scholarly journals Patterns of axillary bud activity in white clover

1990 ◽  
pp. 247-249
Author(s):  
P.C.D. Newton ◽  
M.J.M. Hay ◽  
V.J. Thomas ◽  
E.M. Glasgow ◽  
H.B. Dick
Keyword(s):  
White Clover ◽  
Environmental Conditions ◽  
Axillary Buds ◽  
Axillary Bud ◽  
Ecological Significance ◽  
Physiological Basis ◽  
Bud Site

The activity of white clover axillary buds was studied over a 13 month period in populations from set-stocked (S) and rotationally grazed (R) pastures. Bud activity in the field was observed and the viability of inactive buds was tested in the laboratory. R populations had significantly greater percentages of nodes bearing active buds, potentially active buds and roots. Two kinds of dormancy were identified in axillary buds. For much of the year buds at approximately 26% of nodes were prevented from growing, probably by a combination of correlative factors and the environmental conditions surrounding each bud-site. During spring, very few buds could be stimulated to grow; these buds were regarded as showing the second form of dormancy. The R population had a deeper but less prolonged 'spring dormancy'. The physiological basis and ecological significance of 'spring dormancy' are considered. Keywords white clover, dormancy, axillary buds

scholarly journals Experiments on growth and inhibition. I.—The increase of inhibition with distance

1931 ◽  
Vol 108 (756) ◽  
pp. 209-223 ◽  
Keyword(s):  
Pisum Sativum ◽  
Axillary Buds ◽  
Axillary Bud ◽  
Inhibiting Effect ◽  
Different Ages ◽  
Young Leaves

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.

Picloram Absorption by Broom Snakeweed (Gutierrezia sarothrae) Leaf Tissue

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 390-394 ◽  
Author(s):  
Tracy M. Sterling ◽  
Norman K. Lownds
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Leaf Tissue ◽  
Axillary Bud ◽  
Solution Ph ◽  
Simple Diffusion ◽  
Foliar Absorption ◽  
Ph Dependent ◽  
Gutierrezia Sarothrae ◽  
Diffusion Absorption

Foliar absorption of picloram by broom snakeweed, a rangeland shrub, was investigated. Picloram uptake into leaf, axillary bud, and stem tissues was similar. In addition, picloram uptake by leaf tissue from greenhouse- and field-grown broom snakeweed did not differ. Picloram accumulated rapidly and absorption saturated between 15 min and 1 h of application; no further absorption occurred through 72 h with maximum uptake ca. 15% of applied picloram. Picloram content increased linearly with increasing external picloram concentration, implying that movement of the herbicide across the cuticle is via diffusion. Absorption was dependent on relative humidity and temperature with the greatest uptake at 94% relative humidity and 35 C, respectively. Absorption was pH dependent; picloram absorption was greatest at pH 4 and least at pH 8. In addition, picloram absorption was less at pH 3 compared to pH 4. These results provide evidence that picloram is absorbed across the cuticle via simple diffusion and absorption is dependent on environmental conditions and solution pH at and following application.

Morphology of white clover (Trifolium repens L.) plants in pastures under intensive sheep grazing

1988 ◽  
Vol 111 (2) ◽  
pp. 273-283 ◽  
Author(s):  
J. L. Brock ◽  
M. J. M. Hay ◽  
V. J. Thomas ◽  
J. R. Sedcole
Keyword(s):  
White Clover ◽  
Plant Morphology ◽  
Dry Weight ◽  
Plant Size ◽  
Early Spring ◽  
Axillary Buds ◽  
Branching Order ◽  
Wide Range ◽  
Stolon Length ◽  
Total Plant

