The effect of leaf removal on flowering time in subterranean clover

1970 ◽  
Vol 21 (6) ◽  
pp. 893 ◽  
Author(s):  
WJ Collins ◽  
Y Aitken
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Early Growth ◽  
Grazing Management ◽  
Flower Initiation ◽  
Leaf Removal ◽  
Main Shoot ◽  
Delayed Flowering ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The removal of fully expanded leaves delayed flowering by up to 30 days in subterranean clover cv. Mt. Barker sown in winter at Melbourne (38�S.). This effect on flowering was attributable partly to a delay in flower initiation and partly to a slower rate of leaf appearance after flower initiation. Thus leaf removal may be added to the factors already known to influence flower initiation in subterranean clover. When plants were grown under a 24 hr photoperiod. leaf removal had no effect on flower initiation; the slight delay that leaf removal caused in flowering was therefore due entirely to its effect in reducing the rate of leaf appearance. In other experiments leaf removal delayed the time of flower initiation but had no effect on the rate of leaf appearance. The effect of leaf removal on the time of flowering on the main shoot in lateral-dominant plants (as occur in the field) was qualitatively the same as in plants from which the laterals had been removed. Grazing management of subterranean clover which results in severe defoliation during early growth may delay flowering to such an extent that seed production is reduced substantially, and persistence thereby prejudiced.

Pre-maturation cold acquisition in Trifolium subterraneum

1974 ◽  
Vol 25 (6) ◽  
pp. 875 ◽  
Author(s):  
WJ Collins ◽  
DF Smith
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Maturation ◽  
Flower Initiation ◽  
Appearance Time ◽  
Rate Of Development ◽  
Wide Range ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Different Levels

The influence of different levels of temperature during seed maturation on the subsequent rate of development in plants grown from that seed was studied in a range of subterranean clover cultivars. In one study the cultivars Carnamah, Yarloop, Woogenellup and Mt. Barker were grown at 7, 11, 14 and 17°C, and the seed produced grown on at 17°. Observations were made on the rate of leaf appearance, time of flower initiation, and time and node of first flowering. The rate of development was closely related to the temperature under which the seed was produced—the lower the temperature the faster was the rate of development. This effect was greatest with the later-flowering cultivars. In a second experiment, seed of a number of cultivars harvested commercially from a wide range of sites in southern Australia was grown on at 17°C and the rate of development observed. Time of flowering varied markedly between samples of only three cultivars. Accordingly seed of these samples were grown on for a further generation in a controlled environment. Within two of the cultivars, Mt. Barker and Bacchus Marsh, the differences in flowering observed in the previous generation persisted, which suggests that such differences were not based on environmental factors. In the cultivar Woogenellup the differences in flowering disappeared, which suggests that the original differences arose through different environmental conditions occurring during seed maturation. Cold acquisition in the maturing embryo does not seem to be a matter of practical consequence at present in subterranean clover, but may become so with changes in the location of seed production.

The effect of defoliation on flower production in subterranean clover (T. subterraneum L.)

1972 ◽  
Vol 23 (3) ◽  
pp. 427 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Early Flowering ◽  
Flower Initiation ◽  
Flower Production ◽  
Mature Leaves ◽  
Opposing Effects ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Three experiments were done in an open-sided glasshouse during the normal winter growing season. In experiment 1, swards of the Dwalganup strain which were severely defoliated, either after flower initiation or at early flowering, had 17% more flowers per unit ground area than uncut controls. Swards which were defoliated at both stages had 28% more flowers than the controls. In experiment 2, with single plants of the Dwalganup strain, comparable defoliations greatly decreased flower numbers per plant. The opposing effects of defoliation on flower numbers of single plants and of swards are believed to reflect opposing effects of defoliation on the rate of leaf appearance and on branching. In experiment 3, with single plants of the Dwalganup and Yarloop strains, either the young or the mature leaves were repeatedly removed before flower initiation. This delayed the date of commencement of flowering by 15–19 days; but the node of first flowering was not affected by defoliation.

scholarly journals Vernalization Duration and Light Intensity Influence Flowering of Three Hybrid Nobile Dendrobium Cultivars

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 406-410 ◽  
Author(s):  
Min Lin ◽  
Terri W. Starman ◽  
Yin-Tung Wang ◽  
Genhua Niu
Keyword(s):  
Light Intensity ◽  
Flowering Time ◽  
Photon Flux ◽  
Flower Initiation ◽  
Flower Longevity ◽  
Photosynthetic Photon Flux ◽  
Flower Diameter ◽  
Flower Quality ◽  
Delayed Flowering

