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以甜椒种子为试材,通过风选和硝酸钾引发的方式,研究对甜椒种子萌发和幼苗生长的影响。试验设置1%硝酸钾溶液20℃下分别引发5、6、7 d,以未引发种子为对照,研究不同引发时间对甜椒种子萌发和幼苗生长的影响。结果表明,风选后甜椒种子千粒重较原种子显著增加3.25%,较不合格种子显著增加135.56%,不合格种子发芽势较CK处理显著降低43.42%,优选种子发芽率较CK处理显著提高5%。实验室发芽试验表明,发芽势各处理较CK处理显著提高58.49%、52.83%%、60.38%;发芽畸形数量各处理较CK处理显著降低73.91%、73.91%、69.57%;发芽指数各处理较CK处理显著提高了76.28%、69.87%、78.21%。穴盘育苗幼苗试验表明,在播种后47 d株高较CK处理显著提高13.21%,茎粗显著提高10.29%,叶片数显著提高9.09%,壮苗指数显著增加17.65%。综上可得,风选处理后,选用1%硝酸钾溶液,在20℃条件下,引发处理7 d能够显著提高发芽率和发芽势,促进幼苗生长,提高壮苗指数。 相似文献
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以樱桃番茄砧木品种"海茄砧1号"为试材,采用高温干热处理方法消毒种子,研究了不同干热处理温度和时间对种子发芽情况及幼苗生长的影响,以期为海南樱桃番茄嫁接苗生产提供参考依据.结果 表明:发芽率和出苗率均随着干热处理温度和时间的增加而降低,且差异达到显著或极显著的水平.发芽势和发芽指数则随着干热处理温度的升高呈先升后降,但随着干热处理时间的增加而降低.适当的干热处理可促进种子的萌发,但对幼苗的生长影响不大.最佳的干热处理为75℃处理2 d(T6处理),其发芽势、发芽率、发芽指数和出苗率分别达到89.3%、97.8%、44.35和96.1%,分别较CK提高45.8个百分点、2.2个百分点、11.92和1.3个百分点,且发芽势和发芽指数极显著高于CK. 相似文献
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《中国瓜菜》2014,(Z1)
为解决野生西瓜种子萌发率低和发芽不整齐的问题,以河沙为引发基质,研究了基质湿度和引发温度、时间对种子发芽及生理生化特性的影响。结果表明:固体基质引发处理能显著提高野生西瓜种子的发芽势、发芽指数、简化活力指数,显著缩短种子平均发芽时间;引发温度对种子活力有显著影响,而基质湿度和引发时间对种子活力的影响相对较小。基质湿度、引发温度和时间对野生西瓜种子活力既有单因子效应又存在交互效应,适宜引发条件组合是:基质相对含水率75%、引发温度6℃、处理时间9 d。引发处理后,种子电解质泄露率显著降低,可溶性糖含量和淀粉酶活性显著提高,但可溶性蛋白和MDA含量变化不显著。 相似文献
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茄子(Solanum melongena L.)是世界上第四大蔬菜作物,但是休眠现象比较普遍。该试验选用目前北京地区生产上应用较为广泛的7个茄子品种:"京茄5号"、"京茄10号"、"京茄3号"、"京研2号"、"大明茄"、"快圆茄"、"京茄1号",用1.2%过氧化氢消毒5min后,300mg/L赤霉素浸泡30min,在20~30℃变温条件下进行发芽试验。结果表明:赤霉素处理的种子发芽率最高提高了18个百分点,赤霉素处理对种子萌发有促进作用。同时,赤霉素处理可以提高茄子的发芽速度,缩短发芽天数,有利于播种后迅速出苗。 相似文献
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以老化南瓜种子为试材,设置CaCl_2、GA_3、PEG 6000 3种引发剂的不同浓度、不同引发时间和不同引发温度处理,以H_2O为对照,研究不同引发方式对老化南瓜种子萌发和幼苗生理特性的影响。结果表明:与对照(CK)相比,在8℃低温引发条件下,对老化南瓜种子进行1.0%CaCl_2处理8h引发效果最佳,种子的发芽势、发芽率、发芽指数和活力指数分别提高了20%、22%、18%、66%,且南瓜幼苗叶片中超氧化物歧化酶(SOD)活性和过氧化氢酶(CAT)活性显著增强,丙二醛(MDA)含量显著降低,幼苗长势最好,表明该引发方式不仅能够有效促进老化南瓜种子萌发,而且能够增强幼苗抗氧化能力,从而减轻种子老化衰变对幼苗生理状态的影响。 相似文献
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以"托鲁巴姆"和"京茄6号"茄子种子为试材,试验设置1%KNO3、15%PEG、200mg/kg GA、1%KNO3+15%PEG、1%KNO3+200mg/kg GA、15%PEG+200mg/kg GA、1%KNO3+15%PEG+200mg/kg GA 7个引发处理,以H2O为对照,通过测定茄子种子的发芽特性、浸出液电导率、MDA含量、可溶性淀粉酶活性和微生物数量,筛选出茄子种子最优引发剂。结果表明:与对照(CK)相比,其它处理的种子发芽特性均增强;200mg/kg GA处理对"托鲁巴姆"种子和"京茄6号"种子的引发效果均最优;1%KNO3处理的茄子种子浸出液电导率和MDA含量均最高,因此,茄子最优引发剂应以200mg/kg GA为主要成分,KNO3和PEG为微量成分。 相似文献
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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. 相似文献
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《International Journal of Fruit Science》2013,13(1):139-156
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. 相似文献
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Fulé Peter Z. Crouse Joseph E. Heinlein Thomas A. Moore Margaret M. Covington W. Wallace Verkamp Greg 《Landscape Ecology》2003,18(5):465-486
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. 相似文献
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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。 相似文献
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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. 相似文献
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采用密闭微波消解法消解香菇样品,在优化微波消解条件的基础上,建立微波消解ICP—MS法同时测定千香菇中As、PI)、Cd、Cr、Cu、Zn、Mn、Fe和Mg九种重金属元素的方法,在最佳试验条件下,加标收率为92.0%~104.6%,RSD为2.2%-5.3%。该方法简便、快速、准确: 相似文献
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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. 相似文献
