Effect of Light Intensity and Temperature on Photosynthetic Rate, Leaf Starch Content and Ultrastructure of Paspalum dilatatum

1975 ◽  
Vol 2 (2) ◽  
pp. 185 ◽  
Author(s):  
BJ Forde ◽  
HCM Whitehead ◽  
JA Rowley
Keyword(s):  
Growth Rate ◽  
Photosynthetic Rate ◽  
Starch Content ◽  
Dry Weight ◽  
Effect Of Temperature ◽  
Starch Accumulation ◽  
Paspalum Dilatatum ◽  
Minor Variation ◽  
Relative Growth ◽  
Light Intensities

;Paspalum dilatatum plants were grown in growth cabinets under two light intensities (224 and 90 W m-2) at day/night temperatures of 27.5/20.0, 20.0/12.5, 17.5/12.5 and 15.0/10.0°C. Additional plants were grown in the glasshouse and outside. Relative growth rate was closely correlated with the mean hourly photosynthetic rate of the plant during the day. Starch varied from 0.8 to 5.3 % of the leaf dry weight at the end of the night and from 3.0 to 11.6% at the end of the day. Photosynthetic rate of cabinet-grown plants remained constant during the day as starch accumulated. The rate declined for plants from outside, although their leaf starch levels were no higher than those of cabinet-grown plants. No evidence was found of feedback repression of photosynthetic rate caused by assimilate accumulation. There was only minor variation in mesophyll chloroplast structure between plants grown at different light intensities at the same temperature. A decline in temperature below 20.0/12.5°C increased swelling of mesophyll chloroplasts, as well as reducing development of the peripheral reticulum. The structure of bundle sheath chloroplasts was little affected by the environment apart from its effect on starch accumulation. While growth rate increased rapidly as temperature increased, there was much less effect of temperature on accumulation of starch during the day. It was concluded that photosynthesis and the accumulation of starch are less sensitive to temperature than is overall plant growth.

Low temperature effects on the growth of evening primrose (Oenothera spp.) rosettes

2004 ◽  
Vol 52 (1) ◽  
pp. 19-28
Author(s):  
A. F. Fieldsend
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Relative Rate ◽  
Field Trials ◽  
Effect Of Temperature ◽  
Relative Growth ◽  
Evening Primrose ◽  
Intermittent Exposure ◽  
Environment Experiment

In field crops of evening primrose (Oenothera spp.) the post-winter growth of rosettes is slow to re-start. The effect of temperature on the growth of rosettes was assessed in a controlled environment experiment. Relative growth rate was positively correlated with temperature, but in apparent contrast to the results from field trials, the rosettes grew at constant temperatures as low as 6.5ºC. However, following transfer to warmer temperatures an increase in relative growth rate did not occur until 7-10 days later, whilst a change to a cooler environment caused an immediate reduction in relative growth rate. Thus, it seems likely that growth is inhibited by intermittent exposure to temperatures of 0°C or below. Partitioning of biomass between root and shoot was independent of temperature, but at 6.5ºC the relative rate of leaf area increase was very low. Consequently, the specific leaf area was lower in rosettes growing at lower temperatures.

scholarly journals Influence of Soil Amendment on the Relative Growth Rate and Net Assimilation Rate of Phaseolus vulgaris and Vigna aconitifolia

2020 ◽  
pp. 1-13
Author(s):  
E. A. Effa ◽  
A. A. J. Mofunanya ◽  
B. A. Ngele
Keyword(s):  
Growth Rate ◽  
Phaseolus Vulgaris ◽  
Relative Growth Rate ◽  
Soil Amendment ◽  
Dry Weight ◽  
Organic Manure ◽  
Assimilation Rate ◽  
Vigna Aconitifolia ◽  
Relative Growth ◽  
Net Assimilation

