Flower initiation in Trifolium subterraneum L. 1. Analysis of the partial processes involved

1959 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
LT Evans
Keyword(s):  
High Temperatures ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Controlled Environment ◽  
Flower Initiation ◽  
Inhibitory Process ◽  
Inhibitory Effects ◽  
Other Hand ◽  
Short Days

The influence of various temperature and photoperiod regimes on flower initiation and flowering in eight strains of T. subterraneum has been examined, using the controlled environment facilities of the Earhart Laboratory. Flower initiation in subterranean clover appears to be under the control of three interacting partial processes, two of which are synergistic and promotive while the third is inhibitory. The promotive processes are possibly both light-independent, one being favoured by high temperatures and the other (the vernalization process) by low temperatures. The inhibitory process, on the other hand, is restricted to the diurnal dark period and is favoured by high temperatures. The interaction between the vernalization and dark inhibitory processes is such that in the absence of dark inhibition no vernalization is required by any strain, while on. the other hand sufficient vernalization can apparently overcome all dark inhibitory effects. Treatment with gibberellic acid eliminates the need for vernalization by plants of at least one early-flowering strain when. grown in short days at high temperatures. The strains of subterranean clover differ markedly in their responses to the three partial processes. In their response to the dark inhibitory process two strains are more affected by night temperature than by night length, while in two other strains the opposite is the case, which suggests that the dark inhibitory process could be resolved into more than one component.

Flower initiation in Trifolium subterraneum L. II. Limitations by vernalization, low temperatures, and photoperiod, in the field at Canberra

1959 ◽  
Vol 10 (1) ◽  
pp. 17 ◽  
Author(s):  
FHW Morley ◽  
LT Evans
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Day Length ◽  
Flower Initiation ◽  
Inhibitory Effects ◽  
Low Field ◽  
The Times ◽  
Short Days

At various times throughout the winter, autumn-sown plants of five strains of subterranean clover were removed from the field to a series of day length and temperature treatments. The times to inflorescence initiation in all treatments were determined by dissection. As vernalization proceeded the requirement of all strains for long days was progressively reduced until, by midwinter, several strains had become virtually independent of day length. Similarly, with the progress of vernalization the inhibitory effects of high temperatures during short days became progressively less marked. Whereas exposure to long days at high temperatures greatly accelerated inflorescence initiation in all strains, long days at low field temperatures had little effect. Evidence is presented which suggests that the limiting effect of very low temperatures on initiation is due not only to retardation of the rate of inflorescence primordium formation (realization), but also to limitation of an inductive process other than vernalization and dark period inhibition. The flowering behaviour of the various strains is discussed in terms of their responses to the partial processes leading to inflorescence initiation, and the interrelationships of these processes are considered.

Distribution of recently absorbed zinc in subterranean clover (Trifolium subterraneum L.) determined by adding radioactive zinc to the culture soultion

1960 ◽  
Vol 11 (6) ◽  
pp. 887 ◽  
Author(s):  
DS Riceman ◽  
GB Jones
Keyword(s):  
Zinc Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Main Axis ◽  
Leaf Primordia ◽  
The Other ◽  
Subsequent Growth ◽  
Other Hand ◽  
Radioactive Zinc ◽  
High Concentrations

The distribution of zinc recently absorbed as 65Zn into subterranean clover (T. subterraneum L. var. Bacchus Marsh) from culture solutions has been examined by means of radioautographs in normal plants and in plants recovering from a state of zinc deficiency. In normal plants which had been grown initially in cultures containing non-radioactive zinc, the recently absorbed zinc reached high concentrations in the roots, main axis, and youngest leaves but very little of it moved into the older, fully expanded leaves. In plants recovering from the deficiency, on the other hand, the recently absorbed zinc reached high concentrations in all the living organs, including the oldest leaves. Growth of the "little" leaves or other leaves affected by the deficiency was not resumed after the entry of zinc into their tissues. Recovery of the plant depended upon the production of new leaves by the leaf primordia and upon their subsequent growth and emergence.

The effects of fertilizer treatments on the oestrogenic potency of Trifolium subterraneum L

1952 ◽  
Vol 3 (1) ◽  
pp. 24 ◽  
Author(s):  
G Alexander ◽  
RC Rossiter
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Other Hand

The oestrogenic potency of subterranean clover from plots which received superphosphate together with several other fertilizers did not differ significantly from that of clover from a plot which had received superphosphate only. On the other hand, clover from plots which had received no fertilizer recently was significantly more potent than clover from plots which had received superphosphate.

