龙眼光合特性及其影响因子的研究

 在田间和试验室条件下研究了龙眼叶片的光合作用特性。结果表明:龙眼叶片光合速率(Pn)的季节变化呈双峰曲线,最高峰在6月,次高峰在8月,5～9月Pn均维持在较高水平;春季(5月)Pn的日变化曲线为单峰型,高峰在正午,夏季(7月)Pn的日变化为双峰型,高峰在10时,16时有一小高峰;晴天Pn的日变化有明显的“午休”现象,多云天“午休”现象不明显,阴雨天pn较低,且无“午休”现象;Pn由负转正的叶龄为7～10天,30～40天叶龄叶片的Pn最高,60天后Pn缓慢下降;Pn的最适温度范围比较狭窄;环境温度为27℃和22℃时的光合最适温分别为28±2℃和25±2℃。龙眼的光合作用光补偿点和光饱和点分别为600～800μEm^-2s^-1和30～40μuEm^-2s^-1。最适土壤相对含水量为58％～84％。灌水临界期为土壤相对含水量38％～42％。     

套种绿肥对幼龄龙眼园微生态环境的影响

套种绿肥能平稳地温：在寒冷季节，可提高龙眼园冠下气温0．2～0．5℃，提高叶温0.2～1.0℃，提高地表温度2～3℃，提高根标土温1～2℃；在炎热季节，可降低冠下气温0．5～0．8℃，降低叶温0.4～1.7℃，降低冠下地表温度最高达8．5℃，降低根标土温4．0℃。套种绿肥能减少土壤中过高的含水量，促进龙眼根系的生长和吸收养分，还可延长光合作用时间，提高光合速率。     

阿月浑子光合特性及其影响因子的研究

阿月浑子叶片光合速率日变化呈双峰曲线, 最高峰在１１ 时, 次峰在１５ 时, 中午有明显的“午休”现象; 季节变化亦呈双峰曲线, 最高峰在６ 月, 次峰在８ 月;６ 月份枝条中部叶片光合速率大于顶部和下部叶片。光合作用的光补偿点和饱和点分别为５１ μｍｏｌ·ｍ － ２·ｓ－ １ 和１ ６００ μｍｏｌ·ｍ － ２·ｓ－ １ , ＣＯ２ 补偿点和饱和点分别为１３６ μＬ／Ｌ 和８３０ μＬ／Ｌ; 光合作用的最适温度为３０ ℃, 最适土壤相对含水量为７０％ , 灌水临界期的土壤相对含水量为３０ ％ ～３５％ 。     

冬春茬日光温室苦瓜主要光合特性研究

冬春茬日光温室苦瓜的主要光合作用特性,不同叶位间净光合速率明显不同,幼叶和老叶的光合能力较低,健壮叶片净光合速率最高.净光合速率日变化表现为双峰曲线,有明显的"午休"现象.中午空气湿度低,叶表蒸气压亏缺急剧升高造成气孔导度下降是造成光合"午休"的主要原因.温度明显影响光合作用,苦瓜光合作用最适温度为23℃～34℃.     

猕猴桃的光合作用

猕猴桃光合作用的光补偿点与光饱和点分别为50～88、678～922μmol·m~(-2)·s~(-1),光合最适叶温为25～31℃,因品种而有差异。光合作用的最适土壤相对含水量为68.8％～74.9％。不同品种及不同时期抽发的枝梢叶片光合速率有所不同。光合速率的日变化进程在阴天、多云天为单峰曲线,晴天为双峰曲线。高温干旱天,叶片光合作用与光合产物的积累主要在11～12时之前。光合速率的年变化进程主要受叶片发育状况、阶段性园地生态因素组成与物候期交替的综合影响。     

蔬菜植物光合作用研究进展

从单个叶片光合特性、光合速率的日变化、光合"午休"、主要环境因子对光合作用的影响及光合产物的运输与分配等五个方面对前人在蔬菜植物上的光合作用研究作了简要综述,并对今后的研究方向进行了展望.     

树莓光合特性的研究

 以美国红树莓为试材，对其光合特性进行了研究。结果表明：树莓叶片光合速率日变化呈双峰曲线，有明显的“午休”现象；光合速率与气孔导度呈显著的正相关，但光合速率变化与气孔导度和胞间CO₂浓度的变化并不完全同步；光合速率季节性变化也呈双峰曲线变化；影响光合作用的主导环境因子为光照强度和湿度；光合作用的饱和点和补偿点分别为750 μmol·m^-2·S^-1 和21.4 μmol·m^-2·S^-1 。     

甜橙叶片形态解剖特征与光合速率的关系初探

甜橙叶片形态解剖特征的季节变化与光合作用速率变化的关系如何,迄今在国内外尚未见有报道。本试验在不同生长季节测定了锦橙、脐橙树冠内外部位叶片的叶厚度、栅栏组织厚度、气孔密度及光合速率,对测定值分别进行了方差分析、相关分析     

