Effect Of Management On Leaf Growth And Senescence Of Three Contrasting Grass Species,
2024
Massey University
Effect Of Management On Leaf Growth And Senescence Of Three Contrasting Grass Species, B M. Butler, J Hodgson
IGC Proceedings (1977-2023)
The innuence of continuous grazing management on leaf extension, leaf senescence and tiller density of 3 grass species with contrasting tillering rates, tiller size and growth habit was examined. Perennial ryegrass (Lolium perenne L. cv. Grasslands Nui), tall fescue (Festuca arundinacea Schreb, cv. Grasslands Roa) and Yorkshire fog (Holc,,s la11allls L. cv. Massey Bnsyn) were maintained in as near a steady state as possible at sward heights of 3-10 cm. The balance between leaf extension and senescence, and tiller density resulted in net extension per unit area being generally greatest at sward heights of- 5.5 cm in Yorkshire fog and …
Whole-Stand Carbon Gains And Nitrogen Distribution In Herbaceous Stands,
2024
Utrecht University
Whole-Stand Carbon Gains And Nitrogen Distribution In Herbaceous Stands, M.J A. Werger, T Hirose
IGC Proceedings (1977-2023)
We studied canopy structure and leaf nitrogen distribution in open and dense stands of tall dicot and monocot herbs and compared the results with simulated canopy performance under uniform and optimised leaf nitrogen distributions. Dense stands showed leaf nitrogen distributions that greatly differed from those of uniform distribution but did not completely match optimum distribution. In dense stands this led to strongly enhanced potential whole canopy carbon gains, while in open stands the leaf nitrogen distribution was not very important in this respect. Dense stands of monocots kept more leaf nitrogen in the lower parts of their canopies than is …
Advances In Genetic Transformation Of Plants,
2024
Purdue University
Advances In Genetic Transformation Of Plants, Thomas K. Hodges, Keerti S. Rathore, Jianying Peng
IGC Proceedings (1977-2023)
Many plant species, including both dicots and monocots, can now be genetically engineered with individual genes isolated from any source. Methods for delivery of foreign DNA into plant cells or protoplasts utilise Agrobacterium tumefaciens (and A. gazogenes), microinjection, polyethylene glycol, electroporation and particle guns. Advantages and disadvantages of each system are discussed. At present, all systems involve i11 vitra cell or tissue culture lo some extent, and this is the most difficult and variable aspect of plant genetic engineering. In addition, all systems suffer from random insertions of the foreign DNA into the plant genome. This requires Southern blot screening …
Applications Of Random Amplified Polymorphic Dna (Rapd) Markers In Plant Biology,
2024
New Zealand Institute for Crop and Food Research
Applications Of Random Amplified Polymorphic Dna (Rapd) Markers In Plant Biology, Gail M. Timmerman, John A. Mccalum
IGC Proceedings (1977-2023)
RAPDs are a new class of molecular marker based on PCR amplification of genomic DNA using random sequence primers. Their value for studying plant genomes has been clearly demonstrated in the short lime they have been in use. Uses of RAPD markers include genome mapping, lagging of genes, studying genetic diversity, identifying cultivars and analysing parentage. RAPDs should prove to be as applicable to the study of animal genomes ns they have for plant genomes, It is important that researchers using or planning to use this type of molecular marker be aware of two possible drawbacks of RAPDs. Since RAPDs …
A Strategy For Cloning Apomixis-Associated Cdna Markers From Buffelgrass,
2024
USDA, Agricultural Research Service
A Strategy For Cloning Apomixis-Associated Cdna Markers From Buffelgrass, D L. Gustine, R T. Sherwood, D A. Hulce
IGC Proceedings (1977-2023)
A strategy to select apomixis-associated cDNA sequences was partially tested in buffelgrass (Pennisetum ciliare (L.) Link, = Cenclrrns ciliaris L.). The dominant A gene allele which confers apomixis would likely be expressed as mRNA only in reproductive tissue undergoing megasporogenesis. Sexual lines lack the apomixis allele. Poly A+ mRNA was isolated from meiotic florets of obligately apomictic line Higgins and sexual line B-11-7 and cloned into lwnbda gl23A. cDNA sequences associated with the npomictic phenotype were enriched by subtracting sequences common lo both plants as follows. Insert DNA sequences of sexual and apomictic cDNAs were released with Notl and …
Genetic Transformation Of Dactylis Glomerata By Microprojectile Bombardment,
2024
University of Tennessee, Knoxville
Genetic Transformation Of Dactylis Glomerata By Microprojectile Bombardment, B V. Conger, D D. Songstand, J K. Mcdaniel, J Bond
