A relationship between seedling growth rates and latitude of origin of cocksfoot populations

1967 ◽  
Vol 18 (1) ◽  
pp. 15 ◽  
Author(s):  
P BrouT ◽  
S Kawanabe
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Dactylis Glomerata ◽  
Floral Initiation ◽  
High Latitudes ◽  
Population Differences ◽  
Optimum Temperature ◽  
Relative Growth ◽  
Low Latitudes ◽  
Dactylis Glomerata L

Growth rates of vegetative seedling plants of 15 cocksfoot (Dactylis glomerata L.) populations were measured in long days at near optimum temperature. Relative growth rate of the plant tops was greater in populations from high than in those from low latitudes of origin (r = 0.85; P < 0.001). In a second experiment, the populations from low latitudes were found to initiate inflorescences earlier than those from high latitudes. It is suggested that environmental conditions which maximize population differences in time of floral initiation also maximize differences in growth rates during the vegetative phase of growth.

Temperature and day length response of some cocksfoot populations

1967 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
P BrouT ◽  
CN Williams ◽  
CA Neal-Smith ◽  
L Albrecht
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Leaf Size ◽  
Day Length ◽  
Relative Growth ◽  
Dactylis Glomerata L ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Short Days

Seedling plants of seven cocksfoot (Dactylis glomerata L.) populations were exposed to day/night temperatures of 20/15, 15/10, 12/7, and 9/4°C at day lengths of either 8 or 16 hr. Leaf size, rate of leaf appearance, and relative growth rate decreased as temperature decreased. At higher temperatures, relative growth rate was greater in long than in short days, but at 9/4° it was greater in short days. Long days increased leaf size but slightly reduced the rate of leaf appearance at higher temperatures; the increased leaf size, however, more than compensated for the slightly lower rate of leaf appearance, so that relative growth rate was greater in long than in short days. At 9/4°, however, greater leaf size did not compensate for the much slower rate of leaf appearance in long days. Growth rates were consequently lower in long than in short days at 9/4°. The populations showed a general similarity in response, although significant differences between populations were recorded for particular treatments. There was no apparent relationship between seedling growth rates at low temperatures in this experiment and winter growth of these populations under field conditions.

The Relative Growth of Parts in Palaemon Carcinus

1930 ◽  
Vol 7 (2) ◽  
pp. 165-174
Author(s):  
M. A. TAZELAAR
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Measurements ◽  
Relative Growth ◽  
Male And Female ◽  
Relative Growth Rates ◽  
Rate Of Growth ◽  
The Difference ◽  
Rates Of Growth

Linear measurements of certain appendages and the carapace of P. carcinus were made and plotted in various ways. The following conclusions were drawn: 1. The cheliped shows heterogonic growth in both male and female, but more markedly in the male, the values of k being: male 1.8 and female 1.48 2. The pereiopods in both male and female are slightly heterogonic. The relative growth rates are graded from p3 to p5, that of p3 being slightly greater than that of p5 3. Of the ordinary pereiopods the rate of growth of p1 is the smallest in the male, but the largest in the female. 4. The difference between the rates of growth of p1 and p3 in male and female is greatest where the rate of growth in the heterogonic organ, the cheliped, is most excessive in the male. 5. The growth of the 3rd maxilliped is slightly negatively heterogonic, the value of k in the male being 0.93 and in the female 0.95. Hence there seems to be a correlation between the marked heterogony in the cheliped on the growth rate of neighbouring appendages. In those immediately posterior to the cheliped the growth rate is increased and in those anterior decreased.

