黄花乌头根腐病菌的生物学特性研究

采用凹玻片法,通过不同碳源和氮源处理条件对黄花乌头根腐病的镰刀菌的生长影响进行了研究。结果表明:病原菌的孢子在温度为10～35℃的温度处理中均可以萌发,其最适宜的萌发温度为25～30℃;在pH为6时孢子萌发率最高,在pH 5～6的不同处理条件下最适于病原菌孢子的萌发;黄花乌头根腐病菌的孢子萌发率受光照条件影响不大。     

不同温度和pH对榆白涩病病菌的影响

在不同条件处理下,对菌丝生长和病菌孢子萌发的影响进行系统的分析,研究不同温度及pH对榆白涩病病菌菌丝、病原孢子生长的影响。结果表明:榆白涩病病菌的生长速率受温度条件影响较大,5～30℃,菌丝生长量与温度呈正相关,25℃最适合菌丝生长;5～35℃,病原孢子的萌发率与温度呈正相关,适宜病菌孢子萌发的温度为30℃。pH值在3～11范围内病原菌丝均可生长;菌丝生长最适的pH值为9,pH值在3～11条件下孢子能够生长;最适孢子生长的pH值为8。     

美味黑粉菌冬孢子萌发条件的研究

研究了疏亲水界面、温度、pH值和不同物质对美味黑粉菌冬孢子萌发的影响,以探讨美味黑粉菌冬孢子在自然生境条件萌发的适应性。研究结果表明,疏水界面促进美味黑粉菌冬孢子萌发,在疏水的聚苯乙烯塑料培养皿和茭白茎表皮上,萌发率高;冬孢子萌发的最适温度为27～30℃,温度过高或过低均抑制萌发;酸性条件促进冬孢子萌发,最适pH值为3～4;蔗糖促进冬孢子萌发,且以1%浓度最适,但同样浓度的甘露醇、葡萄糖、海藻糖、D-果糖等抑制冬孢子萌发。     

不同温度、光照及pH对玉竹黑斑病病菌的影响

在实验室条件下,研究了不同的碳源、氮源、温度、光照、pH对玉竹黑斑病病菌的影响.结果表明:pH 7最适于菌丝的生长,pH 7～9适于孢子的萌发;光暗交替可以促进菌丝生长和孢子萌发;最适于菌丝生长和孢子萌发的温度均为28℃.     

贵州省铁树新病害叶枯病病原菌生物学特性研究

对贵州省铁树上发生的一种新病害-叶枯病病原菌进行了生物学特性研究,探讨不同温度、pH、光照、碳源及氮源等条件对该病原体菌丝生长、分生孢子萌发的影响,以期系统掌握该病原菌的生物学特性,为铁树叶枯病防治提供理论依据。结果表明:铁树叶枯病菌菌丝在10～35℃温度范围内均能生长,在15～35℃之间孢子均能萌发,菌丝生长和孢子萌发最适温度分别为30℃和25℃;在pH 2～12之间,病原菌菌丝(孢子)均能生长(萌发),其中pH为6时病原菌菌丝生长最好,pH为10时病原菌孢子萌发率最高;光照条件对菌丝的扩展和孢子萌发影响不明显;该病原菌对单糖、双糖、多糖等碳源以及有机氮和无机氮均能利用,其中以蔗糖作碳源时,菌丝生长和孢子萌发最佳,以硝酸钾作氮源时,菌丝生长最好,供试氮源对分生孢子的萌发均不佳。     

脱皮马勃孢子萌发条件的研究

目的：为了提高脱皮马勃单孢子菌种的分离效果、以及探讨脱皮马勃孢子萌发对自然生境条件的要求，方法：进行了不同温度、不同营养物及浓度和光照等条件对其孢子萌发影响的研究。结果：25℃是脱皮马勃孢子萌发的适宜温度；2％葡萄糖和Bonar液可促进孢子萌发，而氯化钠则对孢子萌发有抑制作用；光照或黑暗对孢子萌发无影响；来源于两个不同年份的孢子萌发率差异显著。     

珍珠绣线菊白粉病生物学特性研究

以新鲜洋葱和珍珠绣线菊白粉病无性孢子为试材,研究不同碳、氮源、pH、温度及光照对孢子萌发的影响.结果表明:适宜孢子萌发的碳源为蔗糖、葡萄糖,氮源为丙氨酸,适宜的萌发温度为23℃,适宜萌发的pH为6～7,全光照条件下适宜孢子萌发.     

菜豆全国区试品种的抗锈性鉴定初报

菜豆锈病在我国各地区均有发生,严重年份可造成50％以上的减产,甚至绝收。为研究各地区不同菜豆品种对不同地区锈病菌的抗性情况,我们以1991年参加全国区试的9个品种和天津市的新秀二号作材料,这十个品种均为目前全国推广面积较大或准备大面积推广的新品种,采集全国五个地区的锈病菌分别接种以研究不同品种对不同地区锈病菌的反应,以便为     

芸薹根肿菌的休眠孢子萌发条件的研究

以哈尔滨市阿城区白菜根肿菌的休眠孢子为试材,对其进行萌发测定,研究了不同因素对休眠孢子萌发的影响。结果表明:休眠孢子萌发的适宜温度为24℃,适宜pH为6.3;黑暗处理的休眠孢子比光照处理的休眠孢子萌发率高,分别为73.33%和12.16%,腐烂处理根肿的萌发率最高为73.33%。以上结果表明白菜根肿病容易发生在低温和偏酸性条件下。     

