Plant Pathology Commons^™

Optimization Of The Pasture Resource In Boundary Environments As A Basis For Regional Nature Management, M. V. Rogova

IGC Proceedings (1977-2023)

In spite of the globalization processes encompassing all spheres of human life and activity, land remains the main resource and provides the feeding source for population and the fodder base for livestock rearing. On the other hand, the activity of local communities can have important global consequences. The study area that includes Lake Baikal’s western shore (East Siberia) and the lake’s largest island exemplifies the traditional type of nature management, namely, grazing management which was originated by an indigenous population within the context of suitable natural climatic conditions. This investigation furnished an opportunity to make an assessment of the status …

Effects Of Landscape Structure On Plants Species Richness In Small Grassland Remnants In Two Different Landscapes, S. A. O. Cousins, O. Eriksson

IGC Proceedings (1977-2023)

There is an increasing interest in using the landscape as the operational scale in many ecological studies. Current species richness in the landscape may be explained by past land use, and habitats may harbour species favoured by an environment that no longer exists. In this study we have included both a landscape scale and a temporal scale. The objective was to explain species pattern and the effect of isolation, habitat size and surrounding land use, and past land use change, on small grassland remnants in rural landscapes.

The Effect Of Alternative Soil Amendments On The Botanical Composition, Basal Cover, Dry Matter Production And Chemical Properties Of Re-Vegetated Mine Land, Wayne F. Truter, N. F. G. Rethman

IGC Proceedings (1977-2023)

Coal mining impacts large grassland areas of the Mpumalanga Province of South Africa. To mitigate such impacts, it is imperative to restore the once productive soils to the best possible condition. The revegetation of mine land presents a particular challenge. Soils being rehabilitated are often acidic and nutrientdeficient, which are major limiting factors in re-vegetation programmes. Conventional methods of liming and inorganic fertilisation have been used to improve the productivity of impacted soils. In the past few years the use of a coal combustion by-product, class F fly ash, and an organic material, such as sewage sludge, have demonstrated the …

Tall Fescue Expressed Sequence Tag And Simple Sequence Repeats: Important Resources For Grass Species, Malay C. Saha, J. C. Zwonitzer, K. Chekhovskiy, M. A. R. Mian

IGC Proceedings (1977-2023)

Expressed sequence tag (EST) databases have been growing exponentially. The simple sequence repeat (SSR) has become one of the most useful molecular marker systems in plant breeding and is widely used in cultivar fingerprinting, genetic diversity assessment, molecular mapping and marker-assisted selection. ESTs are a potential source for SSRs. The EST-SSR markers are of high quality and have versatile applications in molecular breeding (Bughrara et al., 2003; Saha et al., 2004 a, b, c). Here, we present an overview of our efforts to develop SSRs from tall fescue ESTs and their application for the genetic improvement of forage …

Repulsion-Phase Linkage Analysis Of Tetraploid Creeping Bentgrass (Agrostis Stolonifera L.), S. E. Warnke, N. Chakraborty, G. Jung

IGC Proceedings (1977-2023)

Creeping bentgrass is a cool-season grass species primarily used on golf course greens, tees, and fairways because of its tolerance of low mowing heights and recuperative ability. Creeping bentgrass is tetraploid and outcrossing and has been characterized as having bivalent chromosome pairing through cytogenetic analysis (Jones, 1956) and disomic inheritance based on the inheritance of isozyme markers (Warnke et al., 1998). The objective of this experiment was to evaluate the extent of repulsion-phase linkages of single dose AFLP type markers in a creeping bentgrass mapping population and to infer chromosome pairing behaviour based on the ratio of coupling to …

A Core Aflp Map Of Aposporic Tetraploid Paspalum Notatum (Bahiagrass), J. P. A. Ortiz, J. Stein, E. J. Martínez, S. C. Pessino, C. L. Quarin

IGC Proceedings (1977-2023)

Paspalum notatum (Bahiagrass) is a perennial rhizomatous species that reproduces by aposporous apomixis. Tetraploid races (2n=4x=40) are widely distributed from Central to South America and constitute one of the most valuable natural forage grasses for the subtropical areas of Paraguay, southern Brazil and north-eastern Argentina. Apospory in the species is controlled by a single locus, which exhibits a distorted segregation ratio. The objectives of this work were to develop a core genetic linkage map of the species by using AFLP markers and characterize the genomic region related to apospory.

Towards A Genetic Map In Creeping Bentgrass Based On Ssrs, Aflps And Rflps, H. Zhao, S. Bughrara

IGC Proceedings (1977-2023)

Creeping bentgrass (Agrostis palustris) (2n=4x=28) is commonly used in golf course, putting green, tees and fairways. In spite of the importance of the species in turfgrass industry, the genetic study of the creeping bentgrass has received relatively little attention. Genetic mapping, as a new tool, helps traditional turfgrass breeding methods through the construction of linkage, identification of quantitative trait loci linked to traits of interest, and application of marker assisted selection program. Molecular markers such as AFLPs, SSRs and RFLPs have been used extensively for the preparation of linkage maps of a number of crop species. The objective …

Integration Of Perennial Ryegrass (L. Perenne) Genetic Maps Using Gene-Associated Snps, A. C. Vecchies, R. C. Ponting, M. C. Drayton, N. O. I. Cogan, K. F. Smith, G. C. Spangenberg, J. W. Forster

IGC Proceedings (1977-2023)

