首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The growth, accumulation and movement of mineral nutrients (nitrogen,phosphorus, potassium (calcium) and chlorophyll in needles ofyoung radiata pine trees (Pinus radiata D. Don) were examined,from bud break in spring through the following year. Retranslocationof nutrients from needles was measured and is discussed in relationto nutrient requirements for seasonal growth. During the first 4–5 months after bud break when mostneedle growth occurred, all nutrients and chlorophyll accumulatedprogressively, although the concentrations of nitrogen, phosphorusand potassium decreased. During summer, substantial amounts of phosphorus were withdrawnfrom needles less than 6 months old, regardless of positionon the tree and silvicultural practice. In young needles andunder certain environmental conditions, this led to a markedtemporary decline in concentrations, even in fertilized treeson a fertile site. However, the phosphorus content of needleswas quickly restored following autumn rains. Similar fluctuations,including nutrient withdrawal in summer, occurred for nitrogenand potassium, but these were smaller than those observed forphosphorus. Phosphorus was also withdrawn from relatively olderneedles during summer. It was estimated that on a tree basis 86, 48 and 39 per centof the phosphorus, nitrogen and potassium, respectively, insummer shoots could have come from the retranslocation of nutrientsfrom young needles formed during the preceding spring. These results highlight the importance of nutrients stored inneedles to meet the nutrient requirements for growth when environmentalfactors may not be conducive to nutrient uptake from the soil. Pinus radiata D. Don, mineral nutrition, retranslocation, phosphorus, nitrogen, seasonal effects, pine needle growth  相似文献   

2.
Callus cultures of Siberian larch (Larix sibiricaLedeb.) and Siberian spruce (Picea obovataLedeb.) were used to demonstrate the elicitor activity of two ophiostomatoid fungal species, Ceratocystis laricicolaand Ceratocystis polonica, as the pioneer settlers on larch and spruce, respectively. The extract from C. laricicolamycelium stimulated the accumulation of lignin in larch cells by 37% and that of bound proanthocyanidins by 25%. In spruce callus cultures, C. laricicolaand C. polonicaincreased the bound PA content by 25 and 46%, respectively. In the callus cultures of larch and spruce, the addition of extract of C. laricicolaincreased the concentration of p-hydroxybenzoic acid 13-fold and nearly 4-fold, respectively. The metabolic characteristics of accumulation of phenolic compounds in conifer cells are discussed.  相似文献   

3.
水分胁迫对脂松苗木针叶质膜透性和保护酶活性的影响   总被引:1,自引:0,他引:1  
以2年生盆栽脂松苗木为材料,研究了不同土壤水分处理(含干旱和水渍胁迫)及解除胁迫后对脂松苗木针叶质膜透性和保护酶活性的影响。结果表明,随着干旱与水渍胁迫时间的延长,脯氨酸、可溶性糖和丙二醛(MDA)含量均有所上升;过氧化氢酶(CAT)活性逐渐降低;过氧化物酶(POD)活性逐渐升高;解除胁迫后,各项指标均有不同程度的恢复,其中田间含水量为40%、80%、100%处理(即FC40%、FC80%、FC)恢复较快;干旱处理中FC20%和水渍处理中的水渍胁迫(FL)对苗木的生理影响在解除胁迫后14天尚未完全恢复且表现为水淹处理恢复能力较干旱处理差。综上,FC60%为最适土壤水分含量,综合表现最佳。  相似文献   

4.
The pattern of needle growth and the movement of mineral nutrients(nitrogen, phosphorus, potassium and calcium) in needles ofradiata pine (Pinus radiata D. Don) were studied from needleinitiation to 2 years of age. During this period, very prominentcyclic patterns of nutrient accumulation, retranslocation andreplenishment were observed for nitrogen, phosphorus and potassium,which highlighted the potential role of needles as a nutrientreserve for growth. Significant retranslocation occurred from very young needlesabout 3 months after initiation. The phases of retranslocationcoincided with new flushes of shoot growth, and the growth ofnew shoots on a branch resulted in nutrient withdrawal frompre-existing needles, regardless of needle age and season. Suchwithdrawal occurred even in fertilized and irrigated trees onhigh quality sites and under environmental conditions conducivefor nutrient uptake. At all times, except for the short periodafter initiation when needles were actively growing, the nutrientsin the needle were readily available for retranslocation. Contraryto the general view, retranslocation of nutrients was not necessarilyrelated to senescence and ageing of needles. Because new shoots are the primary ‘sinks’ for retranslocatednutrients, an ongoing competition between different parts ofa branch for internal nutrients can be envisaged, preferencebeing for the youngest shoot in the hierarchy. The relevanceof these results to our understanding of ‘optimum nutrition’of pine trees is discussed. Pinus radiata D. Don, radiata pine, mineral nutrition, retranslocation, phosphorus, nitrogen, shoot growth  相似文献   