The flowering time and flower quality of three hybrid Dendrobium nobile cultivars in relation to light intensity during cooling and duration of vernalization were studied in the first experiment. Mature Dendrobium Red Emperor ‘Prince’, Den. Sea Mary ‘Snow King’, and Den. Love Memory ‘Fizz’ plants were vernalized at 10 °C under 300 to 350 μmol·m−2·s−1 photosynthetic photon flux (PPF) (12-h photoperiod) or darkness, each with four cooling durations (2, 4, 6, or 8 weeks). Plants were forced in a greenhouse after vernalization. At least 4 weeks of 10 °C cooling in light was needed for complete flower initiation of Den. Red Emperor ‘Prince’, whereas Den. Sea Mary ‘Snow King’ and Den. Love Memory ‘Fizz’ only needed 2 weeks of 10 °C cooling regardless of light. For all three cultivars, darkness during vernalization slightly delayed flowering and resulted in fewer but larger flowers. Longer cooling duration delayed flowering, decreased flower longevity, and produced more and larger flowers. In a second experiment, Den. Love Memory ‘Fizz’ plants were vernalized at 15 °C for 4 weeks under a 12-h photoperiod and PPF of 0, 50, 100, or 200 μmol·m−2·s−1. Compared with 200 μmol·m−2·s−1, low PPF at 50 or 100 μmol·m−2·s−1 did not affect flowering time or flower qualities; however, darkness delayed flowering and reduced flower qualities except flower diameter.

Vernalization as a factor influencing the rate of development in subterranean clover (Trifolium subterraneum L.)

1975 ◽  
Vol 26 (6) ◽  
pp. 959 ◽  
Author(s):  
WJ Collins ◽  
DF Smith
Keyword(s):  
Environmental Conditions ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Flower Initiation ◽  
Rate Of Development ◽  
Practical Consequence ◽  
Normal Field ◽  
Delayed Flowering

An investigation of the influence of vernalization on the rate of development in three cultivars of subterranean clover was conducted under controlled environmental conditions. Effects were evaluated in terms of the time from imbibition to flower initiation or flowering, i.e. including the time during which vernalization was imposed. In these terms, vernalization actually delayed flowering in the Yarloop and Mt. Barker cultivars, hastening it only in Tallarook. Some practical considerations are discussed. The effects of periods of higher temperatures after vernalization on the rate of development were also studied. No evidence was found for the occurrence of devernalization. If devernalization docs occur in subterranean clover, it is unlikely to be of practical consequence in normal field situations.

A comparison of the growth and development of biculm wheat lines with freely tillering cultivars

1985 ◽  
Vol 104 (1) ◽  
pp. 163-171 ◽  
Author(s):  
C. Marshall ◽  
W. J. R. Boyd
Keyword(s):  
Grain Yield ◽  
Dry Weight ◽  
Total Biomass ◽  
Wheat Cultivars ◽  
Main Shoot ◽  
Australian Wheat ◽  
Leaf Appearance ◽  
Wheat Lines ◽  
Field Plots ◽  
Rate Of Leaf Appearance

SummaryThe growth, development and grain yield of two low-tillering lines of wheat of Israeli origin were compared with those of two freely tillering Australian wheat cultivars (Gamenya and Egret) in field plots. The majority of individuals from the low-tillering selections were uniculms or biculms. Detailed observations were made on the main shoot of the biculms. There was no difference in the duration of primordia production by the main shoot apex between genotypes but the rate of initiation of spikelet primordia in the lowtillering lines was significantly greater than that of the tillering cultivars and this resulted in a large ear with more spikelets. The rate of leaf appearance was very similar in all genotypes but the later-appearing leaves of the biculms were very large in comparison with those of the cultivars. The majority of the biculms produced the tiller in T3 position. At maturity the main shoot and tiller of biculm individuals produced 60 and 40% respectively more dry weight than the equivalent shoots of the tillering cultivars. The total biomass per plant of the biculms was similar to that of Egret but less than that of Gamenya. The grain yield of the main shoot of the biculms was 50% greater than that for the tillering varieties and this was associated with an increase in the number of grains per ear as there was little difference in grain size. In the biculm a high proportion of the spikelets in the mid part of the main shoot ear produced five grains; grains from basal florets were significantly larger than those of upper florets mainly because they had a longer duration of growth. Overall the grain yield of the two tillering cultivars, either per plant or per metre of row length, was approximately 30% greater than that of the low-tillering selections. The greater growth of the main shoot axis in the biculms therefore did not compensate for the grain contributed by the tillers of the freely tillering cultivars.

