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1.
Zinc deficiency decreased pollen viability in maize (Zea mays L. cv. G2) grown in sand culture. On restoring normal zinc supply to zinc-deficient plants before the pollen mother cell stage of anther development, the vegetative yield of plants and pollen fertility could be recovered to a large extent, but the recovery treatment was not effective when given after the release of microspores from the tetrads. If zinc deficiency was induced prior to microsporogenesis it did not significantly affect vegetative yield and ovule fertility, but decreased the fertility of pollen grains, even of those which visibly appeared normal. If the deficiency was induced after the release of microspores from the tetrads, not only vegetative yield and ovule fertility but pollen fertility also remained unaffected. 相似文献
2.
克隆植物,尤其是游击型克隆植物,具有很强的扩展能力,通过克隆扩展可侵入到不同生境斑块。克隆植物入侵可能会影响入侵地土壤营养状况和微生物群落。为了探明克隆植物入侵对DSE(dark septate endophytes)活动和土壤理化性质的影响,于2013年6月在克隆植物羊柴(Hedysarum laeve)和沙鞭(Psammochloa villosa)群落空地沿根状茎延伸方向设置样方,分别于6月、8月和10月在样方内分0—10、10—20、20—30、30—40、40—50 cm土层采集土样和根样,研究了不同采样时间羊柴和沙鞭群落空地DSE和土壤理化性质时空变化。结果表明,从6月到10月,随时间后延,克隆植物逐渐侵入群落空地,沙鞭入侵群落空地数和分株数高于羊柴。羊柴群落空地根系DSE定殖率随采样时间后延,逐渐降低,最大值在6月;沙鞭群落空地根系DSE定殖率随采样时间后延,逐渐升高,最大值在10月。随着克隆植物入侵,入侵地土壤中可利用的营养物质含量显著提高,羊柴入侵提高了入侵群落空地土壤碱解N、有效P和速效K含量,沙鞭入侵提高了入侵群落空地土壤碱解N和有效P含量。相关性分析表明,羊柴群落空地DSE定殖率与土壤p H值和电导率显著正相关,沙鞭群落空地DSE定殖率与土壤p H值极显著负相关,与电导率、碱解N和有效P极显著正相关。克隆植物入侵使得土壤环境更有利于克隆植物自身生长,为荒漠植被恢复提供了前提。 相似文献
3.
A greenhouse pot experiment with different phosphorus supply was conducted to study growth, photosynthesis and free polyamine
(PA) content in Plantago lanceolata L. plants in relation to arbuscular mycorrhizal (AM) colonization. Inoculum of Glomus fasciculatum (BEG 53) was used. Inoculated plants had high colonization intensities which were related to the P supply. Non-mycorrhizal
(NM) plants showed a typical yield response curve for P availability. Dry masses of mycorrhizal (M) plants were higher at
the lowest soil P content than those of NM plants, but the opposite was found at the highest P supply. P contents in M plants
were always higher. There were no differences in chlorophyll (Chl) concentrations (except the lowest soil P content) and ratios
of variable to maximum Chl fluorescence (Fv/Fm) values between M and NM plants, whereas M plants had higher ratios of leaf
area to fresh mass (A/f.m.) at low soil P contents and they had significantly higher CO2 fixation capacities per unit leaf area. Free putrescine (Put), spermidine (Spd) and spermine (Spm) contents in NM plants
were usually highest at the lowest P supply. The ratios of Put/(Spd+Spm) were identical in M and NM leaves. They were significantly
higher, however, in NM roots at the two low P doses. It is concluded, that a P nutritional status might exist, below which
PA concentrations and ratio are increased drastically, possibly indicating P deficiency or a certain state of plant development
with a higher demand for AM symbiosis.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
The modes of action of two benzimidazoles and thiophanate-methyl used for the control of Verticillium wilt of strawberry 总被引:1,自引:0,他引:1
By V. W. L. JORDAN 《The Annals of applied biology》1973,75(1):41-47
Benomyl, thiabendazole and thiophanate-methyl were found to be fungistatic against Verticillium dahliae in vitro. All materials suppressed wilt symptoms on artificially inoculated strawberry plants when applied as a root dip, soil drench or a foliar application. Quantitative bioassays of the amount of toxic residues and fungal colonization in tissues of treated plants after root treatment revealed that these materials or their toxic breakdown products were readily translocated to crown and leaves: they suppressed the internal spread of the pathogen throughout the plant. After foliar application there was no marked basipetal movement of material within the plant: fungal colonization was greatly reduced in treated leaves, but the roots and crowns were colonized to a similar extent to those of untreated plants. 相似文献
5.