IGC Proceedings (1977-2023)
Dactylis glomerata L., cv, Embryogen-P, has been previously genetically transformed by direct uptake of DNA by suspension culture-derived protoplasts. The objective of the present experiments was 10 use this genotype to obtain transformation by microprojec1ile bombardment. Bmbryogenic suspension cultures and plated basal leaf segments were bombarded with DNA coated tungsten particles propelled by two different helium pressure discharge apparatuses. The DNA plasmids contained genes for chlorosulfuron resistance, hygromycin resistance and !i-glucuronidase (GUS). Transient expiession for GUS was obtained on both suspension cultures and leaf segments. A stable event for GUS and 16 plants which rooted well on 2.5 mg/I chlorosulfuron …
Somatic Embryogensis And Plant Regeneration From Immature Inflorescences Of Hyparrhenia Hirta (L.) Stapf,
2024
Cukurova University
Somatic Embryogensis And Plant Regeneration From Immature Inflorescences Of Hyparrhenia Hirta (L.) Stapf, R Hatipoglu, A Gland, C U. Hesemann, T Tukel
IGC Proceedings (1977-2023)
The study was conducted to determine an efficient system for in vitro culture and Hyparrhenia hirta, The effects of 2 different auxins (2,4-D and dicamba) at 3 concentrations (4.5 µM, 22,6 µM and 45,2 µM) and 2 ecotypes with different chromosome numbers (2n= 36 and 2n • 54) on callus induction and plantlet regeneration from immature inflorescences of Hyparrhenia hirta were investigated. Inflorescence segments of 5 mm length from greenhouse-grown plants were cultured on a modified Linsmaier and Skoog medium supplemented with 30 g/1 agar, Large differences In frequency of callus induction and callus weight were observed among lhe different …
Somatic Embryogensis And Plant Regeneration From Long-Term Suspension Culture Of Digitaria Decumbens,
2024
Livestock Research Institute
Somatic Embryogensis And Plant Regeneration From Long-Term Suspension Culture Of Digitaria Decumbens, Yu-Kuei Cheng
IGC Proceedings (1977-2023)
The optimum condition for embryogenic callus formation and plant regeneration from immature inflorescences of Digltarla decumbens was MS medium supplemented with O,S mg/I 2,4-D, 2.0 mg/) kinetin and 0,591, NaCl. For long-term subcultures, pieces of embryogenic callus were cultured on MS liquid medium supplemented with 1-2 mg/1 2,4-D, 0.591, NaCl, 5% coconut milk, SOO mg/I casein hydrolase and O.S mg/I 6-benzylaminopurlne, and were subcultured every 4-S days. Bmbryogenic suspension cultures were maintained for more than 1 year. More than 5000 plants may be produced from an explant within 6 months. Bmbryoids from suspension cultures showed a bipolar organisation.
Transformation Of White Clover With A Gene Encoding A White Clover Mosaic Virus Coat Protein,
2024
AgResearch, NZ
Transformation Of White Clover With A Gene Encoding A White Clover Mosaic Virus Coat Protein, Brigitta Dudas, R L.S Forster, C J. Van Dolleweerd, D.W R. White
IGC Proceedings (1977-2023)
Genes encoding the white clover mosaic virus (WClMV) coat protein . have been introduced into white clover (Trifolimn repens L.) using Agrobacterium tumefaciens mediated T-DNA transfer. Integration of the coat protein gene in regenerated callus has been confirmed hy Southern blotting of polymerase chain reaction (PCR) amplification products generated using specific oligonucleotide primers. A polyclonal antibody, raised against purified WCIMV coal protein, recognised a polypeptide of c. 25 kDa after SOS-PAGE and Western blotting. The recogilised polypeptide co-migrates with the purified coat protein. Using ELISA, levels of coat protein accumulation in transgenic callus have been determined. The scope for …
Embryo Rescue And Somatic Hybridisation For The Production Of Interspecific Hybrids In The Genus Medicago,
2024
Instituto di Ricerche sul Miglioramento Genetico delle Plante Foraggere del CNR
Embryo Rescue And Somatic Hybridisation For The Production Of Interspecific Hybrids In The Genus Medicago, S Arcioni, F Damiani, M Piccirilli, F Pupilli
IGC Proceedings (1977-2023)
T• broaden the germplasm sources available for the genetic improvement of alfalfa, new interspecific hybrids between Medlcago saliva L. and other Medicago species (M. coemlea, M. arborea and M. rugosa) hove been obtained. To • overcome lncompalibility barriers existing between alfalfa and the wild species, ovule-embryo culture and somatic hybridisation were used. Viable plants were obt11incd through the utilisation of both techniques Md their hybrid nature was demonstrated by analysis of morphological traits, by cylological investigations and by electrophorelic profiles of esterascs and peroxidases. Hybrids were fertile and In the fulure their backcross to alfalfa should allow the useful tr11i,s …