Control of lupin flower initiation by vernalization, photoperiod and temperature under controlled environment

1972 ◽  
Vol 12 (59) ◽  
pp. 638 ◽  
Author(s):  
MS Rahman ◽  
JS Gladstones
Keyword(s):  
High Temperatures ◽  
Vernalization Requirement ◽  
Controlled Environment ◽  
Flower Initiation ◽  
Growing Period ◽  
New Crop ◽  
Short Days

Controlled environment studies of the effects of vernalization, photoperiod, and growing period temperatures were carried out on selected cultivars of four annual Lupinus species. All responded to both vernalization and photoperiod to varying degrees, and in at least two there were indications of an additional effect of growing period temperatures specifically on flower initiation. Flower initiation in L. angustifolius was found to be controlled mainly by its vernalization requirement, with subsidiary control by photoperiod. In L. cosentini vernalization, photoperiod, and an acceleration of initiation by high temperatures all appeared to play important roles, with critical control by photoperiod under short days. L. luteus responded strongly to both vernalization and photoperiod, but long days were able to substitute for vernalization to a marked degree. The results are discussed in the context of the ecology of lupins and the breeding of new crop cultivars.

scholarly journals Effects of Heating Rate on Formation of Globular and Acicular Austenite during Reversion from Martensite

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 266 ◽  
Author(s):  
Xianguang Zhang ◽  
Goro Miyamoto ◽  
Yuki Toji ◽  
Tadashi Furuhara
Keyword(s):  
Heating Rate ◽  
High Temperatures ◽  
The Other ◽  
Growth Mode ◽  
High Heating Rate ◽  
Heating Rates ◽  
Other Hand ◽  
High Heating ◽  
Martensite Matrix

The effects of heating rate on the formation of acicular and globular austenite during reversion from martensite in Fe–2Mn–1.5Si–0.3C alloy have been investigated. It was found that a low heating rate enhanced the formation of acicular austenite, while a high heating rate favored the formation of globular austenite. The growth of acicular γ was accompanied by the partitioning of Mn and Si, while the growth of globular γ was partitionless. DICTRA simulation revealed that there was a transition in growth mode from partitioning to partitionless for the globular austenite with an increase in temperature at high heating rate. High heating rates promoted a reversion that occurred at high temperatures, which made the partitionless growth of globular austenite occur more easily. On the other hand, the severer Mn enrichment into austenite at low heating rate caused Mn depletion in the martensite matrix, which decelerated the reversion kinetics in the later stage and suppressed the formation of globular austenite.

scholarly journals An electric furnace for experiments in vacuo at temperatures

1912 ◽  
Vol 87 (598) ◽  
pp. 519-524
Keyword(s):  
High Temperatures ◽  
Electric Furnace ◽  
Cuprous Oxide ◽  
The Other ◽  
Resistance Furnace ◽  
Heterogeneous Equilibrium ◽  
Other Hand ◽  
Large Current ◽  
Dissociation Pressures ◽  
Reduction Of Oxides

This furnace was designed with a view to investigating at temperatures up to 1500° C. certain cases of heterogeneous equilibrium in which the equilibrium is defined by the pressure of the system. Instances are the dissociation of certain oxides, nitrides, and carbonates, and the reduction of oxides by carbon. The furnace could not be constructed of carbon, as carbon would react with some of the gases of which the pressure had to be measured, and also because it is almost impossible to remove the adsorbed gases from large quantities of carbon. Tubes of Royal Berlin porcelain in a platinum-wound resistance furnace may be used for temperatures up to 1200°, but at about this temperature they become soft, while the glaze runs and combines with any boat or other substance in the furnace. Tubes of silica are not suitable, because they are porous at high temperatures, and because they disintegrate owing to crystallisation taking place. It was decided to make the furnace of a platinum tube and to heat it by passing a large current through it. As some of the substances which it would be necessary to place in the furnace react with platinum, e. g . copper formed by the dissociation of cuprous oxide, it was necessary to make the furnace sufficiently large to take a boat or crucible of magnesia large enough to contain the reacting substance and thick enough to protect the tube. On the other hand, the tube ought to be as small as possible, in order that in determining the dissociation pressures all the charge should not be decomposed before the equilibrium is attained.

Flower initiation in pasture legumes. I. Factors affecting flower initiation in Trifolium subterraneum L.