In a greenhouse experiment involving an acid soil teff [Eragrostis tef (Zucc.) Trotter] plants failed to grow unless the soil was limed or inoculated with either of two vesicular-arbuscular-mycorrhizal
(VAM) fungi,Glomus mosseae orGlomus macrocarpum. Plant growth increased by liming and to a lesser extent by VAM fungal inoculation. Liming also enhanced root colonization
by VAM fungi. Shoot micronutrient content generally increased as a result of inoculation, and decreased by increased lime
applications. 相似文献
6.
The interaction of a vesicular-arbuscular mycorrhizal fungusGlomus fasciculatum with a wilt-causing soil borne pathogen,Fusarium oxysporum, was studied in cowpea (Vigna unguiculata). It was found that pre-establishment by vesicular-arbuscular mycorrhizal fungus reduced the colonization of the pathogen and
the severity of the disease, as determined by reduction in vascular discolouration index. In mycorrhizal plants, the production
of phytoalexin compounds was always higher than in the nonmycorrhizal plants. There appeared to be a direct correlation between
the concentration of the phytoalexins and the degree of mycorrhizal association. Three different compounds withR
f values of 0.23 (I), 0.17 (II) and 0.11 (III) were obtained from mycorrhizal plants. Similar compounds were also found to
be induced by an abiotic elicitor CuSO4. The first compound was identified as an isoflavonoid, daidzein and the other two remain to be identified. These compounds
were checked for their antifungal activityin vitro. The germination of conidial spores ofFusarium oxysporum was strongly inhibited by the compound III than the other two. It is argued that the production of phytoalexin compounds
in mycorrhizal plant could be one of the mechanisms imparting tolerance of the plants to wilt disease. 相似文献
7.
Nikolay Vassilev Maria Vassileva Rosario Azcon Almudena Medina 《Biotechnology letters》2001,23(11):907-909
Two arbuscular mycorrhizal fungi (Glomus deserticola and Glomus fasciculatum) were entrapped in calcium alginate, alone or in combination with a phosphate-solubilizing yeast (Yarowia lipolytica) and, after storage for 60 days, were inoculated into soil microcosms with tomato as the test plant. The average extent of root colonization by gel-entrapped G. deserticola and G. fasciculatum were 32 ± 5.6 and 24 ± 12.1%, respectively. Improved infective potential and colonization efficiency were observed when Y. lipolytica was co-entrapped with the mycorrhizal fungi. The best value, 49%, of mycorrhizal colonization was in roots of plants inoculated with G. deserticola co-entrapped with Y. lipolytica. 相似文献
8.
