scholarly journals Attempts at establishing the culture conditions for Lemna minor L.

2015 ◽  
Vol 44 (2) ◽  
pp. 243-253 ◽  
Author(s):  
M. Krzychowska ◽  
J. Zimna ◽  
K. Bytniewska ◽  
W. Macjejewska-Potapczyk
Keyword(s):  
Light Intensity ◽  
Surface Area ◽  
Vegetative Propagation ◽  
Total Protein ◽  
Dry Matter ◽  
Lemna Minor ◽  
Culture Conditions ◽  
Protein Determination ◽  
The Media ◽  
Aseptic Conditions

The influence of the concentration, composition and pH of the substrate as well as of light intensity on the growth and vegetative propagation of <i>Lemna minor</i> L. was investigated. The media of Hutner, Hoagland and Pirson and Seidel were used. At first the experiments were carried out under unsterile conditions. Later sterilized duckweed was cultured in aseptic conditions. The dry matter was determined. Surface area increment and an increase in the number of fronds were evaluated by the planimetric method. For total protein determination in <i>Lemna minor</i> L. from unsterile and sterile cultures Lowry's method was used.

scholarly journals Light intensity drives different growth strategies in two duckweed species: Lemna minor L. and Spirodela polyrhiza (L.) Schleiden

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12698
Author(s):  
Małgorzata Strzałek ◽  
Lech Kufel
Keyword(s):  
Light Intensity ◽  
Surface Area ◽  
Growth Rates ◽  
Lemna Minor ◽  
Growth Strategies ◽  
Light Conditions ◽  
Natural Habitats ◽  
Spirodela Polyrhiza ◽  
Trade Off ◽  
Open Habitat

Duckweed species Lemna minor and Spirodela polyrhiza are clonal plants with vegetative organs reduced to a frond and a root in L. minor or a frond and several roots in S. polyrhiza. They reproduce vegetatively by relatively rapid multiplication of their fronds. The habit of S. polyrhiza (large fronds with up to 21 roots) makes it a strong competitor among representatives of the family Lemnaceae, probably due to different resource-use strategies compared to small duckweed. In our study, light was the resource that affected the plants before and during the laboratory experiment. We sampled the plants from natural habitats differing in light conditions (open and shady) and grew them for 16 days in a thermostatic growth room at 22 °C under a 16:8 photoperiod and three light intensities (125, 236, 459 µmol photons m–2 s–1) to investigate the trade-off between frond enlargement and multiplication. Both species from the open habitat had higher growth rates based on the frond numbers and on surface area of fronds compared to plants from the shady habitat. They adopted different species-specific strategies in response to the experimental light conditions. The species size affected the growth rates in L. minor and S. polyrhiza. Spirodela polyrhiza grew slower than L. minor, but both species grew fastest at medium light intensity (236 µmol m–2 s–1). Lemna minor maintained the growth rates at high light intensity, while S. polyrhiza slowed down. Spirodela polyrhiza responded to deteriorating light conditions by increasing its frond surface area, thus optimising light capture. Lemna minor from the shady habitat enhanced light harvest by increasing chlorophyll a concentration, but did not invest more in frond enlargement than L. minor from the open habitat. Under shady conditions, S. polyrhiza is likely to achieve an advantage over L. minor due to the larger frond size of the former. Our findings suggest the existence of a trade-off between size and number in duckweed.

scholarly journals Responses of Root Characteristic Parameters and Plant Dry Matter Accumulation, Distribution and Transportation to Nitrogen Levels for Spring Maize in Northeast China

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 308
Author(s):  
Yang Yu ◽  
Chunrong Qian ◽  
Wanrong Gu ◽  
Caifeng Li
Keyword(s):  
Surface Area ◽  
Nitrogen Fertilizer ◽  
Root Length ◽  
Dry Matter ◽  
Projection Area ◽  
Dry Matter Accumulation ◽  
Characteristic Parameters ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Matter Transport

