苹果炭疽病菌对多菌灵抗药性研究

利用抑菌圈法和果实接种法测定了河南各苹果产区苹果炭疽病菌对多菌灵的敏感性.结果表明,连续用药3年以上的炭疽病菌株对多菌灵产生严重的抗药性,其他依次为农-4<许-3<泛-9.用药3年以上的炭疽病菌抗性菌株对甲基托布津具有交互抗性.初步观察,混配药剂花麦特(50%多菌灵+50%退菌特+50%扑海因+70%代森锰锌)对抗性和敏感性菌株有显著效果,可作为替换药剂.     

甜瓜枯萎病的病原鉴定及药剂筛选研究

以采自吉林鲁家镇、四家子镇、乐山镇3地的甜瓜枯萎病病株为试材,采用组织分离法对其病原菌进行分离;同时进行病菌形态学鉴定和ITS序列测定;并采用生长速率法研究比较了21种杀菌剂单剂及3种混配剂对该病原菌的毒力作用。结果表明:该试验共获得7个具有致病性的菌株,表明该病菌为尖孢镰孢(Fusarium oxysporum);室内药剂筛选出了4种抑菌效果较好的杀菌剂,即450g/L咪鲜胺EC、50%多菌灵WP、400g/L氟硅唑EC、30%氟菌唑WP;混配剂30%氟菌唑WP和50%多菌灵WP按2∶1配比毒力作用最强,其次为30%甲霜灵WP和50%多菌灵WP按2∶1配比。     

戊唑醇与代森锰锌对苹果3种主要病菌的联合毒力

为了弄清戊唑醇与代森锰锌混配对苹果轮纹病菌等3种苹果主要病菌的抑制作用,找出2种药剂混配的最佳配比,为田间使用提供依据,采用共毒系数法测定了戊唑醇与代森锰锌不同配比对苹果轮纹菌、苹果炭疽菌和苹果腐烂菌的联合毒力。结果表明,戊唑醇∶代森锰锌以1∶4比例混配对苹果轮纹病菌和苹果炭疽病菌的抑制效果最好,共毒系数分别为351.42和405.82;戊唑醇∶代森锰锌以4∶1比例混配对苹果腐烂病菌的抑制效果最好,共毒系数为169.49,增效作用显著。     

洋葱颈腐病药剂筛选及毒力测定试验研究

采用菌饼法,对7种药剂及其药剂组配进行洋葱颈腐病菌的室内毒力测定。结果表明:1～3d所试药剂均有一定的抑制作用;第5天多菌灵、95%三乙磷酸铝原粉+纯品甲托、95%三乙磷酸铝原粉+80%纯品多菌灵、80%纯品多菌灵、95%三乙磷酸铝原粉的抑菌效果依次降低,抑菌率为零或零以下,以95%三乙磷酸铝原粉效果最差,抑菌率为-0.301,但能抑制菌核的形成;纯托(甲基托布津)、70%精甲托以及95%三乙磷酸铝原粉+纯托(甲基托布津)、80%纯品多菌灵+纯托(甲基托布津)、50%福美双可湿性粉剂+纯托(甲基托布津)对洋葱颈腐病菌生长的抑制效果最好;第7天的抑菌率均为1;50%福美双可湿性粉剂次之,抑菌率为0.888。     

50%多霉清对苹果轮纹病、炭疽病病原菌的抑制作用

一、试验材料 1.供试药剂:50％多霉清(保定化工八厂生产),70％甲基托布津(日本曹达株式会社生产)。 2.供试菌种:苹果轮纹病菌(Physalosproa piricola Nose),苹果炭疽病菌(Glom-erella cingulata Schr.et Spaulad)(由本所从苹果病果上分离得到)。 二、试验方法 1.药剂抑菌测定 采用菌落生长速率法进行室内药效测定。设50％多霉清试验浓度为800x、1000x、1200x、1500x,以70％甲基托布津800x药液为对照药剂,将药剂按一定倍数加入溶化的定量PDA培养基中,制作药剂培养基,     

内吸性杀菌剂对甜瓜枯萎病菌的室内毒力测定

采用生长速率法测定了几种内吸性杀菌剂对甜瓜枯萎病菌的毒力.试验结果表明,多菌灵和氟硅唑的毒力最高,其EC50分别为2.267 1 mg/L和13.341 8 mg/L;而且枯萎病菌对多菌灵和氟硅唑的敏感性也较高;多菌灵和氟硅唑时枯萎病菌的联合毒力测定结果表明,两种药以6:1和1:6混配,具有增效作用.     