Mycorrhizal plants often have greater tolerance to drought than nonmycorrhizal plants. This study was conducted to determine the effects of arbuscular mycorrhizal (AM) fungi inoculation on growth, grain yield and mineral acquisition of two winter wheat (Triticum aestivum L.) cultivars grown in the field under well-watered and water-stressed conditions. Wheat seeds were planted in furrows after treatment with or without the AM fungi Glomus mosseae or G. etunicatum. Roots were sampled at four growth stages (leaf, tillering, heading and grain-filling) to quantify AM fungi. There was negligible AM fungi colonization during winter months following seeding (leaf sampling in February), when soil temperature was low. During the spring, AM fungi colonization increased gradually. Mycorrhizal colonization was higher in well-watered plants colonized with AM fungi isolates than water-stressed plants. Plants inoculated with G. etunicatum generally had higher colonization than plants colonized with G. mosseae under both soil moisture conditions. Biomass and grain yields were higher in mycorrhizal than nonmycorrhizal plots irrespective of soil moisture, and G. etunicatum inoculated plants generally had higher biomass and grain yields than those colonized by G. mosseae under either soil moisture condition. The mycorrhizal plants had higher shoot P and Fe concentrations than nonmycorrhizal plants at all samplings regardless of soil moisture conditions. The improved growth, yield and nutrient uptake in wheat plants reported here demonstrate the potential of mycorrhizal inoculation to reduce the effects of drought stress on wheat grown under field conditions in semiarid areas of the world. 相似文献
9.
10.
Jolanta Jaroszuk-
cise Ewa Kurek Krystyna Winiarczyk Anna Baturo Aleksander ukanowski 《Biological Control》2008,45(3):297-307
Colonization of rye (Secale cereale) tissues by nonpathogenic rhizosphere Fusarium culmorum isolates DEMFc2 and DEMFc5 and a pathogenic strain DEMFc37, and their effect on plant fresh weight were studied in pot experiments. Both rhizosphere isolates colonized the epidermis and the cortex but were not found in vessels, while the pathogen colonized all three layers of root cells. The numbers of pathogen CFU isolated from plant tissues were much higher than those of the rhizosphere isolates in spite of the same number of macroconidia used as inoculum (1 × 105 g−1 of soil). Inoculation of seedlings with DEMFc2 resulted in a 20% increase, with DEMFc5 in more than a 20% reduction, and with DEMFc37 in a 38% reduction of shoot fresh weight of 14-day-old plants. Pre-colonization of plants with (either of) the rhizosphere isolates and subsequent inoculation with the pathogen resulted in plant weights the same as those observed in plants inoculated with the rhizosphere strain alone. The disease severity index for shoots of plants pre-colonized with DEMFc2 was reduced from class 4 (86% diseased plants) observed for plants inoculated with the pathogen alone to class 2 (average of 8% diseased plants) when pre-treated with the rhizosphere strain. The CFU number of the pathogen isolated from the interior of roots of plants pre-colonized with the rhizosphere isolates was as low as 10% of the number isolated from plants inoculated with the pathogen alone. A study of in vitro interactions between the rhizosphere isolates and the pathogen suggests that changes in plant colonization by the pathogen and its effect on fresh weight of plants pre-colonized with the rhizosphere isolates were not connected with inhibition of its growth by a direct action of the rhizosphere isolates. The results suggest that strain DEMFc2 can be considered as a potential biocontrol agent. 相似文献
11.
Summary Effects of zinc supply on shoot and root dry weight, root length, zinc concentrations and carbonic anhydrase activity were measured in 52 day old seedlings ofEucalyptus maculata, E. marginata, E. patens and wheat grown in a zinc deficient soil in the glasshouse.Symptoms of zinc deficiency in the eucalyptus and wheat appeared within 20 to 35 days. Eucalypt seedlings had short internodes and small necrotic leaves, reduced dry weight of shoots and roots, root length and zinc concentrations in young leaves; the measurable level of leaf carbonic anhydrase activity decreased to zero. Similar responses also occurred in wheat.The level of zinc fertilizer required for normal growth of Eucalyptus seedlings is therefore likely to be similar to that used for wheat and other agricultural crops. 相似文献
12.
