共查询到20条相似文献，搜索用时 625 毫秒
1.
2.
复合基质的理化特性对瓜叶菊育苗的影响 总被引：2，自引：0，他引：2
利用美国引进的优良瓜叶菊F1代杂种'小丑'作为试验试材,采用草炭、蛭石、炉渣组成不同配比的复合基质,研究其理化特性及对瓜叶菊穴盘育苗效果的影响.结果表明:不同配比的复合基质对瓜叶菊穴盘育苗效果的影响有显著差异.处理B(草炭∶蛭石=1∶1)的理化性质好,秧苗和花期的综合指标明显好于CK(草炭∶蛭石=2∶1)及其它处理.表现为出苗时间早、秧苗生长健壮、干物质积累快、壮苗指数和生长函数大、叶绿素含量高、根系活力强.处理C(草炭∶蛭石=7∶3)在瓜叶菊的育苗中出现了徒长现象,表现为植株过高、根系活力差.而处理D(草炭∶蛭石∶炉渣=5∶2∶3)在各方面的表现都不理想,育苗效果最差.草炭∶蛭石=1∶1基质配比对瓜叶菊'小丑'育苗效果最好. 相似文献
3.
为筛选经济、资源节约型容器育苗基质,采用草炭土、秸秆粉、有机肥、河沙、珍珠岩、蛭石材料,按不同比例配成4种配方基质,以常用商用配方基质(珍珠岩∶蛭石∶草炭=1∶1∶1)为对照,进行刺槐容器播种育苗试验,测定不同配方基质下种子发芽出苗率、幼苗生长指标(株高、生物量、地径等)。结果表明:不同配方基质下刺槐种子出苗及其前期生长情况不一;其中T2配方(草炭土∶沙子∶有机肥∶蛭石=1∶1∶1∶1)基质刺槐种子发芽种苗出苗率及幼苗生物量、苗高、地径、根长等与对照间没有显著差异,可以作为刺槐容器播种育苗基质。 相似文献
4.
为了提高草莓脱毒苗在驯化移栽阶段的壮苗率,以草炭、蛭石、珍珠岩等为育苗基质,以V(草炭)∶V(珍珠岩)∶V(蛭石)=2∶1∶1为对照,探索不同配比基质对草莓幼苗生长发育的影响,从而筛选出适宜的栽培基质。结果表明:不同基质对草莓脱毒苗驯化移栽有明显影响,配方D(草炭∶蛭石=2∶1)对草莓苗的株高、茎粗、叶面积、地上/地下部生物量、根系总长、根表面积、根体积、壮苗指数等效果最好,适宜草莓脱毒苗驯化移栽,培育壮苗;而配方A(大厂基质∶蛭石∶珍珠岩=1∶1∶1)的草莓苗地上部长势显著优于对照,根部及壮苗指数无显著差异,且每1 m~3成本比对照少50.0元,降低14.18%,对于提高育苗企业利润具有重要意义;因此,建议根据实际需求选择以上2种基质配方。 相似文献
5.
6.
利用花生壳替代基质培育番茄穴盘苗的研究 总被引：1，自引：0，他引：1
以常用的草炭、珍珠岩育苗基质为对照,研究了3种花生壳替代基质配方的理化性质、对番茄幼苗生长的影响,从而筛选出可部分替代草炭的基质配方。试验结果表明,配方T1(草炭∶珍珠岩∶花生壳=1∶1∶1)的混合基质,具有容重小、孔隙度大的特点,且其盐浓度、pH值均在番茄幼苗生长的适宜范围内,其培育的番茄穴盘苗的形态指标和生理指标均与对照(草炭∶珍珠岩=2∶1)的无显著差异,而配方T2(草炭∶蛭石∶花生壳=1∶1∶1)、T3(珍珠岩∶花生壳=1∶2)的混合基质的育苗效果不如对照,因此可利用花生壳代替部分草炭培育番茄穴盘壮苗,其中以T1(草炭∶珍珠岩∶花生壳=1∶1∶1)的配方为最优。 相似文献
7.
8.
9.
以腐熟的牛粪和花生壳粉为主要原料,与草炭、蛭石和珍珠岩按不同体积比混配成8种基质,以市场上商品育苗基质为对照,研究不同育苗基质的基本性质及其对番茄和黄瓜幼苗生长的影响,筛选出适合番茄和黄瓜幼苗生长的育苗.结果表明,牛粪、花生壳粉、草炭、蛭石、珍珠岩体积比为20:20:40:15:5的复配基质(T4处理)各项理化性质符合瓜类蔬菜幼苗生长要求,该基质配方培育的番茄和黄瓜幼苗出苗率、壮苗指数、SPAD值、根系活力等生长和生理指标均表现较好.根据番茄和黄瓜幼苗的生长情况,并结合环境和经济等因素,在生产上推荐使用T4处理作为番茄和黄瓜育苗基质配方. 相似文献
10.
玉米秸秆、棉籽壳菇渣替代草炭作为番茄和甜椒育苗基质研究 总被引：4，自引：0，他引：4
利用腐熟玉米秸秆、棉籽壳菇渣与草炭和蛭石按照不同的比例组配成复合基质,进行番茄和甜椒穴盘育苗的结果表明：番茄穴盘苗培育以等体积的棉籽壳菇渣、草炭、蛭石混配基质的效果最好,其次是等体积玉米秸秆、草炭、蛭石混配的基质;玉米秸秆2 V、蛭石1 V 混配的基质适于甜椒穴盘育苗,其次是等体积的棉籽壳菇渣、草炭、蛭石混配的基质。合理使用腐熟玉米秸秆和棉籽壳菇渣可以减少草炭用量,改善基质理化性状,促进番茄和甜椒幼苗生长,培育优质壮苗。 相似文献
11.
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
12.
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. 相似文献
13.
《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
14.
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. 相似文献
15.
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
16.
《International Journal of Fruit Science》2013,13(3):101-120
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. 相似文献
17.
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. 相似文献
18.
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
19.
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
20.
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