Use Of Molecular Markers In Alfalfa For Construction Of A Genetic Map And Studying Genetic Rearrangements In Non-Sexually Derived Hybrids,
2024
Instituto di Ricerche sul Miglioramento Genetico delle Plante Foraggere del CNR
Use Of Molecular Markers In Alfalfa For Construction Of A Genetic Map And Studying Genetic Rearrangements In Non-Sexually Derived Hybrids, F Damiani, F Pupilli, M Piccirilli, S Arcioni
IGC Proceedings (1977-2023)
Two genomic libraries have been constructed from Medicago saliva DNA reslfictcd with both Pstl and EcoRT. The libraries have been screened and compared for the presence of highly repeated DNA sequences. Restriction fragment length polymorphism among 3 varieties of M. saliva (Rangelander, Adriana, CADL) and 3 species of the genus Medicago (M. coerulea, M. falcata, M. arborea) has been investigated using a large number of probe-enzyme combinations .. Four-and 6-base cutter restriction enzymes have been used. DNA electrophoresis has been performed with· 2 substrates (agarose and polyacrylamide) in order to detect polymorphism at a higher range of fragment lengths. About …
Use Of Allozyme Genetic Markers To Follow The Establishment Of White Clover Oversown Into Hill Country,
2024
University of Walkato
Use Of Allozyme Genetic Markers To Follow The Establishment Of White Clover Oversown Into Hill Country, K D. Adam, M E. Wedderburn, L A. Greaves
IGC Proceedings (1977-2023)
Allozyme marker loci Gpi-3,4 and Pgm-3,4 were used to monitor establishment of plants of the white clover (Trifolium repens L., cv. Grasslands Huia) oversown into 3 steep, north-facing hill country pastures. Comparisons of genotype frequencies in samples of the unimproved (resident) populations, the oversown populations 18 months after oversowing and Huia, provided information about changes in the genetic composition of the white clover populations after oversowing. In each case, oversowing brought about significant changes in allele frequencies but the estimated proportions of plants of cuhivar Huia were variable at 24.2%, 92.4% and 100%, indicating that establishment rates can vary not …
Tissue Culture Of Sainfoin,
2024
Hokkaido University
Tissue Culture Of Sainfoin, Nakashima Hiroshi, Yang Zhuomeng
IGC Proceedings (1977-2023)
The effecls of 1-napthaleneacetic acid (NAA) and 6-benzylamino purine (BAP) on callus induction, callus proliferation and plant regeneration were examined ip sainfojn (011ob1ycl1is viciifo/ia Scop.) from differen! ex plant. Then the effects of indole-3-butyric acid (IBA) on root formation from differentiated shoot from calli were examined. The combinations of 1-10 µM ofNAA an4 BAP were better for sainfoin culture. For callus induction, there was no significant difference among 3 explants, but Chere were interactions between explant and media. For plant regeneration, hypocotyl and root are ��ter explants than cotyledon. The effects of NAA and BAP showed less effective on callus …
Use Of Allozyme Genetic Markers To Follow The Establishment Of White Clover Oversown Into Hill Country Pastures,
2024
University of Walkato
Use Of Allozyme Genetic Markers To Follow The Establishment Of White Clover Oversown Into Hill Country Pastures, K D. Adam, M E. Wedderburn, L A. Greaves
IGC Proceedings (1977-2023)
Allozyme marker loci Gpi-3,4 and Pgm-3,4 were used to monitor establishment of plants of the white clover (Trifolum repens L., cv. Grasslands Huia) oversown into 3 steep, north-facing hill country pastures. Comparisons of genotype frequencies in samples of the unimproved (resident) populations, the oversown populations 18 months after oversowing and Huia, provided information about changes in the genetic composition of the white clover populations after oversowing. In each case, oversowing brought about significant changes in allele frequencies but the estimated proportions of plants of cuhivar Huia were variable at 24.2%, 92.4% and 100%, indicating that establishment rates can vary …
Application Of The Somaclone Method In Fertility Restoration Of The Partially Sterile Hybrid Of Agropyron Repens X Bromus Inermis: Callus Initiation And Plant Regeneration,
2024
Godollo University of Agricultural Sciences
Application Of The Somaclone Method In Fertility Restoration Of The Partially Sterile Hybrid Of Agropyron Repens X Bromus Inermis: Callus Initiation And Plant Regeneration, L E. Heszky, J Janovsky, G Gyulai, E Kiss, L T. Hangyel
IGC Proceedings (1977-2023)