Background: Soil pH is one of the most important factors that contribute to crop growth and productivity. The present research was designed to assess the influence of soil amendment using organic manure and agricultural lime on the relative growth rate (RGR) and net assimilation rate (NAR) of Phaseolus vulgaris and Vigna aconitifolia grown on soils from different locations. Methodology: The three locations were: Akamkpa, Calabar Municipality and Odukpani. The pH for the three soil locations were 4.0, 7.0 and 9.0, respectively. The treatments were; control (0 g), OM1 (100 g organic manure), OM2 (200 g organic manure), AL1 (100 g agricultural lime), AL2 (200 g agricultural lime), OM1 + AL1 (50 g organic manure + 50 g agricultural lime) and OM2 +AL2 (100 g organic manure and 100 g agricultural lime). Results: Results obtained on the RGR of the leaf dry weight of P. vulgaris treated with OM2 was the highest (0.50 g/wk) followed by OM1 (0.41 g/wk). OM1 + AL1 had the highest RGR of the stem dry weight of P. vulgaris grown on soil from Calabar Municipality. In the RGR of the root dry weight, OM2 had the highest mean value in both plants grown on Akamkpa soil. Results obtained at 4 weeks after planting (WAP) revealed that there was significant (P<0.05) increase in NAR of plants grown on soil from Akamkpa. The highest NAR was obtained for V. aconitifolia treated with OM2 (0.0447 g/wk) followed by OM2 + AL2 (0.0057 g/wk) for both V. aconitifolia and P. vulgaris. P. vulgaris grown on Akamkpa and Odukpani soils treated with AL2 (0.0032 g/wk), OM1 + AL1 (0.0041 g/wk) and OM2+ AL2 (0.0062 g/wk) had the highest NAR at 8 WAP. Conclusion: The RGR and NAR of the two bean varieties were improved following treatments with organic manure and agricultural lime.

Growth and Development of Organic Arsenical-Susceptible and -Resistant Common Cocklebur (Xanthium strumarium) Biotypes Under Noncompetitive Conditions

1994 ◽  
Vol 8 (1) ◽  
pp. 154-158 ◽  
Author(s):  
William E. Haigler ◽  
Billy J. Gossett ◽  
James R. Harris ◽  
Joe E. Toler
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Growing Season ◽  
Xanthium Strumarium ◽  
Relative Growth ◽  
Growth Development

The growth, development, and reproductive potential of several populations of organic arsenical-susceptible (S) and -resistant (R) common cocklebur biotypes were compared under noncompetitive field conditions. Plant height, leaf area, aboveground dry weights, and relative growth rate (RGR) were measured periodically during the growing season. Days to flowering, bur dry weight, and number of burs per plant were also recorded. Arsenical S- and R-biotypes were similar in all measured parameters of growth, development, and reproductive potential. Populations within each biotype varied occasionally in plant height, leaf area, aboveground dry weights, and reproductive potential.

scholarly journals Growth Analysis of Wheat Using Machine Vision: Opportunities and Challenges

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6501
Author(s):  
Mohammad Ajlouni ◽  
Audrey Kruse ◽  
Jorge A. Condori-Apfata ◽  
Maria Valderrama Valencia ◽  
Chris Hoagland ◽  
...  
Keyword(s):  
Growth Rate ◽  
Machine Vision ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Growth Analysis ◽  
Growth Parameters ◽  
Dry Weight ◽  
Projected Area ◽  
Relative Growth ◽  
Leaf Dry Weight

Crop growth analysis is used for the assessment of crop yield potential and stress tolerance. Capturing continuous plant growth has been a goal since the early 20th century; however, this requires a large number of replicates and multiple destructive measurements. The use of machine vision techniques holds promise as a fast, reliable, and non-destructive method to analyze crop growth based on surrogates for plant traits and growth parameters. We used machine vision to infer plant size along with destructive measurements at multiple time points to analyze growth parameters of spring wheat genotypes. We measured side-projected area by machine vision and RGB imaging. Three traits, i.e., biomass (BIO), leaf dry weight (LDW), and leaf area (LA), were measured using low-throughput techniques. However, RGB imaging was used to produce side projected area (SPA) as the high throughput trait. Significant effects of time point and genotype on BIO, LDW, LA, and SPA were observed. SPA was a robust predictor of leaf area, leaf dry weight, and biomass. Relative growth rate estimated using SPA was a robust predictor of the relative growth rate measured using biomass and leaf dry weight. Large numbers of entries can be assessed by this method for genetic mapping projects to produce a continuous growth curve with fewer replicates.

