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1.
In our experiments, one-year-old Larix olgensis seedlings were cultivated in sand, and supplied with solutions with different concentrations of nitrate or phosphate. The
effects of nitrogen and phosphorus supply on chlorophyll biosynthesis, total nitrogen content, and photosynthetic rate were
studied. The experimental results are listed below: 1) 5-aminolevulinic acid (ALA) synthetic rate increased as nitrate concentrations
supplied to larch seedlings increased from 1 to 8 mmol/L. But the rate decreased by 17% when nitrate concentration increased
to 16 mmol/L, in contrast to the control. Under phosphate treatments, ALA synthetic rates were similar to those under nitrate
treatments. The activities of porphobilinogen (PBG) synthase reached a maximum when larch seedlings were supplied with 8 mmol/L
of nitrate or 1 mmol/L of phosphate. 2) when larch seedlings were supplied with 8 mmol/L of nitrate and 0.5 mmol/L of phosphate,
the contents of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids reached a maximum. The total nitrogen contents
in leaves increased as nitrate concentrations increased. 3) When phosphate concentrations increased from 0.125 to 1 mmol/L,
the total nitrogen contents in leaves slightly increased; however, continuous increase of phosphate concentrations resulted
in the decrease in total nitrogen contents in leaves. When nitrate concentrations increased from 1 to 8 mmol/L, soluble protein
contents in leaves increased in general, and continuous increase of nitrate concentrations induced a decrease in soluble protein
contents in leaves. Under treatment of 0.25 mmol/L of phosphate, the soluble protein contents reached a maximum. 4) In general,
F
v/F
m increased as nitrate concentrations increased from 1 to 8 mmol/L, and continuous increase of nitrate concentration resulted
in decrease in F
v/F
m. The similar changes occurred under phosphate treatments. As nitrate concentrations increased from 1 to 8 mmol/L, photosynthetic
rates gradually increased, but when nitrate concentrations increased to 16 mmol/L, photosynthetic rate reduced by 16%, in
contrast to the control. Photosynthetic rates reached a maximum when seedlings were supplied with 1 mmol/L, and an oversupply
of phosphate (2 mmol/L) resulted in decrease in photosynthetic rates. The results suggested that supply levels of nitrogen
affected ALA biosynthetic rates, activities of PBG synthase, and affected contents of chlorophyll and carotenoids. Moreover,
nitrogen supply levels affected contents of total nitrogen and soluble proteins in leaves, and net photosynthetic rates. ALA
biosynthesis rates and activities of PBG synthase were affected by phosphate supply, but contents of chlorophyll and carotenoids
were not affected. And net photosynthetic rates were affected little by phosphate supply.
__________
Translated from Scientia Silvae Sinicae, 2005, 41(4) [译自:林业科学, 2005, 41(4)] 相似文献
2.
Iglesias DJ Levy Y Gómez-Cadenas A Tadeo FR Primo-Millo E Talon M 《Tree physiology》2004,24(9):1027-1034
We analyzed the effects of nitrate availability on growth of Navelina (Citrus sinensis (L.) Osbeck) scions grafted on three citrus rootstocks differing in salt tolerance: Carrizo citrange (Citrus sinensis (L.) Osbeck x Poncirus trifoliata (L.) Raf.), Citrus macrophylla Wester and Cleopatra mandarin (Citrus reshni Hort. ex Tanaka). Salt stress reduced total plant biomass by 27-38%, whereas potassium nitrate supplementation partially counteracted this effect by increasing dry matter and new leaf area. Salinized Carrizo citrange had the greatest response to nitrate supplementation, whereas the effects on salinized Cleopatra mandarin and C. macrophylla were less apparent. Nitrogen and chlorophyll contents and photosynthetic activity also increased in leaves of the nitrate-supplemented salinized plants. In salinized plants, nitrate supplementation reduced leaf abscission, stimulated photosynthetic activity and increased growth of new leaves. The nitrate treatment did not modify chloride concentration in leaves, but it reduced chloride concentrations in Carrizo and Macrophylla roots. Therefore, in both rootstocks, chloride content was similar in mature leaves, higher in immature leaves and lower in roots of the nitrate-supplemented salinized plants compared with salinized plants unsupplemented with nitrate. We suggest that the nitrate-induced stimulation of growth reduced chloride concentration in roots through the reallocation of chloride to new leaves. 相似文献
3.