Improving nitrogen use efficiency is a significant scientific problem to be solved. Two maize hybrids JD27 (Jidan 27) and SD19 (Sidan 19) were selected to study the effects of nitrogen levels on root characteristic parameters and plant dry matter accumulation, distribution and transportation. We set five different nitrogen levels, which were nitrogen deficiency (000N), low nitrogen (075N), medium nitrogen (150N), high nitrogen (225N) and excessive nitrogen (300N). The results showed that the root length and root surface area of JD27 were significantly higher than those of SD19 under 075N. With the increase of nitrogen levels, the root difference among varieties gradually decreased. The root length, projection area, total surface area and total volume reached the maximum values at silking stage. The average root diameter kept stable or decreased slowly with the growth stage. The dry matter accumulation of JD27 was higher than that of SD19 at all growth stages. Increasing the amount of nitrogen fertilizer can promote the transport of dry matter to grain and improve dry matter transport efficiency after anthesis. Under the treatment of medium and high nitrogen fertilizer, maize was easy to obtain a higher yield, but excessive nitrogen fertilizer inhibited the increase of yield. This study provides theoretical and practical guidance for maize production techniques.

Factors affecting the hydrogen cyanide potential of forage sorghum.

1990 ◽  
Vol 41 (6) ◽  
pp. 1093 ◽  
Author(s):  
JL Wheeler ◽  
C Mulcahy ◽  
JJ Walcott ◽  
GG Rapp
Keyword(s):  
Water Stress ◽  
Light Intensity ◽  
Hydrogen Cyanide ◽  
Dry Matter ◽  
Early Stage ◽  
Phosphorus Fertilizer ◽  
Factors Affecting ◽  
Forage Sorghum ◽  
Plant Maturity ◽  
Selection For

The effect of seven factors, namely genotype, plant maturity, nitrogen fertilizer, phosphorus fertilizer, water stress, light intensity and temperature, on the hydrogen cyanide potential (HCNp) of forage sorghum was studied in three pot experiments. Fivefold differences occurred between genotypes in HCNp, with a breeder's line, X45106, selected for low HCNp having a maximum of 520 mg HCN kg-1 DM (dry matter) compared with 2300 and 2450 mg kg-1 DM for cvs Zulu and Silk respectively. In X45 106, HCNp (mg HCN kg-1 DM) declined curvilinearly with age d (days from sowing) (HCNp=8460- 320d+ 3.1d2) and linearly in Silk (HCNp = 9020 - 110d), but the decline in Zulu was not statistically significant. Nitrogen (equivalent to 200 kg ha-1 of N) increased HCN, (P< 0.001), but more so in full light (100 mg kg-1 compared with 1430 mg kg-1) than in 50% shade (190 mg kg-1 compared with 690 mg kg-1). In one experiment, acute water stress appeared to reduce HCNp, but this was confounded with the strong decline due to aging. In another study, acute water stress had no effect on HCNp. Neither the application of superphosphate nor change in light intensity, nor change in temperature had a direct significant effect on HCNp in these studies. Breeding and selection for low HCNp appears a promising approach to ensuring that sorghum plants will provide non-toxic forage from an early stage of growth.

Growth of Amaranthus Hybridus (African Spinach) under diffferent Daylight Intensities in the Dry Season in Southern Nigeria

1987 ◽  
Vol 23 (2) ◽  
pp. 193-200 ◽  
Author(s):  
J. M. O. Eze
Keyword(s):  
Light Intensity ◽  
Biochemical Parameters ◽  
Dry Matter ◽  
Maximum Growth ◽  
Area Ratio ◽  
Dry Matter Accumulation ◽  
Amaranthus Hybridus ◽  
Maximum Accumulation ◽  
Southern Nigeria ◽  
Reduced Light

SummaryThe growth of Amaranthus hybridus under different daylight intensities was assessed in terms of physical, morphological and biochemical parameters. Maximum growth in many respects was achieved at about 70% of full daylight. However, full daylight favoured chlorophyll stability and maximum accumulation of total dry matter, carbohydrate, chlorophyll and ascorbic acid. The leaf area ratio increased uniformly with decrease in light intensity. Ageing was accelerated by full daylight. Reduced light intensity reduced dry matter accumulation in the roots more than in the stems or leaves.

