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1.
Three F_2 populations of cotton(Gossypiumhirsutum L.)from the crosses of Simian 3×TM-1,Simian 3 × CARMEN andXiangzamian2 were characterized for RAPD andSSR.301 pairs of SSR primers and 1040 RAPDPrimers were used in the Simian 3 × TM-1population analysis,which resulted in 49polymorphic loci.An analysis of these loci with  相似文献   

2.
The present PCR assay was conducted to develop rapid and sensitive detection of Phytophthora colocasiae,in order to provide a robust and reliable tool for healthy seedling production of taro and limiting the transmission and spread of the causal organism of taro leaf blight in taro planting regions.The samples were used to extract total DNA and to be detected by PCR with P.colocasiae specific primer pairs PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.Distinct fragments of about 200 bp and 240 bp were amplified by PCR using primers PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.The analysis of the nucleotide sequence of the PCR products were found to be 99% identical to sequence of RAS-related protein (Ypt1) and phospho-ribosylanthranilate isomerase (TRP1) in P.colocasiae,respectively.It is concluded that rapid and sensitive developed PCR assay for detection of P.colocasiae could be used in routine diagnosis and aid in management practices to mitigate taro leaf blight.  相似文献   

3.
[Objective] To establish and optimize the ISSR-PCR system satiable for Nerviliae fordii(Hance) Schltr. [Methods]Five factors affecting the ISSR-PCR system reaction of N. fordii were optimized by orthogonal test,which were d NTP,template DNA,primer,Mg2 +and Taq DNA polymerase. Single factors in the test were analyzed by new multiple range method. [Results] The optimal reaction system for N. fordii was as follows: the 20 μL total reaction volume included 2 μL 10 × PCR buffer,225 μmol / L d NTP,60 ng template DNA,0. 4μmol /L primer,2. 5 mmol /L Mg2 +,1. 0 U Taq DNA polymerase,and 20 μL total reaction volume. A total of 16 ISSR primers were screened from 100 ISSR primers,which was stable and had abundant polymorphism. [Conclusions] The established ISSR-PCR reaction system for N. fordii was stable and reliable,and could be used for the genetic differentiation analysis of N. fordii.  相似文献   

4.
Cytoplasmic male sterility (CMS) is a maternally inherited trait that prevents the production of function pollen, but maintains female fertility. It has been widely used in breeding programs to product F1 hybrid seed in some crops (Hanson, 1991). However, in some plants the CMS lines usually have some harmful characters such as plant dwarfness, etiolation in cauliflower. To obtain perfect CMS lines, a long time usually five to eight years is necessary. So how to fully utilize the obtained CMS lines for accelerating the development of new hybrid seed is very important. Here, in order to select high-quality paternal materials for cytoplasmic male sterility (CMS) cauliflower NKC-A in early stage, analyses of RAPD and ISSR were performed. Total 2 160 detectable bands were obtained by RAPD using 406 random primers. Among all these primers only the amplifications of primer S2121(5' GTGGCTCTCC 3') were polymorphic. A 934 bp band only existed in maintainer line. After cloning and sequencing, specific primers were designed to transform the RAPD marker into specific PCR marker, which was named S2121900. Furthermore, total of 30 ISSR primers were also analyzed which produced 306 detectable bands.  相似文献   

5.
In American code for design of Concrete Structures (ACI 318-08), the strut-and-tie model method was used as a normative appendix for D-region design of reinforced concrete members. The constituent of the strut-and-tie model was introduced. Calculation of internal forces in struts, ties and node zone were proposed according to the design parameters (loading, concrete strength, steel strength) of the current Chinese code (GB 50010-2010).Then the design procedure was provided. Strut-and-tie model design method for reinforced concrete corbels was proposed following Chinese code parameters which degree of safety was compared with in ACI 318-08 through an example. The compared result shows that the proposed method can be used for the design of reinforced concrete corbels with clearer mechanical concepts and easier calculations.  相似文献   

