, new plants are needed as few perennial pasture options currently exist. Preliminary research into the potential of …

Heterogeneous Nutrient Distribution Across Dairy Grazing Systems In Southeastern Australia, C. J. P. Gourley, I. Awty, P. A. Durling, J. Collins, A. Melland, S. R. Aarons

IGC Proceedings (1977-2023)

The Australian dairy industry is largely based on a grazed pasture system, although most cows also consume substantial amounts of imported feed (Fulkerson & Doyle 2001). This trend is expected to increase as the Australian dairy industry continues to intensify. Fertiliser inputs of nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) are still viewed as necessary to maintain adequate pasture and milk production despite the fact that most dairy farms are in net positive balance for all of these nutrients (Reuter 2001). Nutrient losses from dairy farming regions and eutrophication of waterways has gained strong public and political attention …

An Evaluation Of Grazing Value Of Maize And Companion Crops For Wintering Lactating Ewes, E. A. Van Zyl, C. S. Dannhauser

IGC Proceedings (1977-2023)

Northwestern KwaZulu-Natal (KZN), in South Africa, is well known for its sheep production from natural rangeland in summer (October to May). During winter, however, the nutritional value of the rangeland cannot maintain young growing sheep or pregnant and lactating ewes. With this in mind, Lyle (1991) suggested the use of planted pastures for the winter. Crichton et al. (1998) and Esterhuizen & Niemand (1989) suggested the use of maize crop residues for both cattle and sheep during winter, whereas Moore (1997) evaluated grazing (not harvested) maize for this purpose. He found that the crude protein content of the crop was …

Rainfall And Grazing Impacts On The Population Dynamics Of Bothriochloa Ewartiana In Tropical Australia, D. M. Orr, Peter J. O'Reagain

IGC Proceedings (1977-2023)

Bothriochloa ewartiana (desert bluegrass) is a palatable, native perennial (C4) grass of considerable importance to the northern Australian grazing industry. However, little is known of the interaction between grazing pressure and the highly variable rainfall found in this area, on its population dynamics. This paper reports interim results (1998-2004) from a long-term study, in which its population dynamics were examined under 3 grazing strategies.

Herbage Quality Of Dwarf Napier Grass Under A Rotational Cattle Grazing System Two Years After Establishment, Yasuyuki Ishii, A. A. Sunusi, M. M. Mukhtar, Sachiko Idota, Kiichi Fukuyama

IGC Proceedings (1977-2023)

Dwarf Napier grass (Pennisetum purpureum Schumach) of a late-heading type (dwarf-late, DL), introduced by the Dairy Promotion Organization, Thailand, has a high over-wintering ability and is suitable for grazing. The objective of this study was to examine the digestibility and crude protein (CP) concentration of DL Napier grass both before and after rotational grazing in relation to the daily liveweight gain of cattle 2 years after establishment in the lowland area of Kyushu, Japan.

Grazing Suitability Of Various Napier Grass Varieties In Paddocks Of Different Ages, Yasuyuki Ishii, M. M. Mukhtar, Sayan Tudsri, Sachiko Idota, Y. Nakamura, Kiichi Fukuyama

IGC Proceedings (1977-2023)

Previous studies have demonstrated that late-heading type dwarf (DL) Napier grass (Pennisetum purpureum Schumach) introduced to Japan from Thailand by the Dairy Promotion Organization of Thailand was able to overwinter in the lowland areas of southern Kyushu (Mukhtar et al., 2003). The species has a higher proportion of leaf blade than other normal and dwarf varieties. These studies were conducted to assess the suitability of the various Napier grass varieties for grazing (Mukhtar et al., 2004). The objective of this study was to examine the grazing suitability, herbage quality and wintering ability of three Napier grass varieties …

Gene-Associated Single Nucleotide Polymorphism Discovery In White Clover (T. Repens L.), M. C. Drayton, R. C. Ponting, A. C. Vecchies, T. C. Wilkinson, J. George, N. O. I. Cogan, N. R. Bannan, K. F. Smith, G. Spangenberg, J. W. Forster

IGC Proceedings (1977-2023)

Single nucleotide polymorphism (SNP) discovery permits the discovery of molecular marker variation associated with functionally-defined genes. SNP markers have been developed for the temperate pasture legume crop white clover (Trifolium repens) using public and proprietary genic sequences correlated with key agronomic traits of interest.

