Significant Differences In Dry Weight Research Articles

The growing profile of Diplotaxis tenuifolia (L.) DC. under different LED lighting

The growth of rocket Diplotaxis tenuifolia (L.) DC. profiles was studied during 30 days of growing in the chamber under different lighting regimes; T5_ peak at 630 nm, LED1_ peak at 545 nm and LED2_ peak at 599 nm. There were no significant differences in dry weight after 15 days, however, from day 15 to 30, the increase in dry weight was significantly biggest under LED2. This agrees well with estimated average leaf area (LA) per plant (43.83 cm2 ), the increase of LA (39.70 cm2 ) and total fresh weight (7.898 g per plant). The regression analysis revealed the strongest correlation between the dry weight and PPFD_R light intensity (0.792**), showing the positive effect of additional LED lighting in comparison with standard T5 light.

A near-isogenic line for spikelet number in rice with a genetic background of IR64 under various fertilizer conditions

ABSTRACT The total spikelet number (TSN) per panicle is an essential factor involved in grain yield among yield components in rice. IR64-NIL12 carrying qTSN12.2-YP4, which was detected on chromosome 12 for TSN per panicle, has been developed in a previous study. It is important to characterize the environment of gene function to increase yields. Thus, we attempted to evaluate IR64-NIL12 grown under no, low, and high fertilizer conditions in 2019 and 2020. Grain yields of IR64-NIL12 were significantly higher than that of IR64 in all conditions. The average grain yield of each condition for IR64 and IR64-NIL12 ranged from 387 to 616 g m−2. Therefore, qTSN12.2-YP4 would have an increasing effect on grain yield within this range. The ratio of fertility improved in IR64-NIL12. This rice line exhibited modified traits, such as tiller number and plant height (during the vegetative stage), as well as panicle number (at maturity), which may confer an advantage in terms of light-intercepting characteristics. We also focused on the number of unproductive tillers and dry weight per tiller at the heading stage to investigate the mechanism of the increasing effect of qTSN12.2-YP4 on TSN per panicle. There is a significant difference in dry weight per tiller at heading between IR64 and IR64-NIL12, but not in the percentage of unproductive tillers. Therefore, this result indicated that qTSN12.2-YP4 contributes to increasing dry weight per tiller until the heading stage and, consequently, TSN per panicle.

Effects of crop rotations on microbial community in rhizosphere soil of cucumber seedlings and its feedback

We studied the effects of 7-crop rotations and continuous - monocropping systems on soil microorganism and its feedback. The results showed that absolute abundance of soil bacteria (Pseudomonas and Bacillus) in tomato - celery - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than control (CK). Absolute abundance of soil fungi in tomato - celery - cucumber - cabbage, kidney bean - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than CK. Dry weight of cucumber seedlings was significantly positively correlated with bacterial (Pseudomonas and Bacillus) abundance, and negatively correlated with fungal count. The results of inoculation with Fusarium oxysporum f.sp. cucumerinum showed that plant dry weight of cucumber seedlings in tomato - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage, cucumber - tomato - cucumber - cabbage rotation soil was significantly higher than other treatments, and their disease index was significantly lower than other treatments. There was no significant difference in dry weight of cucumber seedlings in rotation and CK in the soil sterilization test. The results of plant - soil feedback experiment showed that soil microbial changes caused by different rotation patterns had a positive feedback effect on growth of cucumber seedlings.

ROOT ASSOCIATED BACTERIAL ENDOPHYTES FROM POACEAE PLANTS: IDENTIFICATION, CHARACTERIZATION AND PLANT GROWTH PROMOTION

Diazotrophic endophytic bacteria contribute to the plant growth using various plant growth promoting traits as well as by inducing the plant defence mechanism upon pathogen attack. Aim of the present study was to isolate true diazotrophic endophytic bacteria from the total diazotrophic bacterial community of wheat and pearl-millet plants. Further, these isolates were evaluated for their potential of plant growth promotion by in vitro and in vivo experiments. We isolated total three diazotrophic endophytic bacteria based on their growth after repetitive subculturing on nitrogen free medium. Molecular characterization of all three isolates showed affiliation to the genera Agrobacterium, Pseudomonas and Brevundimonas. In vitro analysis of plant growth promoting traits showed positive result for indole acetic acid (IAA) production, cellulase and protease activity. The IAA production is found between the ranges of 98 to 113 µg ml-1. All the endophytic bacterial isolates showed the PCR amplification of NifH gene and ammonia production. Diazotrophic endophytic bacterial isolates (PR1, JB3 and JB6) were tested for their capacity to promote the plant growth using pot experiment. All the diazotrophic endophytic bacteria differ in their plant growth promotion ability as analyzed by various plant growth parameter compared to the untreated control plants. In Pot experiment, PR1 and JB6 showed a significant difference in dry weight of root, whereas JB3 and JB6 showed the significant differences in shoot length and total nitrogen content (p≤0.05) compared to the untreated plants.

