scholarly journals Respiratory Q10 of Lettuce Increases with Increasing Plant Size

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 854D-855
Author(s):  
Marc W. van Iersel*
Keyword(s):  
Growth Rate ◽  
Exchange Rate ◽  
Plant Growth ◽  
Plant Size ◽  
Maintenance Respiration ◽  
Relative Growth ◽  
Growth Respiration ◽  
Increasing Temperature ◽  
Growth Respiration Coefficient ◽  
Maintenance Respiration Coefficient

Literature reports on the Q10 for respiration vary widely, both within and among species. Plant size and metabolic activity may be responsible for some of this variation. To test this, respiration of whole lettuce plants was measured at temperatures ranging from 6 to 31 °C during a 24-h period. Subsequently, plant growth rate (in moles of carbon per day) was determined by measuring the CO2 exchange rate of the same plants during a 24-h period. Environmental conditions during this 24-h period resembled those that the plants were exposed to in the greenhouse. The measured growth rate was then used to estimate the relative growth rate (RGR) of the plants. The respiratory Q10 ranged from 1.4 for small plants to 1.75 for large plants. The increase in Q10 with increasing plant size was highly significant, as was the decrease in Q10 with increasing RGR. However, growth rate had little or no effect on the respiratory Q10. One possible explanation for these findings is that the Q10 depends on the ratio of growth to maintenance respiration (which is directly related to RGR). The growth respiration coefficient generally is considered to be temperature-insensitive, while the maintenance respiration coefficient normally increases with increasing temperature. Based on this concept, the Q10 for the maintenance respiration coefficient can be estimated as the estimated Q10 at a RGR of zero (i.e. no growth and thus no growth respiration), which was 1.65 in this experiment. Although the concept of dividing respiration into growth and maintenance fractions remains controversial, it is useful for explaining changes in respiratory Q10 during plant development.

Low levels of ozone increase bean leaf maintenance respiration

1988 ◽  
Vol 66 (4) ◽  
pp. 724-726 ◽  
Author(s):  
Jeffrey S. Amthor ◽  
Jonathan R. Cumming
Keyword(s):  
Phaseolus Vulgaris ◽  
Dark Respiration ◽  
Relative Increase ◽  
Maintenance Respiration ◽  
Metabolic Intermediates ◽  
Pinto Bean ◽  
Growth Respiration ◽  
Low Levels ◽  
Growth Respiration Coefficient ◽  
Maintenance Respiration Coefficient

Pinto bean (Phaseolus vulgaris) plants were exposed to charcoal-filtered air with or without added low levels of ozone (90 nL∙L−1). Dark respiration (CO2 efflux) by expanding primary leaves of the plants was measured and mathematically partitioned into growth and maintenance components. The growth respiration coefficient was unaffected by ozone, whereas the maintenance respiration coefficient increased 15%. Such a relative increase in maintenance respiration results in a diversion of energy and metabolic intermediates from growth processes.

Water Relations of Beans I. Effects of Water Stress on Growth and Flowering

1969 ◽  
Vol 5 (3) ◽  
pp. 195-207 ◽  
Author(s):  
A. H. El Nadi
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Water Stress ◽  
Plant Growth ◽  
Relative Growth Rate ◽  
Broad Bean ◽  
Day Length ◽  
Vegetative Period ◽  
Relative Growth ◽  
Made In

SummaryExperiments were made in glasshouses, growth cabinets and growth rooms to study the differential responses of the broad bean to water stress during the vegetative and flowering phases of growth. Plants in the flowering phase proved to be more sensitive to drought than in the vegetative period, and there were different responses (Relative Growth Rate) to temperature at different stages of plant growth. Day length and temperature influenced the position of the earliest flower initials on the stem, and intensity of flower shedding was aggravated by high temperature.

scholarly journals Growth Respiration, Maintenance Respiration, and Carbon Fixation of Vinca: A Time Series Analysis

2000 ◽  
Vol 125 (6) ◽  
pp. 702-706 ◽  
Author(s):  
Marc W. van Iersel ◽  
Lynne Seymour
Keyword(s):  
Carbon Balance ◽  
Carbon Fixation ◽  
Plant Size ◽  
Carbon Gain ◽  
Maintenance Respiration ◽  
Carbon Use Efficiency ◽  
Size Growth ◽  
Growth Respiration ◽  
Use Efficiency ◽  
Traditional Approaches