5.
The time course of freezing damage in pine needles and in bark of apple trees was followed at different subzero temperatures. From these data the killing rate by freezing was determined for trees which differed in degree of cold hardiness. The activation energy of the killing reaction was also calculated. The killing rate was lowest in cold-acclimated trees, but the activation energy of the killing reaction was very high indicating a high degree of structured water in the cells. Non-acclimated trees showed uniform low values of the activation energy of the killing reaction at all subzero temperatures studied. It is suggested that intracellular supercooling could be a part of the mechanism of frost protection in cold-acclimated apple trees within the – 30 to – 20°C range, but not in the –20 to –10°C range.  相似文献   

6.
The effects of N application on tree growth and the retranslocationof N, P, and K from young needles to new growth were examinedin young radiata pine (Pinus radiata D. Don) trees. Nitrogen fertilization increased the number and size of needles,rates of shoot production, stem volume growth and tree biomass.Foliar N and P contents (µg per needle) fluctuated ina cyclic fashion with prominent phases of accumulation, retranslocationand replenishment. The patterns of these fluctuations in controland N-fertilized trees were similar, although the fluxes ofN, P and K in and out of needles were increased by N fertilization.Greater translocation (g per tree) of N and K from needles ofN fertilized trees occurred because fertilization increasedthe needle weight and the proportion of N and K retranslocatedfrom individual needles. Nitrogen fertilization increased theretranslocation of P largely as a result of higher needle mass.Trees supplied with more than adequate amounts of P in the soilretranslocated up to 58 per cent of the initial pool of P fromyoung needles. The periods of high retranslocation coincidedwith periods of high concentrations of soil mineral N and withshoot production. Conversely, the periods of rapid replenishmentof N and P into the needles coincided with the time of slowshoot growth and low concentration of soil mineral N. The growthrate of trees, rather than the availability of nutrients inthe soil was the main factor controlling retranslocation. For radiata pine, retranslocation from needles is not a mechanismspecific for coping with low soil fertility. It seems to bea mechanism which enhances the nutrient supply to apical growingpoints, especially during periods of flushing. Pinus radiata, nitrogen supply, shoot growth, nutrient fluctuations and retranslocation, nutrient use and adaptation  相似文献   

7.
Pine (Pinus sylvestris L.) callus culture was treated with the mycelium extracts from six Fusarium strains. Previously, pine seedlings were infected with a spore suspension in order to test the pathogenicity of the used strains. Callus culture infection resulted in a decrease in the free proanthocyanidin (PA) and an increase in bound PA content. After treating the calli with all strains except F. oxysporum var. orthoceras, the lignin content became lower than the control one. The most considerable changes involved the p-hydroxybenzoic acid (HBA) content, and its greatest change was observed after treating the calli with F. nivale, when the HBA concentration (1229 g/g dry wt) exceeded fourfold the control one. There was a positive correlation (R = 0.81) between the HBA content in the callus culture cells treated with a fungal extract and the virulence of Fusarium strains. At the same time, there was an inverse correlation (R = –0.80) between the lignin content in a callus culture and the fungal virulence; the latter did not affect the contents of both free and bound PA.  相似文献   

8.
Image analysis has become a powerful tool for the quantification of histochemical detections mainly in animal and medical sciences. There is not, however, much information about the accuracy of image analysis quantification of histochemical products and their comparison to biochemical analyses. Our study focused on the quantification of histochemically detected amounts of phenolic compounds, lignin and activity of peroxidases in the two youngest age classes of Norway spruce (Picea abies (L.) Karst) needles with the use of image analysis and its comparison with biochemical assays. The image analysis-determined amount of lignin and peroxidase activity was well correlated with its biochemical assay. On the other hand, no optical parameters of the reaction product of the histochemical reaction of phenolics correlated with the biochemical quantification. This proves that results of quantification of histochemical detection with image analysis greatly depend on the character and procedure of the histochemical proof. If it is done in full respect of the conditions of a histochemical reaction it can gain reliable and interesting results. Great advantage of the image analysis approach is quantification of the studied substance in different tissues within single sample as well as among different samples, which in many cases cannot be detected with biochemical tools. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
Twelve-day-old seedlings of Scots pine (Pinus sylvestris L.) were infected with a virulent spore suspension of the fungus Fusarium sporotrichiella var. sporotrichioides Bilai. 72 h after infection, the seedlings were divided into infection-susceptible and infection-resistant ones, and phenolic compounds in the seedling hypocotyls were analyzed. Susceptible seedlings contained 4.3-fold less lignins, 1.4-fold less free and bound proanthocyanidins, 12.7-fold less free hydroxybenzoic acids, 56.6-fold less bound hydroxybenzoic acids, 2-fold less quinic acid, and 5.1-fold less shikimic acid as compared to the resistant seedlings. At the same time, L-phenylalanine content was increased 3-fold and that of L-tyrosine, 1.3-fold. The activity of quinate:NAD(P)+ oxidoreductase and L-phenylalanine ammonia-lyase in the hypocotyls of susceptible seedlings was 2.3-fold and 1.4-fold lower, respectively, whereas the activity of shikimate:NAD(P)+ oxidoreductase remained unchanged.  相似文献   

