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1.
Human activities have recently caused severe destruction of Sphagnum wetlands in subtropical high-mountain regions, calling for urgent efforts to restore Sphagnum wetlands. Through a greenhouse experiment in western Hubei, China, we studied the effects of different substrate types (peat and mountain soil) and different levels of nitrogen (N) (0, 2, 4, 6, 10 g m?2 year?1) and phosphorus (P) (0, 0.2, 0.5, 1, 2 g m?2 year?1) on the growth of Sphagnum palustre, which was evaluated by four growth indicators: length growth, number of capitula, coverage change and biomass. We aimed to determine the optimal nutrient conditions for S. palustre growth, which would contribute to the rapid colonization and restoration of Sphagnum wetlands. The results showed that the different substrates significantly influenced S. palustre growth. Compared with those of peat, the acidic properties of the local yellow brown soil in the subtropical high-mountain regions were more favorable for S. palustre growth. As N addition increased, the four growth indicators responded inconsistently to the different substrates. While the number of capitula markedly increased, the other three indicators significantly decreased in the mountain soil or exhibited no definitive changes in the peat. The addition of P markedly promoted S. palustre growth in both substrates. However, a threshold for P fertilization existed; the highest productivity occurred at P additions of 0.2 and 0.5 g m?2 year?1 in the peat and mountain soil, respectively. The N and P contents in the capitula increased in parallel as the N and P fertilization rates increased, suggesting that these nutrients were absorbed proportionately and were used during the growth of S. palustre.  相似文献   

2.
The molecular composition of lipids in three samples of leafy mosses (Aulacomnium palustre, Warnstorfia fluitans, and Calliergon giganteum) has been determined. The revealed acyclic compounds included normal and isoprenoid alkanes, isoprenoid alkenes, normal and isoprenoid ketones, carboxylic acids and their esters, alcohols, and aldehydes. Among cyclic compounds, bi-, tri- and tetracyclic polycycloaromatic hydrocarbons (PAHs), bicyclic and pentacyclic terpenoids, steroids and tocopherols have been observed. The identified organic compounds consisted mainly of carbocyclic acids and n-alkanes with the prevalence of C27 homologues. A. palustre is characterized by a reduced content of isoprenoid compounds, alcohols, and ketones, while the content of unsaturated acids, pentacyclic terpenoids, and aldehydes is rather heightened. A. palustre differs from W. fluitans and C. giganteum in the steroid composition and contains eremophylene, a sesquiterpenoid, which is absent in the mosses of the family Amblystegiaceae. Compared to C. giganteum, W. fluitans has a higher content of lycopadiene, carboxylic acids, n-alkanes, phyt-2-ene, aldehydes, esters, squalene, diploptene, α-tocopherol, and triphenyl phosphates.  相似文献   

3.
Fusarium palustre is an endophyte/pathogen of Spartina alterniflora, a saltmarsh grass native to North America that has been associated in the USA with a saltmarsh decline known as Sudden Vegetation Dieback (SVD). Since the intentional introduction of S. alterniflora to stabilize mud flats on Chongming Island, Shanghai, China, S. alterniflora has become invasive, but shows no symptoms of dieback even though F. palustre can be isolated from the plant. When declining S. alterniflora from SVD sites in the northeastern USA were assayed for Fusarium species, an average of 8 % of tissues sampled gave rise to a species of Fusarium of these, 64 % were F. palustre and 16 % were F. incarnatum, a nonpathogenic species. To determine if low densities of F. palustre could explain the lack of dieback symptoms on S. alterniflora from Chongming Island, we assessed the incidence and distribution of Fusarium spp. on S. alterniflora from 12 sites on Chongming Island. On average, 26 % of the stem and root tissues sampled were colonized by a Fusarium species. Of 196 isolates recovered from S. alterniflora, 44 % were F. incarnatum and 41 % were F. palustre. Species determinations were confirmed for a subset of these isolates using a phylogenetic analysis of partial sequences of the translation elongation factor (tef) gene. The observation that Fusarium incidence on S. alterniflora was much greater on Chongming Island than in the USA survey raises the question as to why S. alterniflora on Chongming Island is showing no dieback. Other factors, such as predator release, enhanced nutritional, edaphic and/or other unidentified environmental constraints on Chongming Island may afford S. alterniflora protection from dieback.  相似文献   