Respiration is important in the overall carbon balance of plants, and can be separated into growth (Rg) and maintenance respiration (Rm). Estimation of Rg and Rm throughout plant development is difficult with traditional approaches. Here, we describe a new method to determine ontogenic changes in Rg and Rm. The CO2 exchange rate of groups of 28 `Cooler Peppermint' vinca plants [Catharanthus roseus (L.) G. Don.] was measured at 20 min intervals for 2 weeks. These data were used to calculate daily carbon gain (DCG, a measure of growth rate) and cumulative carbon gain (CCG, a measure of plant size). Growth and maintenance respiration were estimated based on the assumption that they are functions of DCG and CCG, respectively. Results suggested a linear relationship between DCG and Rg. Initially, Rm was three times larger than Rg, but they were similar at the end of the experiment. The decrease in the fraction of total available carbohydrates that was used for Rm resulted in an increase in carbon use efficiency from 0.51 to 0.67 mol·mol-1 during the 2-week period. The glucose requirement of the plants was determined from Rg, DCG, and the carbon fraction of the plant material and estimated to be 1.39 g·g-1, while the maintenance coefficient was estimated to be 0.031 g·g-1·d-1 at the end of the experiment. These results are similar to values reported previously for other species. This suggests that the use of semicontinuous CO2 exchange measurements for estimating Rg and Rm yields reasonable results.

scholarly journals Error estimation in plant growth analysis

2014 ◽  
Vol 65 (3-4) ◽  
pp. 207-212 ◽  
Author(s):  
Andrzej Gregorczyk
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Growth Analysis ◽  
Growth Curves ◽  
Logistic Function ◽  
Relative Growth ◽  
Unit Leaf ◽  
Joint Application ◽  
Richards Function ◽  
Maize Plants

The scheme is presented for calculation of errors of dry matter values which occur during approximation of data with growth curves, determined by the analytical method (logistic function) and by the numerical method (Richards function). Further formulae are shown, which describe absolute errors of growth characteristics: Growth rate (GR), Relative growth rate (RGR), Unit leaf rate (ULR) and Leaf area ratio (LAR). Calculation examples concerning the growth course of oats and maize plants are given. The critical analysis of the estimation of obtained results has been done. The purposefulness of joint application of statistical methods and error calculus in plant growth analysis has been ascertained.

scholarly journals Response of Physiological Parameters in Greengram (Vigna radiata L. Wilckzek) cv. GAM-5 to Source Manipulation, Plant Growth Regulators and Chemical

2021 ◽  
Author(s):  
Parthvee Rupsinh Damor ◽  
Arvind D. Patel
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Leaf Area ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Physiological Parameters ◽  
Assimilation Rate ◽  
Relative Growth ◽  
Crop Growth Rate ◽  
Net Assimilation

Background: Among the pulse crops mungbean is one of the richest sources of protein. There is great loss in the yield of mungbean due to various reasons may be biotic or abiotic constraints. To overcome the yield loss various physiological activities are studied. Physiological activities of the plant are greatly influenced by the source manipulation, plant growth regulators and chemical in mungbean. In correspondence to this, an experiment was conducted to study the physiological parameters in greengram.Methods: A factorial randomized block design in two respective years, i.e. 2016 and 2017 to study the response of source manipulation (nipping, 25% defoliation and 50% defoliation), plant growth regulators (GA3 and NAA at 25 and 50mg/l respectively) and chemical (Thiourea 500 and 1000mg/l) on the physiological parameters like Crop Growth Rate (CGR), Relative Growth Rate (RGR), Net Assimilation Rate (NAR) and Leaf Area (LA) in greengram at 30, 45, 60 and 75 DAS/harvest at Regional Research Station, Anand Agricultural University, Anand. Result: From the obtained results it can be proposed that the physiological parameters like crop growth rate, relative growth rate and net assimilation rate increased with the increasing phase and decreased at harvesting stage. While leaf area increased significantly at each growth phase. The treatment of nipping M2 was noted significantly higher value for CGR i.e., 8.42, 16.17 and 11.48 g/cm2/day/10, for RGR i.e., 0.544, 2.967 and 1.290 g/day, for NAR i.e., 0.466, 2.959 and 1.484 mg/cm2/day and for LA i.e. 96.87, 218.94, 381.88 and 588.78 cm2. While the treatment S2 GA3 25 mg/l was noted significantly higher value for CGR i.e, 8.60, 16.67 and 11.69 g/cm2/day/10, for RGR i.e., 0.568, 2.938 and 1.202 g/day, for NAR i.e., 0.372, 3.043 and 1.529 mg/cm2/day and for LA i.e., 96.61, 224.75, 382.20 and 580.42 cm2 contributing to the higher seed yield under M2 nipping treatment i.e., (1719.7 kg/ha) and S2 treatment i.e., GA3 25 mg/l (1714.1 kg/ha). Thus, GAM-5 had a better source-sink partitioning efficiency.

