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81.
82.
以纤毛婆婆纳(Veronica ciliateFisch.)无菌苗的顶芽作为外植体,在不同激素和浓度组合的MS培养基上进行愈伤组织诱导和快速繁殖的研究。结果表明,愈伤组织诱导的最佳培养基为:MS+6-BA 0.5 mg/L+NAA1.0 mg/L,诱导率达到95%;顶芽在MS+6-BA 0.5 mg/L+NAA 0.1 mg/L增殖培养基中增殖效果最佳,增殖系数高达5.4;丛生芽在1/2 MS+IBA 0.05 mg/L生根培养基生根效果最好,不仅根的质量好,而且生根率也达到95%;此再生苗的移栽成活率也最高,在适宜条件下可达40%。  相似文献   
83.
The forest under-storey herbs Anemone nemorosa, Lamiastrum galeobdolon and Veronica montana are generally considered indicator species of old, broadleaved woodland sites where the soil fertility is often low. In a glasshouse bioassay, however, all three species not only showed large positive growth responses to supplied P concentrations (0–10mgL –1) solutions, but also tolerated high P concentrations (20–40mgL –1), well above those normally found in their natural habitat. Plants responded by raising the concentrations of P in their shoot and root tissues and increasing their biomass, resulting in an increased P uptake. A shade-tolerant competitor species, Urtica dioica, also grew vigorously across the full range of P concentrations, restricting the growth of the woodland species. This emphasises the difficulty of establishing semi-natural woodland vegetation in the presence of competitor species, for example in situations where new woodlands are planted on fertile ex-agricultural soils containing large residual concentrations of P. The influence of soil pH on the growth and nutrient relations of A. nemorosa, L. galeobdolon, V. montana, Poa trivialisandU. dioicawas determined in a separate experiment using an ex-arable soil as the growing medium with pH levels adjusted from 7.4 to 5.8 and 4.3 respectively. Acidifying the soil enhanced growth, but reduced the concentrations of N, P and K in the leaves of all three woodland species, probably due to dilution of these minerals in the increased dry matter production. The competitor species (P. trivialis and U. dioica) responded in similar manner to the woodland indicator species. These results suggest that manipulating soil pH as a means of facilitating the establishment of woodland indicator species in new farm woods is unlikely, in the short term, to be effective where competitor species are present.  相似文献   
84.
 A map with 246 markers (11 isozymes and 235 RFLPs) was constructed using an interspecific F2 population between almond (cv Texas) and peach (cv Earlygold). RFLPs were obtained using 213 probes from the genomic and cDNA libraries of different species (almond, peach, P. ferganensis, cherry, plum and apple), including 16 almond probes which correspond to known genes. All markers were distributed in eight linkage groups, the same as the basic chromosome number of the genus, covering a total distance of 491 cM. The average map density was 2.0 cM/marker and only four gaps of 10 cM or more were found; the two largest gaps were 12cM each. This map was compared with one constructed previously with an intraspecific almond population sharing 67 anchor loci. Locus order was nearly identical and distances were not significantly different. A large proportion of the mapped loci (46%) had skewed segregations; in approximately half of them, the distortion was due to an excess of heterozygotes. One of the distorted regions could be associated with the position of the self-incompatibility gene of almond. Received: 6 November 1997 / Accepted: 26 May 1998  相似文献   
85.
As the preferred nitrogen (N) source, ammonium (NH4+ ) contributes to plant growth and development and fruit quality. In plants, NH4+ uptake is facilitated by a family of NH4+ transporters (AMT). However, the molecular mechanisms and functional characteristics of the AMT genes in peach have not been mentioned yet. In this present study, excess NH4+ stress severely hindered shoot growth and root elongation, accompanied with reduced mineral accumulation, decreased leaf chlorophyll concentration, and stunned photosynthetic performance. In addition, we identified 14 putative AMT genes in peach (PpeAMT). Expression analysis showed that PpeAMT genes were differently expressed in peach leaves, stems and roots, and were distinctly regulated by external NH4+ supplies. Putative cis-elements involved in abiotic stress adaption, Ca2+ response, light and circadian rhythms regulation, and seed development were observed in the promoters of the PpeAMT family genes. Phosphorylation analysis of residues within the C-terminal of PpeAMT proteins revealed many conserved phosphorylation residues in both the AMT1 and AMT2 subfamily members, which could potentially play roles in controlling the NH4+ transport activities. This study provides gene resources to study the biological function of AMT proteins in peach, and reveals molecular basis for NH4+ uptake and N nutrition mechanisms of fruit trees.  相似文献   
86.
Carbohydrate levels and activities of enzymes associated with starch, sucrose and sorbitol metabolism were assayed in leaves of peach [ Prunus persica (L.) Batsch cv. Redhaven] of different ages, in order to examine developmental changes in leaf carbohydrate metabolism. Dry matter, soluble protein, chlorophyll and the activities of key enzymes of the reductive pentose phosphate pathway increased during leaf development. The levels of leaf carbohydrates, especially sorbitol and starch, also increased. Changes of starch levels were related to increases in the activities of enzymes associated to starch metabolism, such as ADPglucose-pyrophosphorylase (E.C. 2.7.7.27) and amylase (E.C. 3.2.1.1. plus E.C. 3.2.1.2). The activities of enzymes involved in sucrose and sorbitol degradation decreased during leaf development, whereas the activities of aldose-6-phosphate reductase (E.C. 1.1.1.200) and cytosolic fructase-1,6-bisphosphatase (E.C. 3.1.3.11) increased. In contrast, the activity of sucrose-phosphate synthase (E.C. 2.4.1.14) did not vary in a significant manner. The results suggest that the ability to synthesize and utilize both sucrose and sorbitol changes as peach leaves mature, and also that there are differences in metabolism of these two transport sugars during leaf development.  相似文献   
87.
