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1.
Nasser Aliasgharzad Saheb Ali Bolandnazar Mohammad Reza Neyshabouri Nader Chaparzadeh 《Biologia》2009,64(3):512-515
Drought is a world-spread problem seriously influencing crop production. Arbuscular mycorrhizal (AM) association and soil
microorganisms can help plant growth under water stress condition by improvement of its nutrient and water uptake. In this
experiment, onion plants (Allium cepa L. cv. Red Azar Shahr) were inoculated with three AM fungi species (Glomus versiforme, G. intraradices, G. etunicatum) or left un-inoculated as non-mycorrhizal plants, in a sterile or non-sterile sandy loam soil. Plants were irrigated at 7,
9 or 11-day intervals to keep the soil moisture content to field capacity at the irrigation time. Mycorrhizal root colonization
decreased (p < 0.05) with an increase in irrigation interval, and the highest root colonization was achieved at 7-day irrigated onions
in symbiosis with G. versiforme. Phosphorus content in plant tissue was significantly increased in mycorrhizal than non-mycorrhizal onions. Plants inoculated
with G. versiforme at 9-day interval treatment had the highest leaf P content, while the lowest P was observed in non-mycorrhizal plants at
all irrigation intervals. Onions inoculated by G. versiforme or G. etunicatum at 9-day irrigation interval had the highest K content. Results revealed that the inoculation of onion plant with G. versiforme or G. etunicatum and increasing irrigation interval up to 9 days, could improve P and K uptake. 相似文献
2.
Influence of arbuscular mycorrhiza on organic solutes in maize leaves under salt stress 总被引:1,自引:0,他引:1
A pot experiment was conducted to examine the effect of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae, on plant biomass and organic solute accumulation in maize leaves. Maize plants were grown in sand and soil mixture with
three NaCl levels (0, 0.5, and 1.0 g kg−1 dry substrate) for 55 days, after 15 days of establishment under non-saline conditions. At all salinity levels, mycorrhizal
plants had higher biomass and higher accumulation of organic solutes in leaves, which were dominated by soluble sugars, reducing
sugars, soluble protein, and organic acids in both mycorrhizal and non-mycorrhizal plants. The relative abundance of free
amino acids and proline in total organic solutes was lower in mycorrhizal than in non-mycorrhizal plants, while that of reducing
sugars was higher. In addition, the AM symbiosis raised the concentrations of soluble sugars, reducing sugars, soluble protein,
total organic acids, oxalic acid, fumaric acid, acetic acid, malic acid, and citric acid and decreased the concentrations
of total free amino acids, proline, formic acid, and succinic acid in maize leaves. In mycorrhizal plants, the dominant organic
acid was oxalic acid, while in non-mycorrhizal plants, the dominant organic acid was succinic acid. All the results presented
here indicate that the accumulation of organic solutes in leaves is a specific physiological response of maize plants to the
AM symbiosis, which could mitigate the negative impact of soil salinity on plant productivity. 相似文献
3.
Effects of arbuscular mycorrhizal fungus on photosynthesis and water status of maize under high temperature stress 总被引:4,自引:0,他引:4
The purpose of this study was to investigate the effects of arbuscular mycorrhizal (AM) symbiosis on gas exchange, chlorophyll fluorescence, pigment concentration and water status of maize plants in pot culture under high temperature stress. Zea mays L. genotype Zhengdan 958 were cultivated in soil at 26/22°C for 6 weeks, and later subjected to 25, 35 and 40°C for 1 week. The plants inoculated with the AM fungus Glomus etunicatum were compared with the non-inoculated plants. The results showed that high temperature stress decreased the biomass of the maize plants. AM symbiosis markedly enhanced the net photosynthetic rate, stomatal conductance and transpiration rate in the maize leaves. Compared with the non-mycorrhizal plants, mycorrhizal plants had lower intercellular CO2 concentration under 40°C stress. The maximal fluorescence, maximum quantum efficiency of PSII photochemistry and potential photochemical efficiency of mycorrhizal plants were significantly higher than corresponding non-mycorrhizal plants under high temperature stress. AM-inoculated plants had higher concentrations of chlorophyll a, chlorophyll b and carotenoid than non-inoculated plants. Furthermore, AM colonization increased water use efficiency, water holding capacity and relative water content. In conclusion, maize roots inoculated with AM fungus may protect the plants against high temperature stress by improving photosynthesis and water status. 相似文献
4.