Effects of phenolic acids on soil nitrogen mineralization over successive rotations in Chinese fir plantations 总被引：1，自引：0，他引：1
Long-Chi Chen Xin Guan Qing-Kui Wang Qing-Peng Yang Wei-Dong Zhang Si-Long Wang 《林业研究》2020,31(1):303-311
Phenolic acids are secondary metabolites of plants that significantly affect nutrient cycling processes.To investigate such effects,the soil available nitrogen(N)content,phenolic acid content,and net N mineralization rate in three successive rotations of Chinese fir plantations in subtropical China were investigated.Net N mineralization and nitrification rates in soils treated with phenolic acids were measured in an ex situ experiment.Compared with first-rotation plantations(FCP),the contents of total soil nitrogen and nitrate in second(SCP)-and third-rotation plantations(TCP)decreased,and that of soil ammonium increased.Soil net N mineralization rates in the second-and third-rotation plantations also increased by 17.8%and 39.9%,respectively.In contrast,soil net nitrification rates decreased by 18.0%and 25.0%,respectively.The concentrations of total phenolic acids in the FCP soils(123.22±6.02 nmol g^-1)were 3.0%and 17.9%higher than in the SCP(119.68±11.69 nmol g^-1)and TCP(104.51±8.57 nmol g^-1,respectively).The total content of phenolic acids was significantly correlated with the rates of net soil N mineralization and net nitrification.The ex situ experiment showed that the net N mineralization rates in soils treated with high(HCPA,0.07 mg N kg^-1 day^-1)and low(LCPA,0.18 mg N kg^-1 day^-1)concentrations of phenolic acids significantly decreased by 78.6%and 42.6%,respectively,comparing with that in control(0.32 mg N kg^-1 day^-1).Soil net nitrification rates under HCPA and LCPA were significantly higher than that of the control.The results suggested that low contents of phenolic acids in soil over successive rotations increased soil net N mineralization rates and decreased net nitrification rates,leading to consequent reductions in the nitrate content and enhancement of the ammonium content,then resulting in enhancing the conservation of soil N of successive rotations in Chinese fir plantation. 相似文献
4.
Winter nitrogen use in deciduous species is largely uncharacterized. We investigated nitrate uptake in the fine roots of a
deciduous oak (Quercus serrata Thunb. ex. Murray). We conducted a 15N-labeling experiment using saplings of Q. serrata in the winter. During three weeks of labeled nitrate application, the concentration of 15N in the fine roots increased significantly. The amount of nitrogen absorbed, as nitrate, was 1.16 ± 1.02 mg N g DW−1, equivalent to 7.6 ± 5.8% of the total nitrogen content. Our results indicate that Q. serrata saplings have significant potential for nitrate uptake in the fine roots in midwinter (i.e., in the absence of leaves). Although
a significant amount of nitrogen applied as nitrate was accumulated, nitrate concentration in the fine roots remained low
during the labeling period. Furthermore, significant nitrate reductase activity was detected. These data suggest that Q. serrata saplings can assimilate nitrate in the fine roots in midwinter. 相似文献
5.
The effect of different sources and levels of N on dry matter production, nutrient uptake and ionic balance ofLarlix gmelini was studied. The results showed that the growth of the plants fertilized with ammonium was not as good as the control treatment.
The growth of the plants fertilized with ammonium nitrate did not differ significantly from that in control or nitrate treatment,
but was better than that in the ammonium treatment. Total cation concentrations in shoots varied little with N level in the
ammonium and ammonium nitrate treatments, while those in the shoot increased with N level in the nitrate treatment. The treatments
had little effect on the anion concentrations in the shoot. In the roots, the concentrations of both cations and anions changed
little except for SO4
2− and Ca2+. There existed a higher carboxylate production in the plants fertilized with nitrate. The ratio between the production of
carboxylate and the production of organic N Δ(C-A)/ΔNorg was constant with N supply in the plants receiving nitrate, but obviously declined with N supply for ammonium-fed plants.
Δ (C-A)/ΔNorg values were intermediate between those of the nitrate and the ammonium-fed plants as for the mixed N source.
