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1.
Patterns of photosynthesis and starch allocation in seedlings of four bottomland hardwood tree species subjected to flooding 总被引：5，自引：0，他引：5
Effects of short-term (32 days) flooding on photosynthesis, stomatal conductance, relative growth rate and tissue starch concentrations of flood-intolerant Quercus alba L. (white oak), bottomland Quercus nigra L. (water oak), bottomland Fraxinus pennsylvanica Marshall. (green ash) and flood-tolerant Nyssa aquatica L. (water tupelo) seedlings were studied under controlled conditions. Net photosynthetic rates of flooded N. aquatica seedlings were reduced by 25% throughout the 32-day flooding period. Net photosynthetic rates of flooded Q. alba seedlings fell rapidly to 25% of those of the control seedlings by Day 4 of the flooding treatment and to 5% by Day 16. In F. pennsylvanica and Q. nigra, net photosynthetic rates were reduced to 50% of control values by Day 8 but remained at approximately 30 and 23%, respectively, of control values by Day 32. Leaves of flooded Q. alba seedlings accumulated approximately twice as much starch as leaves of non-flooded control plants, whereas root starch concentrations decreased to 67% of those of control plants by the end of the 32-day flooding treatment. In contrast, flooding caused only a small increase in leaf starch concentrations of N. aquatica plants, but it increased root starch concentrations to 119% of those of the control plants by the end of the experiment. The co-occurring bottomland species, Fraxinus pennsylvanica and Q. nigra, differed from each other in their patterns of stomatal conductance and root starch concentrations. We conclude that the maintenance of low leaf starch concentrations, and high pre-flood root tissue starch concentrations are important characteristics allowing flood-tolerant species to survive in flooded soils. 相似文献
2.
研究了基于3种饲料植物空心菜、水稻和水葫芦处理体系中猪场厌氧废液的pH值变化规律以及其与其它水质指标之间的关系.结果表明:随着植物生长,各处理体系中废水pH值总体呈下降趋势,在处理第15天时,空心菜和水稻处理体系中废水pH值从起初8.22降至约为7,水葫芦处理体系中pH值则降为5;随着处理时间增加,pH值变化量增大,COD、NH4 -N、TN、TP去除率也在提高. 相似文献
3.
Rebekah Alcock Alan McCubbin Vera Camões-Costa Ricardo J.S. Costa 《The Forestry Chronicle》2018,29(4):508-520
To assess the impact of rationed versus full estimated energy provisions on markers of physiological strain in response to a simulated 250 km multistage ultramarathon (MSUM), on two separate occasions, the ultraendurance runner performed a laboratory simulated MSUM, with rationed (RP: 3303±75 kcal?day-1) and full (FP: 7156±359 kcal?day-1) provisions. Total daily energy expenditure was determined using dual-method indirect calorimetry. Resting metabolic rate, iDXA, and body water were measured at baseline, day 3, and post-MSUM. Blood, urine, and feces were collected, and mood state was measured, d 1 to 5 (before and after running) to determine various physiological strain indices. Heart rate, RPE, thermal comfort, gastrointestinal symptoms, and non-protein oxidation rates were measured every 30 min during running. Data were analyzed using single-subject design analysis and interpreted using Cohen's effect size. Energy expenditure was lower on RP (6943±145 kcal?day-1) than FP (7486±143 kcal?day-1) (Cohen's δ=-3.1). More pronounced exertional strain (RPE δ=1.2, thermal conform δ=0.6, rectal temperature δ=1.0, and plasma cortisol concentration δ=1.7) was observed on RP as the MSUM progressed. Total carbohydrate and fat oxidation during running decreased (0.76 vs. 1.82 g?min-1; δ=-3.9) and increased (0.91 vs. 0.54 g?min-1; δ=3.7), respectively, more profoundly on RP as the MSUM progressed. Gastrointestinal symptoms were modestly lower in RP (δ=-0.26). Exercise-induced leukocytosis, cytokinaemia, and neutrophil responses were higher on RP. Iron status markers were trivial. Higher mood disturbance and fatigue were reported on RP. The ultraendurance runner presented greater physiological and psychophysiological disturbances, in response to a laboratory simulated MSUM, on rationed energy provisions, despite the lighter pack-weight. 相似文献
4.