1955 ◽  
Vol 6 (2) ◽  
pp. 211 ◽  
Author(s):  
Y Aitken
Keyword(s):  
Low Temperature ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Cold Period ◽  
Effect Of Temperature ◽  
Flower Initiation ◽  
Temperature Level ◽  
Factors Affecting ◽  
Pasture Legumes ◽  
Precise Knowledge

The value of the annual legume Trifolium subterraneum L. (subterranean clover) in Australian agriculture warrants more precise knowledge of factors affecting flowering and prolific seeding. The effect of temperature and photoperiod on flower initiation in early and later flowering varieties has been investigated in an effort to determine the geographical limits of the use of subterranean clover in Australia. At any time of sowing, the length of the growing season of a variety depends greatly on the variety's response to the temperature level and to the photoperiod of the first few weeks after germination. In all varieties of subterranean clover so far examined flower initiation is accelerated by a period of low temperature. In the later varieties, flower initiation is prevented by an insufficient period of low temperature. The length of the necessary cold period is shortened under longer photoperiod. Early varieties are early flowering because they do not require so long a cold period or so low a temperature as late varieties.

Phosphorus, sulphur, and molybdenum deficiencies in soils from eastern Australia in relation to nutrient supply and some characteristics of soil and climate.

1955 ◽  
Vol 6 (5) ◽  
pp. 673 ◽  
Author(s):  
KD McLachlan
Keyword(s):  
Phosphorus Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Parent Material ◽  
The Other ◽  
Podzolic Soils ◽  
Sulphur Deficiency ◽  
Eastern Australia ◽  
Yield Responses ◽  
Western Victoria

Subterranean clover (Trifolium subterraneum L.) was grown on 32 virgin soils in pot cultures, and the yield responses to phosphorus, sulphur, and molybdenum were determined for each soil. The soils were collected from a wide area in eastern Australia, extending from south-western Victoria to southern Queensland. Sulphur deficiency occurred almost as frequently as phosphorus deficiency. In fact, 75 per cent. of the soils were deficient in both phosphorus and sulphur. Thirty-one per cent. were deficient in all three elements. The effect of the interaction between the elements on the occurrence and intensity of the deficiencies is shown. Molybdenum responses were obtained only after the other deficiencies had been corrected. A deficiency in one of the elements is no indication of deficiency or sufficiency of either of the other two. There was no correlation between the occurrence or intensity of the deficiencies and the geological origin of the soil parent material, the climate of the regions from which the soils were collected, or such soil characters as colour, organic matter, and texture. Responses to phosphorus were less on the black earths than on the red or yellow podzolic soils; those on the red earths were intermediate. The intensity of sulphur deficiency increased, and the intensity of molybdenum deficiency decreased, with increasing soil pH.

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.) III. Effects of light

1967 ◽  
Vol 18 (1) ◽  
pp. 23 ◽  
Author(s):  
RC Rossiter ◽  
AB Beck
Keyword(s):  
Light Intensity ◽  
Subterranean Clover ◽  
Substantial Effect ◽  
The Other ◽  
Light Environment ◽  
Natural Light ◽  
Ecological Studies ◽  
Other Hand ◽  
Isoflavone Content ◽  
Per Se

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".

Some characteristics of "Carnamah", a very early-flowering strain of Trifolium subterraneum L., when grown as single plants

1961 ◽  
Vol 12 (1) ◽  
pp. 27 ◽  
Author(s):  
RC Rossiter ◽  
AJ Millington
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Early Flowering ◽  
Winter Period ◽  
Flower Initiation ◽  
Total Production ◽  
Initiation Rate ◽  
The Difference ◽  
Early Flower ◽  
Early Strain

A very early-flowering strain of subterranean clover was discovered in 1957 at Carnamah, W.A. From extensive studies at several field centres, it was demonstrated that the new strain – now called Carnamah – commenced flowering from 30 to 10 days before Dwalganup (the standard commercial "early" strain) when sown in the autumn-early winter period. With very early planting – late March – the difference in flowering time was even greater (about 45–50 days). The very early-flowering nature of the Carnamah strain is associated with early flower initiation. Rate of flower development (from flower initiation to flower appearance) in relation to temperature was similar for Carnamah and Dwalganup. Under spaced-plant conditions the total production of Carnamah was much less than that of Dwalganup, a finding which conforms to the results of previous single-plant studies. The new strain was not readily distinguished from Dwalganup, but several minor differences in morphology are mentioned. The chromosome number was normal for the species (2n = 16). The relevance of these data to sward conditions is discussed briefly, and it is suggested that the Carnamah strain may be more effective than Dwalganup in extending the "clover belt" inland in southern Australia.

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