10.
The pigment composition and light-response curves of the indices of prompt chlorophyll fluorescence were investigated in needles sampled from various parts of the tree crown in pine trees growing under natural conditions at various distances from a source of industrial air pollution (a copper-melting works). Shading and pollution decreased the threshold light level of the state corresponding to the second phase of the light-response curve of nonphotochemical chlorophyll fluorescence quenching, increased a nonradiating dissipation of the absorbed light energy, and decreased the rate of electron transfer between PSII and PSI. The patterns thus established demonstrate the existence of nonspecific chloroplast responses to pollution and shading similar in their mechanism, which decrease the efficiency of light energy utilization.  相似文献   

11.
针对山东省大青山省级自然保护区典型植物群落,设置21个样方,分析主要乔木种群和群落特征.结果表明:1)大青山样方内共发现维管植物111种,其中乔木29种、灌木14种、草本植物68种,群落植物种类少,物种多样性低.2)29种乔木根据径级结构划分为13种扩展种、2种隐退种,5种稳定侵入种、6种随机侵入种和3种随机隐退种.主要乔木种群径级结构型为2种:黑松种群、栓皮栎种群、麻栎种群、小叶朴种群、黄檀种群、君迁子种群和槲树种群为增长型;刺槐种群和赤松种群为稳定型.大青山群落乔木整体上为增长型群落.3)大青山乔木层物种丰富度指数、Shannon-Wiener多样性指数和Simpson多样性指数从高到低依次为赤松林、黑松林、刺槐林,而Pielou均匀度指数从高到低依次为黑松林、赤松林、刺槐林,显示赤松更适合作为大青山造林树种.  相似文献   

12.
采用顶空吸附法对健康松、衰弱松的针叶进行了活体挥发性物质收集。通过GC-MS联用技术和计算机信息检索法对两种状态下松树的针叶挥发物化学成分进行了分离鉴定,用离子流峰面积归一法通过化学工作站数据处理系统确定了各成分的相对含量。比较结果表明:云南松由健康松转向衰弱松的过程中挥发性成分及含量发生了很大变化。两种状态下针叶挥发性物质中共有15种相异化合物成分,18种相同化合物成分,相同化合物成分在含量上存在很大差异。  相似文献   

13.
Phenolic Compounds of Apple and their Relationship to Scab Resistance   总被引:4,自引:0,他引:4  
The contents of 15 different phenolic compounds in apple leaves and fruit skin from various orchards were determined by HPLC. High concentrations of flavan-3-ols were found in those orchards which were not infected by Venturia inaequalis . This observation corroborates earlier findings on different cultivars. The hypothesis that these compounds could be involved in the resistance of apple to scab was tested by inhibiting the key enzyme of the phenol biosynthesis, the phenylalanine-ammonia-lyase, in young shoots of the resistant genotype 'Sir Prize'. After inoculation of the inhibitor-treated leaves, severe symptoms of the disease occurred. The fungal infection was confirmed by histological studies. No flavonal-accumulation could be observed at the infection site which was the case in the non-inhibited but inoculated controls.  相似文献   

14.
Phenolic compounds in tea plant [Camellia sinensis (L.)] play a crucial role in dominating tea flavor and possess a number of key pharmacological benefits on human health. The present research aimed to study the profile of tissue-specific, development-dependent accumulation pattern of phenolic compounds in tea plant. A total of 50 phenolic compounds were identified qualitatively using liquid chromatography in tandem mass spectrometry technology. Of which 29 phenolic compounds were quantified based on their fragmentation behaviors. Most of the phenolic compounds were higher in the younger leaves than that in the stem and root, whereas the total amount of proanthocyanidins were unexpectedly higher in the root. The expression patterns of 63 structural and regulator genes involved in the shikimic acid, phenylpropanoid, and flavonoid pathways were analyzed by quantitative real-time polymerase chain reaction and cluster analysis. Based on the similarity of their expression patterns, the genes were classified into two main groups: C1 and C2; and the genes in group C1 had high relative expression level in the root or low in the bud and leaves. The expression patterns of genes in C2-2-1 and C2-2-2-1 groups were probably responsible for the development-dependent accumulation of phenolic compounds in the leaves. Enzymatic analysis suggested that the accumulation of catechins was influenced simultaneously by catabolism and anabolism. Further research is recommended to know the expression patterns of various genes and the reason for the variation in contents of different compounds in different growth stages and also in different organs.  相似文献   

