Recruitment limitation, germination of dust seeds, and early development of underground seedlings in six Pyroleae species

Botany ◽  
2013 ◽  
Vol 91 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Veronika A. Johansson ◽  
Ove Eriksson
Keyword(s):  
Seedling Development ◽  
Limiting Factor ◽  
Microsite Limitation ◽  
Seed Limitation ◽  
Seed Availability ◽  
Negative Effect ◽  
Dust Seeds ◽  
Chimaphila Umbellata ◽  
Nutrient Reserves ◽  
Growth Of Seedlings

We investigated recruitment of six mixotrophic Pyroleae species in relation to soil and adult presence. Pyroleae have dust seeds containing minimal nutrient reserves, and subterranean seedlings are mycoheterotrophic needing fungal hosts for germination and development. Germination and seedling development were studied by retrieving seed bags that had been placed within plots with adults present and at unoccupied control plots. There are two main alternatives to what limits recruitment of plants, seed limitation or microsite limitation. Results suggested that a combination of microsite and seed limitation was important for all investigated species. Microsite availability was the main limiting factor for Chimaphila umbellata (L.) W.P.C. Barton, Orthilia secunda (L.) House, and Pyrola chlorantha Sw., whereas seed availability was the main limiting factor for Pyrola minor L. For Moneses uniflora L. A. Gray and Pyrola rotundifolia L., it was not clear whether microsite or seed limitation dominated. Growth of seedlings responded positively to adult presence (O. secunda and P. minor), whereas others were negatively affected (M. uniflora and P. chlorantha). Increased levels of soil nutrients (N and P) had a negative effect on seedling growth in C. umbellata and P. chlorantha. These results provide the first evidence of the importance of microsite and seed limitation for germination and development of seedlings of Pyroleae species.

The use of nutrient bioassays to assess the response of Eucalyptusgrandis to fertilizer application. 2. A field experiment

1993 ◽  
Vol 23 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Helen E. Jones ◽  
John Dighton
Keyword(s):  
Trace Elements ◽  
Nutrient Status ◽  
Fertilizer Application ◽  
Limiting Factor ◽  
Significant Drop ◽  
Fertilizer Experiment ◽  
Root Bioassay ◽  
Negative Effect ◽  
Root Response ◽  
Bioassay Data

The nutrient status of a Eucalyptusgrandis Hill ex Maiden field fertilizer experiment in Natal, South Africa, was assessed at 6 and 18 months by a bioassay test in which the rate of influx of 15N, 32P, and 86Rb in roots excised from trees was measured. Fertilizer treatments consisted of all combinations of two levels of nitrogen (N), phosphorus (P), potassium (K), and trace elements, applied at planting and at either 3 or 6 months. There were also untreated control plots. At 6 months, bioassay influx rates of the three isotopes by the roots were all higher when a nutrient was applied at a lower level than when it was applied at a higher level. Foliar analysis did not indicate that any of the trees were deficient in N, P, or K, although control plants were significantly smaller than fertilized ones. There was no difference in the foliar P or K content between the treatments, although percent N increased with increasing application of N. The greatest difference in the root response between fertilizer levels was in the influx of 15N. Height of the trees was significantly increased by increasing N levels. There was no effect of P or K levels, but there was a negative effect of the combination of high levels of K and trace elements. From the significant drop in root 15N influx following the 6 month fertilizer addition, growth of the trees in response to fertilizer was predicted. At 18 months of age trees receiving their second application of fertilizer at 6 months were as large as those receiving fertilizer at 3 months, confirming growth predictions based on root bioassay data. The bioassay results at 18 months suggested that P may be supplanting N as the major growth limiting factor at this later stage in the development of the stand.

scholarly journals Влияние гидротермального нанокремнезема на проращивание семян пшеницы в темновом режиме как один из методических аспектов биотехнологии получения функциональных продуктов на основе микрозелени

2020 ◽  
Vol 13 (5) ◽  
pp. 284-297
Author(s):  
В.Н. Зеленков ◽  
В.В. Латушкин ◽  
В.В. Потапов ◽  
М.И. Иванова ◽  
Б.И. Сандухадзе ◽  
...  
Keyword(s):  
Seed Germination ◽  
Winter Wheat ◽  
Seed Treatment ◽  
Plant Biomass ◽  
Calcium Content ◽  
Food Product ◽  
Dark Mode ◽  
Additional Illumination ◽  
Negative Effect ◽  
Growth Of Seedlings