Influence of the arbuscular mycorrhizal fungus Glomus mosseae on uptake of arsenate by the As hyperaccumulator fern Pteris vittata L. 总被引:11,自引:0,他引:11
We report for the first time some effects of colonization by an arbuscular mycorrhizal (AM) fungus (Glomus mosseae) on the biomass and arsenate uptake of an As hyperaccumulator, Pteris vittata. Two arsenic levels (0 and 300 mg As kg–1) were applied to an already contaminated soil in pots with two compartments for plant and hyphal growth in a glasshouse experiment. Arsenic application had little or no effect on mycorrhizal colonization, which was about 50% of root length. Mycorrhizal colonization increased frond dry matter yield, lowered the root/frond weight ratio, and decreased frond As concentration by 33–38%. Nevertheless, transfer of As to fronds showed a 43% increase with mycorrhizal colonization at the higher soil As level. Frond As concentrations reached about 1.6 g kg–1 (dry matter basis) in non-mycorrhizal plants in the As-amended soil. Mycorrhizal colonization elevated root P concentration at both soil As levels and mycorrhizal plants had higher P/As ratios in both fronds and roots than did non-mycorrhizal controls. 相似文献
5.
Arbuscular mycorrhizae improves low temperature stress in maize via alterations in host water status and photosynthesis 总被引:4,自引:0,他引:4
The effect of arbuscular mycorrhizal (AM) fungus, Glomus etunicatum, on growth, water status, chlorophyll concentration and photosynthesis in maize (Zea mays L.) plants was investigated in pot culture under low temperature stress. The maize plants were placed in a sand and soil mixture at 25°C for 7 weeks, and then subjected to 5°C, 15°C and 25°C for 1 week. Low temperature stress decreased AM root colonization. AM symbiosis stimulated plant growth and had higher root dry weight at all temperature treatments. Mycorrhizal plants had better water status than corresponding non-mycorrhizal plants, and significant differences were found in water conservation (WC) and water use efficiency (WUE) regardless of temperature treatments. AM colonization increased the concentrations of chlorophyll a, chlorophyll b and chlorophyll a + b. The maximal fluorescence (Fm), maximum quantum efficiency of PSII primary photochemistry (Fv/Fm) and potential photochemical efficiency (Fv/Fo) were higher, but primary fluorescence (Fo) was lower in AM plants compared with non-AM plants. AM inoculation notably increased net photosynthetic rate (Pn) and transpiration rate (E) of maize plants. Mycorrhizal plants had higher stomatal conductance (gs) than non-mycorrhizal plants with significant difference only at 5°C. Intercellular CO2 concentration (Ci) was lower in mycorrhizal than that in non-mycorrhizal plants, especially under low temperature stress. The results indicated that AM symbiosis protect maize plants against low temperature stress through improving the water status and photosynthetic capacity. 相似文献
6.
Studies of iron transport by arbuscular mycorrhizal hyphae from soil to peanut and sorghum plants 总被引:4,自引:0,他引:4
The influence of an arbuscular mycorrhizal (AM) fungus on phosphorus (P) and iron (Fe) uptake of peanut (Arachis hypogea L.) and sorghum (Sorghum bicolor L.) plants was studied in a pot experiment under controlled environmental conditions. The plants were grown for 10 weeks
in pots containing sterilised calcareous soil with two levels of Fe supply. The soil was inoculated with rhizosphere microorganisms
only or with rhizosphere microorganisms together with an AM fungus (Glomus mosseae [Nicol. & Gerd.] Gerdemann & Trappe). An additional small soil compartment accessible to hyphae but not roots was added to
each pot after 6 weeks of plant growth. Radiolabelled P and Fe were supplied to the hyphae compartment 2 weeks after addition
of this compartment. After a further 2 weeks, plants were harvested and shoots were analysed for radiolabelled elements. In
both plant species, P uptake from the labelled soil increased significantly more in shoots of mycorrhizal plants than non-mycorrhizal
plants, thus confirming the well-known activity of the fungus in P uptake. Mycorrhizal inoculation had no significant influence
on the concentration of labelled Fe in shoots of peanut plants. In contrast, 59Fe increased in shoots of mycorrhizal sorghum plants. The uptake of Fe from labelled soil by sorghum was particularly high
under conditions producing a low Fe nutritional status of the plants. These results are preliminary evidence that hyphae of
an arbuscular mycorrhizal fungus can mobilise and/or take up Fe from soil and translocate it to the plant.