4.
5.
The pigment composition of phytoperiphyton algocenoses on stones and macrophytes (Potamogeton lucens L., P. perfoliatus L., P. gramineus L., P. pectinatus L., Mirophyllum spicatum, Petasites hybridus (L.) Gaertn., Mey. et Sxherb, Nuphar lutea L., and Alisma plantago-aquatica L.) in the submontane Sylva River (Middle Ural) is considered based on the surveys of 2000–2012. The wide variability in the content of plant pigments in phytoperiphyton depends on the season and type of substrate. The maximum values similar for all substrates are observed at the end of summer. The concentrations of Chl a increase during warm low-water years. Chlorophyll a prevails among green pigments in periphyton; the relative concentration of other pigments is lower. The concentration of plant carotenoids in epiphyton is slightly higher compared to epilithon and is comparable to the Chl a level. The trophic state index of the Sylva River may be determined as mesotrophic or weakly eutrophic when the Chl a concentration in phytoperiphyton is used as a marker.  相似文献   

6.
An analysis of indicator values of four Saussurea DC. species, S. baicalensis (Adams) B. L. Rob., S. frolowii Ledeb., S. salicifolia (L.) DC., and S. schanginiana (Wydl.) Fisch. ex Serg., have been carried out by the method of indicator scales of soil moisture and nutrient availability and salinity in more than 1600 relevés. The size of their ecological ranges and the values of their competitiveness in phytocenoses are determined. As a result of a comparison of the locality of local populations within the ecological range and their occurrence, the vulnerability of S. baicalensis, S. frolowii, S. salicifolia, and S. schanginiana in the Kuznetsk Alatau is evaluated. The types of rarity for these species in the Kuznetsk Alatau are determined.  相似文献   

7.
The effect of copper and nickel ions at concentrations of 1, 10, 25, 50, and 100 mg/L on morphometric and pigment indicators of the seedlings of narrowleaf water-plantain Alisma gramineum and seashore dock Rumex maritimus was studied. It was found that the pigment characteristics were more sensitive to nickel and copper than the morphometric characteristics. It was noted that copper started to be toxic at relatively low concentrations and lead to a significant degradation of the pigment complex compared with nickel. An inverse correlation was found in seedlings between metal concentrations in the medium and chlorophyll a (Chl a). It was shown that the synthesis of chlorophyll a was inhibited by metal salts more strongly than by chlorophyll b and carotenoids, and seedlings of seashore dock were more resistant to the action of the factors studied than seedlings of the narrowleaf water-plantain.  相似文献   

8.
9.
The composition of protein complexes in seeds was studied in plants of the subfamily Scilloideae. Seed protein contents were compared in 59 species of 12 genera: Scilla L., Hyacinthus L., Bellevalia Lapeyr., Chionodoxa Boiss, Puschkinia Adam., Muscari Mill., Ornithogalum L., Eucomis L’Herit, Galtonia Desne, Velthemia Gleditsch., Hyacinthoides Linn., and Hyacinthella Schur. The results confirmed the heterogeneity of the subfamily: its constituent genera proved to differ in the composition of protein complexes and in the coefficient of evolutionary advancement. The group of salt-soluble proteins dominated by albumins prevailed in seeds of all species studied.  相似文献   

10.
Data on habitats, food plants of larvae and adults, feeding, mating, oviposition, larval and pupal development, natural enemies, and distribution of seven weevil species (Lixus canescens F.-W., L. iridis Ol., L. myagri Ol., L. punctirostris Boh., L. subtilis Boh., L. incanescens Boh., and L. brevipes Bris.) are given. New host plants of L. canescens and L. iridis are revealed. Gall induction by L. brevipes is reported for the first time. Distribution of all the species in Ukraine and Russia (the latter based on the literature) are given in more detail. Information on the known and potential economic importance of every species is provided.  相似文献   

11.
Effect of the ions of heavy metals (copper, zinc, and nickel) on growth of and ferrous iron oxidation by extremely acidophilic archaeal strains of the genus Acidiplasma (Acidiplasma sp. MBA-1; A. aeolicum V1T; and A. cupricumulans BH2T) was studied. Effect of the metals depending on their concentration was studied within the range from 5 to 1000 mM. All studied strains were able to oxidize iron in the presence of the highest tested heavy metal concentrations (1000 mM). All metal ions had, however, a noticeable inhibitory effect both on both growth and on iron oxidation. The lowest concentrations of copper, zinc, and nickel partially suppressing microbial growth were determined (5, 10, and 5 mM, respectively). These findings are of interest, since almost no literature data on resistance of Acidiplasma archaea to heavy metals are available, although these prokaryotes are among the most important groups of microorganisms used in biohydrometallurgy.  相似文献   