scholarly journals The effect of differing types of cloth and of contamination by non-feed nitrogen on intestinal digestion estimates using porous synthetic-fibre bags in a cow

1990 ◽  
Vol 63 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Tuomo Varvikko ◽  
Aila Vanhatalo
Keyword(s):  
Free Surface ◽  
Chemical Composition ◽  
Pore Size ◽  
Surface Area ◽  
Dry Matter ◽  
Synthetic Fibre ◽  
Aqueous Suspension ◽  
Barley Straw ◽  
Intestinal Digestion ◽  
Free Surface Area

The influence of free surface area and pore size of a synthetic-fibre bag, and flow of intestinal substances into the bag, on the intestinal digestion estimates by the nylon-bag method of dry matter (DM), neutral detergent fibre (NDF), nitrogen, NDF-N and feed 15N was studied using a non-lactating cow fed on hay supplemented with barley and oats at maintenance level. The bags containing 15N-labelled ground ryegrass (Lolium perenne), barley, barley straw or rapeseed (Brassica napus) straw were introduced into the duodenum through a T-shaped cannula and collected from the faeces. Also, the disappearance of N from the bag was related to the true intestinal N digestion by comparing it with the net loss between duodenum and faeces of 15N in ryegrass introduced into the duodenum in an aqueous suspension. It was noted that the bag cloth often significantly affected both disappearance values and the subsequent chemical composition of the residues. Re-analysing part of the data as a 2x2 factorial (free surface x pore size) suggested that free surface area was often more important than pore size as a determinant of both disappearance values and chemical composition. Lower apparent (Kjeldahl N) than true (15N) feed N disappearance from the bag suggested a notable proportion of non-feed N in the residues, especially with fibrous feeds with low N. With ryegrass, 15N net loss within the intestine was lower than 15N disappearance from the bags. It was concluded that disappearance of Kjeldahl N is an underestimate of feed N disappearance from bags, but may possibly be an overestimate of the true intestinal digestion of feed N.

scholarly journals Biochemical processes in cows and the biological value of milk under influence of cobalt citrate

2017 ◽  
Vol 19 (74) ◽  
Author(s):  
M. Khomyn ◽  
I. Kovalchuk ◽  
S. Kropyvka ◽  
M. Tsap
Keyword(s):  
Milk Production ◽  
Total Protein ◽  
Dry Matter ◽  
Inorganic Phosphorus ◽  
Animal Blood ◽  
Biological Value ◽  
Biochemical Processes ◽  
Mineral Supplements ◽  
Daily Milk Production ◽  
Daily Milk

The aim of research was to study the effect of different amounts of cobalt citrate produced by nanotechnology on biochemical processes in cows, their productivity and biological value of milk in the first two months of lactation. To achieve this goal the subsequent problems have been solved. We investigated the effect of different amounts of cobalt citrate on biochemical parameters of blood and milk of cows and controlled their average daily yield. The experiment has been conducted in 3 groups of cows (5 cows each) of Ukrainian black and white dairy cattle, analogue by body weight (590–620 kg), performance (6,5–6,8 thousand kg of milk per past lactation) and lactation (3–4 lactation). Unlike the control cows, animals experimental (ІІ) group for two months were fed by mineral supplements in the form of cobalt citrate in an amount of 19 mg Co/kg of dry matter of diet and research (ІІІ) – cobalt citrate in an amount of 34 mg Co/kg of dry matter of diet. Duration of cobalt citrate feeding of cows of research groups was 2 months. In all groups of cows the samples of venous blood were taken in preparation for feeding additives period and during 60 day of additives feeding period in order to determine the concentration of total protein, ceruloplasmin, sialic acids, hexoses bound to proteins and activity of amino transferases. The milk production has been controlled in days of sampling with the definition of daily milk yield per cow and taking an average sample for the determination of milk fat, protein, lactose, inorganic phosphorus and calcium. It has been established that the inclusion in the diet of cows of experimental (ІІ) group of mineral supplements contributed to an increase in animal blood total protein content by 11.9% (P < 0.05), inorganic phosphorus by 15.3% (P < 0.05) and hexoses bound protein by 8.8% (P < 0.05). Under these conditions milk content of inorganic phosphorus increased by 5.6% (P < 0.05) and average daily milk production increased by 4.5%. The use of mineral additives in third experimental group of animals within two months contributed to an increase in blood ceruloplasmin content by 5.1% (P < 0.05) and hexoses bound protein by 11.5% (P < 0.01). Mineral supplements promote 5.4% raise of average daily milk production and increase it to the lactose content by 0.10% (in absolute).

