GA3对乙烯利抑制黄瓜苗生长的逆转效应

黄瓜幼苗经过５００×１０＾－６乙烯利喷苗处理，严重抑制了黄瓜幼苗的生长，并趋向老化；用ＧＡ３三种浓度（５×１０＾－６、１０×１０＾－６、２０×１０＾－６）喷叶处理后，有效地逆转了乙烯利对黄瓜幼苗的影响，使其趋向于壮苗。在三种浓度或以１０×１０＾－６处理的效果最好。     

正交试验法在龙眼和荔枝组织培养中的应用

利用正交设计试验法研究了椰乳（ＣＭ）、２，４－Ｄ、赤霉素（ＧＡ３）和蔗糖等四个因素及其组合对石硖龙眼和桂味荔枝的幼胚愈伤组织产生的影响，并讨论了正交设计试验法应用于龙眼和荔枝组织培养培养基筛选的可能性。结果表明：１）对龙眼，诱导愈伤组织的最优组合是 ＣＭ １０％、２，４－Ｄ１．０ｍｇ·１－１、ＧＡ３０ｍｇ·１－１和蔗糖３％；对荔枝，最优组合是ＣＭ０％，２，４－Ｄ１．０ｍｇ·１－１，ＧＡ３０ｍｇ·１－１和蔗糖 ５％。 ２）适当的 ２，４－Ｄ浓度（１．０ ｍｇ·１－１）可提高愈伤组织的产量；３）ＧＡ３抑制了龙眼和荔枝的愈伤组织的产生；４）不同树种的胚需要不同的糖浓度；５）适当ＣＭ浓度（１０％）可提高龙眼愈伤组织的产量，而荔枝愈伤组织的产生并不需要ＣＭ。     

不同包装,药剂和硫处理对龙眼贮藏效果的研究

本试验研究了不同包装、药剂和硫处理对石硖龙眼的贮藏效果，结果表明：内包装以０．０２ｍｍ的聚丙烯呈聚乙烯袋为宜，外包装可采用竹篓。普通药剂以特克多５００×１０＾－６加抑霉唑５００×１０＾－６为最佳配方，硫处理中浸泡试验无效。而缓慢放硫处理可使用加二亚硫内或焦亚硫酸风量为６ｇ或８ｋｇ／ｋｇ果；熏硫处理则用３０ｇ硫磺熏蒸３ｋｇ果，时间２０或３０分钟，或者２０ｇ硫磺熏蒸２．５ｋｇ果，时间１５或２５分钟，随     

无核枇杷生产技术研究

用２５０×１０＾－６,５００×１０＾－６和１０００×１０＾－６ＧＡ对“霸红”枇杷花穗进行喷雾均可诱导无核果实,花前处理效果好于其他时间处理。对ＧＡ诱导的无核枇杷幼果用ＣＰＰＵ＋ＧＡ处理可促进其膨大并减少脱落,多次使用效果更好。花后每月一次用３０×１０＾－６ＣＰＰＵ＋５００×１０＾－６ＧＡ喷雾４次获得了商品果大小的无核枇杷。     

正交试验法在龙眼和荔枝组织培养中的应用

利用正交设计试验法研究了椰乳（ＣＭ）、２，４－Ｄ、赤霉素（ＧＡ３）和蔗糖等四个因素及其组合对石硖龙眼和桂味荔枝的幼胚愈伤组织产生的影响，并讨论了正交设计试验法应用于龙眼和荔枝组织培养基筛选的可能性。结果表明：１）对龙眼，诱导愈伤组织的最优组合是ＣＭ１０％、２，４－Ｄ１．０ｍｇ．ｌ＾－１和蔗糖３％；对荔枝，最优组合是ＣＭ０％，２，４－Ｄ１．０ｍｇ．ｌ＾－１，ＧＡ３０ｍｇ．ｌ＾－１和蔗糖５％。２）适当     

几种植物生长调节剂对葡萄果实大小品质的效应

对ＣＰＰＵ、ＧＡ３ＰＤＪ和Ｓ－ＡＢＡ等几中植物生长调节剂组合对葡萄果实大小和品质的影响进行了研究，结果表明：在盛花期前１０天ＧＡ３５０×１０＾－６配合盛花后１０天ＣＰＰＵ１０×１０＾－６和ＧＡ３１０×１０＾－６混合处理，增大白香蕉葡萄果穗和果粒重量的效果明显，同时增加了果实可溶性固形物含量和着色度。在盛花后１５天ＣＰＰＵ５×１０＾－６配合果实着色始期ＰＤＪ２５０×１０＾－６的处理，可明显增大藤稔葡     

外源ABA和GA3处理对人工控制条件下柑桔抗冻力的影响

在植物人工气候箱条件下，研究了叶面喷布１００×１０＾－６ＡＢＡ和ＧＡ３对锦橙实生苗抗冻力的影响。结果表明，ＡＢＡ可在非锻炼条件（昼２０℃／夜１０℃）下提高抗冻力１．２６℃（处理后第５天）和２．２６℃（处理后第１０天）；而ＧＡ３则在锻炼条件（昼１０℃／夜５℃）下降低抗冻力１．２４℃（处理后第５天）和２．００℃（处理后第１０天）。     

香椿种子发芽特性研究

香椿种子发芽温度以２０￣２５℃为宜，浸种时间以１２ｈ（３０℃）最为适宜。ＧＡ３处理可促进香椿种子发芽，浓度以３０×１０＾－６效果最好。香椿种子寿命较短，生产上应使用新种子播种育苗。     

脐橙修剪及保果技术

脐橙修剪及保果技术１保果永安市在脐橙保果技术上有３种方法：一是在５月上旬对１～３级枝进行环剥保果，一般可比对照增加１倍的产量，不影响树势和第２年产量。二是在５～６月间喷布１５×１０－６２，４－Ｄ１～２次，或４０×１０－６～５０×１０－６九二○两次，夏...     

几种植物生长调节剂对葡萄果实大小和品质的效应

对ＣＰＰＵ、ＧＡ＿３、ＰＤＪ和Ｓ－ＡＢＡ等几种植物生长调节剂组合对葡萄果实大小和品质的影响进行了研究。结果表明：在盛花期前１０天ＧＡ＿３５０×１０￣（－６）配合盛花后１０天ＣＰＰＵ１０×１０（－６）和ＧＡ＿３１０×１０￣（－６）混合处理，增大白香蕉葡萄果穗和果粒重量的效果明显，同时增加了果实可溶性固形物含量和着色度。在盛花后１５天ＣＰＰＵ５×１０￣（－６）配合果实着色始期ＰＤＪ２５０×１０（－６）的处理，可明显增大藤稔葡萄果穗、单粒重及可溶性固形物含量，并促进果面着色。     

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.     

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.     

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.