Dormancy and Impotency of Cocklebur Seeds. VI. Growth and Ethylene Production of Cotyledon Segments in Response to Oxygen

1976 ◽  
Vol 3 (5) ◽  
pp. 711 ◽  
Author(s):  
Y Esashi ◽  
K Kotaki ◽  
O Ishidoya
Keyword(s):  
Seed Germination ◽  
Ethylene Production ◽  
Growth Response ◽  
Maximum Growth ◽  
Growth Responses ◽  
Cooperative Action ◽  
Water Imbibition ◽  
Oxygen Tensions

Cotyledon tissue excised from dormant or non-dormant large cocklebur (Xanthium pensylvanicum Wallr.) seeds were examined for growth responses to CO2 or ethylene and for ethylene production under different oxygen tensions. Regardless of the dormancy status, cotyledons responded to CO2 and ethylene in a very similar manner to axes: the maximum growth response to CO2 and ethylene was obtained in quasi-anaerobioses in the case of the non-dormant cotyledons, but in increased oxygen tensions in the case of the dormant ones. A cooperative action of CO2 and ethylene was prominent in the presence of oxygen in suitable amounts. CO2 began to exert an effect first after water imbibition, then ethylene and lastly oxygen was needed to allow normal cotyledon growth. As the ethylene-producing system of cotyledons, active in quasi-anaerobioses, differed from that of axes in requirement for oxygen, the enhancement of ethylene production by exogenous CO2 was greater under reduced rather than increased oxygen tensions. Finally, the possible mechanism of cocklebur seed germination in subterranean habitats was discussed from the likely involvement of these three gaseous factors in axial and cotyledonary growth.

Growth Responses of Young Sockeye Salmon (Oncorhynchus nerka) to Different Diets and Planes of Nutrition

1971 ◽  
Vol 28 (10) ◽  
pp. 1635-1643 ◽  
Author(s):  
J. R. Brett
Keyword(s):  
Conversion Efficiency ◽  
Sockeye Salmon ◽  
Growth Response ◽  
Fish Meal ◽  
Oncorhynchus Nerka ◽  
Maximum Growth ◽  
Test Diet ◽  
Growth Responses ◽  
Marine Zooplankton ◽  
Conversion Efficiencies

The growth rate and food conversion efficiency of yearling sockeye salmon (Oncorhynchus nerka) (26 ± 2 g) was determined for Halver's test diet, Clark's Chinook mash, Abernathy pellets, frozen marine zooplankton, and sockeye mash, using a number of planes of nutrition. The maximum growth rates at 15 C varied from 3.1% dry body wt/day (Halver's) to 1.5%/day (marine zooplankton) with corresponding gross conversion efficiencies of 48 and 10%. Maintenance rations were determined, mostly by extrapolation, and used to evaluate the net conversion efficiency for each diet. The highest was 74% net conversion on Halver's test diet. Although major differences in growth response existed between the five diets, it was concluded that the various moist diets based on fish meal, used in these and earlier experiments, were not significantly different from each other when on the same plane of nutrition.

scholarly journals The differential effect of synthetic growth substances and other compounds upon plant species II. Seed germination and early growth responses to some arylcarbamic esters and related compounds

1946 ◽  
Vol 133 (873) ◽  
pp. 480-485 ◽  
Keyword(s):  
Seed Germination ◽  
Differential Effect ◽  
Marked Effect ◽  
Early Growth ◽  
Growth Substances ◽  
Growth Responses ◽  
Low Concentrations ◽  
Dicotyledonous Plants ◽  
Related Compounds ◽  
Synthetic Growth

The preparation and biological examination of a number of arylcarbamic esters (arylurethanes) are described. The experiments demonstrate the marked effect of iso propyl phenylcarbamate and some related compounds in very low concentrations upon the germination and seedling growth of cereals. The absence of effect of the same compounds in similar concentrations upon some dicotyledonous plants is noted.