SummaryThere has been little study on the growth and morphology of individual plants constituting the population of white clover in mixed swards under grazing. Such information is required if the mechanisms governing plant productivity and persistence are to be understood.Intact white clover plants were sampled from intensively sheep-grazed pastures under set stocking, rotational grazing, and a combination of both systems, by taking turves (250 × 250 mm), and washing out the plants, every month for a year. Characters measured for every stolon of each plant were: presence of a growing point; numbers of leaves, roots and axillary buds; stolon length. Total plant leaf and stolon dry weight were also recorded. Plants were classified according to degree of branching, and the contribution of each branching order to the population determined.There were strong seasonal variations in plant size (leaf and stolon dry weight, stolon length, and numbers of stolons and leaves per plant) which showed a significant decrease in spring with recovery over the following summer. This was paralleled by a rapid increase in the proportion of less branched plants (1st and 2nd branching order) in the population from 60 to 80% in spring, as higher-order plants broke up into smaller- and lower-ordered plants at this time. Numbers of roots per plant increased over winter to peak in early spring then declined in the following summer-autumn. While system of grazing management had no significant effect on branching structure of plants, it had a large effect on plant dry weight; rotationally grazed plants were 2·5 times larger than set stocked plants (0·182 cf. 0·073 g respectively).Other general features of plant morphology were that each successive order of branch stolons was shorter and length before branching was less than that of their preceding parent stolon. The highest branching order observed was 6th order. There was no relationship between branching and numbers of roots; in branched plants only 55% of stolons were rooted regardless of plant order, but rooted stolons accounted for 85% of total stolon length and carried 62, 48 and 90% of the leaves, growing points and axillary buds per plant, respectively.Comparison with other studies suggests that the processes outlined in this report may be common to white clover growth under grazing over a wide range of favourable environments.

Technique for evaluating the potential for growth of shoot and root buds of white clover (Trifolium repens)

1992 ◽  
Vol 119 (2) ◽  
pp. 179-183 ◽  
Author(s):  
P. C. D. Newton ◽  
M. J. M. Hay
Keyword(s):  
Relative Humidity ◽  
Constant Temperature ◽  
White Clover ◽  
Environmental Conditions ◽  
Trifolium Repens ◽  
Experimental Results ◽  
Root Primordia ◽  
Primary Interest ◽  
Root Buds ◽  
Subtending Leaves

SUMMARYAn assay was developed for assessing the potential for growth of shoot and root buds of white clover. This paper describes the technique and the experimental results on which it was based. The assay involved the incubation of nodes under standard conditions and the monitoring of bud activity at the nodes. Shoot buds were of primary interest but the assay was also used to investigate the activity of root primordia. Correlative influences were reduced by separating individual nodes and by removal of their subtending leaves and petioles. The optimal environmental conditions for incubation were: a constant temperature of 20 °C, a 24 h photoperiod of low irradiance (4 W/m2) and a high relative humidity (≥ 90%). The technique proved suitable for the monthly screening of 1000–2000 nodes sampled from field populations of white clover.

Viability of axillary buds of white clover (Trifolium repens) in grazed pasture

1992 ◽  
Vol 119 (3) ◽  
pp. 345-354 ◽  
Author(s):  
P. C. D. Newton ◽  
M. J. M. Hay ◽  
V. J. Thomas ◽  
H. B. Dick
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Trifolium Repens ◽  
Axillary Buds ◽  
Spring Period ◽  
Grazed Pastures ◽  
Grazed Pasture ◽  
Pattern Of Variation

SUMMARYStolon nodes of white clover were sampled monthly for 18 months from continuously grazed (set stocked) and rotationally grazed pastures in New Zealand. Both pastures were stocked at 22·5 ewes plus lambs/ha. Axillary buds were classified into viability categories using an incubation technique. On average, 54% of nodes had non-viable or dormant buds, 25% had axillary buds that were viable but non-active and 0·1% bore reproductive buds. Although 21% of buds emerged, only 8·5% of nodes bore live branches. Bud activity was strongly inhibited during the spring period of both years and this inhibition could not be removed by incubation.The greatest bud viability occurred at node 4 (from the apex) although 30–40% of the buds at this position were non-viable. This pattern of variation changed somewhat with season. Some viable buds were present at nodes more than 20 from the apex but these were of low vigour. Secondary stolons had different patterns of bud activity from those of primary stolons until they comprised more than 16 nodes.

scholarly journals Transcriptomic and physiological analyses of rice seedlings under different nitrogen supplies provide insight into the regulation involved in axillary bud outgrowth

2020 ◽  
Author(s):  
Rongna Wang ◽  
Junjie Qian ◽  
Zhongming Fang ◽  
Jihua Tang
Keyword(s):  
Growth Rate ◽  
Morphological Changes ◽  
Expression Profiles ◽  
Axillary Buds ◽  
Axillary Bud ◽  
Rice Seedlings ◽  
Transcriptomic Data ◽  
Bud Growth ◽  
Axillary Bud Growth ◽  
Axillary Bud Outgrowth