Growth Indices of Kimiya Cultivar of Lentil in Response to Drought Stress at Flowering and Pod Filling Stages under Greenhouse Conditions

2019 ◽  
Author(s):  
Hossein Jahantigh ◽  
Seyed Reza Amiri
Keyword(s):  
Growth Rate ◽  
Drought Stress ◽  
Plant Growth ◽  
Field Capacity ◽  
Flowering Stage ◽  
Growth Indices ◽  
Relative Growth ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Net Assimilation

Drought stress is one of the most important environmental factors which can limit the lentil production. To evaluate the effect of drought stress at flowering and pod filling stages on growth indices of lentil cultivar Kimiya (a new high yielding lentil cultivar for moderate cold and semi warm climate of Iran), an experiment was conducted at the research greenhouse of Higher Educational Complex of Saravan in completely randomized design with four replications. The drought stress was applied by withholding irrigation until the soil moisture reached to 20% of field capacity at stages of flowering and pod filling. In this experiment, we measured grain yield per plant, growth indices including plant leaf area (PLA), relative growth rate (RGR), plant growth rate (PGR), and net assimilation rate (NAR). Results showed that the flowering stage in lentil plant is more sensitive to drought as exhibited significant decline in PLA, RGR, PGR and NAR. PGR declined at the end of growing season when vegetative growth stop, senescence of leaves, the reduction of NAR, and the allocation of assimilate to the seeds.

Latitudinal variation in plant size and relative growth rate in Arabidopsis thaliana

Oecologia ◽  
1998 ◽  
Vol 115 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Bo Li ◽  
Jun-Ichirou Suzuki ◽  
Toshihiko Hara
Keyword(s):  
Growth Rate ◽  
Arabidopsis Thaliana ◽  
Relative Growth Rate ◽  
Plant Size ◽  
Latitudinal Variation ◽  
Relative Growth

scholarly journals Effect of Temperature Regimes on Morphological Development of Selected Canola (Brassica napus) Genotypes

2019 ◽  
pp. 1-16
Author(s):  
J. S. Nwogha ◽  
G. A. Agenbag ◽  
J. E. Obidiegwu ◽  
C. O. Amadi
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Leaf Area ◽  
Dry Mass ◽  
Flowering Stage ◽  
Relative Growth ◽  
Physiological Maturity ◽  
Maturity Stages ◽  
Temperature Regimes ◽  
Net Assimilation

Seven canola genotypes selected from early and mid-maturing groups of canola genotypes presently planted in the Western Cape canola production area were grown in 3 litre plastic bags filled with a mixture of sand and compost at ratio of 1:1 and irrigated with fully balanced nutrient solution at EC=2.0 in two glasshouses at night/day temperature regimes of 10/15˚C and 15/20˚C. Plant heights were measured at 14 days interval from 28 to 84 days after planting (DAP). Plants were sampled for leaf area (LA) and above ground dry mass (DM) at budding, flowering and seed physiological maturity stages. Plant growth rates (PGR) from planting to budding, from budding to flowering and from flowering to physiological maturity growth stages were calculated. Relative growth rates (RGR) and net assimilation rates (NAR) from budding to flowering and from flowering to physiological maturity stages were also calculated. Days after planting, GDD and PTU at budding, flowering and physiological maturity were correlated with leaf area, dry mass, number of pods plant-1   and pod dry mass plant-1 at budding, flowering and physiological maturity stages to determine whether there were relationships between the variables. The study showed that by increasing night/day temperature from 10/15˚C to 15/20˚C plant height, number of leaves plant-1 at budding stage, leaf area at budding , plant growth rate (PGR) from planting to budding stage and relative growth rate (RGR) from budding to flowering stage were increased. However, PGR from budding to physiological maturity, RGR from flowering to physiological maturity, net assimilation rate (NAR) from budding to flowering stage, leaf area at flowering and physiological maturity stages, as well as  number of flower stems, number of pods  plant-1, above ground total dry mass at flowering and physiological maturity  stages were  decreased. Pod dry mass at physiological maturity decreased by 22.24% to 40.35% for different genotypes which clearly demonstrated the variations in sensitivity of canola genotypes to increasing night/day temperatures and also indicates that canola crop can be genetically improved for heat tolerance.

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