Factors affecting formation of cluster roots in Myrica gale seedlings in water culture 总被引:4,自引:1,他引:3
The effect of nutrient deficiency, aeration, phosphorus supply, and nitrogen source on the formation of cluster (proteoid) roots was examined in Myrica gale seedlings growing in water culture. Only the omission of phosphorus resulted in the formation of significant numbers to cluster roots when plants were grown in a number of 1/4 strength Hoagland's solutions, each lacking one mineral nutrient. Aeration shortened the time required for cluster root formation and increased the percentage of plants forming cluster roots. The proportion of the root system comprised of cluster roots decreased as the phosphorus concentration in the solution increased and no cluster roots formed in solutions containing 8 mg P/L. Phosphorus supply also affected total plant biomass, proportion of biomass comprising nitrogen-fixing nodules, shoot:root ratio, phosphorus concentration in the leaves and phosphorus content of the plants. The plants showed luxury consumption of phosphorus and were able to produce large amounts of biomass utilizing only stored phosphorus.Nitrogen source also affected cluster root formation. Urea-fed plants produced cluster roots more quickly and devoted a substantially larger proportion of root growth to cluster roots than did nitrate-fed plants. The longest cluster root axes were produced in nitrate-fed plants supplied with no phosphorus and the shortest were in urea-fed plants at 4 mg P L–1.Four methods for expressing the extent of cluster root formation were examined and it was concluded that cluster roots as a proportion of total fine root dry weight is preferable in many cases. Formation of cluster roots in response to phosphorus deficiency coupled with previously demonstrated traits allows Myrica gale to adapt to a wide range of soil conditions. 相似文献
13.
Arbuscular mycorrhizal colonization in strangler figs, spore richness, and abundance of arbuscular mycorrhizal fungi were
quantified in epiphytic and ground-rooted trees in a Sabal palmetto woodland that had marked heterogeneity in rooting environments for hemiepiphytic plants. An inoculation experiment
was performed to assess whether low spore density could limit mycorrhizal colonization. There was no significant difference
in mycorrhizal colonization among Ficus species, but epiphytic plants in nutrient-rich rooting environments had less mycorrhizal colonization than ground-rooted
plants in low-nutrient soils. However, richness and abundance of spores was low, and to some extent, this limited the mycorrhizal
colonization of strangler figs. Nevertheless, our results suggest intraindividual adjusting levels of root colonization in
strangler figs in accordance with mineral availability. Such responses could maximize the cost–benefit balance of arbuscular
mycorrhizal interactions throughout the development of strangler figs from epiphytic young plants to ground-rooted trees. 相似文献
14.
Two experiments with soil cores were carried out to investigate the effects of arbuscular mycorrhizal (AM) fungal colonization
on mobility of phosphorus (P) during leaching of repacked columns of a soil with a loamy sand texture. Trifolium subterraneum plants inoculated with an AM fungus or not inoculated were grown in cores with low or high P concentrations for 8 or 10 weeks
in the glasshouse. Cores were then irrigated with 2500 mL water and the leachate collected. Plant growth and the amounts of
P removed by plants, remaining in soil as available P and removed dissolved in leachate were measured. Mycorrhizal fungal
colonization and development of external hyphae were also determined. Inoculation and/or P application significantly increased
plant growth and plant P removal and decreased P leaching. In low P soils AM fungal colonization significantly increased plant
P uptake and decreased soil available P and total dissolved P in leachates. Lower P leaching from cores with AM plants under
low P conditions was related to enhancement of plant growth and to scavenging and removal of P from the soil by roots and/or
external hyphae. When P was applied AM effects were not observed and available P remaining in the soil after leaching was
much higher, regardless of AM fungal colonization. 相似文献
15.