Исследование посвящено изучению некоторых нанотехнологических аспектов применения гидротермального нанокремнезема для получения нового функционального продукта питания – микрозелени растений (на примере озимой пшеницы). В методическом плане поднимается вопрос об использовании этапа получения пророщенных семян выращивания микрозелени с помощью нанобиотехнологий в темновом варианте без дополнительного искусственного освещения. Обработка семян гидротермальным нанокремнеземом в концентрациях 0,1 и 0,01% способствовала увеличению всхожести семян на 5–6%, средней высоты ростков (микрозелени) на 11,3–11,9%, биомассы растений на 11,0% (0,1%-ный раствор) и 17,6% (0,01%). Более низкие концентрации (0,001 и 0,0001%) мало влияли на изменение посевных свойств семян и рост сеянцев, высокие (1%) оказывали отрицательное воздействие (всхожесть снижалась на 4%, а высота ростков на 14%). Показано, что для повышения всхожести семян на первых этапах при выращивании микрозелени озимой пшеницы в темновом режиме без дополнительного подсвечивания перспективно использование гидротермального нанокремнезема для обработки семян в концентрации 0,01%, а также 0,1%. Обработка нанокремнеземом с разными концентрациями приводит к возрастанию накопления кремния в ростках в 1,5–2 раза по сравнению с контролем. Содержание фосфора, серы, магния, натрия в ростках оставалось относительно стабильным. Содержание кальция возрастало в варианте использования кремнезема 0,01% концентрации, калия – в варианте 0,0001%. Отмечено повышение содержания цинка и меди при обработке семян пшеницы водными золями нанокремнезема в варианте 0,001 %. The research is devoted to study certain nanotechnological aspects of hydrothermal nanosilica applications for obtaining a new functional food product called microgreens (as exemplified by winter wheat). In terms of methodology a question is raised concerning use of the stage when the seeds germinate for further growth of microgreens with the aid of nanotechnologies in a dark mode without additional artificial lightning. Treatment of seeds with hydrothermal nanosilica at concentrations of 0.1% and 0.01% contributed to an increase in seed germination by 5–6%, the average sprout height (microgreens) by 11.3–11.9% and plant biomass by 11.0% (0.1 % solution) and 17.6% (0.01 %). The lower concentrations (0.001% and 0.0001%) had little effect on the change in the sowing properties of seeds and the growth of seedlings while the higher concentrations (1%) produced a negative effect (germination decreased by 4%, and the height of sprouts by 14%). It has been shown that for improving seed germination at the first stages, when growing microgreens of winter wheat in the dark mode without additional illumination, it is promising to use hydrothermal nanosilica for seed treatment at a concentration of 0.01%, as well as 0.1%. Treatment with nanosilica at different concentrations leads to the higher accumulation of silicon in the sprouts by 1.5–2 times compared to the control samples. The content of phosphorus, sulfur, magnesium and sodium in the sprouts remained relatively stable. The calcium content increased in the case of using silica of 0.01% concentration, potassium - in the case of 0.0001%. An increase in the content of zinc and copper was noted during the treatment of wheat seeds with aqueous sols of nanosilica in the variant 0.001%.

scholarly journals CRESCIMENTO E NUTRIÇÃO MINERAL DE MUDAS DE BARBATIMÃO SOB EFEITO DA OMISSÃO DE NUTRIENTES

FLORESTA ◽  
2013 ◽  
Vol 43 (4) ◽  
pp. 569 ◽  
Author(s):  
Leandro Carlos ◽  
Nelson Venturin ◽  
Renato Luiz Grisi Macedo ◽  
Emilio Manabu Higashikawa
Keyword(s):  
Mineral Nutrition ◽  
Dry Matter ◽  
Block Design ◽  
Nutrient Deprivation ◽  
Nutritional Requirements ◽  
Limiting Factor ◽  
Randomized Block Design ◽  
Complete Treatment ◽  
Negative Effect ◽  
And Control

