Studies on bud development in the rhizome of Agropyron repens. II. The effect of the nitrogen supply

1972 ◽  
Vol 50 (3) ◽  
pp. 393-401 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Dry Weight ◽  
Nitrogen Supply ◽  
Parent Plant ◽  
Bud Development ◽  
Apical Buds ◽  
Rooting Medium ◽  
Correlative Inhibition ◽  
Bud Growth ◽  
Low Nitrogen ◽  
Agropyron Repens

Bud growth on isolated rhizomes of Agropyron repens showed a basipetal gradient of decreasing activity and was strongly inhibited at the basal nodes. This evident polarity was correlated with a gradient of decreasing nitrogen content at successively older nodes and with an apparent translocation of nitrogen from the basal to the apical nodes. Isolating the buds from one another reduced growth of the apical buds and prolonged the growth of buds at the basal nodes so that the polarity of bud growth, although still apparent, was much reduced.Supplying nitrogen as NH4NO3 through the cut end of rhizomes still attached to the parent plant caused apical buds to develop as shoots instead of rhizomes. Increasing the nitrogen supply to the rooting medium extended this response to buds at older nodes, restricting rhizome production to basal buds whose growth was inhibited in low nitrogen rhizomes.Buds developing as shoots had a considerably higher total nitrogen and moisture content and a lower dry weight than buds developing as rhizomes.The results emphasized the importance of the nitrogen supply not only in determining the polarity of bud growth and the degree of correlative inhibition, but also as a morphogenetic factor controlling bud development.

Influence of Nitrogen and Humidity on Rhizome Bud Growth and Glyphosate Translocation in Quackgrass (Agropyron repens)

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Gordon I. McIntyre ◽  
Andrew I. Hsiao
Keyword(s):  
Apical Dominance ◽  
Growth Response ◽  
Dry Weight ◽  
Nitrogen Supply ◽  
Weight Basis ◽  
High Humidity ◽  
Apical Node ◽  
Bud Growth ◽  
Rhizome Bud ◽  
Agropyron Repens

When buds on the rhizome of quackgrass [Agropyron repens(L.) Beauv.] were released from apical dominance either by increasing the nitrogen supply to the parent shoot (from 5.25 to 210 ppm) or by raising the humidity around the rhizome (from 55 to 100%), the growth response of the buds was closely correlated with their uptake of foliar-applied14C-labeled glyphosate [N-(phosphonomethyl] glycine]. The14C level in the buds, expressed on a dry-weight basis, was greatest in the youngest, most rapidly growing bud at the apical node and decreased in successively older buds along the rhizome. A similar gradient was shown by the14C content of the associated rhizome nodes. The high-humidity treatment also increased the total amount of14C that was translocated into the rhizome, whereas increasing the nitrogen supply, while promoting14C uptake by the buds, markedly reduced the amount in the rhizome nodes and in other parts of the plant. This nitrogen-induced reduction in translocation was associated with a reduction of about 30% in uptake of the herbicide by the treated leaves.

Studies on the growth and development of Agropyron repens: interacting effects of humidity, calcium, and nitrogen on growth of the rhizome apex and lateral buds

1987 ◽  
Vol 65 (7) ◽  
pp. 1427-1432 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Water Status ◽  
Dry Weight ◽  
Apical Growth ◽  
High Humidity ◽  
N Supply ◽  
Lateral Buds ◽  
Low Humidity ◽  
Bud Growth ◽  
Agropyron Repens

A previous investigation of apical dominance in the rhizome of Agropyron repens showed that keeping the rhizome in a high humidity promoted the outgrowth of the lateral buds but strongly inhibited the growth of the rhizome apex. A study of these related responses demonstrated that the inhibition of apical growth was not prevented by excision of the lateral buds and was also induced when only the apex of the rhizome received the high humidity treatment. The necrotic lesions that developed in the arrested apices and the reduction of apical inhibition produced by various Ca treatments indicated that the inhibition of apical growth was caused by Ca deficiency. When the rhizome apex was exposed to low humidity, a localized high-humidity treatment of the lateral buds did not release the buds from apical dominance in low-N rhizomes but strongly promoted bud growth at a higher N level. When growth of the buds was induced at low humidity by increasing the N supply, the increase in bud weight was preceded by an increase in the water content of the bud when expressed on a dry weight basis. These results agree with those of previous investigations and suggest that the interacting effects of N and humidity on the water status of the buds may play a significant role in the mechanism of apical dominance.

