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A total of 137 accessions from 18 wild almond species were collected from Iran and leaf and fruit traits were characterized. Also evaluated were flowering and ripening date, self-incompatibility and kernel bitterness. An extensive phenotypic diversity was found both among and within species. Differences in average leaf dimensions among and within species were associated with average rainfall but not altitude of collection site. Adjacent accessions located in drier areas had smaller leaf dimensions than those located in semi-humid or humid regions. No relation was found between average fruit dimensions and collection site conditions. Principal component analysis revealed that the nut weight and width, and the kernel weight had highest loading in the first component accounting for 45.8% of total variation. In contrast, leaf traits in the second component accounted for 22.3% of total variation. No significant correlations were detected between leaf dimensions and fruit traits in all species evaluated. Results document a rich source of new germplasm for almond improvement programs. Small fruit size, pollen-pistil self-incompatibility, and bitter kernel flavour are the most common obstacles to the utilization of this wild germplasm in breeding.  相似文献   
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This experiment was conducted to evaluate the effects of three nutrient recipes containing different concentrations of macronutrients in the vegetative stage [Vegetative Nutrient Solution: (VNS-I, VNS-II, and VNS-III)] and two nutrient recipes in reproductive stage [Reproductive Nutrient Solution: (RNS-I and RNS-II)], on physiological and biochemical parameters of strawberry ‘Paros’ in a soilless system. The results indicated the significant effects of nutrient solution on the photosynthetic capacity, yield, minerals uptake and titratable acidity of strawberry fruits. In the other hand fruit total soluble solids affected by vegetative nutrient solution. The highest yield was obtained under application of lowest level of minerals. Vegetative growth including leaf number and leaf area, as well as total chlorophyll were the highest as potassium (K+), calcium (Ca2+), and nitrogen (N) concentrations were increased. The highest content of N and Ca2+ uptake were in VNS-III × RNS-I formulation. Additionally, the highest vitamin C was in VNS-I formulation. Moreover, the most firmed fruits and the highest post-harvest shelf life of fruits were produced in VNS-III × RNS-I formulation.  相似文献   
3.
应用23个形态学特征,19个扩增片段长度多态性(AFLP)引物组合,80个随机扩增多态DNA(RAPD)引物和32个简单序列重复(SSR)引物对,比较三种分子标记法在29个杏仁栽培种和3个野生种遗传关系构建中的信息景和效率.根据预期杂合度的评价,与AFLPs和RAPDs相比,SSRs具有较高水平的多态性和较大的信息量.AFLPs预期朵合度值最低,但其辨别效率值最高,因为AFLPs能揭示每个反应中的大量条带,导致各种类型的多样性指数均较高.三种分子标记法对杏仁基因型的辨别效率均较高,只是SSRs无法辨别‘Monagha'和‘Sefied'杏仁基因型.三种分子标记法基因型相似性相关系数统计上显著,但SSR数据要低于RAPDs和AFLPs的值.尽管三种分子标记法树形图拓扑结构存在一些差异,但相似性水平均较高.SSRs、RAPDs和AFLPs的系统树图及其综合数据都能依据地理散布反映大多数栽培种的关系.AMOVA检测到每个地理组中栽培种和野生种的变异.辅助程序分析表明,实验所应用的标记物数量足以保证基因相似性估计的可靠性和标记法间的比较是有意义的.  相似文献   
4.
In many dioecious plants, gender affects economic value, breeding schemes and opportunities for commercial harvests. Hippophae rhamnoides L. is a dioecious plant species in which female genotypes are commercially preferred over male genotypes. Its berries have rich medicinal, nutritional and pharmaceutical properties because of their large amounts of vitamins, essential oils, proteins, fatty acids, free amino acids and flavanoids. Primary limitation for breeding H. rhamnoides L. is its dioecious nature, since gender cannot be identified by traditional methods. Therefore, some reliable and quick methods need to be developed. This communication deals with the development of isozyme and RAPD markers for early sex identification in this dioecious tree. The isozyme analysis was conducted with four enzyme systems, viz. peroxidase, esterase, malate dehydrogenase and catalase. The peroxidase enzyme system produced a female specific sex marker, which successfully differentiated between the staminate and pistillate genotypes of H. rhamnoides L. Thirty five random decamer primers were used in our study and one male sex linked marker was identified. OPD-20 (5′-ACTTCGCCAC-3′) displayed a band at 911 bp that expressed polymorphism between male and female genotypes. The staminate and pistillate genotypes could be distinguished using RAPD marker OPD-20911. These results revealed the immense potential of peroxidase isozyme patterns and RAPD as genetic markers for sex identification in H. rhamnoides L.  相似文献   
5.
Molecular dynamics simulations are used here to study the adsorption of polymer chains on the nanotube surface. Considering three nanotubes, including carbon, boron nitride and gallium nitride nanotubes, the effect of nanotube types on the polymer/nanotube interactions are investigated. Aramid, poly(phenylene sulfide), poly(phenylene oxide) and polycarbonate are selected as the polymer chains. It is seen that the π-stacking of these polymer chains results in large interaction energy between the nanotubes and polymer chains. Comparing the interaction energies between different polymer chains and nanotubes, it is shown that boron nitride nanotubes can reinforce polymer matrices more effectively than carbon and gallium nitride nanotubes. Besides, the effect of temperature on the polymer/nanotube interaction is studied. It is shown that the polymer chains have more expanded shapes at larger temperature which leads to more π-π interactions and larger interaction energies.  相似文献   
6.
The adsorption of poly(phenylacetylene), polystyrene sulfonate and polyvinyl pyrrolidone on the surface of the armchair and zigzag single-walled carbon nanotubes is studied by using molecular dynamics simulations. The wrapping process of polymer chains around the nanotubes is pursued graphically. It is shown that at 20ps, the polymer chains are adsorbed on the nanotube surface. The interaction energy between nanotubes and polymer chains is computed. The effect of nanotube diameter and temperature on the interaction energy is investigated. It is shown that increasing the nanotube diameter results in increasing the energy. However, the effect of temperature on the interaction energy is negligible. The radius of gyration of polymer chains is also computed. It is shown that nanotube diameter has an insignificant role in the radius of gyration of polymer chains.  相似文献   
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