This greenhouse study aimed to determine the effect of colonization by the arbuscular mycorrhizal (AM) fungus (Glomus intraradices Schenck & Smith) on the “wild” tobacco (Nicotiana rustica L. var. Azteca), under soil–zinc (Zn) conditions. Plants of N. rustica were grown in AM or non-AM inoculated substrate and subjected to four soil–[Zn] concentrations (0, 50, 100, and 250 mg Zn kg−1 dry soil). The AM root colonization increased markedly from 14 to 81% with the increasing soil–[Zn] and the mycorrhizal structures were significantly more abundant at the highest soil–[Zn], suggesting that Zn may be involved directly or indirectly in AM root colonization. In addition, total Zn content or Zn concentrations in shoots and roots were shown to increase as soil–[Zn] increased in both AM and non-AM plants. As for the growth parameters studied, there were no significant differences between treatments despite the increase in Zn content or concentration. The AM roots subjected to the highest soil–[Zn] had a significant reduction by about 50% of total Zn content and Zn concentration compared to non-AM roots. Still, the relative extracted Zn percentage decreased dramatically as soil–[Zn] increased. Soil pH was significantly lower in non-AM than AM treatments at the highest soil–[Zn]. In summary, AM plants (particularly roots) showed lower Zn content and concentration than non-AM plants. In this regard, the AM fungi have a protective role for the host plant, thus playing an important role in soil-contaminant immobilization processes; and, therefore, are of value in phytoremediation, especially when heavy metals approach toxic levels in the soil. 相似文献
16.
Pinus banksiana andPicea glauca inoculated or not with the ectomycorrhizal fungusSuillus luteus were grown in a sandy loam soil containing a range of Cd, Cu, Ni, Pb and Zn concentrations. Ectomycorrhizal colonization
rates were significantly reduced on Pinus and Picea seedlings by the heavy metals, particularly Cd and Ni. Needle tissue metal
concentrations were lower in ectomycorrhizal seedlings at low soil metal concentrations. However, at higher soil concentrations,
heavy metal concentrations of needle tissue were similar in ectomycorrhizal and nonmycorrhizal plants. The growth of nonmycorrhizal
seedlings exposed to heavy metals was reduced compared to those inoculated withSuillus luteus. Apparently ectomycorrhizal colonization can protect Pinus and Picea seedlings from heavy metal toxicity at low or intermediate
soil concentrations of Cd, Cu, Ni, Pb and Zn. 相似文献
17.
土壤是植物定居的场所,也是植物-微生物互作的重要界面。古菌是土壤微生物重要组份,在碳、氮、硫、铁等元素的生物地球化学循环和植物的生长发育、适应生境中发挥重要作用。植物定居对土壤古菌群落的影响研究鲜有开展,孑遗植物在研究植物-微生物-环境互作中具有独特的优势。采用扩增子高通量测序技术,研究以荒漠孑遗植物四合木为建群种或优势种的四合木-红砂-珍珠-针茅群落、四合木-针茅群落和四合木群落等三种荒漠植物群落类型中,四合木根区土壤和光板地土体土壤古菌群落特征,揭示四合木定居对土壤古菌物种数量、多样性、群落组成及功能的影响。结果表明,荒漠孑遗植物四合木定居不仅增加了根区土壤古菌的物种数量,提高了根区土壤古菌群落多样性,而且改变了土壤古菌群落组成,减少了奇古菌门Nitrososphaeraceae科未分类的属氨氧化古菌(unclassified_f_Nitrososphaeraceae)和暂定Nitrososphaera属氨氧化古菌(Candidatus Nitrososphaera)相对丰度,增加了Nitrososphaeraceae科暂定Nitrocosmicus属氨氧化古菌(Candidatus Nitrocosmicus)和广古菌门海洋古菌类群Ⅱ中未分类的属(norank_o_Marine_Group_II)相对丰度,广古菌门热原体纲未分类的属(unclassified_c__Thermoplasmata)相对丰度变化显著。植物群落演替对四合木根区土壤和光板地土体土壤古菌群落均无显著影响。Nitrososphaeraceae科氨氧化古菌是三种不同荒漠植物群落类型中土壤古菌的核心微生物组。四合木定居也显著改变土壤古菌群落的功能,减弱了高丰度功能,增强了低丰度功能,对有氧呼吸、核苷酸合成、氨基酸合成等途径影响显著。荒漠孑遗植物四合木定居改变了土壤古菌群落物种数量、多样性、组成、功能等特征。 相似文献
18.