Apical dominance in the rhizome of Agropyron repens: the influence of nitrogen and humidity on the translocation of 14C-labelled assimilates

1979 ◽  
Vol 57 (11) ◽  
pp. 1229-1235 ◽  
Author(s):  
F. A. Qureshi ◽  
G. I. McIntyre
Keyword(s):  
Protein Synthesis ◽  
Apical Dominance ◽  
Nitrogen Supply ◽  
Limiting Factor ◽  
High Humidity ◽  
Bud Size ◽  
Apical Node ◽  
Bud Growth ◽  
Stimulation Of ◽  
Agropyron Repens

When the buds on the rhizome of Agropyron repens were released from apical dominance either by increasing the nitrogen supply or by raising the humidity around the rhizome, their uptake of 14C-labelled assimilates from the parent shoot was significantly increased. While this effect was produced by each treatment when applied separately, the uptake of 14C by the buds was more than twice as great when both treatments were combined. The 14C level in the rhizome was also increased, this effect being greater and more consistent in response to the change in humidity than to the increased nitrogen supply. In the controls, uptake of the labelled assimilates was greatest by the bud at the apical node and decreased basipetally along the rhizome. This pattern was not correlated with bud size and probably resulted from a basipetal gradient of declining metabolic activity. Increasing the humidity around the rhizome altered this pattern, preferentially promoting the uptake of the label by the bud at the subapical node. To account for the stimulation of bud growth by high humidity when nitrogen was apparently the limiting factor, it is postulated that the increase in water potential of the bud may accelerate protein synthesis, thereby enhancing the bud's capacity to compete for the limiting nitrogen supply.

ENVIRONMENTAL CONTROL OF BUD AND RHIZOME DEVELOPMENT IN THE SEEDLING OF AGROPYRON REPENS L. BEAUV.

1967 ◽  
Vol 45 (8) ◽  
pp. 1315-1326 ◽  
Author(s):  
G. I. McIntyre
Keyword(s):  
Low Temperature ◽  
Light Intensity ◽  
Environmental Control ◽  
Nitrogen Supply ◽  
High Nitrogen ◽  
Bud Development ◽  
High Nitrogen Level ◽  
Terminal Shoot ◽  
Rhizome Development ◽  
Agropyron Repens

The effects of various environmental conditions on bud development in seedlings of Agropyron repens L. Beauv. were investigated. The bud in the axil of leaf 1 was the most responsive. At a high nitrogen level (315 p.p.m.) most of the buds at this position developed as tillers, and at a low level (2.1 p.p.m.) as rhizomes. A transition from rhizome to shoot development was induced by increasing the nitrogen supply after the rhizomes were initiated. Temperature had a similar effect, tillers being produced at a high (day) temperature (27 °C) and rhizomes at a low temperature (10 °C). Reducing the daylength from 18 to 9 h strongly promoted tillering and almost completely prevented rhizome development. A reduction of light intensity from 4000 to 2000 ft-c did not affect bud development but appeared to increase the tendency for rhizomes to form a terminal shoot. Similar effects were shown by the buds at the coleoptile and leaf 2 positions but the inherent tendency for the former to develop as rhizomes and the latter as tillers limited their response.There was some evidence from these results that bud and rhizome development is controlled by a similar mechanism and that the carbohydrate level may be an important factor in determining the inherent pattern of bud development.