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Inferring the effects of landscape structure on roe deer (Capreolus capreolus) movements using a step selection function 总被引:1,自引:0,他引:1
Aurélie Coulon Nicolas Morellet Michel Goulard Bruno Cargnelutti Jean-Marc Angibault A. J. Mark Hewison 《Landscape Ecology》2008,23(5):603-614
In this study, we sought to understand how landscape structure affects roe deer movements within their home-range in a heterogeneous
and fragmented agricultural system of south-western France. We analysed the movements of 20 roe deer fitted with GPS collars
which recorded their locations every 2–6 h over several months (mean = 9 months). Based on empirical observations and previous
studies of roe deer habitat use, we hypothesised that roe deer should avoid buildings and roads, move preferentially along
valley bottoms and through the more wooded areas of the landscape. To test these hypotheses we paired each observed movement
step with 10 random ones. Using conditional logistic regression, we modelled a step selection function, which represents the
probability of selecting a given step as a function of these landscape variables. The selected model indicated that movements
were influenced by all the tested landscape features, but not always in the predicted direction: our results suggested that
roe deer tend to avoid buildings, roads, valley bottoms and possibly the more wooded areas (although the latter result should
be interpreted with caution, as it may be influenced by a bias in the rate of GPS fix acquisition in woods). The distances
to buildings and to roads were the most influential variables in the model, suggesting that the avoidance of potential sources
of disturbance may be a key factor in determining ranging behaviour of roe deer in human dominated landscapes. 相似文献
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Inoculation of growing media with plant growth promoting rhizobacteria (PGPR) has a number of potential benefits for the production of ornamental plants. Certain rhizobacteria synthesise the enzyme ACC deaminase, which cleaves ACC, the precursor of the plant hormone ethylene. Bacterial metabolism is now known to lead to a reduction in [ACC] in the plant transpiration stream and bacteria are hypothesised to act on ACC exuded from roots. This in turn reduces the ethylene generated in plants growing in growing media inoculated with these bacteria. Here we tested if applications of the ACC deaminase containing rhizobacteria Variovorax paradoxus5C–2could be of benefit to ornamental growers by reducing ethylene generation in stressed plants. Ethylene is produced at levels that are inhibitory to growth and development under a number of abiotic stresses. The propagation and production of hardy ornamentals is deleteriously affected by abiotic stresses that involve ethylene signalling, including drought and physical wounding. Inoculation of growing media with V. paradoxus 5C-2 lowered ethylene emission from mature leaves of Cytisus × praecox experiencing drought stress. In addition, bacterial inoculation of the growing media resulted in significantly reduced abscission of the mature leaves under drought treatment. Beneficial effects of inoculation where also found in the wounding response of Fargesia murielae following divisional propagation and late season senescence in Aquilegia × hybrida in response to drought stress. Together these results demonstrate that V. paradoxus5C–2has real potential for use on ornamental nurseries in situations where plant stresses are unavoidable. 相似文献