15.
An account is given of the preparation of aqueous extracts ofred beet root which are shown to stimulate potassium uptakein beet discs washed for a short period, but inhibit potassiumuptake in discs washed for four days or more. Analysis of extractsshowed them to contain organic anions (especially citrate andmalate) which affect both the metabolic phase of potassium uptakeand respiration of the tissue. The effects of extracts and organicacids on uptake of manganese by beet discs is described andcompared with effects on potassium absorption. The results arediscussed with respect to current theories of salt accumulationand in relation to the hypothesis relating an inhibitor of saltaccumulation to the lag phase of ion uptake by beet discs.  相似文献   

16.
Background: Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder represented by Crohn’s disease and ulcerative colitis. Currently, there is no cure and pharmacological treatment aims to induce and maintain remission on patients. Because the therapy reveals a relatively high toxicity, during a long-term utilization, it is essential to investigate new pharmacological approaches. Polyphenols, commonly present on red wine, have shown health-beneficial effects related to their antioxidant and anti-inflammatory effects through the inhibition of NF-kB activation, COX-2 and iNOS induction. In this sense, it would be interesting to study their effects in an IBD context. Therefore, this study aims to evaluate the effects of an aqueous extract of phenolic compounds in a 2,4,6-Trinitrobenzenesulfonic acid (TNBS)-induced model of colitis. Method: Experimental colitis was induced in mice through an intrarectal administration of TNBS and then the mice were treated with an aqueous extract of phenolic compounds intraperitoneally for four days. Results and Discussion: The extract demonstrated an anti-inflammatory effect, reducing TNF-α levels in the colon, and had a beneficial effect on the extraintestinal manifestations related to IBD, without any significant side effects. The extract of phenolic compounds demonstrated to be a valuable object of study for the management of IBD in the future.  相似文献   

17.
主要禾谷类作物中所含与农杆菌Vir基因活化诱导有关的酚类物质,在种类和数量上,都较双子叶模式植物烟草和胡萝卜为少,其中水稻、大麦中含量最低(每克鲜重幼苗所含的酚类诱导物均在6μg以下),玉米和小麦中的含量稍高(大约在20μg/gFW左右)。被检测的主要禾谷类作物所含酚类诱导物的种类仅有1~2种,而烟草中却含有除香草醛以外的所有被检测的酚类诱导物,其含量为水稻和大麦的十几倍;胡萝卜仅次于烟草。从总体上看,不同作物所含酚类诱导物的种类与数量分布与其被农杆菌感染的难易程度有较好的一致性。此外,同一作物不同品种和组织中所含酚类诱导物的数量也有些差异。  相似文献   

18.
Changes in the localization of phenolic compounds were investigatedin columella cells of embryonic roots in 1-year-old Brassicanapus seeds during 48 h of imbibition and germination. In dry,dormant seeds, phenolic compounds were located in the apoplasticcompartment between the cell wall and plasmalemma in the outermostlayer of the columella. These apoplastic phenolic deposits disappearedduring the activation processes associated with imbibition andgermination, but new deposits appeared successively in the nucleus,ER cisternae, protein bodies and on the outer surface of theroot cap. A large number of phenolic deposits were observedin the outermost part of the columella, becoming less frequenttowards the initial centre. Their appearance coincided withrestoration of the ER and immediately preceded cytological activation.After the primary root had emerged from the seed coat, depositsof phenolic compounds disappeared from the cytoplasm, but simultaneouslyappeared in the vacuoles. Copyright 1999 Annals of Botany Company Brassica napus var. oleifera, root columella, germination, phenolic compounds localization.  相似文献   

19.
20.
It is shown that during a period of washing in serated distilledwater disks of Red Beet root tissue acquire the capacity toabsorb potassium rapidly. Subsequently the rate of accumulationof this ion is closely related to the internal salt-contentof the material. On the other hand, whilst the level of saltrespiration increases during the preliminary washing, it isnot influenced significantly by the internal potassium concentration.The implications of these observations are discussed in relationto a possible mechanism of mineral salt absorption.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号