Abstract Background: N is an important macronutrient required for plant development and significantly influences axillary bud outgrowth, which affects tillering and grain yields of rice. However, how different N concentrations affect axillary bud growth at the molecular and transcriptional levels remains unclear. Results: In this study, morphological changes in the axillary bud growth of rice seedlings under different N concentrations ranging from low to high levels were systematically observed. To investigate the expression of N-induced genes involved in axillary bud growth, we used RNA-seq technology to generate mRNA transcriptomic data from two tissue types, basal parts and axillary buds, of plants grown under six different N concentrations. In total, 10,221 and 12,180 DEGs induced by LN or HN supplies were identified in the basal parts and axillary buds, respectively, via comparisons to expression levels under NN level. Analysis of the coexpression modules from the DEGs of the basal parts and axillary buds revealed an abundance of related biological processes underlying the axillary bud growth of plants under N treatments. Among these processes, the activity of cell division and expansion was positively correlated with the growth rate of axillary buds of plants grown under different N supplies. Additionally, TFs and phytohormones were shown to play crucial roles in determining the axillary bud growth of plants grown under different N concentrations. Further validation of OsGS1;2 and OsGS2 , the rice mutants of which presented altered tiller numbers, validated our transcriptomic data. Conclusion: These results indicate that different N concentrations affect the axillary bud growth rate, and our study revealed comprehensive expression profiles of genes that respond to different N concentrations, providing an important resource for future studies attempting to determine how axillary bud growth is controlled by different N supplies.

scholarly journals Nitrogen Nutrition Promotes Rhizome Bud Outgrowth via Regulation of Cytokinin Biosynthesis Genes and an Oryza longistaminata Ortholog of FINE CULM 1

2021 ◽  
Vol 12 ◽  
Author(s):  
Kyohei Shibasaki ◽  
Arika Takebayashi ◽  
Nobue Makita ◽  
Mikiko Kojima ◽  
Yumiko Takebayashi ◽  
...  
Keyword(s):  
Nitrogen Nutrition ◽  
Structural Features ◽  
Negative Regulator ◽  
Axillary Buds ◽  
Axillary Bud ◽  
Cytokinin Biosynthesis ◽  
Rhizome Growth ◽  
Oryza Longistaminata ◽  
Rhizome Bud ◽  
Axillary Bud Growth

Oryza longistaminata, a wild rice, can propagate vegetatively via rhizome formation and, thereby, expand its territory through horizontal growth of branched rhizomes. The structural features of rhizomes are similar to those of aerial stems; however, the physiological roles of the two organs are different. Nitrogen nutrition is presumed to be linked to the vegetative propagation activity of rhizomes, but the regulation of rhizome growth in response to nitrogen nutrition and the underlying biological processes have not been well characterized. In this study, we analyzed rhizome axillary bud growth in response to nitrogen nutrition and examined the involvement of cytokinin-mediated regulation in the promotion of bud outgrowth in O. longistaminata. Our results showed that nitrogen nutrition sufficiency promoted rhizome bud outgrowth to form secondary rhizomes. In early stages of the response to nitrogen application, glutamine accumulated rapidly, two cytokinin biosynthesis genes, isopentenyltransferase, and CYP735A, were up-regulated with accompanying cytokinin accumulation, and expression of an ortholog of FINE CULM1, a negative regulator of axillary bud outgrowth, was severely repressed in rhizomes. These results suggest that, despite differences in physiological roles of these organs, the nitrogen-dependent outgrowth of rhizome axillary buds in O. longistaminata is regulated by a mechanism similar to that of shoot axillary buds in O. sativa. Our findings provide a clue for understanding how branched rhizome growth is regulated to enhance nutrient acquisition strategies.

scholarly journals Occurrence of circular vessels above axillary buds in stems of woody plants

2014 ◽  
Vol 56 (3) ◽  
pp. 415-419 ◽  
Author(s):  
Zygmunt Hejnowicz ◽  
Ewa U. Kuczyńska
Keyword(s):  
Woody Plants ◽  
Axillary Buds ◽  
Axillary Bud ◽  
Cell Arrangement ◽  
Cambial Zone ◽  
The Stability

The circular vessels generally occur in intact wood stems just above the axillary buds. In this region the cell arrangement with vortices occurs. We interprete the circular vessels as the result of circular polarity in the cambial zone of the region above the axillary bud. The stability of circular polarity in this region is based on the vorticity of the cambium cells arrangement.

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