Mycorrhizal fungus colonization of roots may modify plant metal acquisition and tolerance. In the present study, the contribution
of the extraradical mycelium of an arbuscular mycorrhizal (AM) fungus, Glomus mosseae (BEG 107), to the uptake of metal cations (Cu, Zn, Cd and Ni) by cucumber (Cucumis sativus) plants was determined. The influence of the amount of P supplied to the hyphae on the acquisition and partitioning of metal
cations in the mycorrhizal plants was also investigated. Pots with three compartments were used to separate root and root-free
hyphal growing zones. The shoot concentration of Cd and Ni was decreased in mycorrhizal plants compared to non-mycorrhizal
plants. In contrast, shoot Zn and Cu concentrations were increased in mycorrhizal plants. High P supply to hyphae resulted
in decreased root Cu concentrations and shoot Cd and Ni concentrations in mycorrhizal plants. These results confirm that some
elements required for plant growth (P, Zn, Cu) are taken up by mycorrhizal hyphae and are then transported to the plants.
Conversely, Cd and Ni were transported in much smaller amounts by hyphae to the plant, so that arbuscular mycorrhizal fungus
colonization could partly protect plants from toxic effects of these elements. Selective uptake and transport of plant essential
elements over non-essential elements by AM hyphae, increased growth of mycorrhizal plants, and metal accumulation in the root
may all contribute to the successful growth of mycorrhizal plants on metal-rich substrates. These effects are stimulated when
hyphae can access sufficient P in soil. 相似文献
19.
To understand the relationships between the distribution of Chosenia arbutifolia and Salix sachalinensis and their mycorrhizal colonization, changes in the quality and types of ectomycorrhizas and arbuscular mycorrhizas of the seedlings of two species were studied at five different sites with different soil conditions in the floodplain of the Satsunai River, Hokkaido. High ectomycorrhizal and low arbuscular mycorrhizal colonization were found in roots of both plants. Ectomycorrhizal colonization of S. sachalinensis in wet sandy or muddy soil conditions was at the same level as that in dry gravelly sites. In contrast, ectomycorrhizal colonization of C. arbutifolia seedlings was lower from wet sandy sites than that from dry gravelly sites. In all study sites, the same three morphological types of ectomycorrhizas were dominant. 相似文献
20.
The effects of liming and inoculation with the arbuscular mycorrhizal fungus, Glomus intraradices Schenck and Smith on the uptake of phosphate (P) by maize (Zea mays L.) and soybean (Glycine max [L.] Merr.) and on depletion of inorganic phosphate fractions in rhizosphere soil (Al-P, Fe-P, and Ca-P) were studied in flat plastic containers using two acid soils, an Oxisol and an Ultisol, from Indonesia. The bulk soil pH was adjusted in both soils to 4.7, 5.6, and 6.4 by liming with different amounts of CaCO3.In both soils, liming increased shoot dry weight, total root length, and mycorrhizal colonization of roots in the two plant species. Mycorrhizal inoculation significantly increased root dry weight in some cases, but much more markedly increased shoot dry weight and P concentration in shoot and roots, and also the calculated P uptake per unit root length. In the rhizosphere soil of mycorrhizal and non-mycorrhizal plants, the depletion of Al-P, Fe-P, and Ca-P depended in some cases on the soil pH. At all pH levels, the extent of P depletion in the rhizosphere soil was greater in mycorrhizal than in non-mycorrhizal plants. Despite these quantitative differences in exploitation of soil P, mycorrhizal roots used the same inorganic P sources as non-mycorrhizal roots. These results do not suggest that mycorrhizal roots have specific properties for P solubilization. Rather, the efficient P uptake from soil solution by the roots determines the effectiveness of the use of the different soil P sources. The results indicate also that both liming and mycorrhizal colonization are important for enhancing P uptake and plant growth in tropical acid soils. 相似文献