scholarly journals Phaeodactylum Trıcornutum Kültürlerinde Biyomas Tahmini

2017 ◽  
Vol 5 (2) ◽  
pp. 182
Author(s):  
Burcu Ak ◽  
Gökhan Tamer Kayaalp ◽  
Oya Işık ◽  
Melis Çelik Güney
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Optical Density ◽  
Phaeodactylum Tricornutum ◽  
Dry Matter ◽  
Nitrogen Deficiency ◽  
Regression Equation ◽  
Control Group ◽  
Analysis Method ◽  
The Mathematical Model

Phaeodactylum tricornutum is the microalgae that is known to produce lipid. In this study, it was aimed to estimate the microalgae Phaeodactylum tricornutum dry matter cultured in the conditions of nitrogen deficiency as a stress factor, in outdoor, in photo bioreactors, by using multiple regression analysis method. In this study, diatom Phaeodactylum tricornutum (Bohlin) was cultured medium of which N was reduced by 50% and with 20% inoculation ratio. The light intensity, temperature, optical density and chlorophyll a, were measured daily. The mathematical model was formed for control group and 50 % of the N applied to the group using optical density, temperature, light intensity, chlorophyll a and without chlorophyll a. The regression equation of control group was estimated. The R2 value of control group was found 95.1% and statistically significant. Then, the regression equation was estimated for control group without chlorophyll a. The R2 value of this equation was found 94.0% and statistically significant. And then, the regression equation was estimated in 50% nitrogen. The R2 value of control group was found 92.4% and statistically significant. Finally, the regression equation was estimated in 50% nitrogen deficiency without chlorophyll a. The R2 value of this equation was found 91.7% and statistically significant.

EFFECT OF DIFFERENT SALINITY AND LIGHT INTENSITY ON THE GROWTH OF PORPHYRIDIUM CRUENTUM

2021 ◽  
Vol 8 (18) ◽  
pp. 71-77
Author(s):  
Leyla USLU
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Optical Density ◽  
Dry Matter ◽  
Porphyridium Cruentum ◽  
Laboratory Conditions ◽  
Light Intensities ◽  
Density Values

In the study, Porphyridium cruentum was cultured under laboratory conditions at 20±2°C, 16:8 (light:dark) photoperiod and continuous aeration to different salinity (20‰, 30‰, 40‰) and two different light intensities (37 µmol m-2s-1 photon and 110 µmol m-2s-1 photon) and growth was determined. Dry matter, optical density and chlorophyll a parameter were used to determine growth. The best growth was determined in culture with a salinity of 30‰ at 110 µmol m-2s-1 photon light intensity. In this group, the optical density (OD) was 1.504±0.003 and the dry matter amount was 1.327gl-1. In the case of 37µmol µmol m-2s-1 photon light intensity, the optical density values were found to be similar in groups with 30‰ and 50‰ salinity and were found to be 1.234±0.004 and 1.215±0.002, respectively. The amounts of dry matter were also similar; 1.168gl-1 and 1.159gl-1, respectively. While the lowest growth was in the culture at 37 µmol m-2s-1 photon light intensity and 20‰ salinity. The optical density obtained on the last day of this group was 1.165±0.004 and the dry matter amount was determined as 0.986gl-1. The amount of chlorophyll a was determined in the cultured groups at the best 37 µmol m-2s-1 photon light intensity.