Foundation item: This paper was supported by “Hundred Scientists” Project of Chinese Academy of Sciences.
Biography: CHEN Yong-liang (1969-), male, Ph. Doctor, lecture of Northeast Forestry University, Harbin 150040, Post-doctor in Institute
of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P.R. China.
Responsible editor: Song Fuman 相似文献
6.
《Scandinavian Journal of Forest Research》2012,27(1-4):469-480
The vegetation of four different forest soils in lysimeters was killed with glyphosate. New vegetation became established in some of the treated lysimeters the year after application. During this year, leachates from lysimeters without vegetation had nitrate concentrations up to 4.5 mM NO3 ? in the fall. A corresponding increase in leached cations was evident. The settlement of one raspberry or one willow herb in treated lysimeters effectively hindered nitrate leaching as soon as the plants were sufficiently large (in mid‐summer). As plants became established in treated lysimeters, the chemistry of these leachates approached those of untreated lysimeters. The absolute effect of even small plants in controlling water regime and water chemistry was evident. 相似文献
7.
The study analyses the effects of two different forms of nitrogen fertilisation (nitrate and ammonium) on root structure and
water uptake of two hybrid poplar (Populus maximowiczii x P. balsamifera) clones in a field experiment. Water uptake was studied using sap flow gauges on individual proximal roots and coarse root
structure was examined by excavating 18 whole-root systems. Finer roots were scanned and analyzed for architecture. Nitrogen
forms did not affect coarse-root system development, but had a significant effect on fine-root development. Nitrate-treated
trees presented higher fine:coarse root ratios and higher specific root lengths than control or ammonium treated trees. These
allocation differences affected the water uptake capacity of the plants as reflected by the higher sapflow rate in the nitrate
treatment. The diameter of proximal roots at the tree base predicted well the total root biomass and length. The diameter
of smaller lateral roots also predicted the lateral root mass, length, surface area and the number of tips. The effect of
nitrogen fertilisation on the fine root structure translated into an effect on the functioning of the fine roots forming a
link between form (architecture) and function (water uptake). 相似文献
8.
《Scandinavian Journal of Forest Research》2012,27(1-4):124-128
Deposition of protons, nitrate and sulphate have caused a decrease in soil pH and base saturation in southern Scandinavia. Floral changes have been suggested to be due to this deposition. This study was made to test if differences in nitrate assimilation capability between plants could be one of the reasons behind reported changes in the flora. Current and maximally induced nitrate reductase activity (C‐NRA and MI‐NRA, respectively) were measured in four beech forest field‐layer species, which have been reported to behave differently with respect to acid rain. The study was conducted at four sites of different soil quality (pH). There were considerable differences between the species as regards both C‐NRA and MI‐NRA. For two of the studied species, Galium odoratum and Stellaria nemorum, the gap between C‐ and MI‐NRA was relatively small but for Mercurialis perennis and Oxalis acetosella, this gap was larger. A small difference between C‐ and MI‐NRA should indicate that a larger portion of the available resources for nitrate reduction is already used. The concentrations of soluble carbohydrates were correlated with the MI‐NRA after leafing of beech, while before leafing no such effect could be detected. It can be concluded that the light environment has a considerable effect on the nitrate nutrition of field‐layer plants. Apparently, some species receive as much nitrate as they can reduce. Fertiliser experiments are needed to test if higher addition rates are harmful to them. 相似文献
9.
Prof. Dr. H. A. Osman A. M. Korayem H. H. Ameen S. M. S. Badr-Eldin 《Journal of pest science》1990,63(7):129-131
The interactions of root-knot nematode and VAM fungus on common bean plants (Phaseolus vulgaris L.), and the sequence of nematode infection were studied in the greenhouse. The inoculation with VAM fungus caused a significant increase in plant height and fresh weight compared with non treated plants.Meloidogyne infection unsignificantly decreased plant height and dry weight. When fungus was inoculated at 15 and 30 days prior toM. incognita infection, a significant increase in fresh weight was observed. There were no significant differences in total nitrogen (mg/plant) between plants inoculated withM. incognita alone or those inoculated with bothM. incognita and VAM fungus at the same time or 15 days after the fungus inoculation. Plants preinoculated with VAM fungus 30 days prior to nematode infection had a significant increase in total nitrogen. The inoculation with VAM fungus caused a significant increase in phosphorus content. However, it was significantly decreased in plants inoculated with nematode alone and in plants inoculated with VAM fungus andM. incognita at the same time. Gall index and final nematode population were significantly increased when nematodes were treated at the same time with fungus, although there were significant decrease in nematode final population and gall index when the plants were treated with nematodes at 15 and 30 days after mycorrhizal infection. A decrease in percentage of fungal colonization was observed when nematodes were inoculated with fungus at the same time. 相似文献
10.