Qtl Analysis Of Mineral Content In Perennial Ryegrass (Lolium Perenne L.), N. O. I. Cogan, A. C. Vecchies, T. Yamada, K. F. Smith, J. W. Forster

IGC Proceedings (1977-2023)

Variation in mineral content of grasses can be strongly influenced by genetic factors. Grass tetany (hypomagnesemia) of cattle and sheep is due to disturbances in serum magnesium levels. In Southern Australia, resultant levels of mortality in cattle vary between 0.5-1.5% of total stock numbers. Serum magnesium variation may be due to feed deficits, or dietary imbalances that interfere with magnesium metabolism. High levels of potassium appear to exert negative effects on the levels of magnesium in the blood. Italian ryegrass genotypes with high levels of magnesium can alleviate the incidence of grass tetany. The genetic control of mineral content, including …

A Molecular Study Of Alfalfa Megasporogenesis, D. Rosellini, Stefano Capomaccio, F. Veronesi

IGC Proceedings (1977-2023)

Our ability to control plant reproduction impacts on both seed production and plant breeding. A female sterility mutation was previously described (Rosellini et al., 1998; 2003) revealing a female-specific arrest of sporogenesis associated with ectopic, massive callose deposition within the nucellus. The goal of this study is to isolate and characterize genes involved in megasporogenesis and female sterility in alfalfa.

Modelling Grazing Animal Distributional Patterns Using Multi-Criteria Decision Analysis Techniques, M. R. George, N. R. Harris, N. K. Mcdougald, M. Louhaichi, M. D. Johnson, D. E. Johnson, K. R. Smith

IGC Proceedings (1977-2023)

Predicting livestock distribution is crucial to reducing livestock impacts on environmentally critical areas. Attempts to model livestock distribution on rangelands have met with varying levels of success. Most of these models described conditions at specific sites and did not work well when they were applied to other sites. In part, the weakness of these models arises from a lack of connection to the spatial arrangement of the study area and the pattern shown by animal distributions. To model the influence of the factors on livestock distribution we developed the Kinetic Resource and Environmental Spatial Systems (KRESS) Modeller. The KRESS Modeler …

Species Richness, Species Identity And Ecosystem Function In Managed Temperate Grasslands, S. C. Goslee, M. A. Sanderson, K. Soder

IGC Proceedings (1977-2023)

Manipulation of plant species diversity may provide a way to improve the ecosystem functioning of managed systems by increasing productivity and suppressing weedy species. As yet, the functional role of species richness is not well-enough understood to enable practical application. We investigated the effects of differing species richness on community stability and invasion resistance in a grazed temperate grassland.

Preference Of Goats For Cool-Season Annual Clovers In The Southern United States, Thomas H. Terrill, W. F. Whitehead, G. Durham, Carl S. Hoveland, B. P. Singh, S. Gelaye

IGC Proceedings (1977-2023)

In the southern U.S.A., annual clovers provide high-quality winter and spring grazing for beef cattle and sheep. New Zealand data on white clover (Trifolium repens L.) suggests that goats do not prefer this plant as much as sheep (Clark et al., 1982) but little data are available on willingness of goats to consume different clover types in the USA.

Production Per Animal And Use Of Intake Estimatives To Predicted Animal Productivity In Pennisetum Purpureum Cv. Mott And Cynodon Spp Cv. Tifton 85 Pastures, Fernando L. F. De Quadros, A. R. Maixner, Gilberto V. Kozloski, D. P. Montardo, A. Noronha, D. G. Bandinelli, M. Da S. Brum, N. D. Aurélio

IGC Proceedings (1977-2023)

Dairy production is a very important activity in southern Brazil, being an essential source of income to small household farms. Milk production from pastures is an alternative to reduce costs in dairy systems. Some C4 grasses, such as dwarf elephant grass (DEG) and Tifton 85, have presented high animal production per animal and per area. Although studies evaluating milk production from these pastures are rare in south Brazil, in vitro studies have demonstrated that the nutritional value of these forages is higher than production registered in grazing. So, it is possible that, in spite of a high intrinsic nutritional value, …