Effect of a pesticide pentachlorophenol on soil microflora. III. Growth rates as an index of pesticide resistance of bacterial groups isolated from soil

1987 ◽  
Vol 33 (9) ◽  
pp. 819-822 ◽  
Author(s):  
Kyo Sato
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Bacterial Species ◽  
Bacterial Flora ◽  
Soil Microflora ◽  
Pesticide Resistance ◽  
Relative Growth ◽  
Bacterial Groups

Pentachlorophenol resistance was investigated in bacteria isolated from glycine- or water-percolated soils where the bacterial flora was modified by the addition of pentachloropenol. The strains isolated from the water-percolated soil amended with PCP had the highest resistance, and the addition of glycine to the percolated soil weakened the resistance. The strains from the glycine-percolated soil without pentachlorophenol had a medium degree of resistance, and the resistance of the strains from the water-percolated soil without PCP was the lowest. The bacterial groups were sorted taxonomically; differences in pentachloropenol resistance were correlated with taxonomic groupings. Relative growth rate in the presence of pentachlorophenol was proposed as a useful means to distinguish among the bacterial species.

GROWTH OF THE SALMON EMBRYO

1943 ◽  
Vol 21d (2) ◽  
pp. 19-33 ◽  
Author(s):  
F. R. Hayes ◽  
F. H. Armstrong
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Growth Curve ◽  
Growth Rates ◽  
Growth Cycle ◽  
Quantitative Relation ◽  
Random Errors ◽  
Relative Growth ◽  
Cycle Growth ◽  
Zero Time

Wet and dry weights of Atlantic salmon are given up to the end of yolk sac absorption, and from them the growth rates are determined. Attempts are made to smooth the growth curve by the methods of Brody, Murray-Schmalhausen, and MacDowell et al. Of these the last is best taking zero time as nine days after fertilization. It is concluded that, as to weight, the interval considered ends before the point of inflection of a Sachs growth cycle. Growth in length, however, represents a complete cycle, hence there can be no simple quantitative relation between length and weight. Deviations from the smoothly descending relative growth rate (RGR or Minot) curve are considered, with the conclusion that all such irregularities so far presented can be attributed to random errors (except possibly the posthatching rise in RGR of the trout at 12° reported by Wood). In general weighing is not sufficiently sensitive as a method, to permit a detailed description of the RGR.

Analyzing growth in cell cultures. I. Calculating growth rates

1986 ◽  
Vol 64 (1) ◽  
pp. 233-237 ◽  
Author(s):  
Susan R. Singer
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Rate Equations ◽  
Constant Growth Rate ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growing Cell ◽  
Absolute Growth ◽  
Plant Tissue Cultures

Growth is the major parameter used to assess novel phenotypes derived from plant tissue cultures. Any quantitative analysis of growth must have an explicit rational basis. Frequently this criterion is not met. For example, the calculation (W2 − W1)/W1(W1 = initial weight; W2 = final weight) approximates neither linear nor exponential growth. Yet, it is a common method of analysis, as is the related calculation W2/W1. When absolute growth values provide insufficient information, meaningful relative growth rate equations can be utilized. Relative growth rates should be evaluated as ln (W2/W1)/(t2 − t1) for t = time, thereby yielding a constant growth rate for exponentially growing cell lines. Linear growth (root growth, for example) can be approximated by 2(W2 − W1)/((W1 + W2)(t2 − t1)). All methods of analysis we have encountered assume that relative growth at a given instant depends on total mass. The possibility exists that growth may actually be proportional to mass raised to some power less than one. For example, growth could be limited to a thin outer shell of a spherical callus. Then the relative growth rate would equal 3(W21/3 − W11/3)/(t2 − t1). Data can be seriously distorted when inappropriate calculations are used. Such distortions are exacerbated when comparisons are made. In all cases an adequate assessment of growth kinetics for each cell line and each treatment is essential.

Growth responses of six bryophyte species to different light intensities

1993 ◽  
Vol 71 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Emmanuel Rincón
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Growth Rates ◽  
Growth Analysis ◽  
Total Chlorophyll ◽  
Light Conditions ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Plastic Responses