Postharvest characteristics of two flowering stages of torch ginger (Etlingera elatior) inflorescences

Torch ginger (Etlingera elatior), a flourish in tropical and subtropical climates crop, with extravagant and showy inflorescence may be used as cut flower at each developmental stage. Limited studies have been undertaken to reveal the postharvest performance of this leafless inflorescence, especially at advanced developmental stages. Therefore, the objective of this study was to elucidate the postharvest performance of the torch ginger inflorescence treated with different vase solutions. Inflorescences at two flowering stages i.e., tight bud stage and torch shows stage at about 35 and 58 days, respectively, after emergence from rhizome, were used in this study. Sucrose (20 g L-1), 8-hydroxyquinoline sulfate (8-HQS, 0.1 g L-1) and distilled water were used as vase solution treatment. Postharvest characteristics, including vase life, relative fresh weight (RFW), dry weight, solution uptake rate, respiration and ethylene production rate were evaluated. Results showed that vase life of tight bud stage inflorescence was significantly higher than torch shows stage irrespective of treatments used. In contrast, significantly higher solution uptake rate was shown in the torch shows stage inflorescence. There was no significant difference in dry weight and respiration rate measured. No ethylene was detected in all treated inflorescences throughout the study. Prolongation of vase life was associated with the increase in RFW. Increase of RFW was found in tight bud stage inflorescence but reduction of RFW was shown in torch stage inflorescence at the end of vase life. The decrease of RFW could be due to the breakdown of stored carbohydrates in peduncle for the development of true flowers for pollination purpose. Supplementation of sucrose promoted the opening of true flowers. The use of 8-HQS and distilled water enabled the development of true flowers, but they failed to open. Sucrose treated inflorescences both in tight bud and torch stage showed better postharvest quality compared to 8-HQS and distilled water.

The Influence of Glucose Exposure Load and Peritoneal Membrane Transport on Body Composition and Nutritional Status Changes after 1 Year on Peritoneal Dialysis.

The characteristics of peritoneal membrane transport differ among patients, affecting the prescription of peritoneal dialysis (PD) modality and glucose exposure in order to achieve an effective dialysis. This study aims to verify the influence of glucose exposure load and peritoneal membrane transport on body composition and nutritional status changes after the first year of PD. We examined a cohort of 85 incident PD patients during the first year of treatment. We established a cut-off of 5% to define changes in dry weight (DW), lean tissue mass (LTM), and fat mass (FM). In total, 50.6% of the patients presented DW gain, 41.2% showed LTM loss, and 65.9% presented FM gain. Over the time (T0 - T12), we found significant differences in DW, body mass index (BMI), adipose tissue mass (ATM), FM and fat tissue index (FTI). Patients with lower dialysate-to-plasma creatinine ratio showed DW and FM gain. We observed a higher percentage of nonfast transporters in DW gain when comparing with DW no gain. As for glucose exposure load, no body composition changes were seen. Most patients presented DW gain, FM gain, and LTM loss. The characteristics of peritoneal membrane transport affected DW during the first year, changes being greater in nonfast than in fast transporters.

Retraction: 'Each of the chloroplast potassium efflux antiporters affects photosynthesis and growth of fully developed Arabidopsis rosettes under short-day photoperiod' by Somnath Dana, Andrei Herdean, Björn Lundin and Cornelia Spetea.

Retraction: 'Each of the chloroplast potassium efflux antiporters affects photosynthesis and growth of fully developed Arabidopsis rosettes under short-day photoperiod' by Somnath Dana, Andrei Herdean, Björn Lundin and Cornelia Spetea.