Heat Stress During Grain Filling in Maize: Effects on Carbohydrate Storage and Metabolism

1994 ◽  
Vol 21 (6) ◽  
pp. 829 ◽  
Author(s):  
GW Singletary ◽  
R Banisadr ◽  
PL Keeling
Keyword(s):  
Heat Stress ◽  
Seed Size ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Grain Filling ◽  
Soluble Starch ◽  
Effect Of Temperature ◽  
Starch Accumulation ◽  
Maize Kernels

Heat stress during maize seed development can interfere with endosperm starch biosynthesis and reduce seed size, an important component of yield. Our objectives were to evaluate the direct influence of temperature during grain filling on kernel growth, carbohydrate accumulation, and corresponding endosperm metabolism. Kernels of maize were grown in vitro at 25�C until 15 or 16 days after pollination and then subjected to various temperatures for the remainder of their development. Mature kernel dry weight declined 45% in a linear fashion between 22 and 36�C. The rate of starch accumulation reached a maximum at approximately 32�C, and when measured at frequent intervals, declined only slightly with further temperature increase to 35�C. Reduced seed size resulted from an abbreviated duration of starch-related metabolism, which did not appear to be limited by endogenous sugars. Instead, a survey of 12 enzymes of sugar and starch metabolism indicated that ADP glucose pyrophosphorylase and soluble starch synthase were unique in displaying developmental peaks of activity which were compressed both in amount and time, similar to the effect of temperature on starch accumulation. We conclude that decreased starch synthesis in heat-stressed maize kernels results from a premature decline in the activity of these enzymes.

scholarly journals Fitness Cost of Imazamox Resistance in Wild Poinsettia (Euphorbia heterophylla L.)

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Weight ◽  
Area Ratio ◽  
Fitness Cost ◽  
Seed Plant ◽  
Growth Indices ◽  
Relative Growth ◽  
Net Assimilation

Wild poinsettia (Euphorbia heterophylla L.) is a difficult-to-control weed in soybean production in Brazil that has developed resistance to herbicides, including acetolactate synthase inhibitors. We investigated the potential fitness cost associated to the Ser-653-Asn mutation that confers imazamox resistance in this weed. Plant height, leaf and stem dry weight, leaf area and seed production per plant as well as the growth indices of specific leaf area, leaf area ratio, relative growth rate and net assimilation in F2 homozygous resistant (R) and susceptible (S) wild poinsettia progenies were pairwise compared. S plants were superior in most of the traits studied. Plant heights for S and R biotypes, recorded at 95 days after planting (DAP), were 137 and 120 cm, respectively. Leaf areas were 742 and 1048 cm2 in the R and S biotypes, respectively. The dry weights of leaves and stems in the S plants were 30 and 35%, respectively, higher than in the R plants. In both biotypes, the leaves had a greater share in dry weight at early development stages, but from 50 DAP, the stem became the main contributor to the dry weight of the shoots. The R biotype produced 110 ± 4 seed plant−1, i.e., 12 ± 3% less seeds per plant than that of the S one (125 ± 7 seed plant−1). The growth indices leaf area ratio and specific leaf area were generally higher in the S biotype or similar between both biotypes; while the relative growth rate and net assimilation rate were punctually superior in the R biotype. These results demonstrate that the Ser-653-Asn mutation imposed a fitness cost in imazamox R wild poinsettia.

Competition, Growth Rate, and CO2Fixation in Triazine-Susceptible and -Resistant Smooth Pigweed (Amaranthus hybridus)

Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 438-444 ◽  
Author(s):  
William H. Ahrens ◽  
E. W. Stoller
Keyword(s):  
Growth Rate ◽  
Dry Weight ◽  
Dry Matter Accumulation ◽  
Lower Growth ◽  
Amaranthus Hybridus ◽  
Relative Growth ◽  
Lower Growth Rate ◽  
Net Assimilation ◽  
Synthetic Capacity ◽  
Smooth Pigweed

Triazine-susceptible (S) and -resistant (R) biotypes of smooth pigweed (Amaranthus hybridusL.) were grown in the field under competitive conditions at varying initial proportions of S and R plants. R plants were less competitive than S plants as measured by accumulation of total above-ground dry weight and seed dry weight. S and R plants were also grown in the field under non-competitive conditions at 100, 40, and 10% light. Growth rate at 10% light did not differ between S and R plants. At the two higher light intensities, dry-matter accumulation 11 weeks after seeding was about 40% less in the R plants. At 100% light, relative growth rate and net assimilation rate were lower in the R plants by about 3.5 and 19%, respectively. The light- and CO2-saturated rates of CO2fixation in intact leaves of glasshouse-grown R plants were 20% less than those in S plants. An apparent 10 and 20% greater number of chlorophyll molecules per photosystem II reaction center in R plants (as compared with S plants) grown in the field at 40 and 100% light, respectively, did not explain differences between the S and R biotypes in photo synthetic capacity. The S and R plants did not differ in specific leaf weight or chlorophyll content on a leaf-area basis. Lower growth rate of R plants may be responsible for inferior competitive ability of R biotypes and could be the result of an impaired photosynthetic capacity.