《Scandinavian Journal of Forest Research》2012,27(1-4):1-14
Analysis of in vivo shoot nitrate reductase activity (NRA) of the grass Deschampsia flexuosa (L.) Trin. has been proposed as a method of indicating the availability of nitrate in northern temperate forest soils. We report the seasonal variation in NRA and the influence of temperature on the NRA assay. Studies were performed in the field or on natural populations on topsoil monoliths in a greenhouse. The induced in vivo NRA as measured at 28°C was higher in plants grown at lower than at higher temperatures within the range 4–20°C, although the induction was faster at higher temperatures. When the assay was performed at various temperatures, enzyme activity was much lower at lower temperatures. The accumulation of organic nitrogen in shoots showed that reduction actually increased with temperature. Transfer of monoliths from high to low temperature led to an increase of in vivo NRA within a day, whereas the decline caused by the reverse began after six days. Variations in temperature accounted for between 0 and 80% of the seasonal variation in NRA in the field, depending on the influence of the variability in nitrate supply. Maximally induced NRA after application of nitrate was mostly higher in a clearfelling than in a closed forest. In the forest, there was a close correlation between current and maximally induced NRA. One interpretation of this result is that low availability of nitrogen may have been a cause of the lower maximally induced NRA there. This is supported by results from other studies. We conclude that variations in temperature and availability of nitrogen, particularly nitrate, are largely responsible for seasonal variations in NRA. The influence of temperature can be adjusted for. 相似文献
11.
本文研究了不同N源对落叶松苗木干物重、养分吸收及离子平衡的影响。结果表明:施铵态N的苗木干物重小于对照处理;施硝铵态N的苗木生长与对照和施硝态N的苗木差别不大,但较施铵态N的苗木生长要好。铵态N与硝铵态N处理苗木地上部的阳离子总浓度受N水平的影响很小,而硝态N处理时则阳离子浓度增加;各处理对地上部阴离子浓度的影响均不大。在根部除硫酸根与钙离子外,阳离子与阴离子浓度均变化不大。硝态N处理的苗木具有较高的C-A值;△(C-A)/△Norg值在硝态N处理的苗木中随N供应量的增加而略有变化,但铵态N处理则明显下降;硝铵态N处理苗木的△(C-A)/△Norg值界于铵态N处理与硝态N处理之间。 相似文献
12.
以尾叶桉、黑木相思苗木混栽为研究对象,采用15N土壤和叶片标记法,在温室盆栽下研究2种植物间在根系完全隔离、部分隔离及无隔离处理下的生长变化及N素传递。结果表明:黑木相思的苗高、地径及生物量等生长指标随着根系隔离的减少而逐渐降低;相反,尾叶桉在根系无隔离处理下,其生长指标都要显著高于根系完全隔离处理,结果表明尾叶桉具有强大的养分吸收能力,混栽条件下会抑制黑木相思的生长。在15N土壤或叶片标记下,尾叶桉在根系部分隔离、无隔离下的总15N含量显著高于完全隔离处理(5.0和59.6倍);在土壤标记下,根系无隔离处理的黑木相思总15N含量显著低于完全隔离、部分隔离处理,而在叶片标记下的完全隔离黑木相思,其总15N含量显著低于其余2种处理。无论土壤或是叶片标记,黑木相思都能将N素传递至相邻尾叶桉,其N素传递率、传递量随着根系隔离的减少而提高。研究结果表明尾叶桉、黑木相思间能通过土壤渗透等方式传递N素,为桉树、相思的混交模式提供可靠的理论依据。 相似文献
13.