海棠锈病病菌特征观察及其冬孢子萌发培养

以海棠锈病病菌为研究对象,通过直接观察、显微结构观测和荧光染色等方法,对海棠锈病病菌特征进行观测,并对锈菌冬孢子进行萌发培养试验。结果表明:该锈菌存在冬孢子、担孢子、性孢子、锈孢子4种孢子类型。其中冬孢子堆生于圆柏瘿瘤上,遇水后萌发产生担孢子,担孢子侵染海棠叶片后产生性孢子、锈孢子;冬孢子在无菌水和海棠叶片浸出液中均可萌发产生担孢子,培养10h后冬孢子累计萌发率基本达到饱和点,叶片浸出液中培养的冬孢子累计萌发率略高于无菌水。     

Relationship between renal hypertension and cardiac α1-adrenoceptor autoantibodies in rats

AIM: To examine the autoantibody against α₁-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α₁-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α₁-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α₁-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension.     

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.     

Influence of Mineral Nutrients on Strawberry Fruit Quality and Their Accumulation in Plant Organs

Abstract

This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality.     

Mixed-severity fire regime in a high-elevation forest of Grand Canyon,Arizona, USA

Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date.     

瓜叶绿素降解关键酶基因PPH和PAO cDNA片段的克隆与表达初步分析

 以西双版纳黄瓜和‘华黄5号’黄瓜叶片为试验材料,研究了衰老过程中两种黄瓜叶片叶绿素含量变化及脱镁叶绿素脱镁叶绿酸水解酶基因PPH和脱镁叶绿酸a加氧酶基因PAO的表达。结果表明：随着叶片衰老,叶绿素a和叶绿素b含量显著降低,叶绿素a与叶绿素b的比值在0.5左右,推测叶绿素b的含量可能对黄瓜叶片保绿起到重要作用。荧光定量RT-PCR分析结果显示：PPH和PAO在西双版纳黄瓜叶片生长35 d时表达量最高,分别为5.50和1.86;PPH在‘华黄5号’叶片35 d时表达量最高,为7.14,而PAO在35和45 d表达量都很高,分别为3.90和3.91;PPH和PAO在西双版纳黄瓜叶片中的表达量低于在‘华黄5号’中。     

Effects of simvastatin on PDGF-BB and serum-induced proliferation of vascular smooth muscle cells and on the expression of tumor suppressor gene PTEN

AIM:To observe the effect of simvastatin on the proliferation of vascular smooth muscle cells(VSMCs) induced by serum and growth factor PDGF-BB and the effect of simvastatin on the expression of PTEN,a important regulator of G₁/S cell cycle transition. METHODS:The DNA synthesis was determined by [³H]-TdR incorporation, cell cycle was examined with flow cytometry, the protein level of PTEN was measured by Western blot method. RESULTS: (1)Simvastatin inhibited [³H]-TdR incorporation in a dose dependent manner. (2) Flow cytometric DNA analysis revealed that simvastatin induced significantly enhancement of G₀/G₁ phase and decrease in S phase VSMCs.(3)Simvastatin increased protein level of PTEN and mevalonate, a metabolite of HMG-COA, reversed the effect of simvastatin on PTEN protein expression. CONCLUSION:Simvastatin may inhibit proliferation of VSMCs and retarded cell cycle in G₀/G₁ phase by increasing PTEN expression through inhibiting synthesis of mevalonate.     

Relationships of landscape,prey and agronomic variables to the abundance of generalist predators in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis>) fields

A two-year field study investigated the possible effects of grain sorghum (Sorghum bicolor [L.] Moench) and uncultivated areas on the abundance of generalist predators in commercially-managed cotton (Gossypium hirsutum L.) fields in Texas, USA. From 63 to 70 fields were sampled for pests and predators over nine consecutive weeks during early stages of cotton development. Additional data on agronomic practices and landscape composition at three spatial scales were also collected for each field. Stepwise regression analyses were used to determine the relationships of landscape, agronomic and prey variables to the abundance of generalist predators. Because the variables most closely linked to predator levels could vary over time, separate regressions were conducted for three time periods corresponding to stages of grain sorghum growth (half-bloom, hard-dough, maturity) in each year. Significant relationships between predator abundance and agricultural landscape composition appear in both years and in all three time periods, but the specific relationships of landscape variables to cotton predator levels differed between and within years. At maturity in 2001, predator levels rose as the amount of uncultivated land from 1.6 to 3.2 km distant and the perimeter shared with grain sorghum increased. During 2002, the area of grain sorghum (half-bloom) and uncultivated land (hard-dough) within 1.6 km of cotton fields were both positively related to predator numbers. Cotton planting dates and the abundance of cotton fleahoppers (Pseudatomoscelis seriatus [Reuter]) were also strongly linked to predator numbers during both years. Results suggest that the total amount of grain sorghum or uncultivated land in an area is more important than the presence of these habitats adjacent to cotton fields, and that landscape composition may sometimes be the most important factor in determining predator abundance.     

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.     

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.