Time to flowering in narrow-leafed lupin

1995 ◽  
Vol 46 (5) ◽  
pp. 1063 ◽  
Author(s):  
MA Reader ◽  
M Dracup ◽  
EJM Kirby
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Flowering Time ◽  
Regression Analyses ◽  
Average Temperature ◽  
Interaction Term ◽  
Using Data ◽  
Leaf Appearance ◽  
The Relationship ◽  
Rate Of Leaf Appearance

The relationship between flowering time and daylength and temperature is described for L. angustifolius using multiple linear regression. The main cultivar was Gungurru but cvv. Danja, Yorrel and the L. albus cv. Kiev Mutant were also studied. Regression analyses were performed on time to flowering observations for lupins grown with serial sowings at up to 12 sites over up to 5 years in Western Australia (there were 102 separate observations of time to flowering for Gungurru). Time to flowering in the L. angustifolius cultivars was best explained by a model incorporating terms for average temperature and daylength between sowing and flowering. Models of this form were not satisfactory for L. albus, probably because of vernalization requirements which the L. angustifolius cultivars do not have. Using data from the experiment with the widest range of sowings, 94.6% of the variation in time to flowering was explained by the above model and an additional 3.5% was explained by including an interaction term. The rate of progress through all stages of development to flowering, except for the period between appearance of the last leaf and flowering, was sensitive to temperature. The rate of leaf appearance responded to both temperature and daylength and the rate of progress through the period between appearance of the last leaf and flowering was sensitive only to daylength.

scholarly journals EjFRI, FRIGIDA (FRI) Ortholog from Eriobotrya japonica, Delays Flowering in Arabidopsis

2020 ◽  
Vol 21 (3) ◽  
pp. 1087
Author(s):  
Weiwei Chen ◽  
Peng Wang ◽  
Dan Wang ◽  
Min Shi ◽  
Yan Xia ◽  
...  
Keyword(s):  
Flowering Time ◽  
Ectopic Expression ◽  
Eriobotrya Japonica ◽  
Flower Initiation ◽  
Wild Type ◽  
Expression Levels ◽  
Functional Roles ◽  
Significant Difference ◽  
Transgenic Lines ◽  
Delayed Flowering

In the model species Arabidopsis thaliana, FRIGIDA (FRI) is a key regulator of flowering time and can inhibit flowering without vernalization. However, little information is available on the function in the Rosaceae family. Loquat (Eriobotrya japonica) belongs to the family Rosaceae and is a distinctive species, in which flowering can be induced without vernalization, followed by blooming in late-autumn or winter. To investigate the functional roles of FRI orthologs in this non-vernalization species, we isolated an FRI ortholog, dubbed as EjFRI, from loquat. Analyses of the phylogenetic tree and protein sequence alignment showed that EjFRI is assigned to eurosids I FRI lineage. Expression analysis revealed that the highest expression level of EjFRI was after flower initiation. Meanwhile, EjFRI was widely expressed in different tissues. Subcellular localization of EjFRI was only detected to be in the nucleus. Ectopic expression of EjFRI in wild-type Arabidopsis delayed flowering time. The expression levels of EjFRI in transgenic wild-type Arabidopsis were significantly higher than those of nontransgenic wild-type lines. However, the expression levels of AtFRI showed no significant difference between transgenic and nontransgenic wild-type lines. Furthermore, the upregulated AtFLC expression in the transgenic lines indicated that EjFRI functioned similarly to the AtFRI of the model plant Arabidopsis. Our study provides a foundation to further explore the characterization of EjFRI, and also contributes to illuminating the molecular mechanism about flowering in loquat.