Effect of Soil Textural Classes on the Biological Nitrogen Fixation by Bradyrhizobium Measured by 15N Dilution Analysis

The current study was conductedas a pot experiment to determine the effect of soil texture on biological nitrogen fixation (BNF) of six most efficient local isolates, specified, of Bradyrhizobium. Cowpea (Vignaunguiculata L.), as a legume host crop, was used as a host crop and 15N dilution analysis was used for accurate determination of the amount of N biologically fixed under experimental parameters specified. Soils used are clay loam, sandy clay loam and sandy loam. Biological Nitrogen Fixation (BNF), in different soil textural classes, was as in the following order: medium texture soil > heavy texture soil > light textured soil. Statistical analysis showed that there is a significant variation in BNF % among six Iraqi isolates in the three soil textural classes. There is a significant variation in the number of the nodules of the six Isolates in one soil texture. However, nodules number does not agree with the BNF% in the same soil for any isolates. Statistical analysis of the data showed that there were significant differences in plant dry weight among the soil textural classes all over local isolates used in this study. Data also showed that there were significant differences in dry weight under different isolates.

Effect of Soil Textural Classes on the Biological Nitrogen Fixation by Bradyrhizobium Measured by 15N Dilution Analysis

The current study was conductedas a pot experiment to determine the effect of soil texture on biological nitrogen fixation (BNF) of six most efficient local isolates, specified, of Bradyrhizobium. Cowpea (Vignaunguiculata L.), as a legume host crop, was used as a host crop and 15N dilution analysis was used for accurate determination of the amount of N biologically fixed under experimental parameters specified. Soils used are clay loam, sandy clay loam and sandy loam. Biological Nitrogen Fixation (BNF), in different soil textural classes, was as in the following order: medium texture soil > heavy texture soil > light textured soil. Statistical analysis showed that there is a significant variation in BNF % among six Iraqi isolates in the three soil textural classes. There is a significant variation in the number of the nodules of the six Isolates in one soil texture. However, nodules number does not agree with the BNF% in the same soil for any isolates. Statistical analysis of the data showed that there were significant differences in plant dry weight among the soil textural classes all over local isolates used in this study. Data also showed that there were significant differences in dry weight under different isolates.

Engineering of Soil Biological Quality from Nickel Mining Stockpile Using Two Earthworm Ecological Groups

Earthworms have the ability in modifying soil biological quality for plant growth. Their ability is mostly depending on its ecological groups. The objectives of the research were to study the influence of two ecological groups of earthworms on soil microbial activity and soil micro-fauna abundance, and to know the potential of soil modified by earthworms as plant growth medium. Eight combination of individual earthworm from epigeic and endogeic groups was applied into pot  that was filled by soil from two years of nickel stockpile and each treatment was repeated by five times. The experiment was following complete randomize design procedure. After sixteen days of research, the soil sample from each pot was analyzed for soil FDA activity, number of flagellate and nematodes. Furthermore, one kg of the soil from each pot was taken and every pot was grown by Paraserianthes falcataria seedling with the age of five days and continued its growth for two months. The results indicated that the soil FDA activity, number of flagellate and nematodes among treatments were significantly differences. In addition, it indicated the significant differences in dry weight of shoot, root, total plant, and root to shoot ratio of P. falcataria seedlings. It concluded that the combination of an individual number of epigeic and endogeic earthworms improved soil biological quality of stock pile, amd  most suitable for seedlings growth in nickel mining area.

The effects of intermittent fasting during the month of Ramadan in chronic haemodialysis patients in a tropical climate country.

BackgroundChronic kidney disease is an emerging problem in the majority Muslim countries. Despite the uncertainties of the risks involved, some Muslim patients undergoing chronic haemodialysis choose to observe intermittent fasting during the month of Ramadan. This study aims to investigate the effect of Ramadan fasting in haemodialysis patients residing in a tropical climate country.MethodsThis prospective cross sectional study recruited Muslim patients on regular haemodialysis from three haemodialysis centres in Kuala Lumpur from 15th July 2011 to 29th August 2011. Patients who fasted for any number of days were included (n = 35, 54% female, age 54±11 years). 89% of patients fasted for more than 15 days and 49% were diabetics. Dialysis parameters and blood samples were obtained one week prior to Ramadan and during the last week of Ramadan. The differences in dialysis parameters and biochemical values pre- and end-Ramadan were examined using paired t-test.ResultsBoth pre- and post-dialysis weight were significantly decreased during Ramadan fasting compared to the month prior (p = <0.001). There was a significant decrease in the amount of ultrafiltration (p = 0.002). There were no significant differences in dry weight, inter-dialytic weight gain, mean urea reduction ratio or blood pressure measurements comparing pre- and end of Ramadan fasting. There was a significant increase in serum albumin level (p = 0.006) and decrease in serum phosphate level (p = 0.02) at the end of Ramadan.ConclusionRamadan fasting is associated with reduced weight, improved serum albumin and phosphate level in our population of haemodialysis patients. A larger multi-centre study will allow us to understand more about the effects of fasting in this population.