12.
Nutrient concentration in wheat and soil under allelopathy treatments   总被引:2,自引:0,他引:2  
Allelopathy is related to soil nutrient availability and allelochemicals can change the soil and therefore the plant nutrient status. Wheat is one of the most important crops for the production of human food in the world. Alhagi maurorum and Cardaria draba are the most important weeds in wheat fields. We performed experiments to assess the allelopathic effect of A. maurorum and C. draba shoots on mineral nutrient concentrations in pot-grown wheat plants and soil. The presence of dry powder of A. maurorum and C. draba shoots reduced concentrations of macronutrients (NO3 ?, K+, Ca2+ and P) and micronutrients (Fe2+ and Cu2+) in roots and shoots of wheat plants, whereas it did not affect concentrations of Mg2+, Mn2+ and Zn2+. Allelopathic effect of A. maurorum was significantly greater than that of C. draba. There was a significantly positive correlation between wheat growth and ion concentration. There was a significantly negative correlation between the soil nutrient concentration and plant nutrient concentration across the treatments. These results suggest that allelopathy increases the nutrient availability in the soil because of the decrease in absorption by plants.  相似文献   

13.
14.
Both quantitative and qualitative immunochemical methods were used for studying the mutual relationships of several spocies and the subspecies of the genusPhaseolus: Ph. vulgaris L. ssp.vulgaris, Ph. vulgaris L. ssp.aborigineus Burk.,Ph. coccineus L.,Ph. acutifolius A. Gray,Ph. lunatus L. (American endemites) andPh. aureus L. (a typical Asian bean). Protein characters of cotyledons (i.e., ?storage” proteins) of the above species were compared with the aid of antisera prepared against seed (cotyledon) proteins ofPh. vulgaris L. ssp.vulgaris, cv. Veltruská Saxa, using
  1. (a)
    the whole complex of cotyledon protein,  相似文献   

15.
Na sání p?irozeně infikovaného p?ena?e?e viru prou?kovitosti p?enice (VPP) k?ísaCalligypona pellucida F. reagovaly charakteristickými p?íznaky v poměrně zna?ném rozsahuBromus arvensis L.,B. mollis L.,Avena fatua L.,A. nuda L. (HOEJ.),Triticum aestivum L. s. s.,T. compactum HOST.,T. dicoccum SCHRANK aHordeum murinum L., v men?ím podílu pakLolium multiflorum LAM.,L. perenne L.,Bromus tectorum L.,Poa annua L., Avena strigosa SCHREB., A. sterilis L.,Triticum spelta L.,T. durum DESF.,T. turgidum L. aT. polonicum L. Dal?ích 42 rostlinných druh? ze 6 ?eledí v této testaci neonemocnělo. Negativně vyzněl i pokus o umělé naka?eníPhleum pratense L.,tîeba?e u tohoto rostlinného druhu jsme v p?írodě pozorovali typické p?íznaky VPP. Máme za to, ?e některé negativní výsledky byly asi v p?í?inné spojitosti se ?na?ně kolísající p? ena?e?skou ú?inností vektora, známou ji? z d?ívěj?ích prací. V kulturách pícnin prvního u?itkového roku v místech s nadměrně hojným výskytem larevCalligypona pellucida bylo p?i terénních pozorováních zaznamenáno v některých lokalitách na ?eskomoravské vyso?ině silněj?í napadení VPP uLolium multiflorum. Charakteristické p?íznaky VPP jsme p?i tom zjistili i naPhleum pratense, Lolium perenne a Bromus mollis.  相似文献   

16.
A detailed characteristic of the beetle fauna associated with Fomitopsis pinicola (Sw.: Fr.) Karst. (Basidiomycetes, Aphyllophorales) in the Urals and Transurals is given. Thirty species from 14 families have been revealed, the commonest species including Eridaulus jacquemarti Mel., Ennearthron laricinum (Mel.) (Ciidae), Dorcatoma dresdensis Hbst., D. lomnickii Rtt., D. punctulata Muls. (Anobiidae), Diaperis boleti (L.) (Tenebrionidae), Scaphisoma agaricinum (L.), S. inopinatum Löbl, S. subalpinum Rtt. (Scaphidiidae), Ostoma ferruginea (L.), and Peltis grossa (L.) (Peltidae). The main trends in the ecological and trophic specialization of mycetophilous beetles are discussed, and some regularities of formation of mycetophilous complexes at different stages of the trees fungi fruit body development are revealed.  相似文献   