【目的】筛选出目前对生活污水净化效果较好的浮床植物。【方法】以14种湖南常见的草本和木本植物为材料,监测了污水处理过程中植物的株高、根系结构和生物量等生长指标,CODcr、TN、NH3-N、TP等水质指标的动态变化,并进行了植物的生长指标与水质净化指标的相关性分析。【结果】1)大部分植物均有较强的生长能力,其中水葱、水蕹菜的株高具有显著性优势(P <0.05);美人蕉、再力花、菖蒲和梭鱼草均表现出极强的生根能力,其根长增长率分别为390%、293.33%、286.67%和270%;植物的生物量增长率在5.1%~500.7%之间,其中菖蒲、美人蕉、水蕹菜和再力花的生物量具有显著性优势(P <0.05)。2)无植物对照组对污染物的去除率明显低于有植物处理组,处理时间的长短对污染物的净化效果具有显著差异性(P <0.05),且主要表现为早期对污染物净化速率快。所有植物处理对CODcr、TN、NH3-N、TP的平均净化率比无植物对照组分别提高了6.30%~36.80%、11.92%~20.97%、22.92%~29.28%、5.51%~41.24%,其中,美人蕉对CODcr的净净化率高达36.80%,水蕹菜对TN、TP的净化效果表现出显著性优势(P <0.05),梭鱼草则对NH3-N具有较好的净化能力。3)根据筛选指标的平均隶属函数值对14种草本和木本植物进行聚类分析,可将植物分为高、中、低净化能力植物三大类,高净化能力植物:梭鱼草、菖蒲、美人蕉、鸢尾、水蕹菜和再力花。中等净化能力植物:花菖蒲、旱伞草、黄菖蒲、花叶芦竹和水葱。低净化能力植物:冬青、女贞和月季。【结论】草本植物中的梭鱼草、菖蒲、美人蕉、鸢尾、水蕹菜和再力花以及木本植物中的冬青对生活污水具有较高的净化能力,适合用作生活污水处理的浮床植物。 相似文献
5.
报道了12个植物分布新记录,其中南泽兰属Austroeupatorium,南泽兰A. inulifolium,龙潭荇菜Nymphoides lungtanensis为中国大陆分布新记录;蒜香茄Solanum sisymbriifolium,三脉猪殃殃Galium kamtschaticum,岩生千里光Senecio wightii为华东分布新记录;芝麻菜属Eruca,芝麻菜E. vesicaria subsp. sativa,祁门过路黄Lysimachia qimenensis,小酸浆Physalis minima,西洋蒲公英Taraxacum officinale,红蓝石蒜Lycoris haywardii为浙江分布新记录。 相似文献
6.
This study demonstrated that disease resistance against anthracnose (caused by Colletotrichum camelliae) in camellia (Camellia pitardii) could be induced by chitosan oligosaccharide (COS) applied to leaves at 50 µg/ml. The induced resistance lasted for 10–15 days, with the optimum induced effect against anthracnose occurring by the third day. Following treatment with C. camelliae alone, COS alone and C. camelliae and COS combined, camellia plants showed different responses, which included the activity of H2O2, the defence‐related enzymes, such as polyphenol oxidase, peroxidase, catalase, phenylalanine ammonialyase, and concentration of soluble proteins. Plants that received COS treatments consistently had higher levels of biochemical activity than plants not treated with COS. Assessment of anthracnose severity on infected plants, as evidenced by reduced lesions on leaves, indicated that COS‐induced camellia plants had significantly lower disease ratings. To our knowledge, we are first to report the inducement by COS on camellia against anthracnose. 相似文献
7.
几种花卉植物体含量分析研究 总被引：7，自引：0，他引：7
1999－2000年，根据物候期分6次测定了月季，西洋杜鹃，冬珊瑚，南洋杉，马拉巴栗，广东万年青，龟背竹年周期内植物体营养元素含量。植物体中许多元素含量因物候期而异，而且类间差别明显，由高至低依次为花果花卉，木本观叶花卉，草本观叶花卉。据此提出了参试花卉施肥配方基本比例与调整意见。 相似文献
8.
The ethanolic extracts of the leaves and flowers of Cleome viscosa and roots of Gmelina asiatica were tested for antimicrobial activity. The two plants exhibited a broad spectrum of antimicrobial activity, particularly significative against Escherichia coli , Proteus vulgaris and Pseudomonas aeruginosa. The leaf extract of C. viscosa showed moderate activity against pathogenic fungi. 相似文献
9.
基于1995年和2011年固定样地调查数据探讨西双版纳四数木一闭花木一多花白头树群落种类组成、群落结构及优势种群个体数量方面的变化。分析显示,群落内高等植物种数净减5种（新增4种,消失9种）,热带分布型科、属比率分别上升7．3％和2％;A、B、C、D4层原有乔木（DBH≥5em）个体死亡率分别为0％、44．4％、16．3％和60％;A、132层乔木个体比例下降2．5％。乔木种群的频度分布格局和构造种群比例维持不变;群落乔木立木级结构保持正金字塔型,优势种群的立木级分布格局无明显变化。研究表明,该群落发育处于较为成熟阶段;15年来群落乔木的优势成分保持不变,群落总体结构稳定,草本层和层间植物的种类和个体数量减少明显;优势树种中,四数木和多花白头树2个种群趋于衰退,油朴有取代四数木或多花白头树在林冠层优势地位的趋势。 相似文献
10.
