几种适宜设施栽培果树需冷量的研究

 1996～1999 年, 采用Utah 加权模型, 先后对5 个树种、65 个常见设施栽培果树品种的需冷量及相关特性进行了研究。结果表明: 不同树种、品种的需冷量差异显著, 葡萄、西洋樱桃的需冷量最高, 桃最低, 李、杏居中, 而且年际间有较大差异, 说明作为一种遗传特性, 需冷量亦受环境因素的调节; 同一树种不同品种的需冷量高低与本品种果实的成熟期无明显关系, 果实成熟期早而需冷量较高的情况普遍存在; 同一品种其需冷量基本趋势是花芽高于叶芽; 根系在低温需求进程中起调控作用, 与地上低温同步的根际高温减少了花芽的需冷量, 而根系低温则没有效果。晚秋根外喷布6-BA 降低了油桃和杏的低温需求量, GA₃ 则有增加低温需求量的趋势, 而ABA 无明显效果。     

几个油桃品种需冷量的研究

采用河北顺平露地栽培油桃早红珠、曙光与瑞光5号枝条为试材,比较了不同低温累积量下的萌芽率,并采用7.2℃低温模型和犹他模型对3个品种的需冷量进行估算。结果表明:瑞光5号的需冷量最高,花芽与叶芽分别为7607、00 h;曙光需冷量最低,花芽与叶芽均为640 h;早红珠介于二者之间,花芽与叶芽需冷量分别为7006、40 h;同一品种需冷量年际间差异不大;通过对7.2℃低温模型和犹他模型作比较,发现在该地区7.2℃低温模型更适合。     

103份桃种质在南京地区的需冷量和需热量研究

【目的】用不同模型估算南京资源圃103份桃种质花芽和叶芽的需冷量和需热量,筛选花芽和叶芽需冷量和需热量的最佳估算模型,探讨需冷量、需热量与开花展叶的关系。【方法】连续2 a(年)(2018年11月—2019年4月和2019年11月—2020年4月),采用3种需冷量估算模型和2种需热量估算模型对103份桃种质(南京地区)的花芽和叶芽需冷量和需热量进行估算,并对不同年际间、不同模型间、不同种质间、花芽与叶芽间、需冷量与需热量间,以及需冷量和需热量与开花期和展叶期之间的关系进行了分析。【结果】0~7.2℃模型和有效积温模型为南京气候区域桃需冷量和需热量估算的最优模型。绝大部分桃种质的花芽和叶芽需冷量基本一致,仅‘帚形山桃’和‘红花山桃’2份种质的叶芽需冷量约为花芽的5倍。桃花芽需热量基本低于叶芽需热量;桃芽需冷量与需热量之间无显著相关关系。需冷量和需热量与盛花期和展叶期均存在相关关系,需冷量和需热量低的种质开花展叶早;需冷量和需热量高的种质开花展叶晚。【结论】适宜南京气候区域桃需冷量和需热量估算的模型分别是0~7.2℃模型和有效积温模型;103份桃种质花芽和叶芽的需冷量和需热量值范围广,分别为151~1 264 h和187~1 108 h,256~391 D·℃和267~498 D·℃;花芽需冷量与叶芽较一致,需热量则基本低于叶芽;需冷量与需热量无相关关系,二者对开花、展叶均起重要作用。     

浙西南地区李主要品种花芽休眠需冷量研究

在浙西南地区气候条件下,采用0～7.2℃模型、7.2℃模型、犹他模型和0～9.8℃模型4种低温模型对主要李品种花芽休眠需冷量进行估算。试验结果表明:采用犹他模型估算需冷量年际间差异小,本地区李需冷量研究宜采用犹他模型。以犹他模型测定结果显示,试验品种中低温需冷量低的品种为芙蓉李和红心李,约为660～720c.u;其次是贵阳李、黑宝石、红肉李、皇家宝石、佛来索、李王和盖县大李,约为720～800c.u;再次是黑琥珀、凯尔斯和玫瑰皇后,约为800～830c.u;需冷量最高的品种为早美丽、红晶李、大石早生、金滴李,约为900～930c.u。     

四川成都早熟梨需冷量研究

2008—2010年连续3年,分别采用0～7.2℃模型、≤7.2℃模型和犹他模型估算四川省成都地区早熟梨品种翠冠和爱甘水的需冷量。结果表明,采用3种模型估算的2个早熟梨品种不同年际间需冷量差异较大;相同模型下,估算爱甘水需冷量数值大于翠冠;在四川省成都地区,适宜选择犹他模型估算2个早熟梨品种需冷量,估算的数值在年际间差异较小,翠冠顶花芽和叶芽需冷量分别为716～952、696～782 C.U,爱甘水顶花芽和叶芽需冷量分别为869～952、831～952 C.U,2个梨品种自然休眠结束期在1月3—17日。建议四川省成都地区翠冠和爱甘水梨设施栽培时,扣棚时间为1月上旬至中旬。     

大棚栽培桃树品种选择的原则

1 选择早熟或极早熟品种 桃树大棚栽培是促使桃果提前上市,所以,必须选择早熟或极早熟品种,果实发育期为60～80天。 2.选择需冷量低的品种 不同品种的需冷量各不相同,品种的需冷量低,通过自然休眠的时间短,扣棚升温的时间可相应提前,果实成熟早。经济效益高。 3.选择复花芽多,花粉量大,自花结实率高,且连年丰产的品种。     

关于PP333在核果类果树上的应用研究

通过文献,综述了核果类(桃、油桃、樱桃、李、杏)施用 PP333后,对抑制营养生长,土施情况下的“呆滞期”,持效期,花芽形成,座果,成熟期,果实品质及抗逆性的影响,以及对不同剂量的反应.     

苏南地区主要落叶果树的需冷量

连续2年对苏南地区主要落叶果树的需冷量进行研究。结果表明:梨的需冷量最低,油桃次之,杏较高,葡萄最高。有些品种(如美人酥梨、华光油桃等)年际间有差异,不同地区间差异更大。用犹他模型统计的落叶果树需冷量年际间差异较小,地区间也较稳定,可作为苏南地区落叶果树需冷量的主要统计方法。     

影响温室桃成熟期的因子研究

通过对 16个桃树品种温室栽培时果实成熟期的研究 ,探讨了温室桃成熟期的因子桃树品种需冷量与需热量之间呈极显著正相关关系 ;温室桃成熟期与桃品种需冷量呈显著正相关关系、与升温至盛花期需热量呈不显著正相关关系、与温室内果实发育天数呈极显著正相关关系     

设施葡萄常用品种的需冷量、需热量及2者关系研究

用3种不同的需冷量估算模型(≤7.2℃模型、0～7.2℃模型和犹他模型)和2种不同的需热量估算模型(生长度小时模型和有效积温模型)分别对22种设施葡萄常用品种的需冷量和需热量进行测定,同时分析2者的相互关系。结果表明,葡萄解除休眠的需冷量和萌芽展叶的需热量因品种和种不同而异。需冷量值品种间差异较大,介于573～1 246 h(≤7.2℃模型)或573～971 h(0～7.2℃模型)或917～1 090 C.U(犹他模型),且欧美杂种品种需冷量值普遍高于欧亚种品种;而需热量值品种间差异较小,介于9 976～12 541 GDH℃(生长度小时模型)或253～353 D℃(有效积温模型),且欧美杂种品种略低于欧亚种品种。同时研究表明葡萄的需冷量和需热量与其果实成熟期没有必然联系。无论以何种估算模型估算葡萄的需冷量和需热量,我国设施葡萄常用品种的需冷量和需热量之间均呈负相关关系。     

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.