A greater relative growth rate of Brassica rapa L. at low temperatures increases biomass at anthesis

2001 ◽  
Vol 52 (6) ◽  
pp. 645 ◽  
Author(s):  
P. Si ◽  
N. Thurling
Keyword(s):  
Growth Rate ◽  
Brassica Rapa ◽  
Seed Yield ◽  
Negative Correlation ◽  
Low Temperatures ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Controlled Environment ◽  
Relative Growth ◽  
Potassium Leakage

0t, n.s.). These relationships suggested that it might be possible to develop early flowering cultivars with increased seed yield by selecting for higher RGR before anthesis. RGR of BC 2 F 3:4 lines in the field during winter was correlated with RGR at low temperatures (13/4°C) in a controlled environment, suggesting that genotypes producing more dry weight at anthesis grew more at the low temperatures normally experienced in the field. This was supported by a significant (P < 0.05 0.05) negative correlation (r = –0.69**) between growth in the field and potassium leakage from leaf tissue at 4

scholarly journals Effect of Transplanting Practices on Growth and Water Relations of ‘Colt’ Cherry Trees During Reestablishment

1989 ◽  
Vol 7 (1) ◽  
pp. 41-45 ◽  
Author(s):  
T.G. Ranney ◽  
N.L. Bassuk ◽  
T.H. Whitlow
Keyword(s):  
Growth Rate ◽  
Water Loss ◽  
Dry Weight ◽  
Root Surface ◽  
Area Ratio ◽  
Root Surface Area ◽  
Plant Water ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Cherry Trees

Abstract Dormant pruning, a film antitranspirant, and soil-applied paclobutrazol were evaluated as transplanting treatments in newly transplanted ‘Colt’ cherry trees under irrigated and water-stressed conditions. Under irrigated conditions all three treatments were effective in reducing plant water loss. However, all three treatments resulted in large reductions in mean growth rate, mean relative growth rate, root dry weight, and root surface area. The pruning treatment had no effect on the leaf area:root area ratio whereas the antitranspirant treatment resulted in an increased leaf area:root area ratio, a response considered undesirable. Paclobutrazol decreased the leaf area:root area ratio but also induced abnormal radial enlargement of plant roots. Under water-stressed conditions all three treatments were effective in reducing plant water loss and were successful in delaying plant water stress. Both pruned and antitranspirant treated plants had improved relative growth rates as compared to the controls.

scholarly journals Effects of Soil Moisture, NPK Fertilizers and Varieties on Grain Growth of Barley (Hordeum vulgare L.)

2013 ◽  
Vol 19 (1) ◽  
pp. 13-21
Author(s):  
MSI Mollah ◽  
MH Rashid ◽  
MS Hossain ◽  
M Khalekuzzaman
Keyword(s):  
Growth Rate ◽  
Soil Moisture ◽  
Hordeum Vulgare ◽  
Relative Growth Rate ◽  
Grain Growth ◽  
Dry Weight ◽  
Spikelet Number ◽  
Grain Number ◽  
Npk Fertilizers ◽  
Relative Growth

The experiments are conducted in the experimental field of the Department of Botany, Rajshahi University during the winter season of 2005-2006 to study the effects of soil moisture and NPK fertilizers on grain growth of four barley varieties (Hordeum vulgare L.) following split-split plot design. The highest grain growth parameters like, spikelet number, spike dry weight, grain number and grain dry weight, spike relative growth rate and grain relative growth rate were observed in the I2 treatment at different days after anthesis. F3 treatment produced the highest spikelet number, spike dry weight, grain number, grain dry weight, spike relative growth rate and grain relative growth rate but the control produced the lowest values. BHL-3 produced higher spikelet number and grain relative growth rate. BL-1 produced higher spike dry weight, grain number, grain dry weight and spike relative growth rate.DOI: http://dx.doi.org/10.3329/pa.v19i1.16985 Progress. Agric. 19(1): 13 - 21, 2008 

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