Com o objetivo de avaliar os requerimentos nutricionais e os efeitos da omissão de nutrientes no desenvolvimento de mudas de barbatimão (Stryphnodendron adstringens (Mart.) Coville), conduziu-se um experimento com o uso da técnica de elemento faltante. Foram empregados 12 tratamentos, em um delineamento de blocos inteiramente casualizados, com oito repetições. Adotaram-se os seguintes tratamentos: completo 1 (adubado com N, P, K, S, B, Cu, Zn e calagem como fonte de Ca e Mg e corrigindo acidez do solo), completo 2 (completo 1 – calagem, tendo CaSO4.2H2O e MgSO4.7H2O como fontes de Ca e Mg sem corrigir acidez do solo), C1 - N, C1 - P, C1 - K, C1 - S, C1 - B, C1 - Zn, C1 - calagem, C2 - Ca, C2 - Mg e testemunha. Foram medidos diâmetros e alturas das plantas, as quais foram separadas em parte aérea e sistema radicular. As mudas foram secas e pesadas, sendo determinados os teores de nutrientes na matéria seca da parte aérea. O fósforo e o boro foram os nutrientes mais limitantes, e a calagem afetou negativamente o crescimento. A sequência de exigência nutricional apresentada pelas mudas de barbatimão em relação ao tratamento completo, em ordem decrescente, foi: P > B > Zn > Mg > K > N > S > Ca.Palavras-chave: Nutriente faltante; cerrado; nutrição florestal. AbstractGrowth and mineral nutrition in seedlings of barbatimão subjected to nutrient deprivation. Aiming to evaluate nutritional requirements and effects of nutrient depravation in developing of seedlings of  barbatimão (Stryphnodendron adstringens (Mart.) Coville), we conducted an experiment in a green house. We employed 12 treatments in a fully randomized block design with eight replications. We applied the following treatments: complete 1 (C1-fertilized with N, P, K, S, B, Cu, Zn and lime as Ca and Mg sources), complete 2 (complete 1 – lime with CaSO4.2H2O and MgSO4.7H2O as Ca and Mg sources), C1-N, C1-P, C1-K, C1-S, C1-B, C1-Zn, C1-lime, C2-Ca, C2-Mg, and control. We measured diameters and heights and separated them into shoot and root system. We dried the samples, weighed them and determined the nutrients levels in shoot dry matter. As result, we identified that phosphorus and boron were the most limiting factor to growth, as well as liming had a negative effect on growth; the sequence of nutritional requirements presented by barbatimão seedlings in relation to complete treatment was: P> B> Zn> Mg> K> N> S> Ca.Keywords: Nutrient missing; savannah; forest nutrition.

Stem Cell Senescence: the Obstacle of the Treatment of Degenerative Disk Disease

2019 ◽  
Vol 14 (8) ◽  
pp. 654-668 ◽  
Author(s):  
Ying Chen ◽  
Liling Tang
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Senescence ◽  
Cell Aging ◽  
Limiting Factor ◽  
Low Back ◽  
The Family ◽  
Stem Cell Aging ◽  
Negative Effect ◽  
Ivd Degeneration

Intervertebral disc (IVD) has a pivotal role in the maintenance of flexible motion. IVD degeneration is one of the primary causes of low back pain and disability, which seriously influences patients’ health, and increases the family and social economic burden. Recently, stem cell therapy has been proven to be more effective on IVD degeneration disease. However, stem cell senescence is the limiting factor in the IVD degeneration treatment. Senescent stem cells have a negative effect on the self-repair on IVD degeneration. In this review, we delineate that the factors such as telomerase shortening, DNA damage, oxidative stress, microenvironment and exosomes will induce stem cell aging. Recent studies tried to delay the aging of stem cells by regulating the expression of aging-related genes and proteins, changing the activity of telomerase, improving the survival microenvironment of stem cells and drug treatment. Understanding the mechanism of stem cell aging and exploring new approaches to delay or reverse stem cell aging asks for research on the repair of the degenerated disc.

scholarly journals The concentration of triiodothyronine and thyroxine in colostrum, milk and plasma of cows

2020 ◽  
Vol 22 (98) ◽  
pp. 69-73
Author(s):  
A. V. Pan’kiv ◽  
M. R. Simonov
Keyword(s):  
Mammary Gland ◽  
Thyroid Hormones ◽  
Blood Plasma ◽  
Enzyme Linked Immunosorbent Assay ◽  
Limiting Factor ◽  
Metabolic Processes ◽  
High Concentration ◽  
Biological Origin ◽  
Black And White ◽  
Negative Effect

Milk contains key nutrients in optimal proportions, which makes it to be an important component of the human diet. Despite the fact that consumers receive with milk a significant amount of readily available nutrients, milk can be a source of dangerous factors of chemical and biological origin. The level of physiological hormones found in milk is not a limiting factor and is studied solely for scientific purposes. However, milk hormones can have a negative effect on the health of consumers. Based on this, the aim of this work was to study the concentration of triiodothyronine and thyroxine in colostrum, milk and blood plasma of cows at different stages of lactation. The secretion of the mammary gland and blood plasma of cows of Ukrainian black-and-white dairy breed, in their 2nd–5th lactations with milk yield 5100–5700 kg of milk per previous lactation was the object of the study. The concentration of triiodothyronine and thyroxine using enzyme-linked immunosorbent assay was investigated in withdrawn samples. The obtained data indicates that the highest level of secretion of iodine-containing thyroid hormones with milk is observed on 1st–4th days of lactation. Thereafter, the concentration of hormones in milk statistically significant decreases by 2.8–3-fold (P ˂ 0.001) till 30–40th day of lactation. The high concentration of iodine-containing hormones in colostrum allows to enhance metabolic processes in calves. Studies of the concentration of thyroid hormones in the blood plasma of cows showed a gradual increase from the beginning of lactation till 10th–14th and then till 30th–40th days of lactation. By 10th–14th days we observed 2.2-fold growth of triiodothyronine level (P ˂ 0.001), and till 30th–40th days this parameter has increased by another 12.5 %. The level of thyroxine on 10th–14th days of lactation was higher, compared to such in the beginning of lactation by 62.2 % (P ˂ 0.001), and by 30th–40th day increase was by 40.9 %. The main reasons for such changes are the formation of lactation dominant, the discharge of hormones secreted by the breast and the stimulation of metabolic processes during lactation. The prospects of further research lie in investigation of the dependence of triiodothyronine and thyroxine levels in the secretion of the mammary gland on productivity, breed, age and diet of animals.

scholarly journals Influência da profundidade e posição de semeadura na emergência de Acacia polyphylla DC.