Accepted: 6 March 1998 相似文献
7.
The influence of the arbuscular mycorrhizal (AM) fungus, Glomus etunicatum, on characteristics of growth, membrane lipid peroxidation, osmotic adjustment, and activity of antioxidant enzymes in leaves
and roots of maize (Zea mays L.) plants was studied in pot culture under temperature stress. The maize plants were placed in a sand and soil mixture under
normal temperature for 6 weeks and then exposed to five different temperature treatments (5oC, 15oC, 25oC, 35oC, and 40oC)
for 1 week. AM symbiosis decreased membrane relative permeability and malondialdehyde content in leaves and roots. The contents
of soluble sugar content and proline in roots were higher, but leaf proline content was lower in mycorrhizal than nonmycorrhizal
plants. AM colonization increased the activities of superoxide dismutase, catalase, and peroxidase in leaves and roots. The
results indicate that the AM fungus is capable of alleviating the damage caused by temperature stress on maize plants by reducing
membrane lipid peroxidation and membrane permeability and increasing the accumulation of osmotic adjustment compounds and
antioxidant enzyme activity. Consequently, arbuscular mycorrhiza formation highly enhanced the extreme temperature tolerance
of maize plant, which increased host biomass and promoted plant growth. 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.
Plant growth enhancing effects of arbuscular mycorrhizal (AM) fungi are suitably quantified by comparisons of mycorrhizal
and non-mycorrhizal plant growth responses to added phosphorus (P). The ratio between the amounts of added P required for
the same yield of mycorrhizal and non-mycorrhizal plants is termed the relative effectiveness of the mycorrhiza. Variation
in this relative effectiveness was examined for subterranean clover grown on a high P-fixing soil. Plants were either left
non-mycorrhizal or inoculated with one of three AM fungal species with well-characterised differences in external hyphal spread.
With no P added, plants from all treatments produced <10% of their maximum growth achieved at non-limiting P supply. The growth
response of non-mycorrhizal plants was markedly sigmoid. Mycorrhizal growth responses were not sigmoid but their shape was
two-phased. The first phase was an asymptotic approach to 25–30% of maximum growth, followed by a second asymptotic rise to
maximum growth. Growth effects of Glomus invermaium and Acaulospora laevis were quite similar. Plants in these treatments produced up to four times greater shoot dry biomass than non-mycorrhizal plants.
Scutellospora calospora was less effective. The relative effectiveness of AM fungi varied with the level of P application. This is expected to apply
to all soils on which a sigmoid response is obtained for growth of non-mycorrhizal plants. In a simple approximation the relative
effectiveness was calculated to range from 1.46 to 15.57. Shoot P contents were increased by up to 25 times by A. laevis, significantly more than by the other two fungi. The further mycelial spread of this fungus is thought to have contributed
to its relatively greater effect on plant P content. 相似文献
10.
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
11.
Tao Zhang Yu Sun Yongchun Song Changyan Tian Gu Feng 《Symbiosis (Philadelphia, Pa.)》2011,55(2):77-84
Desert ephemeral plants play a key role in desert ecosystem stability and environmental conservation. To determine the effect
of indigenous arbuscular mycorrhizal (AM) fungi on the growth and P uptake of the desert ephemeral Plantago minuta, we conducted two on-site experiments in the Gurbantunggut Desert. The co-development of a pre-isolated indigenous AM fungus,
Glomus etunicatum, with the ephemeral was also investigated. The results showed that both the single fungus and the indigenous AM fungal community
enhanced the growth and P uptake of P. minuta. The phenological phases of P. minuta were highly consistent with the phases of the indigenous AM fungus, G. etunicatum, indicating that both symbiotic partners seem to be able to sense the changes in local weather, which might be an important
trait for the survival of both plant and fungus in desert environments. The development of host plant and indigenous AM fungi
were interdependent in the desert. 相似文献
12.
To examine the mechanisms of earlier reported alleviation of fluoride injury in ectomycorrhizal plants by NaCl, jack pine
(Pinus banksiana) and white spruce (Picea glauca) seedlings were subjected to 1 mM and 5 mM KF in the presence of either 60 mM NaCl or 10% polyethylene glycol 3350 (PEG)
for 2 weeks. Before the treatments, seedlings had either been inoculated with the ectomycorrhizal fungus Suillus tomentosus or remained non-inoculated. The inoculation with S. tomentosus reduced Na uptake by shoots and roots of jack pine seedling and by roots of white spruce that were treated with 60 mM NaCl.