Developmental studies on Euphorbia esula. The influence of the nitrogen supply on the correlative inhibition of root bud activity

1972 ◽  
Vol 50 (5) ◽  
pp. 949-956 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Nitrogen Supply ◽  
Euphorbia Esula ◽  
Nitrogen Level ◽  
Developmental Studies ◽  
Subsequent Increase ◽  
Lateral Buds ◽  
Lateral Shoots ◽  
Correlative Inhibition ◽  
Low Nitrogen

When seedlings of leafy spurge (Euphorbia esula L.) were grown at a low nitrogen level (10.5 ppm) the growth of the lateral buds on the shoot was completely arrested by apical dominance while the buds on the roots, although also inhibited, showed considerably greater activity. At a higher nitrogen level (210 ppm) apical dominance was markedly reduced but the resulting outgrowth of the lateral buds increased the inhibiting capacity of the shoot, limiting root bud response. When the main shoot was decapitated the degree to which root bud growth was suppressed by a given number of lateral shoots was inversely related to the nitrogen supply. Inhibition of the root buds by the lateral shoots could be significantly reduced by growing the plants initially at a low nitrogen level so that growth of the lateral buds was arrested. A subsequent increase in the nitrogen supply strongly promoted the growth of the roots buds, some of which were sufficiently released from inhibition to emerge as leafy shoots.

Studies on bud development in the rhizome of Agropyron repens. 1. The influence of temperature, light intensity, and bud position on the pattern of development

1970 ◽  
Vol 48 (11) ◽  
pp. 1903-1909 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Light Intensity ◽  
Environmental Conditions ◽  
Shoot Formation ◽  
Nitrogen Level ◽  
Influence Of Temperature ◽  
Bud Development ◽  
Lateral Buds ◽  
Bud Position ◽  
Low Nitrogen ◽  
Agropyron Repens

When plants of Agropyron repens L. Beauv. are grown at a low nitrogen level, decapitation of the rhizomes releases the lateral buds from inhibition and results in a well-marked polarity of bud development. This polarity is typically characterized by the restriction of shoot development to the bud nearest the apical end of the rhizome, the production of rhizomes from buds at a greater distance from the apex, and a tendency for the buds at the basal nodes to remain inhibited.It was shown that this pattern of bud development is readily affected by environmental conditions. Increasing the temperature from 15° to 25 °C caused a marked increase in shoot formation at the expense of rhizome production and a small increase in the number of dormant buds. Reducing the light intensity had a similar but much more pronounced effect. The position of the buds in relation to the cut end of the rhizome was relatively less important as a morphogenetic factor than their position on the intact plant.As a working hypothesis, based on previous results, it is suggested that a gradient in the C/N ratio might account for the observed polarity of bud development.

PENGARUH JUMLAH MATA TUNAS TERHADAP PERTUMBUHAN STEK BATANG TRUBUSAN SUNGKAI (Peronema canescens)

2021 ◽  
Vol 4 (2) ◽  
pp. 291
Author(s):  
Indri Elang Mayanti ◽  
Basir Achmad
Keyword(s):  
Tropical Forests ◽  
Dry Weight ◽  
Stem Cuttings ◽  
Root Dry Weight ◽  
Randomized Design ◽  
Two Factors ◽  
Experiment Unit ◽  
Bud Growth ◽  
Total Dry Weight

The areas of tropical forests in Indonesia always decrease every year, so that efforts are needed to cultivate plants efficiently for the supply of seedlings. Sungkai (Peronema canescens) has good quality wood that can be used for various purposes, either for construction, furniture, plywood or the leaves can be used for medicine. The purpose of this study was to analyze the growth of stem cuttings of sungkai based on the number of latent buds by calculating the root dry weight, bud dry weight, and total dry weight. This study used a factorial complete randomized design. There were two factors studied, namely the number of buds consisting of 2 levels: 2 buds and 1 bud, and the stem split factor. Each treatment was replicated 3 times and each experiment unit used 5 cuttings. The growth of sungkai cuttings in the treatment of two buds had a total dry weight of 170.04 grams, while the treatment of one bud had a total dry weight of 98.30 grams. The results of this study indicated that the more the number of latent buds, the more root and bud growth of cuttings.Keywords: Coppice; Latent buds; Cuttings; Sungkai

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