Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.). VI. Effects of defoliation including grazing

1969 ◽  
Vol 20 (1) ◽  
pp. 25 ◽  
Author(s):  
RC Rossiter

The effects of defoliating plants of different ages in different ways on the isoflavone content of the remaining leaves were investigated. When the fully expanded leaves were removed from 3-month-old plants, formononetin and genistein were reduced and brochanin A was unaffected in leaves which expanded during the subsequent 10 days. In seedlings, all three isoflavones were reduced in concentration following defoliation. But when young leaves were removed from seedlings, the isoflavones in the older remaining leaves were increased. It is suggested that severe defoliation affects soluble carbohydrate levels which in turn affect the synthesis of the isoflavones. Continuous grazing with 3–7 breeding ewes per acre had little wffect on isoflavone levels in fully expanded clover leaves.

1967 ◽  
Vol 18 (1) ◽  
pp. 23 ◽  
Author(s):  
RC Rossiter ◽  
AB Beck

Isoflavone levels in subterranean clover leaves were higher in 13 hr days of natural daylight than in 6 hr days, but length of photoperiod per se had no substantial effect on these levels. In the field, reduction of light intensity (by shading) to 40% daylight caused no decline in isoflavone levels compared with full daylight; even at 24% daylight the reduction in levels was ill defined. On the other hand, in young seedlings there was a marked fall in isoflavone content, especially in the unifoliate leaf, as light intensity fell from 950 to 320 f.c. However, appreciable isoflavone formation was found in dark-grown clover seedlings. Possible light reactions connected with the promotion of isoflavone synthesis are discussed. Changes in isoflavone levels resulting from variation in the natural light environment are unlikely to be sufficient to affect "clover disease".


Experiments were recently reported showing that, in young seedlings of Pisum sativum , the complete inhibiting effect which the shoot exerts upon its axillary buds comes entirely or almost entirely from three or four of its developing leave acting together (6). A single developing leaf was found usually to inhibit only partially—that is to say, sufficiently to delay the growth of an axillary bud below it, but not to check it completely. The strength of this partial inhibiting effect was measured by the retardation of the outgrowth of the axillary buds of the first or lowest leaf, as compared with their growth in completely defoliated controls. Comparisons were further made of the inhibiting effects of single young leaves of equal sizes near the apex in seedlings of different ages and heights, and it was found that in very young short seedlings the inhibiting effect was very slight or inappreciable, although in seedlings of a height of about 30 mm. or more (but still possessing well filled cotyledons) the effect was strong.


2016 ◽  
Vol 2 (1) ◽  
pp. 61-65 ◽  
Author(s):  
V. Melo-Ruíz ◽  
K. Sánchez-Herrera ◽  
H. Sandoval-Trujillo ◽  
R. Díaz-García ◽  
T. Quirino-Barreda

Escamoles, ant eggs (Liometopum apiculatum M), are edible insects consumed in great numbers and appreciated for their sensory characteristics, but not for their nutritional value. In Mexico, they reproduce in arid and semi-arid zones of Mexico and several states (Puebla, Tlaxcala, Hidalgo). Samples were gathered to determine reproduction conditions and perform an insect analysis to generate data composition in macronutrients, on dry basis, according to AOAC methods. The obtained data were: proteins: 42.12-50.63%; lipids: 30.27-34.96%; minerals: 6.53-7.85%; fibres: 1.91-2.56%; and soluble carbohydrates: 6.80-18.27%. Entomological material was collected in spring 2014, 3 nests for each zone, all from different altitudes and agroclimatic regions. Samples were representative for the insect supply in the areas studied. Insects are high in proteins and lipids, compared with most of the commonly consumed food, due to their high content of fatty acids; they must be refrigerated for later consumption. Minerals are moderated. Fibre and soluble carbohydrate levels are low, but an excess of proteins can be converted into carbohydrates via gluconeogenesis. Escamoles reproduce once a year in the spring, but sometimes one nest can provide escamoles eggs twice in the same season, once at the beginning and again at the end, depending on the biotic and abiotic conditions of their environment. Escamoles are a good source of nutrients; however, some rural people sell them to obtain extra income rather than consume them to improve their nutritional condition and welfare.


Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 874-878 ◽  
Author(s):  
Emerson D. Nafziger ◽  
Fred W. Slife

Thirteen-day-old common cocklebur (Xanthium pensylvanicumWallr. # XANPE) plants were treated with 15 μg glyphosate [N-(phosphonomethyl)glycine] applied to the lowermost true leaves. Growth was inhibited rapidly following treatment. About 56% of applied14C-glyphosate was taken up within 8 h. Within 4 days after treatment, diffusive resistance increased in treated leaves but did not change in untreated leaves. Glyphosate had little effect on nonstructural carbohydrate content of leaves, but soluble carbohydrate levels of stems and roots had increased by 130 and 180%, respectively, by 56 h after treatment. The uptake of33P into roots was unaffected by the herbicide, but transport of P to the aerial tissues was severely inhibited. Effects such as inhibition of P movement could result from inhibition of protein synthesis.


1995 ◽  
Vol 22 (5) ◽  
pp. 747 ◽  
Author(s):  
Z Wang ◽  
B Quebedeaux ◽  
GW Stutte

Potted apple (Malus domestica Borkh. cv. Jonathan) trees were subjected to water stress in a greenhouse. Midday leaf water potential (ΨW), osmotic potential (ΨS), soluble carbohydrates, and starch content of expanding and mature leaves, stems, and roots were measured to determine whether active osmotic adjustment occurred and if water stress affected carbohydrate metabolism. Mature leaves had the highest total soluble carbohydrate level (357 mM) and lowest Ψ (-1.85 MPa), followed by young leaves (278 mM, -1.58 MPa), stems (115 mM, -1.02 MPa), and roots (114 mM, -0.87 MPa). Sorbitol was the major component in all organs ranging from 53% of total soluble carbohydrate in young leaves to 73% in mature leaves. When ΨW decreased from -1.0 to -3.2 MPa, active osmotic adjustments of 0.3-0.4 MPa were observed in mature leaves, stems, and roots while a significantly higher adjustment of 1.0 MPa was detected in young leaves 5 days after the initiation of water stress. Sorbitol levels in leaves and stems gradually increased as ΨW decreased from -1.0 to -2.5 MPa, and then remained relatively stable or decreased slightly as ΨW decreased from -2.5 to -3.2 MPa. However, the percentage of soluble carbohydrate as sorbitol in roots decreased in response to water stress. Sucrose concentration decreased in mature leaves and stems, but increased in young leaves and roots as ΨW decreased. Starch concentrations in stems and roots also decreased as water stress developed. The sorbitol to sucrose ratios increased in mature leaves, but decreased in roots in response to water stress.


1969 ◽  
Vol 20 (6) ◽  
pp. 1043 ◽  
Author(s):  
RC Rossiter

In experiments with young plants of the Dwalganup strain of subterranean clover, nitrogen deficiency was associated with increased concentrations of isoflavones in the expanded leaves and cotyledons. In the first trifoliate leaves the concentration of total isoflavones (formononetin+genistein+ biochanin A) was approximately doubled at low nitrogen supply. Biochanin A was much less affected than the other two isoflavones. The increase in isoflavone contents of nitrogen-deficient leaves was associated with decreased protein synthesis, but not always with increased sugar contents. The supply of carbon substrates for isoflavone synthesis may depend on starch as well as sugar contents. Practical implications of the results are considered briefly.


1970 ◽  
Vol 21 (6) ◽  
pp. 933 ◽  
Author(s):  
WJ Parr ◽  
P Steele ◽  
B Gabbedy ◽  
MC Nottle

In recent years a series of widespread outbreaks of acute urinary obstruction has occurred in spring in Merino wethers. Animals involved have been grazing oestrogenic strains of subterranean clover at a time when isoflavone concentrations can be expected to be high. Studies have been made on one property on the relationships between these outbreaks, the pasture isoflavone content, and the urinary excretion of phenolic and other constituents by wethers. A trial group of animals was grazed on a dominant sward of the highly oestrogenic Trifolium subterraneum cv. Dinninup during winter and spring. Isoflavone concentrations in the clover reached a peak in early August. However, since the pasture became highly clover-dominant in September and early October the maximum daily intake of isoflavones probably occurred during this period, which also coincided with the occurrence of maximum concentration and maximum daily excretion of total phenols and acid-precipitable material (APM) in the urine. It is suggested that the sediments causing clinical obstructions at this time of the year may be a direct result of increased excretion of phenols. APM showed a highly significant direct relationship with total phenols but its excretion increased at a greater rate than did that of phenols. Urinary calcium excretion also increased at the same time.


