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以菠萝[Ananas comosus(L.)Merr.]非胚性愈伤组织为材料,利用离体培养及组织细胞学等方法研究了其在增殖、分化过程中的特性和再生规律。在增殖培养基上经过3次以上继代培养后,非胚性愈伤组织形态上逐渐表现出一定差异。根据其形态结构、分化能力和组织细胞学特征,可把非胚性愈伤组织分为节瘤状组织、薄壁组织团、致密深层愈伤组织和表面疏松愈伤组织4种类型;在增殖培养基MS+3.0mg/LBA+2.0mg/LNAA上,一种类型的非胚性愈伤组织通常只会生长出同类型的非胚性愈伤组织,但通过改变培养基配方等方法可使不同类型之间发生转换。同时,增殖继代过程中的器官发生现象很常见,通常是在薄壁愈伤组织表面细胞分化成具有分生能力的细胞,然后进行不定芽的分化。4类非胚性愈伤组织都可以通过拟原球茎、多芽体以及不定芽的形式进行器官发生;也可以经胚性诱导由体细胞胚发生途径再生成植株,其中拟原球茎产生体细胞胚的能力最强,多芽体其次。生长素及细胞分裂素对非胚性愈伤组织的形态结构、分化途径以及增殖能力有很大的影响。 相似文献
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【目的】为了利用‘突尼斯软籽’石榴开展遗传转化研究,【方法】分别以叶片和茎段为外植体,探讨了不同灭菌时间和不同植物生长调节物质对2种外植体再生的影响,并对2种愈伤组织再生体系进行了比较。【结果】结果表明,茎段比叶片更容易灭菌,但叶片更容易长出绿色致密愈伤组织并分化更多的不定芽,而茎段分化的愈伤相对较为疏松,分化的不定芽也相对较少;来自茎段愈伤组织的不定芽比来自叶片的更容易长高;叶片比茎段再生体系建立所需时间要短;少量翠绿的叶片刀口处可以直接产生不定芽,可以直接利用叶片进行遗传转化的侵染,简化愈伤形成这一步骤,而茎段未发现此现象。在遗传转化试验中,茎段和叶片2种外植体愈伤组织抗生素敏感性试验结果均无显著性差异。【结论】研究结果认为,2者相比,叶片愈伤组织再生体系更适宜于石榴的遗传转化研究。 相似文献
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猕猴桃实生苗组织培养的研究 总被引：1，自引：1，他引：1
分别以猕猴桃实生苗的叶片、茎段和叶柄为材料,研究了不同激素组合和浓度对不同外植体愈伤组织诱导、不定芽分化和平均出苗率的影响.结果表明:茎段、叶柄比叶片容易脱分化,而不同外植体的不定芽分化率和平均出苗率与激素组合和浓度有关,当ZT为1.0mg/L,NAA为0.1mg/L时,茎段和叶柄愈伤组织诱导率和不定芽率均为100%,平均出苗率达到最高值,分别为15.28个/外植体和13.08个/外植体;当BA为3.0mg/L,NAA为0.5mg/L时,叶片愈伤组织诱导率和不定芽率均为100%,平均出苗率达到最高值,为15个/外植体. 相似文献
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采用改良DNS等方法筛选出的生长快、糖苷含量高的甜叶菊品系＂1096＂为材料,研究了不同外植体、不同激素种类和配比对愈伤组织诱导、不定芽分化和生根的影响。结果表明：以茎尖为外植体愈伤组织和不定芽诱导率均最高;其次是带腋芽茎段;再次为叶片。无腋芽茎段和无菌根均能诱导出愈伤组织,但不能诱导成芽。茎尖不定芽诱导的最佳培养基为MS＋6-BA 1.0mg/L;叶片不定芽诱导的最佳培养基为MS＋6-BA 1.0mg/L＋IAA 1.0mg/L;带腋芽茎段不定芽诱导的最佳培养基为MS＋6-BA 1.5mg/L。不定芽继代增殖培养采用MS＋6-BA 0.5mg/L＋NAA0.05mg/L;在1/4MS＋IBA 0.1mg/L＋NAA 0.1mg/L＋1g/L活性炭的培养基上诱导生根,生根率可达100%,生根苗移栽后成活率达95%。 相似文献
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以宁夏葡萄产业中大量种植的3个葡萄品种为试材建立再生体系.采用花药、茎尖进行愈伤组织诱导,比较了3种葡萄用花药、茎尖培养诱导愈伤组织形成、分化、生根的必须培养条件,获得不定芽分化再生植株.结果表明:葡萄花药愈伤组织形成胚性愈伤组织的能力很低,几乎不能分化成苗;而茎尖愈伤组织形成胚性愈伤组织的能力很高,分化成苗率极高,达100％.B5培养基诱导宁夏葡萄茎尖愈伤组织和分化丛生效果最好;KT有利于愈伤组织分化;茎尖浓度以0.8～1.0 cm最好. 相似文献
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《果树学报》2017,(6)
【目的】建立野生种枇杷茎段愈伤组织诱导植株再生的离体培养技术体系。【方法】以枇杷属植物的2个野生种、1个属间杂交后代为试材,采用茎段为外植体,在不同植物生长调节剂的组合配比培养条件下,开展野生枇杷茎段诱导愈伤组织以及愈伤组织诱导出不定芽的植株再生研究。【结果】最适合野生种枇杷茎段愈伤组织诱导植株再生的培养基配方为:MS+6-BA 1.0 mg·L~(-1)+TDZ 0.1 mg·L~(-1)+NAA 0.1 mg·L~(-1),如栎叶枇杷茎段愈伤组织诱导植株再生,其愈伤率、丛芽率和成苗率均达到100%,不定芽数最多可达38.75个;但对于属间杂交后代的石斑木×台湾枇杷最适合茎段愈伤组织诱导植株再生的培养基配方为:MS+6-BA 1.0 mg·L~(-1)+NAA 0.1 mg·L~(-1),其丛芽率和芽苗数量分别为100%和48个,成苗率也为100%;在众多的生长调节剂中,TDZ对野生枇杷的愈伤组织诱导再分化或脱分化是比较敏感的,高浓度的TDZ虽有利于愈伤组织诱导再分化不定芽,但不利于成苗。【结论】研究得出枇杷属植物以及属间杂交后代茎段愈伤诱导植株再生的共性规律和种间的差异性,建立起枇杷属植物野生种离体再生系统,简化植株再生诱导的步骤和缩短植株再生诱导的时间,能在短时间内产生一定数量的组培苗,为枇杷属种质资源研究积累了新的资料。 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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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
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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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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
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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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《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
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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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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
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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