Pre-harvest treatment of spinach with Ascophyllum nodosum extract improves post-harvest storage and quality

Fresh spinach (Spinacia oleracea L.) leaves contain high concentrations of beneficial phytochemicals. However, spinach does not store well and is highly perishable especially during handling and post-harvest storage. In this study, we investigated the effect of pre-harvest root-treatment of spinach with Ascophyllum nodosum extract (ANE) at different concentrations (0, 0.1, 1.0, or 5.0gL−1) on post-harvest quality of fresh-cut spinach over a 35-day storage period. At the time of harvest there was no significant difference in dry weight, chlorophyll, ascorbate and lipid peroxidation between ANE-treated and non-treated plants. However, the loss in fresh weight and visual quality (color and turgor) of spinach leaves during storage was reduced by pre-harvest application of ANE. Lipid peroxidation was significantly reduced in ANE-treated leaves. The total chlorophyll content and ascorbate content in the control and treated leaves was however identical over the storage period and decreased at a similar rate. A negative correlation was observed between visual quality and lipid peroxidation. The results show that pre-harvest ANE application through root drench, especially at 1.0gL−1, enhanced post-harvest storage quality of spinach leaves.

In vitro behaviors of rat mesenchymal stem cells on bacterial celluloses with different moduli

Compressive moduli of bacteria-synthesized cellulose (BC) were altered by two drying techniques: ambient-air drying and freeze drying. While no significant differences in dry weight were found, their cross-sectional structures and thickness varied greatly. Freeze dried BCs had loose cross-sectional structures and a thickness of ~4.7mm, whereas air dried BCs had more compacted cross-sectional structures and a thickness of ~0.1mm. The compressive moduli of the rehydrated freeze dried and rehydrated air dried BCs were measured to be 21.06±0.22kPa and 90.09±21.07kPa, respectively. When rat mesenchymal stem cells (rMSCs) were seeded on these BCs, they maintained a round morphology in the first 3days of cultivation. More spread-out morphology and considerable proliferation on freeze dried BCs were observed in 7days, but not on air-dried BCs. The cells were further grown for 3weeks in the absence and presence of differentiation agents. Without using any differentiation agents, no detectable differentiation was noticed for rMSCs further cultivated on both types of BC. With differentiation inducing agents, chondrogenic differentiation, visualized by histological staining, was observed in some area of the rehydrated freeze dried BCs; while osteogenic differentiation was noticed on the stiffer rehydrated air dried BCs.

방선균의 식물생육촉진 효과와 식물병원균에 대한 항균활성

비농경지의 식물 근권토양에서 식물체의 초기생육촉진 효과가 있는 방선균을 분리하였다. 분리된 미생물의 16S rDNA 염기서열을 분석한 결과 Streptomyces spp.로 동정되었다. Streptomyces griseus (MSS181), Streptomyces griseoaurantiacus (MSS269), Streptomyces microflavus (MSS275), Streptomyces herbaricolor (MSS276)의 배양액을 오이, 고추, 담배와 토마토의 생육초기단계에 관주 처리하여 식물체의 초장, 건조중량을 측정하였다. 방선균 처리에 의해 오이의 초장은 대조구에 비해 16-29% 증가하였으나 건조중량에는 통계적으로 유의한 차이가 없었다. 같은 방선균을 고추에 처리하였을 때 고추의 초장은 대조구에 비해 10-19%, 건조중량은 19-25% 증가하였다. 담배의 건조중량은 44-73% 증가하였고 토마토의 건조중량도 65-165% 증가하였다. 공시균주의 식물병원균에 대한 항균활성을 검정한 결과, MSS275의 Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani와 Sclerotinia sclerotiorum에 대한 강한 항균활성을 확인하였다. Streptomyces spp. were isolated from rhizosphere in fallow lands. The Streptomyces spp. were identified as Streptomyces griseus (MSS181), Streptomyces griseoaurantiacus (MSS269), Streptomyces microflavus (MSS275), Streptomyces herbaricolor (MSS276) based on 16S rRNA gene sequences. Afterwards, cucumber, pepper, tobacco and tomato were drenched with the isolates at early growth stages and plant growth such as height and dry weight of plants was measured. By treatment of Streptomyce spp., plant height of cucumber was increased by 16-29% compared to the control, But there were no statistically significant differences in dry weight. When the same isolates were treated on chili-pepper, plant height and dry weight of chili-pepper were increased respectively by 10-19% and 19-25% compared to the control. The dry weight of tobacco and tomato were increased by 44-73% and 65-165%, respectively compared to the control. When antifungal activities of the isolates were tested against plant pathogenic fungi, Streptomyces microflavus (MSS275) effectively inhibited the mycelial growth of Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani and Sclerotinia sclerotiorum.

