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1.
With a method based on probability of phenotypic ratios being produced by crosses involving two pairs of interacting genes, data from genetic studies of Impatiens Sultana Hook. f. (Balsaminaceae) were analysed. Nine genes postulated to control floral color are: P, purple; I and W, white; R, red; O, orange; F, fuchsia; D, red; E, red; S, salmon. Epistatic action was evaluated, but progeny counts were too small for linkage to be determined. 相似文献
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While gene flow is an important factor determining the genetic structure of populations, there are few studies that quantify it empirically. Paternity-exclusion analysis has recently been employed to assess the number of seeds fathered by individuals from outside of a study population (gene flow by pollen), but appropriate estimation procedures have been limited to special cases. In this report, we illustrate a general Monte Carlo method that provides an approximate maximum-likelihood estimate of gene flow by pollen from paternity-exclusion analysis. We also show that the method can be used to estimate the number of foreign gametes received by individuals in the study population. Using these methods, we estimated that 7% and 6.3% of the seeds assayed from two wild radish populations were fathered by foreign pollen (95% confidence intervals = 5.0–9.0% and 5.4–7.2%, respectively). Each population was isolated from other radish populations by at least 150 m. Estimates of the number of foreign gametes received by individuals in a population were not correlated with selected reproductive or genetic characters, which included total flower production, total fruit production, seeds per fruit, flower color, floral phenology, and number of heterozygous marker loci. 相似文献
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核仁组成区相关嗜银蛋白染色革新法 总被引:1,自引:0,他引:1
李青 《中国组织化学与细胞化学杂志》1996,(3)
核仁组成区相关嗜银蛋白(AgNOR)银染技术已广泛用以研究细胞生长活性,根据AgNOR数目多少来判定肿瘤的良恶性和对肿瘤进行鉴别诊断。然而AgNOR技术至今还存在背景非特异性银颗粒沉积问题而影响结果判定。本研究发现影响背景染色结果的主要因素是明胶的质量,采用Farmer’s液可以清除背景染色,运用微波炉染色不仅可以缩短染色时间而且可以减少银用量。 相似文献
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IIntroductionTheuseofrestrlctlonfragmentlengthpolymorphism(RFLP)markershasgreatlyslmpllfledthegeneticanalysisofquantitativetraits,providingareliableandextensiveframeworkofquantltatlvemarkerstowhichquantltatlyetyaitIOCI(QTL)clnhilinked[‘].TodetectthelinkagebetwwenRFLPmarkersandPhenotyPlcvariationsoh-served,generallinearmodelofanalysisofvariance(ANOVA)hasbeenextensivelyusedL‘zJ.ByusingF、populations,thecompletegeneticInformation,thatIs,thethreegenotypesofageneticfact… 相似文献
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A method of measuring narcotic potency is described. Grain weevils ( Calandra granaria ) are exposed to the narcotic vapour in 2l. round-bottomed flasks illuminated from the bottom, and narcotic potency measured as number of grain weevils so affected as to be unable to climb the glass walls. Some common anaesthetics have been examined as an illustration of this method. Results are fitted by the probit plane
Y= A + b1 log α+ b 2 log t ,
where Y = a function of the number of insects affected (probit); α= the thermodynamic concentration of the narcotic vapour; t = time of exposure of insects to the narcotic vapour. The values of the coefficients b1 and b2 are discussed in relation to the biological action of the narcotic vapours. 相似文献
Y= A + b
where Y = a function of the number of insects affected (probit); α= the thermodynamic concentration of the narcotic vapour; t = time of exposure of insects to the narcotic vapour. The values of the coefficients b
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L. L. Eberhardt 《Marine Mammal Science》1992,8(3):201-212
Abstract: A new method, the dynamic response method, was developed (DeMaster et al. 1982) in an attempt to use time series data on relative population sizes to satisfy the requirements of the Marine Mammal Protection Act of 1972 for maintaining an optimum sustainable population of marine mammals. Three methods of implementing this approach were studied, using a computer simulation of stochastic population growth with density-dependence operating on first-year survival in the form of a generalized-logistic function. Methods developed by Gerrodette (1988) and Boveng et al. (1988) appeared to be less sensitive than desirable when used with the simulated population data. The third method, developed in this study, offers better protection against Type II error (failing to identify populations in the optimum sustainable population range), particularly when combined with Gerrodette's (1988) approach. 相似文献
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ELECTROPHORETIC ANALYSIS OF GENETIC VARIATION IN THE CHAROPHYTA. I. GENE DUPLICATION VIA POLYPLOIDY1
Electrophoretic analysis of 12 species of Chara indicates that functional gene duplication via polyploidy has commonly occurred in the genus. Duplication has been followed by differentiation of the loci encoding phosphoglucose isomerase (PGI). This has led directly to generation of substantial levels of genie variation both within and between taxa. A simple genetic model is proposed to account for the large array of PGI phenotypes encountered in natural populations. Constraints imposed by the reproductive biology of members of the genus, such as selfing, appear to have resulted in selective premiums on intrinsic mechanisms of generating genetic variation. Levels of variation in PGI were higher than would be predicted on the basis of charophyte reproductive characteristics; haploid loci segregate approximately two alleles within each species. 相似文献
9.
