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Attention is increasingly being given to genetic resources in the deep seabed beyond the limits of national jurisdiction owing to their considerable potential scientific and economic value. At the same time, there are concerns that the increased demand for these genetic resources may result in their unsustainable collection or even in the extinction of species in the deep seabed. At present there is no specific legal framework governing these resources in international law. Thus, this article explores the relevant rules of international law applicable to the conservation and sustainable use of genetic resources in the deep seabed.  相似文献   
3.
Summary A marginal fitness theorem is derived for the allocation of a limited resource among alternative activities that have effects on the fitness of an individual. The marginal advantage theorem states that at the evolutionarily stable strategy (ESS), the marginal gains from increasing each of the allocations (expressed as partial derivatives of the fitness advantage of a rare mutant) are equal. The theorem is true for all proportional allocations (a + b + c + ...=j), regardless of the number of allocations, the nature of the response curves describing the direct effects of the allocations [f(a), etc.], or the way the effects of different allocations combine into fitness. The theorem is extended to size-number compromises and packaging strategies. The marginal advantage theorem is used to derive general theorems about the marginal effects of allocations [f (a), etc.] at the ESS and matching rules concerned with the total fitness to cost ratios of allocations at the ESS. The marginal advantage theorem is applicable to diverse allocation strategies, and provides a method for obtaining ESS allocations for any number of allocations and their components.  相似文献   
4.
Genetic diversity and structure of populations of the wild progenitor of barleyHordeum spontaneum in Iran was studied by electrophoretically discernible allozymic variation in proteins encoded by 30 gene loci in 509 individuals representing 13 populations of wild barley. The results indicate that: a)Hordeum spontaneum in Iran is extremely rich genetically but, because of predominant self-pollination, the variation is carried primarily by different homozygotes in the population. Thus, genetic indices of polymorphismP-1% = 0.375, range = 0.267–0.500, and of genetic diversity,He = 0.134, range = 0.069–0.198, are very high. b) Genetic differentiation of populations includes clinal, regional and local patterns, sometimes displaying sharp geographic differentiation over short distances. The average relative differentiation among populations isGst = 0.28, range = 0.02–0.61. c) A substantial portion of the patterns of allozyme variation in the wild gene pool is significanctly correlated with the environment and is predictable ecologically, chiefly by combinations of temperature and humidity variables. d) The natural populations studied, on the average, are more variable than two composite crosses, and more variable than indigenous land races of cultivated barely,Hordeum vulgare, in Iran. — The spatial patterns and environmental correlates and predictors of genetic variation ofH. spontaneum in Iran indicate that genetic variation in wild barley populations is not only rich but also at least partly adaptive. Therefore, a much fuller exploitation of these genetic resources by breeding for disease resistance and economically important agronomic traits is warranted.  相似文献   
5.
四川大型真菌资源调查研究   总被引:1,自引:0,他引:1  
本文介绍了四川大型真菌资源348种,包括药用真菌163种、食用真菌123种、有毒真菌41种、菌根真菌101种等。全国新记录26种。其中冬虫夏草(cordyceps sinensis)、凉山虫草(c.liangshanensis)、松口蘑(Tricholoma matsutake)、银耳(Tremella fuciformis)、短裙竹荪(Dictyophora duplicata)猴头(Hericium erinaceus)、鸡(土从)(Termitomyces albuminosus)、木耳(Auricuiaria auricula)、灵芝(Ganoderma lucidum)等尤为著名。并对四川大型真菌中部分重要种类的分布、资源及用途进行了分析和评价。为合理开发利用及有关教学科研提供了资料。  相似文献   
6.
Synopsis Stomach content data from 32 species of Japanese butterflyfishes of the family Chaetodontidae were used to classify them into feeding groups and to determine their important food resources. Four major feeding groups were distinguished: (1) obligative coral feeders which prey exclusively or mostly on Scleractinian corals, (2) facultative coral feeders that take both corals and other benthic organisms, (3) noncoralline invertebrate feeders which consume benthic invertebrates other than corals, and (4) zooplankton feeders. Ten species representing 31% of the butterflyfishes belong to the first category. The second and third categories include 13 (41%) and 8 (25%) species, respectively. The fourth category is represented by only one species which picks individual zooplankters, especially calanoid copepods, in midwater above the reefs. Facultative coral feeders consumed varying quantities of scleractinians (from 2 to 74% of food volume), along with a variety of benthic organisms including algae, alcyonarians, sea anemones, sedentary polychaetes, sponges, hydroids, etc. Noncoralline invertebrate feeders, on the other hand, tend to have low diversified diets, predominated by one prey item such as sea anemones, zoanthideans, polychaetes, or colonial ascidians. These dietary data suggest that scleractinian corals are the most important food resource for the Japanese butterflyfishes, and next important are sea anemones, sedentary polychaetes, alcyonarians, and algae.  相似文献   
7.