The reference genetic map of perennial ryegrass was developed by the International Lolium Genome Initiative (ILGI), using the p150/112 one-way pseudo-testcross population. A selection of public domain genetic markers including RFLPs, detected by wheat, barley, oat and rice cDNA probes, and AFLPs were mapped, allowing studies of comparative relationships between perennial ryegrass and other Poaceae species. The map was enhanced through the addition of unique perennial ryegrass genomic DNA-derived SSR (LPSSR) markers, providing the basis of framework genetic mapping in other populations. In addition, a small number of RFLP loci detected by candidate genes involved in herbage quality traits were …

Construction And Comparison Of Genetic Linkage Maps Of Four F1 Populations Of Italian Ryegrass (Lolium Multiflorum Lam.), M. Vandewalle

IGC Proceedings (1977-2023)

The objective of this work was to integrate genetic maps and QTL-positions within 4 two-way pseudo-testcross F1 populations (each 110 genotypes) of Italian ryegrass (Lolium multiflorum) To integrate genetic maps and QTL-positions within the 4 populations and to the ILGI reference map, the maps used for initial QTL-analysis and marker assisted selection for yield and for different quality traits were further evaluated.

Qtls For Morphogenetic Traits In Medicago Truncatula, B. Julier, T. Huguet, J. M. Prosperi, P. Barre, Christian Huyghe, G. Cardinet

IGC Proceedings (1977-2023)

Plant morphogenesis that includes growth, development and flowering date, drives a large number of agronomical important traits in both grain and forage crops. Quantitative trait locus (QTL) mapping is a way to locate zones of the genome that are involved in the variations observed in a segregating population. Co-location of QTLs and candidate genes is an indication of the involvement of the genes in the variation. The objective of this study was to analyse segregation of aerial morphogenetic traits in a mapping population of recombinant inbred lines of the model legume species M. truncatula , to locate QTLs and candidate …

A Comprehensive Analysis Of Gene Expression And Genomic Alterations In A Newly Formed Autotetraploid Of Paspalum Notatum, L. G. Martelotto, J. P. A. Ortiz, F. Espinoza, C. L. Quarin, S. C. Pessino

IGC Proceedings (1977-2023)

The proportion of angiosperms that have experienced one or more episodes of chromosome doubling is estimated to be of the order of 50-70%. This prominence of polyploidy probably implies some adaptive significance. The emergence of novel phenotypes could allow polyploids to enter new niches or enhance their chances of being selected for use in agriculture. Although the causes of novel variation in polyploids are not well understood, they could involve changes in gene expression through dosage-regulation, altered regulatory interactions and rapid genetic/epigenetic changes. The objective of this work was to carry out an extensive transcript profiling and genome analysis of …

Effects Of Sowing Date And Phosphorus Fertiliser Application On Winter Survival Of Lucerne Cv. Aohan In The Northern Semi-Arid Region Of China, Z. L. Wang, Q. Zh. Sun, Y. W. Wang, Zh. Y. Li, Sh. F. Zhao

IGC Proceedings (1977-2023)

In the northern semi-arid region of China, winter survival is always a limiting factor for lucerne production, because low temperatures and a dry climate in winter (Zhou et al., 1993; Ma, 2000; Sun & Gui, 2001; Sun et al., 2003). An experiment was conducted to find an appropriate sowing date and P application rate in order to improve lucerne winter survival.

Characterisation Of Perennial Ryegrass Parental Inbred Lines For Generating Recombinant Inbred Lines For Fine Mapping And Gene Cloning, U. C. M. Anhalt, S. Barth, T. Schwarzacher, J. S. Heslop-Harrison

IGC Proceedings (1977-2023)

Intermated recombinant inbred lines (IRIs) are a powerful tool for fine mapping and cloning of genes. Such population structures have been particularly helpful for cloning of genes in the model genetic plant Arabidopsis thaliana. IRIs or recombinant inbred lines (RILs) would be valuable for perennial ryegrass (Lolium perenne), but its allogamous character means that the construction of RILs is a difficult task. The international Lolium community would benefit from the development of such lines. The aims of the projects are to characterise the parental lines and initial generations at the (1) phenotypic, (2) molecular and (3) molecular …

A High-Density Ssr Linkage Map Of Red Clover And Its Transferability To Other Legumes, S. Isobe, S. Sato, E. Asamizu, I. Klimenko, N. N. Kozlov, K. Okumura, S. Tabata

IGC Proceedings (1977-2023)

A high-density linkage map of red clover was constructed based on SSR and RFLP markers. In order to construct a linkage map with user (breeder) friendly markers; i.e. informative and easy detection, two policies were adopted for marker development. One was that the markers should be derived from cDNA or gene-rich regions, and the other was that the SSR markers should be detected polymorphisms on agarose gels. We also discuss the transferability of the markers on the map to other red clover germplasm and legumes. Such highly transferable markers could be used to screen anchor markers for both on a …

Development Of Est And Aflp Markers Linked To A Gene For Resistance To Ryegrass Blast (Pyricularia Sp.) In Italian Ryegrass (Lolium Multiflorum Lam.), Y. Miura, C. Ding, R. Ozaki, M. Hirata, M. Fujimori, H. Cai, K. Mizuno

IGC Proceedings (1977-2023)

Ryegrass blast, caused by the fungus Pyricularia sp. is one of the most serious diseases of Italian ryegrass (Lolium multiflorum Lam.). However, in Italian ryegrass, except for a new cultivar ‘Sachiaoba’, no resistant cultivars were found in Japan (Mizuno et al., 2003). For these reasons, improving the disease resistance of Italian ryegrass is one of the most important goals in the breeding programs. The aim of this study was to identify genes for resistance to ryegrass blast and to develop EST and AFLP markers linked tightly to the resistance genes.

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 …