A Comparison of Liquid Scintillation and Geiger–Müller Estimates of Primary Productivity in an in situ Experiment

1973 ◽  
Vol 30 (5) ◽  
pp. 708-711 ◽  
Author(s):  
F. J. Ward ◽  
Masami Nakanishi
Keyword(s):  
Light Intensity ◽  
Surface Area ◽  
Primary Productivity ◽  
Liquid Scintillation ◽  
Lake Biwa ◽  
In Situ Experiment ◽  
M Estimate ◽  
M Estimates ◽  
Loss Rates

For an in situ experiment conducted in Shiozu Bay, Lake Biwa, Japan, primary productivity estimates from liquid scintillation radioactivity counts of wet algae were generally higher than those from Geiger–Müller radioactivity counts of desiccated algae. Values at 0 m were similar, the G–M estimate at 0.5 m was 10% higher, but from 3 to 13 m the liquid scintillation values ranged from 11 to 33% higher than G–M estimates. The 20-m estimates were low and similar. Differences were caused primarily by 14C losses during desiccation prior to G–M counting. Increasing loss rates between 0.5 and 3.0 m may have been caused by decreasing light intensity. On the basis of surface area, the estimate from liquid scintillation data was 27% greater than that obtained from G–M data.

Lime-slotting technique to ameliorate subsoil acidity in a clay soil II. Effects on medic root-growth, water extraction and yield

Soil Research ◽  
1995 ◽  
Vol 33 (3) ◽  
pp. 443 ◽  
Author(s):  
NS Jayawardane ◽  
HD Barrs ◽  
WA Muirhead ◽  
J Blackwell ◽  
E Murray ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Surface Area ◽  
Dry Matter ◽  
Acid Soil ◽  
Water Extraction ◽  
Undisturbed Soil ◽  
Subsoil Acidity ◽  
Soil Water Extraction ◽  
Limed Soil

Subsoil acidity causes low crop production, which is often associated with shallow root development and restricted soil water extraction. In part I of this series, lime-slotting of an acid soil was shown to improve the soil physical and chemical characteristics for root growth. In a lysimeter study on an acid soil, the effects of several soil ameliorative treatments on root growth, water extraction and yields of a medic crop were evaluated. Large lysimeter cores of 0.75 m diameter and 1.35 m deep were used. The soil treatments included a non-ameliorated acid soil, lime-slotting with a 0.15 m wide and 0.8 m deep slot containing 20 t ha-1 of lime, lime-slotting combined with surface phospho-gypsum application at 10 t ha-1, and complete amelioration of the entire soil volume by mixing lime at 133 t ha-1 and repacking to a low bulk density of 1.1 t m-3. In the non-ameliorated acid soil, medic roots were confined to the surface (0.1 m) layer, resulting in limited water extraction of 32 mm during a prolonged drying cycle, and a low dry matter yield of 70 g m-2. In the lime slotted soil, roots grew within the slot to its full depth, although penetration into the undisturbed soil was restricted to the soil immediately adjacent to the slot. Consequently, the root length per unit surface area (La) at depths below 0.1 m depth was increased to 9.9 km m-2. During a drying cycle, water extraction increased to 58 mm. The increased water extraction came from both the slotted soil and the undisturbed soil between slots. This led to an increase in dry matter yields to 270 g m2. In lime-slotted soils with surface gypsum applications, the root growth and crop water extraction patterns were similar to the lime-slotted soil. Repacking limed soil resulted in similar root lengths (L(a) 10.0 km m-2) as lime-slotted soil. However, owing to more uniform distribution of roots in the repacked soil, water extraction was increased to 100 mm and yields increased to 590 g m-2. Yields of non-ameliorated soil were only 12% of the repacked, limed soil. However, lime-slotting which involves loosening only 25% of the soil surface area and addition of only one-sixth of the amount of lime required for complete soil amelioration, led to marked increases in yield (46% of the yield of repacked soil). Future field studies are required to evaluate the optimum limed-slot configurations required for different soils, crops and climatic regimes.

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