2016 ◽  
Vol 11 (1) ◽  
pp. 23 ◽  
Author(s):  
A. J. Rodrigues ◽  
E. M. C. Batista ◽  
L. M. Oliveira ◽  
A. C. F. Portella ◽  
P. B. Souza
Keyword(s):  
Secondary Succession ◽  
Dry Weight ◽  
Early Growth ◽  
Seedling Development ◽  
Medium Size ◽  
Horizontal Position ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Growth Of Seedlings ◽  
The Ideal

<p>A<em> Acacia polyphylla </em>DC.<em> </em>é uma leguminosa, pertencente à família Fabaceae, conhecida principalmente por monjoleiro, cuja árvore apresenta porte médio e rápido crescimento, a mesma enquadra-se em estágios iniciais da sucessão secundária com grande potencial para o uso na recuperação de áreas degradadas do Bioma Cerrado. Assim, objetivou-se avaliar a influência de diferentes posições e de profundidades de semeadura na emergência e crescimento inicial de plântulas de <em>Acacia polyphylla </em>DC. O experimento foi realizado em delineamento inteiramente casualisado, com quatro repetições de 25 sementes, dispostos em esquema fatorial 3 x 5 (posições e profundidades de semeadura). Os tratamentos consistiram em diferentes posições das sementes no substrato: hilo voltado para cima, hilo voltado para baixo e sementes na horizontal, nas profundidades de 1, 2, 3, 4 e 5 cm. Determinou-se a porcentagem de emergência, índice de velocidade de emergência, bem como o comprimento e a massa seca da parte aérea e da raiz das plântulas. A emergência e o crescimento inicial das plântulas de <em>Acacia polyphylla </em>DC<em> </em>são afetadas pelas posições e profundidades de semeaduras, sendo que o procedimento ideal para o plantio e desenvolvimento das plântulas deve ser em uma profundidade entre 1,4 e 2,8 cm com o hilo na posição horizontal.</p><p align="center"><strong><em>Influence of depth and sowing position in the emergency Acacia polyphylla DC.</em></strong></p><p><strong>Abstract</strong><strong>: </strong><em>Acacia polyphylla</em> DC. is a legume belonging to the Fabaceae family, mainly known for monjoleiro whose tree has medium size and rapid growth, it fits in the early stages of secondary succession with great potential for use in the recovery of degraded areas of the Cerrado Biome. The objective was to evaluate the influence of different positions and sowing depths in the emergence and early growth of seedlings <em>Acacia polyphylla</em> DC. The experiment was conducted in completely randomized design with four replications of 25 seeds, arranged in a factorial 3 x 5 (positions and sowing depths). The treatments consisted of different positions of the seeds in the substrate: hilum facing up, hilum facing down and seeds horizontally at depths of 1, 2, 3, 4 and 5 cm. It was determined the percentage of emergence, emergence speed index, as well as the length and dry weight of shoot and root of seedlings. The emergence and early growth of seedlings <em>Acacia polyphylla</em> DC. are affected by the positions and sowing depths, and the ideal procedure for planting and seedling development must be at a depth between 1.4 and 2.8 cm, with the hilum in horizontal position.</p>

Germination Speed as a Predictor of Nursery Seedling Performance

1984 ◽  
Vol 8 (3) ◽  
pp. 157-162 ◽  
Author(s):  
James P. Barnett ◽  
B. F. McLemore
Keyword(s):  
Pinus Taeda ◽  
Pinus Elliottii ◽  
Seedling Development ◽  
Seedling Performance ◽  
Germination Speed ◽  
Pinus Taeda L ◽  
Favorable Conditions ◽  
Growth Of Seedlings

Abstract Although they are not fully satisfactory, laboratory germination percentages are still better predictors of nursery-tree yield for both loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm.) pine seeds than any other means now available. Germination values, which combine both speed and completeness of germination, improve the predictability of nursery performance only in slowly germinating lots. Analyses of the reasons for better nursery growth of seedlings from stratified seeds reveal that under less favorable conditions they germinate faster than unstratified seeds. When equal-aged germinants from similarly-sized stratified and unstratified seeds are planted at the same time, seedling development is essentially the same. Seedlings from large-sized seeds (half-sib lots) did grow larger over a 10-week period than those from small-sized seeds.

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