Growth responses in red deer hinds from 16-24 months of age when fed two energy levels during their second winter

1998 ◽  
Vol 1998 ◽  
pp. 141-141
Author(s):  
M H Davies ◽  
D W Deakin
Keyword(s):  
Growth Response ◽  
Red Deer ◽  
Energy Levels ◽  
Growth Restriction ◽  
Growth Responses ◽  
Wide Range ◽  
Feeding Regimes ◽  
Cost Of Production ◽  
Red Meats

It is important that venison competes with other red meats in efficiency and cost of production. The growth responses of farmed red deer during the first 15-18 months of life have been well defined under a wide range of feeding and daylength regimes (Davies, 1995). However there is a need to examine less intensive systems of production which aim to maximise growth from grazed grass, following various growth-restriction feeding regimes during winter. The objective of this experiment was to quantify the growth response in 16-24 month old hinds fed two contrasting feeding regimes during their second winter, followed by a period at pasture.

Dose-Dependent Effects of the Action of Sulfur Nanoparticles on the Growth Response and Seed Production of Typical Steppe Phytocenoses

2017 ◽  
Vol 13 ◽  
pp. 156-161 ◽  
Author(s):  
Zinaida N. Ryabinina ◽  
Marija V. Ryabukhina ◽  
Maya V. Kolodina
Keyword(s):  
Seed Production ◽  
Biochemical Parameters ◽  
Growth Response ◽  
Growth Responses ◽  
Seed Productivity ◽  
Typical Steppe ◽  
Forms Of Life ◽  
Dose Dependent ◽  
Biological Group ◽  
Sulfur Nanoparticles

The article presents the results of a study of typical steppe phytocenoses presented one ecological and biological group - xeromesophyte but different systematic affiliation and forms of life, to the action of sulfur nanoparticles. Results of the study showed a relationship between the concentrations of sulfur nanoparticles and growth responses, biochemical parameters and seed productivity of investigated species

Growth responses in red deer hinds from 16-24 months of age when fed two energy levels during their second winter

1998 ◽  
Vol 1998 ◽  
pp. 141-141
Author(s):  
M H Davies ◽  
D W Deakin
Keyword(s):  
Growth Response ◽  
Red Deer ◽  
Energy Levels ◽  
Growth Restriction ◽  
Growth Responses ◽  
Wide Range ◽  
Feeding Regimes ◽  
Cost Of Production ◽  
Red Meats

It is important that venison competes with other red meats in efficiency and cost of production. The growth responses of farmed red deer during the first 15-18 months of life have been well defined under a wide range of feeding and daylength regimes (Davies, 1995). However there is a need to examine less intensive systems of production which aim to maximise growth from grazed grass, following various growth-restriction feeding regimes during winter. The objective of this experiment was to quantify the growth response in 16-24 month old hinds fed two contrasting feeding regimes during their second winter, followed by a period at pasture.

The limits of sodium/calcium interactions in plant growth

2000 ◽  
Vol 27 (7) ◽  
pp. 709 ◽  
Author(s):  
Robert J. Reid ◽  
F. Andrew Smith
Keyword(s):  
High Salinity ◽  
Foliar Application ◽  
Maximum Growth ◽  
Growth Responses ◽  
Wheat Seedlings ◽  
Low Salinity ◽  
High Concentrations ◽  
Main Component ◽  
Dependent Processes ◽  
Root Plasma Membrane

The amelioration of Na toxicity by supplementation of Ca in the growth medium was investigated in wheat with the aims of (1) identifying the Ca-dependent processes that determine the growth responses and (2) defining the limits to Ca effects on these processes. Growth of wheat seedlings was strongly inhibited by 150 mM NaCl but improved as the Ca concentration in the nutrient medium was increased up to 2.34 mM. Further increasing Ca to 10 mM did not increase growth, nor did foliar application of Ca. Even at high concentrations of Ca, the maximum growth was only approximately 50% of the growth at low salinity. We conclude that the main component of improved growth caused by Ca was via its apoplastic effects on the transport of Na and K across the root plasma membrane, rather than by increasing root or shoot Ca concentrations. There was no evidence that high salinity inhibited Ca uptake to the shoot. The limits to improvement of growth by Ca appear to relate to the fact that, although Ca is able to ameliorate the toxicity caused by high intracellular Na, it is not able to overcome the osmotic deficits associated with high salinity.

scholarly journals Brassinosteroids Induce Strong, Dose-Dependent Inhibition of Etiolated Pea Seedling Growth Correlated with Ethylene Production

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 849
Author(s):  
Jiroutová ◽  
Mikulík ◽  
Novák ◽  
Strnad ◽  
Oklestkova
Keyword(s):  
Ethylene Production ◽  
Biological Activities ◽  
Growth Responses ◽  
Pea Seedlings ◽  
Highly Sensitive ◽  
Dependent Inhibition ◽  
Ca 50 ◽  
Dose Dependent Inhibition ◽  
Optimized Conditions ◽  
Dose Dependent