Kasim Bajrovic Kemal Kazan Zeliha İpekçi Nermin Gözükırmızı 《Journal of Forest Research》1999,4(2):161-166
Poplar (Populus tremula) was transformed with a construct carrying an antisense caffeic acidO-methyltransferase (COMT) cDNA (pOMT8) from a tropical pasture legume,Stylosanthes humilis. pOMT8 shows 83% overall homology to the corresponding COMT gene (pPCLA) of poplar. Of the 200 putatively-transformed plants regenerated on selective media after co-cultivation of poplar stem explants
withAgrobacterium tumefaciens harbouring a CaMV 35S-antisensepOMT8 construct, a subset of 20 plants were randomly chosen for further analysis. PCR and Southern blot analysis demonstrated the
stable integration of T-DNA into the genome of these plants. Antisense expression ofpOMT8 resulted in reductions in total COMT activity in the majority of the transgenic plants with the lowest total COMT activities
(61–70% of untransformed control plants) being observed in four transgenic plants. The composition of lignin in transgenic
plants was also changed, as detected by reductions in the content of syringyl units using infrared spectroscopy. However,
no changes were found in the amount of insoluble lignin in transgenic plants as compared to untransformed control plants.
These results indicate the potential of thepOMT8 gene to partially suppress COMT activity and modify the composition of lignin in transgenic poplar.
This work was partly supported by General Management of Turkish Pulp and Paper Mills. 相似文献
14.
Many northern hardwood understory plants have medicinal properties but their cost of production under conventional cultivation
practices is fairly high. Therefore wild harvesting continues putting the natural populations at risk. Their cultivation in
a forest farming system seems a promising alternative. This study was aimed at assessing the impact of canopy opening and
soil fertility on growth and active component production of four medicinal plants: black cohosh (Actaea racemosa), wild ginger (Asarum canadense), blue cohosh (Caulophyllum thalictroides) and bloodroot (Sanguinaria canadensis). Rhizome sections were planted in two sugar maple forests. Mortality and total leaf area were monitored during 3 years,
while subplots were harvested at the end of the second year for biomass and active component analyses. Multiple regressions
indicated that all species responded more to acidity related elements (pH, Al, Al + H, Fe, Zn) than to soil fertility (Ca,
K, Mg, P, C/N, base saturation and cation exchange capacity). This suggests that adjusting the pH by liming could be appropriate.
Growth increased with irradiance, except for blue cohosh, indicating that forest openings could also be part of an appropriate
forest management plan for their cultivation. While active component concentrations of rhizomes and roots increased in conditions
that negatively affected growth, such as low pH, soil fertility or light availability, their total active component content
exhibited responses that were similar to those of the growth variables. Thus, it seems that soil and light conditions that
favour the growth of these medicinal plants also favour their total yield in active components. 相似文献
15.
Aging of the donor tree decreased adventitious root formation in shoot cuttings of Tectona grandis Linn. f. (teak). Exogenous application of auxins, i.e., α-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA) has
a significant positive effect on the percentage of rooting. The maximum percent rooting was obtained with 4,000 ppm IBA as
compared to other treatment. Significant increase in root number was recorded in shoot cuttings treated with 4,000 ppm NAA.
The overall rooting response was better in the treatment with IBA rather than with NAA. Further periodic samples (0, 10, 20,
and 30 days) were taken to assess the total soluble sugar, starch, protein, and peroxidase (PER) activity in the rooting zone
of shoot cuttings of teak during adventitious root formation. Application NAA and IBA to shoot cuttings resulted in an increase
in the level of total soluble sugar, starch, protein, and PER-activity in the rooting zone. The stored carbohydrates were
utilized during adventitious root formation. Hence, total soluble sugar and starch contents of cuttings, irrespective of age
of donor plants, decreased with the passage of time in cuttings planted for rooting. Significant fluctuations were observed
in the protein content of cuttings during the time of root induction. There was an increase in the protein content with the
passage of time from the day of planting up to its 20th day, followed by a sharp decline in the protein content of cuttings
at the 30th day of planting, irrespective of the age of donor plants or the treatment of cuttings with auxins. Irrespective
of donor plant age, PER-activity in the cuttings increased from the day of their planting for rooting up to the 20th day,
and then declined at its 30th day of planting. It was interesting to note that PER-activity remained higher at all stages
in the cuttings of 2-month-old seedlings which rooted profusely as compared to the cuttings of 15- and 30-year-old donor plants
those rooted poorly. This study suggested that the exogenously applied NAA and IBA at different concentration seems to activate
sugar metabolism for release of energy, protein and PER-activity which are necessary for cellular division and differentiation
during adventitious root primordium initiation or development in the rooting zone of shoot cuttings. 相似文献
16.
