香菇单核原生质体的交配型研究

交配型是四极性异宗结合食用菌杂交育种中的一个重要遗传标记.在制备香菇单核原生质体的基础上,我们测定了7个菌株单核原生质体的交配型比例,研究其交配型等位基因的规律.材料与方法(一)供试材料菌株、原生质体制备及再生均按潘迎捷等的方法(食用菌,1992:4).(二)单核原生质体的交配型的测定每个菌株取10个单核原生质体再生菌落做10×10的交配实验,对峙培养后,以交界处菌丝是否出现锁状联合做为两     

灵芝原生质体单核菌株的制备及形态特性比较

对3个灵芝菌株分别进行了原生质体的制备和再生,从中筛选不同交配型单核菌株,并进一步比较了不同交配型单核菌株间的生长差异。结果表明,泰山赤灵芝1号(TL-1),获得了两种交配型单核菌株,两种交配型分离比例为16∶5,灵芝4895(4895)和野生灵芝2(YSL-2)均只获得了一种交配型单核菌株,三个灵芝菌株两种单核体的分离比例均不符合1∶1的理论值。此外,三个灵芝共得到四种交配型单核体的菌丝形态特征差异明显。     

以交配型基因为主要标记的香菇菌种鉴定新方法

在香菇交配型基因研究的基础上,提出了以交配型基因为主要标记的香菇菌种鉴定新方法。这一方法以香菇性亲合性理论为基础,以交配型基因的等位性和多型性为依据,以标准菌株原生质体单核体的两种亲本交配型为遗传标记,以待测菌株的原生质体单核体为材料。该方法中使用的原生质体方法和交配型测定方法都是相当成熟的技术,操作方便可靠。     

香菇135菌株特异SCAR标记的分布和遗传特性

用香菇（Lentinula edodes）135菌株的特异SCAR（Sequence Characterized Amplified Region）引物135F／R（扩增601bp的条带）对135菌株的58个原生质体单核体和97个孢子单核体的基因组DNA进行扩增，检验此特异标记在单核体中的分布和遗传规律。原生质体单核体分为两种交配型A1B1和A282，此标记仅存在于后一种核中；另外，此标记在四种交配型的孢子单核体后代中随机分布，显示这个SCAR标记可以稳定遗传到后代，而且与交配型A、B因子之间没有连锁关系。     

中国主要香菇栽培菌种交配型基因的遗传分析

从我国使用的19个主要香菇栽培菌种中制备了25种原生质体单核体,以此为材料,以交配型基因为标记,在交配反应和RAPD两个水平上对这19个菌株进行了较为详细的遗传相似性分析。25种原生质体单核体两两配以地共300个组合,其中不亲和性反应为110对,占配对总数的36.7％。根据交配反应结果,25个单核体可分为三大类群、7个交配型组。这些结果从交配型角度证明,这19个菌株具有十分狭窄的以交配型基因为标记的遗传背景。RAPD反应和聚类分析中,这三大类群、7个交配型组基本上都能聚为一类,从而在分子水平上验证了交配型折结果,也为交配型基因在菌种鉴定中的作用 提供了依据。     

湖北省香菇自然种群交配型因子分析

以在湖北省无栽培菌株孢子传播的香菇自然发生地随机采集的３２个野生香菇菌株为材料，用原生质体单核体和孢子单核体配对相结合的方法分析鉴定样本中的交配型因子，并用统计学方法分析了菌丝原生质体单核体。     

香菇孢子单核体原生质体的制备和再生的研究

本研究以香菇四种交配型的孢子单核本为材料，用酶解的方法制备出高得率的具四种交配型的原生质体，且均可再生。研究表明：四种交配型原生质体的再生率大小，与原生质体的得率高低并不是一致的，但与菌丝生长速度、再生菌落出现的时间以及交配型之间有一定的关系。这为原生质体的再生能力是受交配型基因控制的推断提供了实验证据。单一交配型的单核原生质体的大量获得也为蕈菌遗传学提供了一种新的研究材料。     

紫芝担孢子交配型的鉴定

以紫芝(Ganoderma sinense)的担孢子萌发获得的单核菌株为试验材料,采用三轮杂交法、OWE-SOJ技术及核迁移技术对其担孢子单核体交配型因子进行准确测定。结果表明,紫芝为四级性异宗结合菌类,其原生质体单核化菌株交配型分离比例符合1:1的预期,不同交配型担孢子的单核体符合1:1:1:1的自由分离规律,采用OWE-SOJ与核迁移试验相互印证,可以对紫芝担孢子交配型进行准确测定。     

白色金针菇原生质体单核菌系的建立及其遗传性特性分析

利用原生质体技术获得的白色金针菇原生质体再生菌株，根据细胞核的分布与数目以及锁状联合的有无，选出２５株单核菌株，对峙试验表明，这些单核株分为核基因型不同的两种类型，两种类型的单核株和始发双核菌株的菌落形态、生长速度、胞体漆酶活性和药物抗性等性状指标均有明显差异，表明生成原生质体的过程中，所再生的单核株发生了变化。     

斑玉蕈交配型位点结构及其多态性分析

为探讨斑玉蕈(Hypsizygus marmoreus)交配型位点结构及其多态性,通过制备双核菌株H3、X3和B3的原生质体及再生获得其单核菌株,分别命名为H3-1、X3-1、B3-1,其他按顺序编号;H3-1、X3-1、B3-1分别与同一菌株的其他单核菌株两两配对,各选取1对亲和单核菌株,两两配对测定交配型,采用生物...     

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.     

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.     

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.     

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.     

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.     

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.     

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.