In the search for new sources of sesquiterpene lactones, six Centaurea species have been analyzed. The activity against the fungus Cunninghamella echinulata of (+)-cnicin (1) and (+)-salonitenolide (2), isolated from the Centaurea plants, as well as that of (+)-costunolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5) and (-)-eremantholide C (6), has been evaluated. Compounds 3 and 4 showed noticeable EC50 values, whilst more polar lactones were inactive. These results suggest that a relatively low polarity is one of the molecular requirements for the antifungal activity of sesquiterpene lactones. 相似文献
11.
Using affinity chromatography, SDS-PAGE, peroxidase activity assay and mass spectrometry data, a new extracellular peroxidase (CMP) from Chelidonium majus milky sap was isolated and characterized. The protein has a molecular weight of about 40 kDa and belongs to secretory class III plant peroxidases. The peroxidase activity is also accompanied by DN-ase activities. A novel CMP combined with other proteins is probably involved in development and differentiation of the plant and defence against different pathogens. It suggests that the biological activity of C. majus whole plants and extracts may depend not only on its alkaloidal content but also on the presence of biologically active proteins. 相似文献
12.
Inhibition of Trypanosoma cruzi growth by medical plant extracts 总被引：4，自引：0，他引：4
Schinella GR Tournier HA Prieto JM Ríos JL Buschiazzo H Zaidenberg A 《Fitoterapia》2002,73(7-8):569-575
This study describes the screening of extracts obtained from 18 plants and two fungi used in the Chinese and Mediterranean traditional medicines on epimastigote forms of Trypanosoma cruzi. The extracts were tested against epimastigote of T. cruzi Bra C15C2 clone in vitro at 27 degrees C and at a concentration of 250 microg/ml in axenic culture. Angelica dahurica, A. pubescens, A. sinensis, Astragalus membranaceus, Coptis chinensis, Haplophyllum hispanicum, Phellodendron amurense, Poria cocos, Ranunculus sceleratus and Scutellaria baicalensis showed significant effects against the parasite with a percentage of growth inhibition between 20 and 100%. C. chinensis and R. sceleratus showed the greatest activity with IC(50) values of 1.7 microg/ml for C. chinensis and 10.7 microg/ml for R. sceleratus. These activities are greater than that of allopurinol. C. chinesis and R. sceleratus extracts did not show cytotoxic effects on rat polimorphonuclear cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactic dehydrogenase assays. These results allowed us to suggest that R. sceleratus and C. chinensis could be a source of new compounds clinically active against T. cruzi. 相似文献
13.
The cytotoxic activity against some tumor cell lines of 16 commonly used species of Asarum was evaluated in this study. All of these plants were widely used in Asian countries as traditional medicines or folk medicines. Their inhibitory activities against four tumor cell lines (HL-60, BGC-823, KB and Bel-7402) were compared. It was observed that 10 of the tested extracts (eight ethanol extracts and two water extracts) among 32 extracts of these plants showed cytotoxic activity. Those 95% ethanol extractions from A. caudigerellum, A. forbesii, A. inflatum and A. maximum exhibited the highest cytotoxic activity, and 95% ethanol extracts or water extracts of A. sieboldii var. seoulense, A. himalaicum, A. splendens and A. crispulatum showed selective activity against one or two cells among the tested tumor cells. This is the first report of Asarum plants possessing cytotoxic activity against tumor cell lines. 相似文献
14.
Shot holes on oriental cherry (Prunus serrulata var. spontanea) leaves were investigated to evaluate their role in the elimination of pathogens using analytical electron microscopy. Small brown spots caused by Mycosphaerella cerasella appeared on the leaf surface and developed into shot holes that were approximately 1–5 mm in diameter. Field emission scanning electron microscopy revealed clusters of fungal conidiophores and hyphal growth on the leaf surface around the shot holes. The fungal structures were mostly located within a radius of 500 μm from the shot holes and confined to the epidermal sector separated by veins. X‐ray microanalysis revealed distinct calcium ring patterns encircling the shot holes. The abscised surfaces consisted of suberized plant cells colonized with filamentous fungi and yeasts. Embedded in the mesophyll tissue, druse crystals were co‐localized with calcium and oxygen. Despite the fungal presence around the shot holes, no further expansion of the shot holes was observed on the leaf surface. These results suggest that shot holes may represent an incomplete but neutral abscission of infection loci in the presence of necrotrophic fungal pathogens. This microscopy study provides insight into the formation and roles of calcium oxalate in plants under pathological conditions. 相似文献
15.