. Callus initiation and plant regeneration from the new intergeneric hybrid of Agropyron repens L., Beauv, x Bromus inermis.1 Leyss. cv. Nanus (Agromus) was carried out. For callus initiation, the inflorescence primordia were incubated on an optimised nutritive medium designated medium-F, supplemented with 2,4-dichlorophenoxyacetic acid (0.5 mg/ I). Within 21 days of plating, embryogenic callus with globular structures were developed, From the 21st day of culture, one-step plant regeneration occurred from callus without subculture. Non-regenerative calli were subcultured to medium-F supplemented with different cytokinins. The cytological analysis of the calli showed wide genetic:il variability in chromosome number with …
Dairying Farming In New Zealand,
2024
RDS
Dairying Farming In New Zealand, Bryan Guy
IGC Proceedings (1977-2023)
Dairy farming in New Zealand is primarily an export industry based almost entirely on the use of perennial ryegrass and while clover. A low cost dairy farming system has been developed and it is this system which enables the New Zealand dairy farmer to survive on returns from the international marketplace. Milk marketing in New Zealand is controlled by a single producer organisation, the New Zealand Dairy Board, which also provides breeding services lo some 14 700 dairy farmers. The industry aims to maximise the net income of dairy farmers. Emphasis is on efficient production and is often measured on …
Sheep And Beef Farming On The West Coast Of The North Island Of New Zealand,
2024
Te Anga, NZ
Sheep And Beef Farming On The West Coast Of The North Island Of New Zealand, R A. Neeley, T G. Parminter
IGC Proceedings (1977-2023)
Over 40% of New Zealand's occupied land area is devoted to hill country farming. The forms are typically owned, managed and ·worked by a single family with some help from seasonal labour. The properly owned by L.D. and R.A. Neeley is a typical example of the type of hill country farms found on the west coast of the North Island. It has an effective area of 520 ha and carries 5000 stock units, 30% of which are cattle. The sheep policy is to finish 60-100% of lambs produced from an improved Romney breed flock (with a 90-100% lambing rate). Friesian …
Policy Developments And Trade Prospects For Grassland-Based Products,
2024
ABARE
Policy Developments And Trade Prospects For Grassland-Based Products, Graeme H. Tie, Jayantha P. Kottege, Brian S. Fisher
IGC Proceedings (1977-2023)
The economic outlook for grassland-based products over the next decade will be influenced by a range of factors. Important among these will be the outcome of the agricultural negotiations in the Uruguay Round of the General Agreement on Tariffs and Trade. Failure to achieve satisfactory agricultural reform in the Uruguay Round could result in an acceleration in the trend toward the formation of regional trading arrangements. This could, in turn, lead to increased fragmentation of the international trading system. Such fragmentation reduces the global economic gains available from trade which stem from specialisation and the associated exercise of comparative advantage. …
European Grassland Farming: Future Prospects,
2024
The University of Newcastle
European Grassland Farming: Future Prospects, David R. Harvey, Caroline Saunders
IGC Proceedings (1977-2023)
The paper reviews recent policy reforms and current pressures in Europe, including the CAP reforms, GATT considerations, the potential for European and CIS integration, and the environmental pressures on policy. The possible consequences of these reforms are then considered, illustrated by estimates of European grassland product market conditions in the event of multilateral free trade in form products. Finally, the implications of these trends for farming practices are considered, with special reference to the UK and European Community. In spite of rather glacial progress towards trade liberalisation, Che conclusions are: i) that future· strategic planning at both national and farm …
A Traditional Exporter's Perspective Of Trade Reforms,
2024
New Zealand Dairy Board
A Traditional Exporter's Perspective Of Trade Reforms, N R. Mitchell
IGC Proceedings (1977-2023)
The agriculture and trade policies which governments commonly have pursued over the last three decades, particularly governments in the large developed countries, have had a major impact on world patterns of production and trade in livestock and livestock products. This has been especially so for milk and dairy products where government involvement in markets has been most pervasive. One effect has been that the comparative advantages derived from the production of livestock products based on pasture feeding of animals \lave been suppressed or overridden. Reform of the international trading system for agricultural products now being developed in the GATT, and …