1967 ◽  
Vol 7 (28) ◽  
pp. 434
Author(s):  
WR McManus

Concentrations of total nitrogen and total volatile fatty acids in the rumen fluid of sheep grazing improved pastures were measured for ten months in a dry year on the southern tablelands of New South Wales, and the concentrations of nitrogen and volatile fatty acids (V.F.A.) were related to season, wool production, and grazing management. The observations were made during two long-term grazing management experiments. In the first experiment four groups of breeding Merino ewes grazed a Wimmera ryegrass-subterranean clover (Lolium rigidum Gaud.-Trifolium subterraneum L.) pasture. A deferred grazing system (autumn saving) of pasture management was compared with continuous grazing at stocking rate treatments equivalent to 7.0 and 3.5 ewes to the acre. In the second experiment two groups of Merino weaners grazed a Phalaris tuberosa-subterranean clover pasture at a stocking rate equivalent to 8.6 sheep to the acre. One group received a hay supplement, the other did not. In both experiments nitrogen values were low between late autumn and mid-winter and again between late spring and summer, and high in early autumn and again in spring (P<0.05). The low levels were about 55 per cent of peak autumn and spring levels in (experiment 1) and 60 per cent of peak autumn and spring levels in (experiment 2). Total V.F.A. did not vary significantly between seasons in either experiment. At the higher stocking rate the ewes had lower levels of rumen total nitrogen than at the lower stocking rate. V.F.A. did not vary consistently between stocking rates. At both stocking rates ewes on the autumn saving system of grazing management had more nitrogen in the rumen fluid during late pregnancy and early lactation than did those on the continuous grazing system (P<0.001). After the ewes had access to the saved pasture, autumn saving resulted in a higher concentration of volatile fatty acids than continuous grazing (P< 0.05). Although feeding a hay supplement benefited the weaners the concentrations of total nitrogen in the rumen fluid of the two groups of sheep were similar. There was a fairly consistent tendency for the group receiving hay to have lower concentrations of volatile fatty acids in their rumen fluid. Possible reasons for these effects are discussed.


2007 ◽  
Vol 47 (1) ◽  
pp. 25 ◽  
Author(s):  
A. G. Kaiser ◽  
B. S. Dear ◽  
S. G. Morris

The effect of harvest time on the dry matter (DM) yield and quality of 10 annual temperate legumes [Trifolium subterraneum, var. brachcalycinum and var. subterraneum L. (subterranean clover), T. michelianum Savi (balansa clover), T. alexandrinum L. (berseem clover), Medicago murex Willd. (murex medic), M. truncatula Gaertn. (barrel medic), T. vesiculosum Savi (arrowleaf clover), Vicia sativa L. (common vetch), V. benghalensis L. (purple vetch), Pisum sativum L. (peas) grown in monoculture or in mixtures with oats (Avena sativa L.)] was examined in a Mediterranean environment in southern New South Wales. Three of the legumes (subterranean clover, berseem and peas) were also grown in mixtures with ryegrass (Lolium multiflorum Lam.). The forages were sown on 29 May and harvested at three times (2 October, 23 October and 6 November), corresponding to the boot, anthesis and dough stage of the cereal oat variety, Kalgan. Peas were the highest yielding of the legume monocultures at each of the three harvest times (6.9, 11.6, 12.3 t DM/ha), followed by purple vetch (6.2, 9.9, 8.7 t DM/ha). Of the small-seeded pasture legumes, berseem, murex and arrowleaf clover were the highest yielding at the second harvest (7.5–8.8 t DM/ha) when most reached their peak biomass. The inclusion of oats with the legumes increased total DM yield at the first, second and third harvests by 10–54, 7–99 and 3–102%, respectively. Oat monocultures were high yielding (up to 17.7 t DM/ha), but had low N contents (6.3–12.5 g N/kg DM). Oat–legume forage mixtures had nitrogen (N) contents of 7–15 g N/kg compared with 17–40 g N/kg in the legume monocultures. The N content and digestibility of most species and mixtures decreased as harvest time was delayed, whereas total DM peaked at the second harvest for all species except Cooba oats. The legume content of the mixtures was negatively correlated with total DM yield, DM content and water soluble carbohydrates, but positively correlated with N content, in vitro digestibility and buffering capacity. The digestibility of oats decreased more rapidly than the legumes with advancing maturity, and it would need to be harvested at the boot stage to produce a silage of sufficiently high metabolisable energy for the production feeding of cattle. A later harvest at anthesis when yield is higher would produce a silage of sufficient quality for production feeding from an oat–large seeded legume mixture with a legume content of 0.50. The oats and ryegrass had high water soluble carbohydrate and low to medium buffering capacity and would, therefore, be expected to produce well-preserved silages. The legume monocultures had low water soluble carbohydrate contents and high buffering capacity values and there would be a high risk of a poor silage fermentation in these forages without field wilting or the use of a silage additive.


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