The antimicrobial activity and chemistry of the African Combretaceae has been well studied in recent years. The present study aimed to investigate the phytochemistry and antimicrobial activity of lesser known members of this family viz. C. hereroense, C. apiculatum and C. collinum. Pulverized leaves of C. collinum and C. apiculatum, and the fruit of C. hereroense were extracted with organic solvents and subjected to preparative chromatography. Seventeen phenolic constituents including four phenanthrenes from the fruit of C. hereroense and two known bibenzyls (including a combretastatin) from the leaves of C. collinum were isolated. The compounds were then subsequently tested for their antimicrobial activity against Candida albicans, Mycobacterium fortuitum, Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Pinocembrin showed excellent activity against C. albicans (MIC - 6.25 μg/ml), superior to that of the positive control, fluconazole and against S. aureus (MIC - 12.5 mg/ml). The phenanthrenes (compounds 1, 2, 3 and 5) showed some activity against M. fortuitum and S. aureus with a uniform MIC of 25 μg/ml. From this study it was evident that most stilbenoids and flavonoids from the selected Combretaceae have little or no antimicrobial activity. 相似文献
16.
17.
Free radical scavenging effect of Diospyros kaki,Laminaria japonica and Undaria pinnatifida 总被引：9，自引：0，他引：9
Diospyros kaki folium, Laminaria japonica thallus and Undaria pinnatifida thallus have been used traditionally in Korea to promote maternal health. The scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals of the methanol extracts of these plants were investigated. The extract of D. kaki was found to be the most potent, with an IC(50) value of 0.11 mg/ml. 相似文献
18.
Synthetic seed technology is an emerging and broadly used technique in the field of plant biotechnology to conserve economically important plants. In the present study, nodal segments of Capparis decidua were entrapped in calcium alginate gel matrix to produce firm and uniform synthetic seeds. 3% sodium alginate and 75 mM calcium chloride were found best for encapsulation. Among all the concentrations and combinations of thidiazuron (TDZ) either singly or with indole -3- acetic acid (IAA) augmented in Murashige and Skoog medium used, TDZ (5.0 µM) + IAA (0.5 µM) was found most effective in conversion of synthetic seeds into plantlets as 79% plantlets were developed on this combination with 13.2 ± 0.87 shoots and 5.5 ± 0.40 cm shoot length after 8 weeks of culture. Further, synthetic seeds stored at low temperature (4 °C) can retain their viability up to 4 weeks and showed maximum conversion rate (93%) into plantlets, when placed back to regeneration medium. Root formation was also occurred in the same regeneration medium and roots were healthy. Plantlets were successfully hardened in culture room in plastic cups filled with sterile vermiculite and after 4 weeks, they were transferred to greenhouse where they exhibited normal growth with 80% survival. Growth parameters were evaluated in micropropagated plants and compared with the seedlings of same age. Effect of different days of acclimatization were also recorded on various physio-biochemical activities and showed a positive response that can be interpreted as better protection mechanism of micropropagated plants against the stress possibly generated due to reactive oxygen species when transferred to ex vitro environment. 相似文献
19.
将轻质材料(能浮于水)制成多孔蜂窝状,蜂窝状孔除了有助于植物根系的附着外,同时有利于微生物的挂膜,植物、植物根系和微生物膜团形成一个综合生态场.先在轻质材料上钻孔(往往不钻穿),植物栽种前,在轻质材料浸水面上培养驯化微生物菌膜,后在其背水面栽培湘南典型的水生植物,通过微生物菌膜与栽种植物所形成的综合生态场的综合作用,净... 相似文献
20.
研究了等渗的盐和水分胁迫及其钙调节下,青钱柳幼苗叶肉细胞中ATP酶活性在亚细胞中的分布及其超微结构变化。在人工气候室中采用水培法,将青钱柳幼苗进行5个不同浓度处理：对照,85mMNaCl,85mMNaCl＋12mMCa（NO3）2,PEG（渗透势等于85mMNaCl）及PEG（渗透势等于85mMNaCI）＋12mMCa（NO3）2。结果表明：正常生长条件下,ATP酶活性较低并主要定位在细胞核中 等渗胁迫12d以后,ATP酶活性增大并以液泡中居多。等渗水分胁迫下出现的嗜锇颗粒较等渗盐胁迫下的多。由于外源钙的调节作用,等渗胁迫下ATP酶活性增加并主要转移至细胞核上,且在等渗水分胁迫下的嗜锇颗粒明显减少。ATP酶定位在细胞核中表明幼苗遭受胁迫伤害程度较轻,而定位在液泡中则表明受伤害程度较重。等渗处理4和20d后,等渗胁迫及其钙调节下青钱柳幼苗叶片超微结构被破坏程度较无钙调节处理,尤其是较等渗水分胁迫下的轻。初步认为,等渗盐胁迫下青钱柳幼苗遭受的胁迫伤害程度较等渗水分胁迫下的轻,而钙调节作用则以等渗水分胁迫下的效果较佳。 相似文献