Fluctuations in nitrate reductase activity (NRA), nitrate, nitrite, protein and total nitrogen content of bare-root Scots pine seedlings (Pinus sylvestris L.) raised outdoors were investigated during the first growing season. Nitrate reductase activity was higher in roots than in needles, whereas NO(3) (-) content was higher in needles than in roots and increased in both from June to October. Nitrate reductase activity in roots correlated more closely with NO(3) (-) N in the soil than did NO(3) (-) in the roots. In autumn, there was a closer correlation between foliar NRA and NO(3) (-) in the needles than with NO(3) (-)-N in the soil. Nitrite was not detected in the seedlings during the growing season. Total nitrogen content decreased toward the autumn, whereas protein content initially decreased but increased again in autumn. Acrylic netting placed above the seedlings increased both air and soil temperatures and apparently accelerated the use of nitrate. 相似文献
17.
18.
《Scandinavian Journal of Forest Research》2012,27(1-4):204-212
Seedlings of Larix leptolepis were grown in a growth chamber under short day conditions (8 h day) at 4 different photosynthetic photon flux densities (PPFD's). After a period of 8 weeks frost hardiness of the shoot tips and roots, dry matter content, dry weight (dw), content of glucose and starch were determined. The frost hardiness in the shoot tips increased from ‐15°C at a PPFD of 55μmol m‐2s‐1 to about ‐35°C at 440 μmol m‐2s‐1. No effect of PPFD was found on frost hardiness of the roots. A high PPFD results in a high dry matter content. The effect on dry matter content was most pronounced for the shoot tips and less pronounced for the roots. The total dry weight increased for both root and top with increasing PPFD. The height of the plants increased when the PPFD increased up to 220 μmol m‐2s‐1. 相似文献
19.
The effects of the arbuscular mycorrhizal (AM) fungus Glomus mosseae on plant growth, leaf solutes and root absorption area of trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings were studied in potted culture under water stress conditions. Inoculation with G. mosseae increased plant height, stem diameter, leaf area, shoot dry weight, root dry weight and plant dry weight, when the soil water
content was 20%, 16% and 12%. AM inoculation also promoted the active and total absorption area of root system and absorption
of phosphorus from the rhizosphere, enhanced the content of soluble sugar in leaves and roots, and reduced proline content
in leaves. AM seedings had higher plant water use efficiency and higher drought tolerance than non-AM seedlings. Effects of
G. mosseae inoculation on trifoliate orange seedlings under 20% and 16% soil water content were more significant than under 12% soil
water content. AM infection was severely restrained by 12% soil water content. Thus, effects of AM fungi on plants were probably
positively related to the extent of root colonization by AM fungi. The mechanism of AM fungi in enhancing drought resistance
of host plants ascribed to greater osmotic adjustment and greater absorption area of root system by AM colonization.
__________
Translated from Journal of Plant Physiology and Molecular Biology, 2005, 30(5): 583–588 [译自: 植物生理与分子生物学报, 2005, 30(5): 583–588] 相似文献
20.
为了解紫外线辐射时间对杉木生长的影响,本研究以杉木优良杂交组合的体胚再生植株为材料,用紫外灯模拟自然界UV-B辐射对其进行处理,研究0、1、3、5、7、9天紫外胁迫下杉木的光合作用效率及生理状态的变化。结果表明:随着紫外线辐射时间的延长,杉木体胚再生植株叶片的叶绿素含量明显降低、叶绿素荧光参数(Fv/Fm、YⅡ、qP、qN)数值均降低,MDA含量先降低后增加,POD活性提高、可溶性蛋白含量明显增加;紫外线辐射3天叶片杉木体胚再生植株叶片尖端开始变黄, 5-7天黄化现象加剧,9天叶片完全失水,干枯死亡,说明长时间紫外辐射会阻碍杉木体胚再生植株的生长发育。 相似文献