《生物数学学报》1989,(2)
A comprehensive regression model was developed for estimating theaction pattern of three cellulase fractions (β-1,4-glucan cellobiohydrolase,endo-glucanase and cellobiase)in hydrolysis of cellulose.The effect of stru-cture feature of cellulose on hydrolysis can also be evaluated by using thismodel.The results suggested that this technique was suitable for estimatingthe action pattern of cellulase fractions in cellulose hydrolysis,especiallyin quantitative eluciation of the effect of each fraction,alone or in combin-ation of which. 相似文献
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A quantitative method for the investigation of electrostenolysis has been developed. Electrostenolysis is redefined in the light of the discovery that organic molecules are subject to it. The experimental requirements for a quantitative study are enumerated, and the apparatus and procedure described. It is found that with ferrous and ferric ions and a cellulose acetate membrane, the potential drop across the membrane must be above about 2150 v./cm. in order to effect any oxidation and reduction. With the present apparatus and conditions the ratio of equivalents oxidized or reduced to faradays passing the membrane is low,— of the order of one to several thousand. 相似文献
13.
A SENSITIVE ENZYMATIC-ISOTOPIC METHOD FOR THE ANALYSIS OF TYRAMINE IN BRAIN AND OTHER TISSUES 总被引:5,自引:5,他引:0
Abstract— An enzymatic-isotopic assay for the measurement of tyramine with a sensitivity of 1.0 ng has been developed. Using this assay, the endogenous content of tyramine in various tissues from adult rats has been determined. The highest tyramine content was found in rat heart atria, followed by salivary gland, kidney, and brain. Within the brain the distribution of tyramine is heterogeneous and the highest tyramine content was localized in the striatum. 相似文献
14.
A FIELD TECHNIQUE FOR RECORDING THE ACTIVITY OF LIMPETS 总被引:1,自引:0,他引:1
A field technique for recording both temporal and spatial parametersof activity in limpets was tested on a Tyrrhenian populationof Patella rustica Linnaeus which shows definite homing behaviour.Timing of foraging excursions was recorded using reed switchesactivated by a magnet glued to the shell apex. The lsquo;athome-away status of each animal was continuously screenedthroughout one month by interfacing the sensors with a computer.Moreover, individual excursions were minutely reconstructedby using a moto-graphic technique which combined LED-tracking(nocturnal activity) and instantaneous photography (daytimemovements). An original wave-meter was designed to monitor thesea-status during the study period. The quality of the temporaland spatial data obtained with this technique is evaluated,and further improvements of the technique are discussed. (Received 24 October 1989; accepted 25 January 1990) 相似文献
15.
The development of a technique for testing insecticidal aerosols produced from pressure dispensers is described. The method of rearing the test insect, Musca domestica L., is given in detail.
Both free-flying and caged flies were exposed in a room of 1194 cu. ft. Six insecticidal solutions were selected for test.
The biological efficiency of each aerosol was judged on the time required to paralyse 50% of the test insects (KD 500) and on the percentage kill obtained in 24 hr. Statistical analysis of some of the estimated figures for KD 500 showed a standard error of 4–5% of the mean.
The effects of temperature, of distribution and of dosage of the aerosol on the results were investigated.
Free-flying flies were preferred, mainly because of better replication of results.
The technique adopted is described as a specification and suggestions are made for its practical application. 相似文献
Both free-flying and caged flies were exposed in a room of 1194 cu. ft. Six insecticidal solutions were selected for test.
The biological efficiency of each aerosol was judged on the time required to paralyse 50% of the test insects (KD 500) and on the percentage kill obtained in 24 hr. Statistical analysis of some of the estimated figures for KD 500 showed a standard error of 4–5% of the mean.
The effects of temperature, of distribution and of dosage of the aerosol on the results were investigated.
Free-flying flies were preferred, mainly because of better replication of results.
The technique adopted is described as a specification and suggestions are made for its practical application. 相似文献
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John H. Northrop 《The Journal of general physiology》1919,2(2):113-122
1. A quantitative method for the determination of pepsin is described depending on the change in conductivity of a digesting egg albumin solution. 2. The combination of pepsin with an insoluble substrate has been followed by this method. 3. The amount of pepsin removed from solution by a given weight of substrate is independent of the size of the particles of the substrate. 4. There is an optimum zone of hydrogen ion concentration for the combination of enzyme and substrate corresponding to the optimum for digestion. 5. It is suggested that the pepsin combines largely or entirely with the ionized protein. 相似文献
18.
Norman Bethune 《CMAJ》1929,21(6):662-667
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心外膜标测的技术与方法 总被引:3,自引:0,他引:3
本文简述了心外膜标测技术的发展与特点,报告了一种新型心外膜标测系统,其中使用了软基底64点镀金电极和64路放大器,标测结果用等时图和新颖的除极矢量图及除极矢量散点图表示。 相似文献