“红富士”苹果离体/活体枝叶光合作用及水分利用效率的季节变化

以25a生"红富士"苹果为试材,于生长季节对饱和水分环境的离体枝条叶片与活体叶片的水势和光合作用进行了连续观测,以探索年周期内果树生长不同发育阶段叶片水分状况对光合作用和水分利用效率的影响。结果表明:在"红富士"苹果生育期前半阶段的展叶抽梢期、开花坐果期、花芽分化期,由于尚未进入降雨季节,叶片水势不断下降,光合速率和蒸腾速率都明显小于离体枝条叶片,叶片水势的降低在一定程度上限制了蒸腾速率,但是也同样降低了光合速率,导致水分利用效率逐渐下降。因此在4~5月份抽梢展叶期和开花坐果期应当及时进行灌水补充,6月份适度的水分胁迫则有利于花芽分化。在7、8月份冠层蒸腾作用强烈,叶片的水势下降明显,此时的水分胁迫限制了蒸腾速率,提高了水分利用效率。由于此期已经进入雨季,除个别干旱年份以外,通常无需灌溉。在9月份以后进入果树生长发育后期,随着日照时数和气温逐日下降,活体叶片的光合速率和蒸腾速率与离体枝条叶片的差异变小,树体的水分利用效率提高,一般不予灌溉。     

生姜光合特性的研究

本试验对生姜不同品种、不同部位叶片的光合能力以及温度、光照等环境因素对生姜光合作用的影响进行了研究。结果表明,莱芜‘大姜’的光合速率高于莱芜‘片姜’。中部壮龄叶的光合作用最强,其次为基部叶,顶部嫩叶光合作用软弱。在22-24℃条件下,生姜单叶光合作用的适宜照度为20000-350001x。在光强为30000 1x时, 20—28℃,生姜光合作用较强,若温度过高,对光合作用不利。在生姜全生长过程中,其光合速率变化呈一单峰曲线。在旺盛生长季节,其光合作用的日变化,呈一双峰曲线,第一次高峰在上午9时前后,中午为一低谷,第二次高峰在16时左右。     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

Ergebnisse der Leistungsprüfungen der Süßkirschensorte ‚Stella‘ auf Gisela- und Weiroot-Unterlagen in Bulgarien

Zusammenfassung Die Leistungsprüfungen wurden im Zeitraum 1997 bis 2003 mit den Unterlagen Gisela 4 und 5, den Klonnummern 195/20 und 497/8 aus der Gisela-Serie sowie Weiroot 10, 13, 53, 72 und 158 durchgeführt. Dabei dienten Sämlinge von P1 (bulgarische Selektion aus Prunus mahaleb) als Kontrolle. Alle Unterlagen waren mit der Sorte Stella veredelt und im Dezember 1996 in der Versuchsanlage der Agraruniversität in Plovdiv, Bulgarien, im Abstand von 6 m×4,5 m gepflanzt worden. Dabei erfolgte ein Pflanzschnitt. Nach Abschluss der natürlichen Kronenentwicklung wurde jedes Jahr ein Winterschnitt vorgenommen. Der Boden wurde durch mechanische Bearbeitung offen gehalten und nach dem 4. Standjahr wurden die Baumstreifen mit Herbiziden behandelt. Die Wasserversorgung erfolgte durch eine dem natürlichen Gefälle folgende Überflutung, allerdings nicht immer zum optimalen Zeitpunkt, da keine eigene Wasserquelle zur Verfügung stand.Basierend auf den Ergebnissen bis zum Anfang des 7. Standjahres können die untersuchten Unterlagen in zwei Gruppen differenziert werden: starkwüchsig—Weiroot 10, P1 und Weiroot 13; mittelstarkwachsend bis schwachwüchsig—Gi 497/8, Gisela 4, Weiroot 53, Weiroot 158, Gi 195/20, Weiroot 72 und Gisela 5. Letztere zeichnete sich durch besondere Schwachwüchsigkeit aus. Die meisten Wurzelschosser bildeten Gisela 4, Weiroot 10 und Weiroot 13. Weiroot 53, Weiroot 72 und Weiroot 158 entwickelten deutlich weniger und P1, Gisela 5, Gi 195/20 sowie Gi 497/8 keine Wurzelschosser. Den frühesten Blühbeginn induzierte Gisela 4. Die anderen Unterlagen führten, in Abhängigkeit von den Temperaturbedingungen des jeweiligen Jahres, zu einer Verspätung der Blüte: P1 und Weiroot 10 um 1–2 Tage; Gi 497/8, Weiroot 13 und Weiroot 158 um 2–4 Tage; Weiroot 72 um 2–7 Tage; Gi 195/20 um 3–6 Tage; Weiroot 53 um 3–8 Tage und Gisela 5 um 3–10 Tage. Die Reifezeit der Früchte war bei den Bäumen auf Gisela 5 im Vergleich zu den anderen Varianten um 2–3 Tage verspätet. Gisela 5, Weiroot 72 und Gisela 4 induzierten bei der aufveredelten Sorte die höchsten Ertragsleistungen, P1 die geringsten. Bei den Bäumen auf Gisela 5 war die Fruchtgröße geringer als bei den anderen Unterlagen. Bäume auf Gisela 5 brauchen intensive Pflege. Nur wenn alle Produktionsfaktoren und kulturtechnischen Maßnahmen optimiert werden, kann das hohe Ertragspotenzial dieser Unterlage ausgeschöpft werden.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.