PASTURE RESPONSES TO GRAZING MANAGEMENT IN HILL COUNTRY

1984 ◽  
pp. 168-176
Author(s):  
D.F. Chapman ◽  
D.A. Clark
Keyword(s):  
White Clover ◽  
Leaf Growth ◽  
Leaf Length ◽  
Animal Production ◽  
Grazing Management ◽  
Leaf Removal ◽  
Hill Country ◽  
Defoliation Frequency ◽  
Tiller Density ◽  
Leaf Appearance

Components of growth and defoliation of perennial ryagrass and browntop tillers and white clover stolen apices ware measured for 12 months in hill pastures set stocked (SS) or rotationally grazed (RG) with sheep. Leaf appearance intervals of the grasses were unaffected by grazing management. Tiller densities were greater under SS (annual mean 29,700 total tillers/m' cf. 20,100/m* under FIG), compensating for greater leaf extension rates and lamina lengths of individual tillers under RG. White clover leaf appearance intervals were similar under both managements except in summer when RG was superior to SS during 3 grazing rotations. Defoliation of grass tillers was more frequent under SS when rotation lengths exceeded 3 weeks, but more severe (in terms of leaf length removed) under RG throughout the year. These mechanisms, combined with tiller density differences.contributed to the likelihood of equal leaf removal per unit area under both managements. Some advantage to RG in ryegrass leaf growth and total leaf removal was indicated but the differences were small and unlikely to affect animal production. White clover leaf removal was similar under both managements. Grazed swards are dynamic and can change rapidly under different grazing managements; however, at acceptable levels of pasture utilisation, the dominant responSes appear to maintain an equilibrium in leaf growth. Thus the use of other procedures, e.g. fertiliser application and increases in stocking rate, in conjunction with management changes is required to substantially alter pasture and animal production. Keywords: hill country, grazing management, pasture productivity, perennial ryegrass, browntop, white clover, leaf growth, tiller density, defoliation frequency, defoliation severity.

scholarly journals Potential transceptor AtNRT1.13 modulates shoot architecture and flowering time in a nitrate-dependent manner

2021 ◽  
Author(s):  
Hui-Yu Chen ◽  
Shan-Hua Lin ◽  
Ling-Hsin Cheng ◽  
Jeng-Jong Wu ◽  
Yi-Chen Lin ◽  
...  
Keyword(s):  
Flowering Time ◽  
Nitrate Transport ◽  
Dependent Manner ◽  
Transport Activity ◽  
Node Number ◽  
Shoot Architecture ◽  
Glucuronidase Reporter ◽  
Uptake Activity ◽  
Delayed Flowering ◽  
Severe Growth

Abstract Compared with root development regulated by external nutrients, less is known about how internal nutrients are monitored to control plasticity of shoot development. In this study, we characterize an Arabidopsis thaliana transceptor, NRT1.13 (NPF4.4), of the NRT1/PTR/NPF family. Different from most NRT1 transporters, NRT1.13 does not have the conserved proline residue between transmembrane domains 10 and 11; an essential residue for nitrate transport activity in CHL1/NRT1.1/NPF6.3. As expected, when expressed in oocytes, NRT1.13 showed no nitrate transport activity. However, when Ser 487 at the corresponding position was converted back to proline, NRT1.13 S487P regained nitrate uptake activity, suggesting that wild-type NRT1.13 cannot transport nitrate but can bind it. Subcellular localization and β-glucuronidase reporter analyses indicated that NRT1.13 is a plasma membrane protein expressed at the parenchyma cells next to xylem in the petioles and the stem nodes. When plants were grown with a normal concentration of nitrate, nrt1.13 showed no severe growth phenotype. However, when grown under low-nitrate conditions, nrt1.13 showed delayed flowering, increased node number, retarded branch outgrowth, and reduced lateral nitrate allocation to nodes. Our results suggest that NRT1.13 is required for low-nitrate acclimation and that internal nitrate is monitored near the xylem by NRT1.13 to regulate shoot architecture and flowering time.

Distribution and variability in development of the genus Trigonella in Asia Minor and its possible use in Australian environments

1981 ◽  
Vol 32 (5) ◽  
pp. 793 ◽  
Author(s):  
GM Halloran ◽  
AL Pennell
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Asia Minor ◽  
Vernalization Response ◽  
Developmental Patterns ◽  
Late Flowering ◽  
Commercial Cultivars ◽  
Wide Variability ◽  
Upper Level ◽  
Autumn Sowing

A number of Trigonella species were examined for their possible use in Australian environments. There was a wide variability in flowering time in Trigonella. Under an outdoor autumn sowing the range in flowering time was comparable with that found within early- to late-flowering Australian commercial cultivars of subterranean clover. The upper level of vernalization response was much lower in Trigonella than in subterranean clover. Good prospects exist within Trigonella for selecting genotypes with close adaptation (in terms of appropriate developmental patterns) to a range of Australian environments, a range at least as wide as that now occupied by subterranean clover and annual medic.

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