Using Lindenmayer systems to model morphogenesis in a tropical pasture legume Stylosanthes scabra

1999 ◽  
Vol 77 (3) ◽  
pp. 394-403 ◽  
Author(s):  
Peter A Wilson ◽  
James S Hanan ◽  
Peter M Room ◽  
Sukumar Chakraborty ◽  
David Doley
Keyword(s):  
Morphological Data ◽  
Growth Data ◽  
Lindenmayer Systems ◽  
Virtual Plant ◽  
Total Leaf ◽  
Systems Modelling ◽  
Plant Form ◽  
Pasture Plant ◽  
Stylosanthes Scabra ◽  
Pasture Legume

This paper summarizes the processes involved in designing a mathematical model of a growing pasture plant, Stylosanthes scabra Vog. cv. Fitzroy. The model is based on the mathematical formalism of Lindenmayer systems and yields realistic computer-generated images of progressive plant geometry through time. The processes involved in attaining growth data, retrieving useful growth rules, and constructing a "virtual plant" model are outlined. Progressive output morphological data proved useful for predicting total leaf area and allowed for easier quantification of plant canopy size in terms of biomass and total leaf area.Key words: Lindenmayer systems, modelling, Stylosanthes, morphogenesis, plant form.

Using Lindenmayer systems to model morphogenesis in a tropical pasture legume Stylosanthes scabra

1999 ◽  
Vol 77 (3) ◽  
pp. 394-403 ◽  
Author(s):  
Peter A. Wilson ◽  
James S. Hanan ◽  
Peter M. Room ◽  
Sukumar Chakraborty ◽  
David Doley
Keyword(s):  
Tropical Pasture ◽  
Lindenmayer Systems ◽  
Stylosanthes Scabra ◽  
Pasture Legume

scholarly journals Harvesting subterranean clover seed – current practices, technology and issues

2021 ◽  
Vol 72 (3) ◽  
pp. 223
Author(s):  
Wesley M. Moss ◽  
Andrew L. Guzzomi ◽  
Kevin J. Foster ◽  
Megan H. Ryan ◽  
Phillip G. H. Nichols
Keyword(s):  
Soil Erosion ◽  
Case Studies ◽  
Seed Production ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Cause ◽  
Pasture Plant ◽  
Clover Seed ◽  
Production Industry ◽  
Pasture Legume

Subterranean clover (Trifolium subterraneum L.) is Australia’s most widely sown annual pasture legume. Its widespread use as a pasture plant requires a well-functioning seed production industry, and Australia is the only significant producer of subterranean clover seed globally. However, the sustainability of this industry is under threat due to its reliance on ageing harvest equipment and the resultant environmental impacts. In order to evaluate seed harvesting practices, technology, and issues, we report on case studies, workshops, and a survey of seed producers across southern Australia. The Horwood Bagshaw Clover Harvester, designed in the 1950s, remains the most popular subterranean clover seed harvester. We discuss its use and modifications, and document several contemporary issues facing the seed production industry. Issues are primarily soil erosion and degradation; the expensive, slow and labour-intensive harvest process; and poor reliability and maintainability of harvesters that are now at least 30 years old. We conclude the root cause of these issues is the suction harvest technology utilised by the Horwood Bagshaw Clover Harvester. Analysis of the current harvest system is provided to support the development of new approaches to harvest subterranean clover seeds.

Expression of quantitative resistance to Colletotrichum gloeosporioides in Stylosanthes scabra at different inoculum concentrations and day-night temperatures

1990 ◽  
Vol 41 (1) ◽  
pp. 89 ◽  
Author(s):  
S Chakraborty
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Quantitative Resistance ◽  
Controlled Environment ◽  
Post Inoculation ◽  
Inoculum Concentration ◽  
Coefficient Of Concordance ◽  
Uninoculated Control ◽  
Number Of Leaves ◽  
Stylosanthes Scabra ◽  
Pasture Legume

Expression of quantitative resistance to anthracnose was studied following inoculation of accessions of the tropical pasture legume Stylosanthes scabra with five different concentrations of Colletotrichum gloeosporioides conidia and at five day-night temperatures in separate experiments. According to Kendall's coefficient of concordance for rankings of accessions at the various inoculum concentrations, resistance in all six accessions was expressed consistently at 102,103, 104, 105 and 106 conidia/ml for race 3 but not for race 4a. Anthracnose severity did not increase with an increase in the inoculum concentration from l05 to 106 conidia/ml for either of the two races. Height and number of leaves/plant in the uninoculated control increased significantly at 30-25�C when glasshouse-grown seedlings were transferred to four controlled environment cabinets maintained at one of the four day-night temperatures of 30-25,32-22,30-15 or 34-14�C. Accessions were subjected to one of the four day-night temperatures for a 3 week pre- and 2 week post-inoculation exposures was not significant, predisposition of some accessions to anthracnose resulted in a significant accession X exposure interaction.