Shoots, root and flowering time studies in chickpea (Cicer arietinum L.)&lt;br&gt;under two moisture regimes

The shoot and root behavior and flowering time of two chickpea genotypes (kabuli and desi types) was examined under well watered and moisture stress conditions in split drainpipes in 2006. The data on shoot and root fresh weight and dry weight and plant and soil moisture percentage were recorded at the late flowering stage. The observations on root and soil moisture were recorded at three depth level with gap of 15 cm each. The results revealed that both the plant types of chickpea behaved alike except for days to flower initiation which was significantly different in the two varieties. Root and Shoot fresh weights were significantly greater in well watered conditions, but on the other hand, there was no any significant effect of moisture stress on shoot dry matter content, suggesting that higher weight of fresh shoot was due to high uptake of water under well watered conditions which evaporated after drying. Fresh root weight was only significantly affected at 30 cm depth level due to varieties and 45 cm depth level due to treatments. The root moisture percentage was significantly affected at 15, 30 and 45 cm depth level due to varieties × treatments interaction, varieties and treatments, respectively. There found no significant difference in dry weight among the rooting depths. The cultivar Sheenghar-2000 retained higher root moisture content (7.57%) at 15 cm depth level under well watered.

Estudio de la metodología aplicada para el cálculo del peso seco del cristalino como criterio de edad en la liebre ibérica (Lepus granatensis Rosenhauer, 1856).

The influence of handling and preservation processes on the physical appearance and dry weight of hare’s eye lenses as an age criterion was studied in Lepus granatensis. A methodological protocol is proposed as a conclusion. In total, 341 lenses were removed from 217 individuals collected in Navarra province. Two main storage treatments were employed: previously frozen or fresh; and two physical appearances were distinguished: shiny surface or undamaged, and dull surface or damaged. Lenses were dried and weighed following a standardised protocol and the effect of storage treatment on the physical appearance of the lenses was studied as well as the effect of this physical appearance on the final dry weight of lenses. No significant differences in dry weight between lenses from the same individual were found regardless of whether the lens was frozen or fresh. Freezing had a clear effect on the final physical appearance of lenses, and thus we suggest rejecting those samples presenting a dull surface after the preservation process. At the same time, there was a significant correlation between the time lenses had been kept frozen and the difference in dry weight compared to those preserved fresh.

Zn Acquisition by Extraradical Hyphae in Arbuscular Mycorrhizal Plant Depending on Zn Nutritional Status of Cucumber(Cucumis sativus cv. Baekdadagi)

The contribution of plant nutrition status in arbuscular mycorrhizal (AM) plant to the nutrient acquisition by extraradical hyphae of AM fungi was investigated using cucumber colonized with Glomus intraradicies (BEG 110) focusing on the Zn. Compartmentalized pots with separated Bones for hyphal growth were used to determine the contribution of extraradical AM hyphae to Zn uptake from hyphal zones. <TEX>$0.5\;{\mu}M$</TEX> Zn was supplied into the hyphal zones as nutrient solution (10 mL/day) with a form of <TEX>$ZnSO_4$</TEX>. Zn foliar application was made two times for one week before harvest (8 mL/plant). The colonization rate by AM were high in all of Zn treatments. The dry weight of cucumber increased by AM colonization compared to those of non-mycorrhizal counterpart. However: Zn foliar application resulted in no significant difference in dry weight between mycorrhizal- and non-mycorrhizal plant. In addition, the enhancement of Zn content in cucumber shoot by AM colonization were also reduced by Zn foliar application. These results indicate that the interaction between host plant and AM fungus for nutrient uptake might be related to plant nutritional status and nutrient contents. In consequence, higher Zn contents in host plant by foliar application of Zn could restrict the role of extraradical hyphae of AM fungus on the Zn acquisition and transfer from fungus to host plant.

