Polysaccharides of tropical pasture herbage. III. The distribution of the major polysaccharide components of Townsville lucerne (Stylosanthes humilis) during growth

1971 ◽  
Vol 24 (5) ◽  
pp. 1041 ◽  
Author(s):  
CP Way ◽  
GN Richards

Stylosanthes humilis, the predominant pasture legume in North Queensland, has been collected at three different stages of growth, viz. flowering, seeded, and senescence. The plants have been divided into stem, leaf, root, seed, and pod and each fraction has been analysed for the following types of polysaccharide components: water- solubles, pectic substances, hemicelluloses, and cellulose. The absolute monosaccharide composition of each of these fractions has been determined by hydrolysis and gas chromatography. Most of the polysaccharide components are similar in nature to those previously found in temperate pasture legumes (e.g. Medicago sativa), but the seeds are unusual among legumes in containing no galactomannan and there is evidence of the presence of a glucomannan in all parts of the plant.

1977 ◽  
Vol 30 (7) ◽  
pp. 1583 ◽  
Author(s):  
RJ Beveridge ◽  
CW Ford ◽  
GN Richards

A pinitol galactoside isolated from ethanol extracts of seeds of T. subterraneum has been shown to be 1D-2-O-(α-D-galactopyranosyl)-4-O- methy-chiro-inosito (1). The structure is based on successive periodate oxidation, borohydride reduction, hydrolysis and acetylation (Smith degradation), yielding the tetraacetate of 2-O-methyl-L-xylitol. The seeds of 39 pasture legumes from 13 different genera and 26 species have been analysed by gas chromatography for (1), myo-inositol, D-(+)- pinitol and galactinol.


1969 ◽  
Vol 20 (4) ◽  
pp. 665 ◽  
Author(s):  
CS Andrew ◽  
MF Robins

Nine tropical and one temperate pasture legume species were grown in pots of soil with varying additions of phosphate. Growth responses and chemical conlposition of the plant tops were recorded, and from the latter, critical percentages of phosphorus were established. These were verified by using data from two soils in the pot culture investigation and a total of six field sites. Glycine javanica and Desmodium intortum were the most responsive species in pots, and Stylosanthes humilis and Lotononis bainesii were the least responsive species. The quantity of phosphorus per pot accumulated in the tops of the plants was greatest for Stylosanthes humilis and Lotononis bainesii at all treatment levels. Critical percentages of phosphorus in the tops of Phaseolus Iathyroides, Phaseolus atropurpureus, Stylosanthes humilis, Centrosema pubescens, Glycine javanica, Lotononis bainesii, Medicago sativa, Desmodium uncinatum, Desmodium intortum, and Vigna luteola sampled at the immediate pre-flowering stage of growth were 0.20, 0.24, 0.17, 0.16, 0.23, 0.17, 0.24, 0.23, 0.22, and 0.25% phosphorus respectively.


1970 ◽  
Vol 21 (2) ◽  
pp. 215 ◽  
Author(s):  
PC Whiteman

Changes in plant dry weight, leaf weight, nodule weight per plant, nodule number and size, and nitrogen content of stem, leaf, and nodules were followed throughout the growing season in Desmodium sandwicense an indeterminate flowering type, D. uncinatum which flowers in April, and D. intortum which flowers in late May. The seasonal build-up and decline of the nodule population was not related to the onset of flowering, peak nodulation occurring 3 months before flowering in D. intortum and 1 month before in D. uncinatum. D. sandwicense had three flowering periods, with some loss of nodules after flowering, but in its general trend of build-up and decline was similar to the other species. Changes in nodule weight per plant were a function mainly of changes in nodule number. The relationship between loglo nitrogen yield per plant and nodule weight per plant was similar for the three species at early samplings, but at later samplings the nitrogen yield did not increase linearly with increases in nodule weight. Thus the regression coefficient could not be taken as a constant index of nitrogen-fixing efficiency for a species at all stages of growth.


1977 ◽  
Vol 28 (5) ◽  
pp. 807 ◽  
Author(s):  
CS Andrew

Seven tropical and five temperate pasture legume species were grown in pots of three sulphur-deficient soils with varying additions of sulphate. Growth responses and the chemical composition of the plant tops were recorded, and from the latter, tentative critical concentrations of sulphur were established. These were compared with data from two field sites (six species only). Critical concentrations of sulphur in the tops of species sampled at the immediate pre-flowering stage of growth were: Macroptilium lathyroides 0.17%, Macroptilium atropurpureum 0.15%, Desmodium intortum 0.17%, Desmodium uncinatum 0.17%, Stylosanthes humilis 0.14%, Lotononis bainesii 0.15%, Glycine wightii 0.17%, Trifolium repens 0.18%, Trifolium semipilosum 0.17%, Medicago sativa 0.20%, Medicago truncatula 0.20% and Medicago denticulata 0.20%. Sulphate concentration and nitrogen/sulphur ratios were investigated as alternative diagnostic indices, but were not considered as suitable as total sulphur indices for the assessment of sulphur deficiency in legumes. Nitrogen concentrations in the plant tops were increased by sulphate supply, and excellent correlations were established between the nitrogen and sulphur concentrations in the plant tops.


1971 ◽  
Vol 11 (52) ◽  
pp. 532 ◽  
Author(s):  
WW Bryan ◽  
CS Andrew

Using soils known to be grossly deficient in phosphorus, and with a basal dressing of sulphur (and other deficient nutrients) plants were grown in pots and in the field with single superphosphate or Nauru rock phosphate. The plants fell into two groups, those that gave moderate yield responses to rock phosphate as compared with superphosphate (Lotononis bainesii, Stylosanthes guyanensis, Centrosema pubescens, Indigofera spicata, and Medicago sativa) and those whose response to rock phosphate was poor (Desmodium uncinatum and Phaseolus lathyroides). In no case was the response to rock phosphate as good as that to superphosphate, even when twice as much phosphorus, in the form of rock phosphate, was applied. The residual value of rock phosphate was low with Desmodium, high with Lotononis, but never as high as that of superphosphate.


1973 ◽  
Vol 24 (3) ◽  
pp. 325 ◽  
Author(s):  
CS Andrew ◽  
AD Johnson ◽  
RL Sandland

The effects of aluminium (0, 0.5, 1.0, 2.0 p.p.m.) on the dry matter production (tops and roots) and chemical composition of five tropical and six temperate pasture legumes grown in a cultu1.e solution containing 2 p.p.m. phosphorus were ascertained. The tolerances of the tropical species to aluminium were in the order Desmodiunz uncinatum = Macroptilium latlzyyuoides = Lotonis bainesii = Stylosanthes humilis = Glycine wightii > Medicago sativa, and temperate species in the order Trifolium rueppellianum= Trifolium sernipilosum > Trifolium repens = Medicago scutellata = Medicago truncatula = Medicago sativa. In the tolerant species the yield of plant material from the 0.5 p.p.m. aluminium treatment was greater than from the control. The top/root weight ratios of the tolerant species were unaffected by treatment; the ratios of the sensitive species were reduced. The effect of aluminium treatment on aluminium, nitrogen, phosphorus, potassium, calcium, magnesium, and sodium concentrations in the plants are given. The principal nutrients to be affected were calcium and phosphorus. Aluminium treatment reduced the calcium concentrations in the tops of all species and there were reciprocal relationships between calcium, magnesium, and potassium concentrations. In the sensitive species aluminium treatment reduced phosphorus in the plant tops and roots; in some of the tolerant species the intermediate aluminium treatment increased the phosphorus concentration in the plant tops; however, the high aluminium treatment reduced the phosphorus concentration.


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