首次采用顶空固相微萃取结合气质联用技术提取并分析了白碧桃花蕾和花的挥发性成分。分别从白碧桃花蕾和花中鉴定了19和21个化合物。结果发现,油酸-2羟-基乙酯在花蕾中的含量高达43.62%,且仅存在于花蕾中;油酸在花蕾中的含量仅为2.65%,而在花中则高达58.69%,这表明在白碧桃花蕾开放的过程中,油酸-2羟-基乙酯被其体内的水解酶逐渐水解成油酸。  相似文献   
88.
松会能   《广西植物》1985,(4):389-396
青桃盛果期,特别中庸偏旺的植株,单、复花芽果枝数大体均等,复花芽果枝以其复芽个体较大,枝条较粗而往往表现为优势。然而笔者于1974—1979年观察了青桃树以单、复花芽结果对盛果初期的影响,结果表明:利用单花芽结果,控制了强旺枝和结果部位,使果枝分布均匀,树势稳定,尤其果枝数、花芽数、单株产量等的变动趋势与年度增加无关,r为:-0.2899、0.0620(单、复花芽果枝数分别占总果枝数的35.1%和16.7%),-0.3830、-0.1804(单、复花芽朵数分别占总花芽朵数的44.5%和13.4%),0.4093(单株年产量为179.4公斤,从而延长了盛果期;利用复花芽结果却相反,促进树势极性生长,旺枝增强,果枝外移,内膛空虚,尤其果枝数、花芽数、单株产量等的变动趋势随年度增加而呈显著与极显著负相关,r为:-0.8938~(**)、-0.9818~(**)(单、复花芽果枝数分别占总果枝数的27.1%和21.1%),-0.953~(**)、-0.8908~(**)(单、复花芽朵数占总花芽朵数的35.3%和6.8%).-0.8853~(**)(单株产量较单花芽结果减产19.4%),从而明显缩短盛果期。  相似文献   
89.
Concurrent measurements of leaf gas exchange and on-line 13C discrimination were used to evaluate the CO2 conductance to diffusion from the stomatal cavity to the sites of carboxylation within the chloroplast (internal conductance; gi). When photon irradiance was varied it appeared that gi and/or the discrimination accompanying carboxylation also varied. Despite this problem, gi, was estimated for leaves of peach (Prunus persica), grapefruit (Citrus paradisi), lemon (C. limon) and macadamia (Macadamia integrifolia) at saturating photon irradiance. Estimates for leaves of C. paradisi, C. limon and M. integrifolia were considerably lower than those previously reported for well-nourished herbaceous plants and ranged from 1.1 to2.2μmol CO2 m?2 s?1 Pa?1, whilst P. persica had a mean value of 3.5 μmol CO2 m?2 s?1 Pa?1. At an ambient CO2 partial pressure of 33Pa, estimates of chloroplastic partial pressure of CO2 (Cc) using measurements of CO2 assimilation rate (A) and calculated values of gi, and of partial pressure of CO2 in the stomatal cavity (Cst) were as low as 11.2 Pa for C. limon and as high as 17.8Pa for peach. In vivo maximum rubisco activities (Vmax) were also determined from estimates of Cc. This calculation showed that for a given leaf nitrogen concentration (area basis) C. paradisi and C. limon leaves had a lower Vmax than P. persica, with C. paradisi and C. limon estimated to have only 10% of leaf nitrogen present as rubisco. Therefore, low CO2 assimilation rates despite high leaf nitrogen concentrations in leaves of the evergreen species examined were explained not only by a low Cc but also by a relatively low proportion of leaf nitrogen being used for photosynthesis. We also show that simple one-dimensional equations describing the relationship between leaf internal conductance from stomatal cavities to the sites of carboxylation and carbon isotope discrimination (Δ) can lead to errors in the estimate of gi. Potential effects of heterogeneity in stomatal aperture on carbon isotope discrimination may be particularly important and may lead to a dependence of gi upon CO2 assimilation rate. It is shown that for any concurrent measurement of A and Δ, the estimate of Cc is an overestimate of the correct photosynthetic capacity-weighted value, but this error is probably less than 1.0 Pa.  相似文献   
90.
利用柱层析、薄层层析、重结晶等分离手段,从玄参科婆婆纳属长果婆婆纳的脂溶性成分中,分离得到8个化合物,经^1HNMR、^14CNMR、DEPT等现代波谱技术鉴定它们为5个单萜环烯醚苷,3个苯甲酸衍生物。该植物采自青海互助县海拔3700~3800m山坡上,为高海拔、高寒植物,其化学成分为首次报道。  相似文献   
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