Protein content and dry weight of seeds from various pea genotypes

Pea seed protein content (SPC) and seed dry weight (SDW) are both influenced by genetic and environmental factors. To assess the variations of these within-plant traits between seeds, six genotypes were field tested. The sequential seed development at nodes along the main stem was determined. Nitrogen fixation was measured by the acetylene reduction assay (ARA). At maturity, protein content and dry weight were measured according to seed position on the plant. Individual protein content was determined by near-infrared transmission spectroscopy. The results show a significant difference in protein content between nodes of the genotypes Solara, L765 and L833. Protein content tended to decrease from the bottom to the top of the plant for these genotypes. The difference in protein content between the lowest and the uppermost node was about 26 g kg -1 for Solara, 40 g kg -1 for L765 and 49 g kg -1 for L833. There were also significant differences in dry weight between plant nodes for all genotypes, except Finale. In addition, the range of difference in dry weight between plant nodes was higher than that for protein content. Further, to determine the influence of morphological position on individual protein content and dry weight, multiple linear regression was established on node position, pod position on the node, and seed position within pods. The results showed that protein content and dry weight were not influenced either by within-pod seed position or pod position on the raceme. Moreover, protein content and dry weight were mainly influenced by node position on the main stem. However, for protein content, the effect of node position varied with genotype, indicating a genetic variability for this character. This genetic variability could be attributed to the difference between genotypes in the ability to maintain nitrogen fixation during the onset of seed filling. For dry weight, the decrease in seed weight for upper nodes of the plant also varied with genotype in relation to the duration of seed filling and the seed growth rate.

Peas grown in media with elevated plant-available silicon levels have higher activities of chitinase and β-1,3-glucanase, are less susceptible to a fungal leaf spot pathogen and accumulate more foliar silicon

Pea seedlings grown for 5 weeks in a growing medium amended with potassium silicate fertiliser had significantly greater activities of the enzymes chitinase and β-1,3-glucanase in leaf extracts compared with those grown in coir-based control mix, prior to challenge by a foliar pathogen. Additionally, fewer lesions developed on pea leaves inoculated with the fungal pathogen Mycosphaerella pinodes 5 weeks after growth in the Si-amended mix. Plant-available Si, as monosilicic acid, in the Si-amended mix was more than five times that in the control mix. Peas accumulated nearly twice as much silicon (w/w dried foliage) after 3 weeks growth in an alternative potting mix amended with silicon from rice hull derivatives, as those grown in a conventional perlite/sand medium as control. The monosilicic acid content of the rice hull mix was approximately three times greater than that of the perlite/sand mix. There were no significant differences in dry weights between plants from control and Si-amended mixes. The results suggest associations in pea between available silicon in growth media, accumulation of Si within the plant, early activation of host defences and subsequent resistance to fungal pathogens, with potential for reduction and control of diseases.

Growth of conifer seedlings on organic and inorganic nitrogen sources.

Effects of organic and inorganic nitrogen sources on growth and mineral nutrient concentrations of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings were compared in a 100-day experiment in a greenhouse. Seedlings were grown in pots containing peat. Nutrient solutions differing in ammonium, nitrate, arginine and glycine composition were supplied to the seedlings at three nitrogen (N) concentrations: 1, 3 and 10 mM. We used dual (13C, 15N) and single (15N) isotopic labeling to determine the uptake of organic and inorganic N at the end of the experiment. Seedling dry weights and mineral nutrient concentrations of the needles showed that both conifer species were able to grow well and maintain nutrient balance on all investigated N forms except for the ammonium-dominated nutrient mixtures at the 10 mM N concentration. In Scots pine, no significant differences in dry weights were found between seedlings grown on the amino acids and seedlings grown on a commercial fertilizer containing 61.5% NO(3-)-N and 38.5% NH(4+)-N. Isotopic labeling of seedlings indicated that uptake rates of arginine-N, glycine-N and NH(4+)-N were similar, and 7-8 times greater than uptake rates for NO(3-)-N in both species. In Scots pine seedlings, 100% of arginine-N, and at least 67% of glycine-N was derived from the uptake of intact amino acids through seedling roots or mycorrhizae. Corresponding figures for Norway spruce were 83% for arginine and 96% for glycine. The gas chromatography-mass spectrometry analyses confirmed the presence of intact labeled molecules of both arginine and glycine in seedlings. We conclude that arginine and glycine are comparable to inorganic N as N sources for growth of conifer seedlings.