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Exogenous spermidine (Spd) and methylglyoxal bis(guanylhydrazone) (MGBG), a putative inhibitor of Spd synthesis, improved somatic embryo formation of Scots pine (Pinus sylvestris L.). The induced maturation due to MGBG and Spd was accompanied by significantly retarded proliferation growth and by reduction in the concentration of free polyamines compared to the control cultures. The action of MGBG revealed that it has a non-specific effect on the whole polyamine metabolism of Scots pine. Furthermore, at certain concentrations it may induce plant differentiation as well. 相似文献
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Helena Rintala Tytti Graeffe Lars Paulin Nisse Kalkkinen Per E. J. Saris 《Biotechnology letters》1993,15(10):991-996
Summary Plasmids having the structural gene of nisin (nis A) combined with the subtilin or two hybrid subtilin-nisin leaders were integrated into the subtilin operon in the chromosome of a nisin-resistant and subtilin-producing strain of B. subtilis by single crossing over. Nisin was produced only when the leader consisted mainly of the nisin part. This indicates that nisin and its leader sequence might work as a couple that makes a recognizable conformation for the subtilin modification enzymes. Therefore recognition does not depend on the primary structure of the leader sequence itself. 相似文献
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Michael L. Zettler Anna Karlsson Tytti Kontula Piotr Gruszka Ari O. Laine Kristjan Herkül Kerstin S. Schiele Alexey Maximov Jannica Haldin 《Helgoland Marine Research》2014,68(1):49-57
In the Helsinki Commission Red List project 2009–2012, taxonomic and distributional data of benthic (macro) invertebrates were compiled by the present authors in a comprehensive checklist of the Baltic Sea fauna. Based on the most recent and comprehensive data, this paper presents the diversity patterns observed among benthic invertebrates in the Baltic Sea. As expected, the total number of species per sub-region generally declined along the salinity gradient from the Danish Straits to the northern Baltic Sea. This relationship is well known from the Baltic Sea and has resulted in a general assumption of an exponentially positive relationship between species richness and salinity for marine species, and a negative relationship for freshwater species. In 1934, Remane produced a diagram to describe the hypothetical distribution of benthic invertebrate diversity along a marine–freshwater salinity gradient. Our results clearly indicated the validity of this theory for the macrozoobenthic diversity pattern within the Baltic Sea. Categorisation of sub-regions according to species composition showed both separation and grouping of some sub-regions and a strong alignment of similarity patterns of zoobenthic species composition along the salinity gradient. 相似文献
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Turkia Tytti Jousimo Jussi Tiainen Juha Helle Pekka Rintala Jukka Hokkanen Tatu Valkama Jari Selonen Vesa 《Oecologia》2020,192(2):425-437
Oecologia - Spatial synchrony between populations emerges from endogenous and exogenous processes, such as intra- and interspecific interactions and abiotic factors. Understanding factors... 相似文献
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Krista Peltoniemi Sylwia Adamczyk Hannu Fritze Kari Minkkinen Taina Pennanen Timo Penttilä Tytti Sarjala Raija Laiho 《Environmental microbiology》2021,23(10):5733-5749
A substantial amount of below-ground carbon (C) is suggested to be associated with fungi, which may significantly affect the soil C balance in forested ecosystems. Ergosterol from in-growth mesh bags and litterbags was used to estimate fungal biomass production and community composition in drained peatland forests with differing fertility. Extramatrical mycelia (EMM) biomass production was generally higher in the nutrient-poor site, increased with deeper water table level and decreased along the length of the recovery time. EMM biomass production was of the same magnitude as in mineral-soil forests. Saprotrophic fungal biomass production was higher in the nutrient-rich site. Both ectomycorrhizal (ECM) and saprotrophic fungal community composition changed according to site fertility and water table level. ECM fungal community composition with different exploration types may explain the differences in fungal biomass production between peatland forests. Melanin-rich Hyaloscypha may indicate decreased turnover of biomass in nutrient-rich young peatland forest. Genera Lactarius and Laccaria may be important in nutrient rich and Piloderma in the nutrient-poor conditions, respectively. Furthermore, Paxillus involutus and Cortinarius sp. may be important generalists in all sites and responsible for EMM biomass production during the first summer months. Saprotrophs showed a functionally more diverse fungal community in the nutrient-rich site. 相似文献
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The aim of this study was to investigate the potential of different isolates of ectomycorrhizal (EM) fungi to enhance the
growth of Pinus sylvestris seedlings in five natural peat substrates with different nitrogen concentrations, and the effect of the Scots pine seedlings
and fungal inoculum on the formation of dissolved inorganic and organic nitrogen in peat. Utilization of different organic
nitrogen compounds by microbial community in the peat was also investigated using Biolog MT MicroPlates. Inoculation of the
seedlings with EM fungi enhanced seedling growth. Piloderma croceum increased root growth especially, whereas Lactarius rufus increased needle growth and Suillus variegatus I, II and III improved both root and needle growth. All the EM fungi also significantly affected stem growth. Nitrogen concentration
of the peat did not affect seedling growth as much as the EM fungi. At the lowest peat N concentration (1.17%) NH
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mineralisation was lower and DON (dissolved organic nitrogen) accumulation higher than at higher peat N concentrations. The
EM fungal isolates had different effects on NH
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and DON accumulation/degradation in peat. The EM fungal isolates significantly increased NH
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formation in the peat, whereas L. rufus and P. croceum had an opposite effect on DON accumulation. S. variegatus I significantly decreased the DON concentrations during peat incubation. The N concentration of the peat slightly affected
the utilization of amino acids and polyamines by the microbial community, whereas inoculation with S. variegatus I, II or III had no effect. 相似文献
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Thirty-four novel microsatellite markers developed for wood cricket (Nemobius sylvestris) were tested and optimized. Twenty-five microsatellite loci were polymorphic, exhibiting between two and nine alleles. Observed heterozygosities ranged from 0.038 to 0.925. The microsatellites were also tested in a species belonging to another genus of the Gryllidae family (Gryllus bimaculatus). Two markers produced clear banding patterns with the expected product size. These markers will be used to study the effects of forest fragmentation on genetic connectivity using wood cricket as a model species. 相似文献