6.
FEMlab3.3(Finite Element Model Lab) is used to develop an energy delivery model for implanted devices. We designed three different shape electrodes made of Ag to enhance current transmitting efficiency. Several voltages were used for pursuing perfect goal. With the body safety current, we can get the results with a current transmitting efficiency of 20% and the energy delivery efficiency of 4%~9%. It is clear that the high energy delivery efficiency can be obtained and the results provide references for further study of energy delivery through body conduction.  相似文献   

7.
In this paper the theory of Fuzzy Mathematics is used to set up the case-based reasoning(CBR) mathematic model system on the price-estimation of the land-rental and the related process and conditions of its application are suggested.The calculation example of CBR in land business demonstrates that the CBR model is effective;it can be used as the reference for the decision-making on estimating the price in land business.  相似文献   

8.
Three crosses,Hawaii7981×PI128216,Hawaii7981×LA1589,and PI128216×LA1589,were made to develop F_2 populations for testing allelism among three genes Xv3,Rx4,and Rx_(LA1589) conferring resistance to bacterial spot caused by Xanthomonas perforans race T3 in tomato. Each population consisted of 535–1 655 individuals. An infiltration method was used to inoculate the leaves of the parental and F_2 plants as well as the susceptible control OH88119 for detecting hypersensitive resistance(HR). The results showed that all the tomato plants except OH88119 had HR to race T3,indicating that Xv3,Rx4,and Rx_(LA1589) were allelic genes. Genomic DNA fragments of the Rx4 alleles from Hawaii7981,PI128216,and LA1589 were amplified using gene-specific primers and sequenced. No sequence variation was observed in the coding region of Rx4 in the three resistant lines. Based on the published map positions of these loci as well as the allelic tests and sequence data obtained in this study,we speculated that Xv3,Rx4,and Rx_(LA1589) were the same gene. The results will provide useful information for understanding the mechanism of resistance to race T3 and developing resistant tomato varieties.  相似文献   

9.
Aimed to analyze the influence of rainfall on slope stability. The finite element method (FEM) is used for the calculation of 2-D transient seepage in the unsaturated slope, while the method of limit equilibrium is used for computing its safety factor. The change of pore water pressure, slip surface and safety factor are investigated through numerical calculations with consideration of various intensity and duration of rainfall. Special attention has been paid to slope stability after rainfall. It is found that sometimes the minimum safety factor may occur several hours or several days after the rainfall, instead of the time during the rainfall or when the rain just stops.  相似文献   

10.
Genetic algorithm (GA) is used for the optimal design of shell-and-tube heat exchangers due to the fact that traditional designs for shell-and-tube heat exchangers are complicated and uneconomical. To optimize the design of heat exchangers, mathematical models are established and the total costs are used as the objective function. Taking advantage of GA’s intelligent and multi-searching characteristics, researchers continuously iterate optimization variables and then obtain the minimum objective function of the design results within the optimal variable values and constraints. Two practical heat exchangers are used to test the research results. The Optimization results show that the optimized total costs have decreased by 18.2% and 7.98% respectively, which can also satisfy the heat transfer performance. Moreover, the results show that the design based on GA for shell-and-tube heat exchangers can significantly improve the economic efficiency of heat exchangers and thus can be applied to engineering practice.  相似文献   

11.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.  相似文献   

12.
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.  相似文献   

13.
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...  相似文献   

14.
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.  相似文献   

15.
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...  相似文献   

16.
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.  相似文献   

17.
T. Visser  E. H. Oost 《Euphytica》1981,30(1):65-70
Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.  相似文献   

18.
[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...  相似文献   

19.
E. Keep 《Euphytica》1986,35(3):843-855
Summary Cytoplasmic male sterility (cms) is described in the F1 hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf 1) and recessive for the other (Rf 2).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph 3(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf 1(one of two dominant additive genes controlling early season leafing out) indicated that Rf 1and Rf 2were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf 1, and 0.15 for Lf 1-Sph 3were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph 3.It is suggested that competitive disadvantage of lf 1-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph 3. Poor performance of lf 1- (and possibly lf 2-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).  相似文献   

20.
Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.  相似文献   

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