scholarly journals Hydrolysis of Plant Mannans by Rumen Protozoal Enzvmes

1969 ◽  
Vol 22 (1) ◽  
pp. 267 ◽  
Author(s):  
RW Bailey ◽  
Blanche DE Gaillard
Keyword(s):  
Trifolium Pratense ◽  
Red Clover ◽  
Rumen Microorganisms ◽  
Polysaccharide Fraction ◽  
Minor Constituents ◽  
Rumen Microflora ◽  
Pasture Plant ◽  
Hydrolysis Of ◽  
Pasture Legume

Mannans or heteromannans (gluco-or galactoglucomannans) are commonly considered to be present in plants only in wood or associated with seeds. The present authors (Gaillard and Bailey 1968) have, however, recently isolated from the leaves and stems of red clover (Trifolium pratense) a polysaccharide fraction giving on hydrolysis galactose, glucose, mannose, and xylose (approximate ratios 1: 4�0: 2�0: 1�3), and which may, therefore, contain a mannan or heteromannan. This polysaccharide is designated "clover mannan" in the present work. Although apparently absent from grasses, such mannans may be common as minor constituents of pasture legume leaves and stems; for example, 1-2% of polymer mannose was reported present in lucerne (Hirst, MacKenzie, and Wylam 1959). Ivory nut (Phytelephas macrocarpa) mannan has been reported to be digested by ruminants (Beals and Lindsey 1916) and these pasture-plant mannans are probably also digested, presumably after hydrolysis by mannanases secreted by the rumen microflora. The only study of the action of rumen microorganisms on plant mannans appears to be that of Williams and Doetsch (1960), who isolated from the rumens of cows fed guaran (soluble galactomannan) several bacteria which could grow on this poly-saccharide and which secreted extracellular mannanase.

Interaction between Helicoverpa armigera and Colletotrichum gloeosporioides on the tropical pasture legume Stylosanthes scabra

2000 ◽  
Vol 51 (1) ◽  
pp. 107 ◽  
Author(s):  
Peter A. Wilson ◽  
Peter M. Room ◽  
Myron P. Zalucki ◽  
Sukumar Chakraborty
Keyword(s):  
Host Plant ◽  
Adult Female ◽  
Helicoverpa Armigera ◽  
Colletotrichum Gloeosporioides ◽  
Life Stages ◽  
Tropical Pasture ◽  
Helicoverpa Armígera ◽  
Stylosanthes Scabra ◽  
Lepidoptera Noctuidae ◽  
Pasture Legume

Glasshouse experiments determined effects of a moth, Helicoverpa armigera (Lepidoptera: Noctuidae), and the anthracnose pathogen, Colletotrichum gloeosporioides (Penz.) Penz. and Sacc., on each other when attacking the same host plant, Stylosanthes scabra (Vog.) (Leguminosae) cv. Fitzroy. The host was treated with both organisms in 2 ways of succession and at 2 different life stages each. Larvae of the moth preferred to feed on healthy plants rather than plants recently infected with C. gloeosporioides, and preferred such newly infected plants to severely diseased ones. Adult female moths laid more eggs on healthy and recently infected plants than on diseased plants, when given a choice of all 3 plant types. Severity of anthracnose disease was neither promoted nor retarded by damage to leaves caused by larvae of the moth.

Vegetation change 10 years after cattle removal in a savanna landscape

2020 ◽  
Vol 42 (2) ◽  
pp. 73 ◽  
Author(s):  
Jeanette E. Kemp ◽  
Alexander S. Kutt
Keyword(s):  
Species Richness ◽  
Vegetation Change ◽  
Floristic Composition ◽  
Grazing Pressure ◽  
Plant Functional Groups ◽  
Negative Results ◽  
Introduced Plants ◽  
Relative Cover ◽  
Stylosanthes Scabra ◽  
Pasture Legume

Following the establishment of a conservation reserve, changes in ground stratum vegetation following removal of cattle were examined in a northern Australian savanna over a 10-year period. The floristic composition of 40 vegetation plots in lowland savannas were surveyed shortly after acquisition of the property, and then surveyed twice in the following 10 years after cattle removal. Some notable ecosystem-transforming introduced species (weeds) such as Themeda quadrivalvis remained relatively stable, whereas the pasture legume Stylosanthes scabra increased in cover. The species richness of both native and introduced plants increased. Various plant functional groups changed in relative cover, with a decline in relatively unpalatable grasses and a corresponding increase in palatable grasses, responses that are consistent with recovery from grazing pressure. Our results show that removal of cattle in highly disturbed savanna ecosystems can have both positive and negative results for native ground stratum vegetation in the first decade of recovery.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

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