化学药剂敌力脱与拮抗细菌协同作用防治梨轮纹病研究

从南京、连云港、高邮三地的梨园采样,分离得到梨轮纹病病原菌25株及871个细菌分离物,25株病原菌致病性分化测定结果表明菌株N-BG-L5的致病力最强;871细菌分离物拮抗能力试验结果表明,拮抗细菌sf628对梨轮纹病菌菌丝生长具有很强的抑制性,抑菌圈直径达45mm。常见26种化学药剂对梨轮纹病菌的室内毒力测定结果表明,25%敌力脱能有效抑制梨轮纹病菌菌丝生长,EC50值为0.1522mg·L-1。将拮抗细菌sf628与25%敌力脱进行复配,结果表明配比为1∶3、1∶2、1∶1、2∶1时增效比均大于1.5,2种单剂复配后有增效作用。其中配比为1∶3时对梨轮纹病菌的毒力最强,增效比为2.942。拮抗细菌sf628与25%敌力脱配比为3∶1时,增效比为1.071,2种单剂复配后有相加作用。     

5种杀菌剂对桃炭疽病菌的毒力测定

以桃炭疽病菌为试验菌,采用生长速率法,测定5种杀菌剂对病菌的毒力,结果表明:咪鲜胺锰盐、氟啶胺、多菌灵、苯醚甲环唑和吡唑醚菌酯5种杀菌剂都具有较高的毒力。咪鲜胺锰盐与氟啶胺的联合毒力测定结果表明:咪鲜胺锰盐和氟啶胺按3∶1和6∶1复配表现为增效作用,咪鲜胺锰盐和氟啶胺按1∶6、1∶3和1∶1复配表现为相加作用。     

食用菌主要杂菌——绿色木霉、黑根霉药剂防治试验

通过室内抑菌力测定和棚内药剂试验，筛选出对绿色木霉、黑根霉的有效药剂为力克霜、多菌灵、甲基托布津；观察测定其对食用菌菌丝生长的生长影响，结果表明，在拌料时加药力克霜2g/L、1g/L，多菌灵、甲基托布津1g/L在拌料时加药对菌丝生长影响较小、菌丝满袋率在90％～100％，多菌灵、甲基托布津2g/L对食用菌菌丝生长速度有较明显的影响，总满袋率77％～86．8％；装袋前各药剂按2g/L、1g/L用药，对食用菌菌丝生长有严重抑制作用。     

苹果轮纹病菌对多菌灵的敏感性测定

2007年8-10月从山东主要苹果产区轮纹病果上分离获得83个苹果轮纹病菌(Botryosphaeria berengriana f.sp.piricola)菌株,采用菌丝生长速率法分别测定了各菌株对多菌灵的敏感性。结果表明,多菌灵对83个菌株的EC50值呈单峰频次分布,分布在0.0196～0.4867mg·L-1,均值为0.1080±0.0152mg·L-1;在83个菌株中选择对多菌灵最敏感的泰山海棠菌系进行重复测定,将其EC50平均值0.0428mg·L-1确定为苹果轮纹病菌对多菌灵的敏感基线;通过Duncan氏新复极差法和系统聚类分析结果表明,不同地理来源的苹果轮纹病菌对多菌灵的敏感性都处在较高水平,总体上不存在明显差异,没有出现敏感性下降的抗药性亚群体。     

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.     

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.     

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.     

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.