17.
18.
At least two billion people around the world suffer from micronutrient deficiency, or hidden hunger, which is characterized by iron-deficiency anemia, vitamin A and zinc deficiency. As a key staple food crop, wheat provides 20% of the world’s dietary energy and protein, therefore wheat is an ideal vehicle for biofortification. Developing biofortified wheat varieties with genetically enhanced levels of grain zinc (Zn) and iron (Fe) concentrations, and protein content provides a cost-effective and sustainable solution to the resource-poor wheat consumers. Large genetic variation for Fe and Zn were found in the primitive and wild relatives of wheat, the potential high Zn and Fe containing genetic resources were used as progenitors to breed high-yielding biofortified wheat varieties with 30–40% higher Zn content. Grain protein content (GPC) determines processing and end-use quality of wheat for making diverse food products. The GPC-B1 allele from Triticum turgidum L. var. dicoccoides have been well characterized for the increase in GPC and the associated pleiotropic effect on grain Zn and Fe concentrations in wheat. In this study effect of GPC-B1 allele on grain Zn and Fe concentrations in wheat were measured in different genetic backgrounds and two different agronomic management practices (with- and without foliar Zn fertilization). Six pairs of near-isogenic lines differing for GPC-B1 gene evaluated at CIMMYT, Mexico showed that GPC-B1 influenced marginal increase for grain Zn, Fe concentrations, grain protein content and slight reduction in kernel weight and grain yield. However, the magnitude of GPC and grain Zn and Fe reductions varied depending on the genetic background. Introgression of GPC-B1 functional allele in combination with normal or delayed maturity alleles in the CIMMYT elite wheat germplasm has the potential to improve GPC and grain Zn and Fe concentrations without the negative effect on grain yield due to early senescence and accelerated maturity.  相似文献   

19.
Separate and combined action of temperature, pH, and heavy metals (copper and zinc) upon whole body activities of casein-and hemoglobinlytic proteinases were studied in perch (Perca fluviatilis), ruff (Gymnocephalus cernuus), roach (Rutilus rutilus), kilka (Clupeonella cultriventris), and common carp (Cyprinus carpio). Also, these activities were determined in cyprinids’ underyearlings (in sum) dominating the food of typical and facultative piscivores. It was revealed that, following a decrease in temperature to 0°C and in the presence of heavy metals (copper and zinc) at concentrations of 10 mg/l, casein-and hemoglobinlytic proteinase activities decreased statistically significantly in all studied fish. Both decrease and increase in pH values lead to less pronounced changes in the enzymatic activities varied in different species. As a rule, decrease in pH values resulted in considerable increase of the hemoglobinlytic activity, while pH increase caused inconsiderable enzyme activation. Combined action of natural factors and, in some cases, combined action of low temperature and metals, changed the caseinlytic activity to a greater extent than at their separate actions. Magnitude of multifactor effects in most cases is lower than of bifactor effects of temperature and metals.  相似文献   

20.
Plant species generate specific soil communities that feedback on plant growth and competition. These feedbacks have been implicated in plant community composition and dispersion. We used Lactuca sativa and its wild progenitor Lactuca serriola to test the hypotheses that separate Lactuca species generate unique soil communities and that these soil communities differentially influence host, and neighboring, plant growth and competition. We grew each Lactuca in competition with the other, in sterile and non-sterile soils. We then examined the growth of each Lactuca species in sterile, non-sterile, and preconditioned soil. Finally, we used TRFLP techniques to explore whether the two Lactuca species generate significantly different bacterial communities in their rhizosphere soils. L. sativa proved to be the stronger competitor of the two species. However, sterilization increased the competitive effect of L. serriola background competitors. The growth experiment showed a significant effect on plant species, soil treatment, and the interaction of the two. Preconditioning soil caused reduced growth in both Lactuca species. Only L. serriola showed significantly increased growth in sterile soils. Our TRFLP analysis showed that the L. sativa soil community was significantly less diverse and that soil preconditioning had the largest impact on the community composition. These results show that Lactuca serriola’s rhizosphere communities generate a stronger negative feedback for plant growth than do the communities associated with L. sativa. Our study suggests that selection for plants that are able to grow in dense monoculture may have released Lactuca from species-specific negative soil feedbacks. This has important implications for both agriculture and the evolution of invasive plant species.  相似文献   

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