The growth responses of Brachythecium rutabulum, Eurhynchium praelongum, Lophocolea bidentata, Plagiomnium undulatum, Pseudoscleropodium purum, and Thuidiurn tamariscinum, growing under seven different light conditions, were determined in a 36-day laboratory experiment. Biomass production, relative growth rate, chlorophyll content, and morphological plastic responses (bending of the shoots) were determined following initial and final harvests. All species achieved greater biomass as irradiance increased. This trend was also observed in the relative growth rates, which were higher as irradiance increased, for all the bryophytes investigated. All species except L. bidentata showed an increased elevation of the shoot as irradiance decreased. Total chlorophyll was higher in all species at the lowest irradiance level, but no clear differences were observed in the ratios of chlorophyll a to b for all the species. Key words: grassland bryophytes, light intensity, growth analysis, plasticity.

scholarly journals Interrelationship of Nitrogen and Light on Episodic Growth of Ligustrum japonicum

1994 ◽  
Vol 12 (1) ◽  
pp. 43-46
Author(s):  
Jeff S. Kuehny ◽  
Dennis R. Decoteau
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Shoot Growth ◽  
Fertilizer Application ◽  
Relative Growth ◽  
Mature Leaves ◽  
Episodic Growth ◽  
Ligustrum Japonicum

Abstract Exclusion of nitrogen and light from existing leaves at initiation of an episode of shoot growth decreased shoot and root relative growth rate. The combination of both nitrogen and light exclusion synergistically impacted relative growth rate for shoot (RGRs) and relative growth rate for root (RGRr). The next episode of shoot growth provided sufficient leaf area for carbohydrate assimilation and maintaining shoot and root growth rates when light was excluded from mature leaves. A better understanding of the developmental and biochemical changes of this episodic species provided useful information for timing of fertilizer application and transplanting of Ligustrum and other episodic species.

GROWTH RATES, HARVEST INDEX AND MOISTURE USE OF MANITOU SPRING WHEAT AS INFLUENCED BY NITROGEN, TEMPERATURE AND MOISTURE

1984 ◽  
Vol 64 (4) ◽  
pp. 825-839 ◽  
Author(s):  
H. R. DAVIDSON ◽  
C. A. CAMPBELL
Keyword(s):  
Growth Rate ◽  
Spring Wheat ◽  
Growth Rates ◽  
Harvest Index ◽  
Net Photosynthesis ◽  
Moisture Stress ◽  
Growth Stages ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth

Manitou spring wheat (Triticum aestivum L.) was grown at combinations of three day/night temperatures (27/12 °C (T27), 22/12 °C (T22) and 17/12 °C (T17)), three levels of fertilizer N (58, 116 and 174 kg/ha), and three moisture stresses (nominally −0.03, −1.5 and −4.0 MPa) applied for four durations (viz., no stress throughout, stress from (i) four-tiller (Tg), (ii) near ligule of last leaf visible (LLV), or (iii) flowering (F1) stages to harvest (Hvst)). Weights of plant parts and photosynthetic area of leaves and stems were measured at eight growth stages. Mean net rate of photosynthesis [Formula: see text] was estimated by dividing plant dry weight by photosynthetic area duration. Temperature was the main factor affecting net photosynthesis and growth. Under optimum moisture and fertility, net photosynthesis was inversely related to temperature being 1.15, 1.19 and 1.29 μg∙cm−2∙day−1 at T27, T22 and T17, respectively. However, absolute growth rates were highest at T22. For example, at low moisture stress and N174, absolute growth rates were 0.69, 0.77 and 0.66 g∙day−1 at T27, T22 and T17, respectively. High moisture stress from Tg to maturity reduced absolute growth rate by about 60%. Low N rates also reduced absolute growth rate. Relative growth rate was constant and highest between emergence and LLV; it then declined rapidly and was negative after soft dough. It was suggested that the absolute growth rates and relative growth rates generated in this study could be adapted for use in simulation modelling exercises. Moisture stress was the most important factor influencing the proportion of the plant’s weight that was harvested in the grain (harvest index). Moisture stress from Tg to harvest resulted in a harvest index of 0.34 ± 0.03; for all other treatments the index was 0.28 ± 0.01. The rate and amount of water used by the plants was greatest at T27 and lowest at T22, consequently water use effeciency was lowest at T27 and highest at T22.Key words: Net photosynthesis, growth kinetics of wheat, leaf area duration

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