Environmental control of apical dominance in Phaseolus vulgaris

1973 ◽  
Vol 51 (2) ◽  
pp. 293-299 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Water Stress ◽  
Phaseolus Vulgaris ◽  
Light Intensity ◽  
Nitrogen Content ◽  
Apical Dominance ◽  
Growth Response ◽  
Environmental Control ◽  
Nitrogen Supply ◽  
Soluble Nitrogen ◽  
Bud Growth

When seedlings of Phaseolus vulgaris were grown under controlled conditions at a light intensity of 3200 ft-c, 60% relative humidity, and at nitrogen levels of 5.25, 52.5, and 210 ppm, growth of the buds at the cotyledonary node, which served as a measure of apical dominance, showed a positive correlation with the nitrogen supply and with the soluble nitrogen content of the hypocotyl. Increasing the nitrogen supply to 420 ppm caused a proportionate increase in soluble nitrogen content but no additional bud growth response. That the growth response was limited by water supply was shown by growing plants at 420 ppm nitrogen and relative humidities of 30, 60, and 90%. Each reduction in water stress, as measured by leaf relative turgidity, caused a highly significant increase in growth of the cotyledonary buds. Under high nitrogen, low water stress conditions, bud growth was markedly inhibited by reduction of the light intensity from 3200 to 700 ft-c.These results support the concept of nutrient competition as a major factor in the mechanism of apical dominance and also suggest that conflicting reports on the effect of externally applied growth-regulating substances on lateral bud inhibition may be due partly to environmentally induced differences in nutritional status of the experimental plants.

Environmental control of lateral bud growth in the sunflower (Helianthus annuus)

1977 ◽  
Vol 55 (21) ◽  
pp. 2673-2678 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Water Stress ◽  
Helianthus Annuus ◽  
Apical Dominance ◽  
Environmental Control ◽  
High Light Intensity ◽  
Nutrient Competition ◽  
N Supply ◽  
Lateral Bud ◽  
Bud Growth ◽  
Lateral Branches

A study of environmental effects on lateral bud growth in the sunflower, Helianthus annuus, showed that the provision of a high relative humidity (90 ± 5%) in conjunction with a high light intensity (about 30 000 lx) and an abundant N supply (420 ppm) permitted the buds at the basal nodes to escape from apical dominance and to develop as lateral branches. A reduction in any one of these three factors was sufficient to prevent the release of the buds from inhibition. The marked effect of humidity on bud growth suggested that the degree of water stress is the factor most likely to limit the growth of the lateral buds under field conditions. The mode of action of water stress and the N supply is discussed in relation to the genetic control of bud activity and to the role of nutrient competition in the mechanism of apical dominance.

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.

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.

The nitrogen nutrition of the peach tree. IV. Storage and mobilization of nitrogen in mature trees

1969 ◽  
Vol 20 (5) ◽  
pp. 869 ◽  
Author(s):  
BK Taylor ◽  
den Ende B van
Keyword(s):  
Nitrogen Content ◽  
Total Nitrogen ◽  
Fruit Set ◽  
Growing Season ◽  
Nitrogen Supply ◽  
Soluble Nitrogen ◽  
Nitrogen Status ◽  
Mature Trees ◽  
Nitrogen Treatments ◽  
Peach Trees

An experiment was carried out on 8-year-old peach trees in the field to further study the chemical composition of storage nitrogen in mature trees and to relate tree performance in one growing season to the level of storage nitrogen in tree tissues during the previous winter. Storage nitrogen in dormant trees consisted mainly of soluble organic nitrogen, and free arginine was a principal constituent of this fraction. The arginine nitrogen content of the soluble nitrogen fraction increased with increasing nitrogen supply, but values were low compared with those found in young peach trees. The concentration of arginine in roots of dormant trees was the most sensitive indicator of the nitrogen status of the trees. In comparison, conventional leaf analysis for total nitrogen in midsummer was only about one-half as sensitive as an index of nitrogen status. Since there could be objections to using root tissue for analysis it is of interest to note that the next best estimate of the nitrogen status of the trees was given by the level of arginine nitrogen in leaf + flower buds. The growth of new shoots and especially the nitrogen content of leaves were in proportion to the levcl of storage nitrogen in dormant trees before growth commenced. However, flowering performance and fruit set per tree were not dependent upon the level of storage nitrogen in the trees. Flowers at full bloom from nil nitrogen and plus nitrogen treatments contained approximately the same content of total nitrogen and this may be the reason why nitrogen treatments did not influence fruit set. Nitrogen analyses and field observations indicated that stored nitrogen in nil nitrogen trees was preferentially used for reproductive processes rather than for vegetative growth. The amount of total nitrogen per leaf first increased and then decreased with elapsed time during the growing season. This latter loss was attributed to migration of nitrogen from ageing leaves to fruits and/or woody tissues in late summer and early autumn. Nitrogen treatment did not significantly alter the proportion of total nitrogen lost per leaf at this time, but the amount of total nitrogen lost per leaf usually increased with increasing nitrogen supply. Results are compared with those obtained in earlier work and the importance of reaccumulation of nitrogen from abscising leaves in the nitrogen economy of the trees is briefly discussed.

Genetic diversity of french bean (Phaseolus vulgaris L.) under water stress condition

2011 ◽  
Vol 22 (1) ◽  
Author(s):  
AK Choudhury ◽  
MA Karim ◽  
QA Khaliq ◽  
MM Haque ◽  
JU Ahmed ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Water Stress ◽  
Phaseolus Vulgaris ◽  
Stress Condition ◽  
French Bean ◽  
Water Stress Condition

Yields and Nitrogen Content of Corn Hybrids as Affected by Nitrogen Supply

1949 ◽  
Vol 13 (C) ◽  
pp. 303-306 ◽  
Author(s):  
Frank G. Viets ◽  
Clifford E. Domingo
Keyword(s):  
Nitrogen Content ◽  
Nitrogen Supply ◽  
Corn Hybrids
Sign in / Sign up

Export Citation Format

Share Document