蜀冠龙眼幼树结果母枝质量评价研究

研究结果表明，8月上中旬抽发的健壮秋梢是蜀冠龙眼最重要的结果母枝，其着果量与枝粗度及单位长度枝梢上的复叶数呈极显著正相关，并提出了蜀冠龙眼优良结果母枝的生物学指标；花芽分化期叶片的营养元素及可溶性糖含量是影响龙眼秋梢能否成花、结果的决定因素，在营养达标范围内，叶片氮素含量与秋梢的成花、着果量成正比关系，与磷、钾素含量无相关。     

龙眼结果母枝单元的研究

本文提出了龙眼“结果母枝单元”的概念；阐述了龙眼枝梢能否演变良好的结果母枝，就其内因来说，是由结果母枝单元的状况决定的；指出石硖龙眼优良结果母枝单元的生长量指标为基部直径０．８ｃｍ以上复叶数１５张以上，这样的枝梢一般为三次或三次以上梢组成；并进一步指出，适当疏花疏果、夏季修剪，促生秋梢结果母枝的基枝以及加强肥水管理是培养优良结果母枝单元，实现丰产稳产的关键措施。     

四季花龙眼冬梢结果母枝花芽分化过程中内源激素含量变化研究

研究了300 mg/L多效唑处理后四季花龙眼冬梢结果母枝顶芽在花芽分化过程中内源激素含量变化的规律.结果表明,在花芽分化过程中,300 mg/L多效唑处理和对照顶花芽赤霉素(GA3)和生长素(IAA)含量总体均呈下降趋势,但在花序抽穗期含量升高；玉米素(ZRs)含量一直保持快速增加；300 mg/L多效唑处理脱落酸(ABA)含量呈波浪式升高；300 mg/L多效唑处理顶花芽IAA含量一直明显低于对照,ZRs及ABA含量基本上均高于对照.结果母枝顶芽中ZRs/GA3、ABA/GA3、ZRs/IAA及ABA/IAA值升高有利于花芽分化.     

负载平衡对龙眼结果母枝生长、结果和果实品质的影响

【目的】探明龙眼单株挂果率与初始单穗果数之间的交互作用，确定龙眼疏花疏果时的合理挂果量，以及其对龙眼结果母枝生长、结果和果实品质的影响。【方法】以石硖龙眼(Dimocarpus longan Lour‘Shixia’)为试材，以不同挂果率单株为区组(3个水平)，以初始单穗果数为处理(3个水平)，设计了一个单因素随机区组试验，共9个区组×处理组合(H11～H13、H21～H23、H31～H33)；分析了区组和处理对成熟时单穗余果数、落果率和单果质量等指标的影响。【结果】(1)果实发育期间，植株树势逐渐下降，单果质量和落果率逐渐升高，而成熟时各组合在结果母枝生长、结果和品质方面均表现出显著或极显著差异。(2)相关分析表明，区组水平与树势及成熟期结果母枝叶片生长状态呈显著相关，而处理水平主要影响了单穗余果数和小叶果比；成熟树势与果穗盲节粗度、叶光泽度等呈极显著正相关，与叶片色度指标l＿L^*、l＿b^*和l＿C^*呈极显著负相关。(3)回归与方差分析表明，区组与处理之间不存在交互作用，协变量中的小叶果比、有叶枝长比等对区组和处理水平...     

龙眼施用氯酸钾催花及激素的保花保果研究

试验证明 :1 2月中、下旬和 4月至 5月初施用KClO3 进行龙眼产期调节 ,可以获得明显的产量和效益。培养充实粗壮的结果母枝是龙眼产期调节成功的重要前提。随着结果母枝粗度增大、叶片数增多 ,单株产量也明显提高。母枝粗度 >0 5cm、叶片数 >1 0片的单株产量比母枝粗度 <0 5cm、叶片数 <1 0片的增加 1 30 % ;母枝粗度 >0 7cm、叶片数 >1 5片的单株产量增加 4 75 %。在春季龙眼严重“冲梢”的情况下 ,4月至 5月初施用KClO3 ,可以再催生花穗 ;盛花期至幼果期遇到高温天气 ,喷洒激素有较好的保花保果效果 ,比对照增产 4 5 7%～ 2 4 7 0 % ,可以在生产上示范推广     

桂花龙眼的生物学特性及其栽培技术

石硖龙眼Dimocarpus longan Lour．是广东省著名的龙眼品种，风味与品质好，但不足之处就是果型偏小。仲恺农业技术学院、台山市红岭种子园和广东省农学会的科技人员经过多年试验，在石硖龙眼无性系群体中通过芽变途径选育出了一个大果型石硖龙眼新品系，2005年7月通过了广东省科技厅的成果鉴定，初步定名为“桂花”龙眼。现将其在广东省台山市试验点的生物学表现及栽培技术介绍如下。     

结果母枝粗度及其负载量对龙眼果实生长发育的影响

1　材料与方法试验于 2 0 0 0年 5～ 8月在珠海市下栅果场 7年生石硖龙眼园进行。果实成熟时 (7月 2 9日 ) ,在果园随机调查分析 6种不同结果母枝粗度 (0 4 1～0 5、0 5 1～ 0 6、0 6 1～ 0 7、0 71～ 0 8、0 81～ 0 9和>0 9ｃｍ)上 ,末次结果母枝长度、有效叶片数、每穗果数、单果重、果实含糖量和含酸量等 ,每种母枝粗度至少调查 4 0枝花穗。结果母枝粗度测量末次秋梢中部的直径。于同一株龙眼树上选两种粗度的结果母枝 (0 4～ 0 6ｃｍ和 0 7～ 0 9ｃｍ)进行 3种不同疏果量处理 (每穗分别留果 6 0、4 0和 2 0果 ) ,共 6个…     

套袋对石硖龙眼果实发育和品质的影响

以石硖龙眼为试材，研究了不同时期套袋对果实生长发育、病虫害及果实品质的影响。结果表明：套袋不影响果实的生长发育类型；套袋后果实的还原糖、总糖含量，单果重，果径，TSS和可食率与对照均没有显著差异；套袋使虫果率有所下降，但增加了落果率，且会使石硖龙眼出现较严重的日灼病。     

大乌圆龙眼结果母枝的培育

对龙眼品种大乌圆结果母枝的形成与培育进行了8年的观察研究表明，秋梢是第二年形成结果母枝的枝梢在自然气候条件下，采取相应的栽培管理措施，在9月下旬至11月上旬留秋梢，11月下旬至12月上旬老熟．营养积累多，冬梢抽生少。翌年1月份低温条件有利于花芽分化，形成结果母枝率高，花穗质量好，着果率高。     

龙眼新品种东良龙眼果实生长发育和果实性状

分析龙眼新品种东良果实生长发育特性和果实经济性状,并与珠三角主要栽培优质品种石硖龙眼进行对比。结果表明,东良花后32天左右开始长出半透明果肉,15～20天后包满种子。花后84天左右果肉开始快速生长,可溶性固形物含量快速增加。在果实接近成熟时,东良单果和果肉的重量还在快速增长;其果大,可食率高,味甜,肉质爽脆,品质好,可与石硖龙眼相媲美。     

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.     

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.     

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.     

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.     

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.     

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.     

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.