We have recently discovered that brassinosteroids (BRs) can inhibit the growth of etiolated pea seedlings dose-dependently in a similar manner to the ‘triple response’ induced by ethylene. We demonstrate here that the growth inhibition of etiolated pea shoots strongly correlates with increases in ethylene production, which also responds dose-dependently to applied BRs. We assessed the biological activities of two natural BRs on pea seedlings, which are excellent material as they grow rapidly, and respond both linearly and uni-phasically to applied BRs. We then compared the BRs’ inhibitory effects on growth, and induction of ethylene and ACC (1-aminocyclopropane-1-carboxylic acid) production, to those of representatives of other phytohormone classes (cytokinins, auxins, and gibberellins). Auxin induced ca. 50-fold weaker responses in etiolated pea seedlings than brassinolide, and the other phytohormones induced much weaker (or opposite) responses. Following the optimization of conditions for determining ethylene production after BR treatment, we found a positive correlation between BR bioactivity and ethylene production. Finally, we optimized conditions for pea growth responses and developed a new, highly sensitive, and convenient bioassay for BR activity.

scholarly journals Are Commonly Measured Functional Traits Involved in Tropical Tree Responses to Climate?

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Fabien Wagner ◽  
Vivien Rossi ◽  
Christopher Baraloto ◽  
Damien Bonal ◽  
Clément Stahl ◽  
...  
Keyword(s):  
Functional Traits ◽  
Tree Growth ◽  
Water Availability ◽  
Growth Response ◽  
Climate Models ◽  
Growth Strategy ◽  
Limiting Factor ◽  
Maximum Height ◽  
Growth Strategies ◽  
Growth Responses

Climate models predict significant rainfall reduction in Amazonia, reducing water availability for trees. We present how functional traits modulate the tree growth response to climate. We used data from 3 years of bimestrial growth measurements for 204 trees of 53 species in the forest of Paracou, French Guiana. We integrated climate variables from an eddy covariance tower and functional trait values describing life history, leaf, and stem economics. Our results indicated that the measured functional traits are to some extent linked to the response of trees to climate but they are poor predictors of the tree climate-induced growth variation. Tree growth was affected by water availability for most of the species with different species growth strategies in drought conditions. These strategies were linked to some functional traits, especially maximum height and wood density. These results suggest that (i) trees seem adapted to the dry season at Paracou but they show different growth responses to drought, (ii) drought response is linked to growth strategy and is partly explained by functional traits, and (iii) the limited part of the variation of tree growth explained by functional traits may be a strong limiting factor for the prediction of tree growth response to climate.

Canopy tree growth responses following selection harvest in seven species varying in shade tolerance

2009 ◽  
Vol 39 (2) ◽  
pp. 430-440 ◽  
Author(s):  
Trevor A. Jones ◽  
Grant M. Domke ◽  
Sean C. Thomas
Keyword(s):  
Community Dynamics ◽  
Time Lag ◽  
Species Abundance ◽  
Basal Area ◽  
Maximum Growth ◽  
Forest Community ◽  
Growth Responses ◽  
Canopy Tree ◽  
Tolerant Species ◽  
Shade Tolerant Species

We used tree ring measurements to investigate the temporal response of basal area increment (BAI) of canopy trees following selection harvests by sampling across a chronosequence of stands with known harvest dates in tolerant hardwood (Great Lakes – St. Lawrence) stands in central Ontario. Seven tree species of various shade tolerances ranged widely in their responses to reduced competition. The more shade-tolerant species responded more positively: shade-tolerant species showed an average increase in BAI of 35% 4–15 years postharvest compared with 16% for mid-tolerant species and –7.5% for intolerant species. All species showed a time-lag in postharvest growth responses, with maximum growth responses occurring between 3 and 15 years postharvest. Tree size was the most important factor determining the magnitude of BAI response, with smaller trees consistently responding more than larger trees. We suggest that higher growth responses to selection harvests among shade-tolerant species may contribute to declines in mid-tolerant species abundance in selection-managed stands. More broadly, interspecific variability in canopy tree responses to forest disturbance appears to follow patterns distinct from seedling and sapling responses, with important implications to forest community dynamics in both managed and unmanaged forests.

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