Ingestive Behaviour Of Steers In Native Pastures In Southern Brazil, C. E. Pinto, Paulo C. De F. Carvalho, A. Frizzo, J. A.S.F. Júnior, T. M. S. Freitas, Carlos Nabinger

IGC Proceedings (1977-2023)

The Campos biome, particularly its native pastures, is the main resource for livestock production in southern Brazil (Boldrini, 1997). It has a huge floristic diversity in which more than 400 grass and 150 legume species are found. These pastures are very heterogeneous with horizontal as well as vertical structure. Hodgson (1985) stressed the importance of sward structure upon diet selection, emphasizing the difficulties animals could have to access all pasture layers in temperate pastures. This experiment investigates how variation in herbage allowance along the growing season influences the ingestive behaviour of steers.

The Efficacy Of Genethresher® Methylation Filtering Technology In The Plant Kingdom, U. Warek, J. A. Bedell, M. A. Budiman, A. N. Nunberg, R. W. Citek, D. Robbins, N. Lakey, P. D. Rabinowicz

IGC Proceedings (1977-2023)

The genomes of many plants are known to be composed of a large fraction of repetitive DNA, while a small portion is dedicated to genes. The bulk of the repetitive DNA constitutes transposable elements and is heavily methylated. GeneThresher technology has been developed to take advantage of these differential methylation patterns by filtering genomic shotgun libraries to exclude methylated sequences (Rabinowicz et al., 1999; Palmer et al., 2003; Martienssen et al., 2004). The result is a gene-enriched genomic shotgun library. Random shotgun sequencing of plant gene space, enabled by GeneThresher technology, is a rapid and cost-effective strategy …

Translational Genomics For Alfalfa Varietal Improvement, G. D. May

IGC Proceedings (1977-2023)

Key points

1. Medicago truncatula is a model legume with available mapping, genome, and RNA, protein and metabolite profiling databases and genetically diverse populations.
2. Genomics resources developed for M. truncatula have application in the study and improvement of alfalfa making it an excellent model for this forage legume.

Species Richness Affects Grassland Yield And Yield Stability Across Seasons, Sites And Years, David J. Barker, Reuben M. Sulc, M. R. Burgess, T. L. Bultemeier

IGC Proceedings (1977-2023)

The benefits of biodiversity (specifically species richness) are proposed to include both greater yield and greater stability of yield in a variable environment (Sanderson et al., 2004). Experimental evidence showing yield benefits is inconsistent (White et al., 2004). There is relatively little experimental data showing the effects of species richness on yield stability. The objective of this study was to measure the yield from mixtures with up to 12 species, and to measure the variability of yield between 2 sites, between spring and summer, and in 2 successive years.

Discovery And Functional Categorisation Of Expressed Sequence Tags From Flowers Of Eragrostis Curvula Genotypes Showing Different Ploidy Levels And Reproductive Modes, V. Echenique, S. Felitti, N. Paniego, L. Martelotto, S. C. Pessino, D. Zanazzi, P. Fernández, M. Díaz, P. Polci, G. C. Spangenberg

IGC Proceedings (1977-2023)

Two novel genotypes of weeping lovegrass (Eragrostis curvula) - a dihaploid strain obtained in vitro from an apomictic cultivar and a tetraploid plant derived from the dihaploid after chromosome duplication – have recently been developed. These materials represent an excellent system for the identification, through transcriptional profiling, of genes involved in diplospory and/or ploidy level gene regulation. The aim of this work was the discovery and functional classification of expressed sequence tags (ESTs) from immature inflorescences of the apomictic E. curvula cultivar Tanganyika (2n=4x=40), a dihaploid sexual strain derived from it (2n=2x=20) and a tetraploid sexual strain …

Protection Of Agrobiodiversity: Model Calculations In Rhineland-Palatia: Costs And Implications For Farmers, H. Bergmann

IGC Proceedings (1977-2023)

Biological conservation and production use the same areas of land in less favoured areas. Grassland in these areas makes an important contribution to the protection of agro-biodiversity. However, under existing market conditions and production needs, the use of low yielding grasslands is not economically efficient. The objective of this study was to analyze the economic consequences of different mowing strategies in a small region in Rhineland-Palatia (Germany) that served the protection of two butterfly species.