A K/Rb isotope dilution method was used to determine the uptake of K from undisturbed subsoils. Rb was applied to the topsoil (0–30 cm) to trace the K taken up from the topsoil by crops. The K/Rb ratio in the crops increases when roots contact the Rb-free subsoil. This change in the K/Rb ratio enables the calculation of the uptake of K from the subsoil. Results of 34 field experiments on loess-parabrown soils in N. Germany showed that the subsoil (>30 cm) supplied, on average, 34% of the total K uptake by spring wheat (range 9–70%). The range between the experimental sites is considered in relation to the contents of K in the top and subsoils (as extracted by 0.025 N CaCl2 solution), the proportion of the total root length in the subsoils, and competition for K between roots in the top and subsoil. In subsoils with similar K contents, uptake from the subsoil decreased significantly from 65 to 21% of total K uptake, as K contents in the topsoils increased from 4 to 8 mg K/100 g. On sites with the same K contents in topsoils (9 mg K/100 g), the subsoil supplied 12 to 61% of total K uptake as the K contents of the subsoil increased from 2 to 27 mg K/100 g. The contribution of uptake of K from the subsoil increased with the development of the crop, from 8% at first node stage to 35% at ear emergence, as the proportion of total root length in the subsoil increased. High root length densities in the topsoil (9 cm/cm3) resulted in competition for K between roots and increased uptake of K from the subsoil.  相似文献   
8.
We compared above-ground allocation patterns in mature shrubs of Banksia hookeriana from three 13-year-old populations, growing on nutrient-impoverished sands to determine whether C (dry mass) could be a substitute for mineral nutrients (N, P, K, Ca, Mg and NA). The percentage of reproductive structures to total above-ground growth (reproductive effort; RE) was integrated over nine successive reproductive cycles. Only 0.5% of above-ground dry mass was allocated to seeds compared with 31% to total RE. Allocations of N (24%) and P (48%) to seeds, and N (44%) and P (65%) to RE were much higher. Allocations of K, Ca, Mg and Na to seeds (<1–3%), and RE (21–35%) were closer to that of dry mass. Relative allocation (RA) is defined as the proportion of a nutrient element allocated to a structure relative to its dry mass. RA of P to seeds was 91 and N was 44, but for K, Ca, Mg and Na ranged from only 6 for K to<1 for Na. Thus P, and to a lesser extent N, provide a much more sensitive measure of the relative cost of reproduction than C in this nutrient-limited system.  相似文献   
9.
蔷薇属38个野生种果实的维生素含量及其与分组的关系   总被引:6,自引:0,他引:6  
对蔷薇属 (Rosa) 38个野生种果实 (以下简称蔷薇果 )的经济性状进行了分析 ,并测定了 VC、VE 和胡萝卜素等重要维生素的含量。蔷薇果 VC 含量在该属种间差异很大 ,以秦岭蔷薇 (R.tsinglingensis)的含量为最高 (2 576mg/ 1 0 0 g) ,德钦蔷薇 (R.deqenensis)的含量为最低 (49mg/ 1 0 0 g)。胡萝卜素含量种间差异明显 ,以软条七蔷薇 (R.henryi)的含量为最高 (1 9.2 4 mg / 1 0 0 g) ,黄刺玫 (R.xanthina)的含量为最低 (0 .0 6 mg/ 1 0 0 g)。 VE 含量种间差异较小 ,在 1 .34 mg/ 1 0 0 g(黄刺玫 )至 3.86 mg/ 1 0 0 g(硕苞蔷薇R.bracteata)之间。对蔷薇亚属 54种野生种果实重要维生素含量的统计分析表明 ,维生素含量与分组具有一定相关性 ,尤以 VC 含量与分组的相关性最为明显 ,桂味组和小叶组 Vc含量很高 (均值都高于 1 80 0mg/ 1 0 0 g) ;合柱组、月季组、木香组和硕苞组含量很低 (均值都在 30 0 mg/ 1 0 0 g以下 ) ,芹叶组除宽刺蔷薇 (R.platyacantha) VC含量很高外 ,其余种类含量都很低 (均值为 1 90 mg/ 1 0 0 g)。胡萝卜素含量与分组也具有一定相关性 ,桂味组、芹叶组、合柱组和硕苞组的胡萝卜素含量较高 ,均值在 6 mg/ 1 0 0 g以上 ;月季组、小叶组和木香组含量较低 ,均值在 0 .4mg/ 1 0 0 g以下。V  相似文献   
10.
本文提出了畜禽遗传资源系统保存的概念、基本思想及其群体遗传结构变化的数学模型。该理论是将一定时空内某一畜种所拥有的全部基因作为保存对象,既将活体保存作为基本方法,又将其有机地与高新生物技术结合在一起;既追求系统地保存控制畜种特性的基因资源,又可达到保存地方品种的目的。在假定无世代重叠,群体内存在选择、突变、迁移,且考虑漂变效应的情况下,本文所构建的两个数学模型可分别用来描述一个座位上多个主基因频率或数量性状群体均数的动态变化。  相似文献   
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