Mycorrhizal associations also drastically decreased fluoride uptake by jack pine seedlings, but did not affect shoot fluoride
concentrations in white spruce. When NaCl was replaced by PEG in the 5 mM KF treatment solution, shoot fluoride concentrations
were reduced by more than twofold without corresponding reductions in transpiration rates in mycorrhizal and non-mycorrhizal
white spruce seedlings. When fluoride was present in the treatment solution, Na concentrations were lower in shoots and roots
of both jack pine and white spruce mycorrhizal and non-mycorrhizal seedlings. The results suggest that Suillus tomentosus may help alleviate the effects of soil fluoride and salinity in jack pine and that fluoride uptake in white spruce is sensitive
to osmotic stress. 相似文献
13.
The influence of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae, on characteristics of growth, photosynthetic pigments, osmotic adjustment, membrane lipid peroxidation and activity of antioxidant
enzymes in leaves of tomato (Lycopersicon esculentum cv Zhongzha105) plants was studied in pot culture under low temperature stress. The tomato plants were placed in a sand and
soil mixture at 25°C for 6 weeks, and then subjected to 8°C for 1 week. AM symbiosis decreased malondialdehyde (MDA) content
in leaves. The contents of photosynthetic pigments, sugars and soluble protein in leaves were higher, but leaf proline content
was lower in mycorrhizal than non-mycorrhizal plants. AM colonization increased the activities of superoxide dismutase (SOD),
catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) in leaves. The results indicate that the AM fungus is capable
of alleviating the damage caused by low temperature stress on tomato plants by reducing membrane lipid peroxidation and increasing
the photosynthetic pigments, accumulation of osmotic adjustment compounds, and antioxidant enzyme activity. Consequently,
arbuscular mycorrhiza formation highly enhanced the cold tolerance of tomato plant, which increased host biomass and promoted
plant growth. 相似文献
14.
Improved tolerance of maize plants to salt stress by arbuscular mycorrhiza is related to higher accumulation of soluble sugars in roots 总被引:24,自引:0,他引:24
The effect of colonization with the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe on the growth and physiology of NaCl-stressed maize plants ( Zea mays L. cv. Yedan 13) was examined in the greenhouse. Maize plants were grown in sand with 0 or 100 mM NaCl and at two phosphorus (P) (0.05 and 0.1 mM) levels for 34 days, following 34 days of non-saline pre-treatment. Mycorrhizal plants maintained higher root and shoot dry weights. Concentrations of chlorophyll, P and soluble sugars were higher than in non-mycorrhizal plants under given NaCl and P levels. Sodium concentration in roots or shoots was similar in mycorrhizal and non-mycorrhizal plants. Mycorrhizal plants had higher electrolyte concentrations in roots and lower electrolyte leakage from roots than non-mycorrhizal plants under given NaCl and P levels. Although plants in the low P plus AM fungus treatment and those with high P minus AM fungus had similar P concentrations, the mycorrhizal plants still had higher dry weights, soluble sugars and electrolyte concentrations in roots. Similar relationships were observed regardless of the presence or absence of salt stress. Higher soluble sugars and electrolyte concentrations in mycorrhizal plants suggested a higher osmoregulating capacity of these plants. Alleviation of salt stress of a host plant by AM colonization appears not to be a specific effect. Furthermore, higher requirement for carbohydrates by AM fungi induces higher soluble sugar accumulation in host root tissues, which is independent of improvement in plant P status and enhances resistance to salt-induced osmotic stress in the mycorrhizal plant. 相似文献
15.
Effects of mycorrhizal fungus isolates on mineral acquisition by Panicum virgatum in acidic soil 总被引:1,自引:0,他引:1
Plant ability to withstand acidic soil mineral deficiencies and toxicities can be enhanced by root-arbuscular mycorrhizal
fungus (AMF) symbioses. The AMF benefits to plants may be attributed to enhanced plant acquisition of mineral nutrients essential
to plant growth and restricted acquisition of toxic elements. Switchgrass (Panicum virgatum L.) was grown in pHCa (soil:10 mM CaCl2, 1 : 1) 4 and 5 soil (Typic Hapludult) inoculated with Glomus clarum, G. diaphanum, G. etunicatum, G. intraradices, Gigaspora
albida, Gi. margarita, Gi. rosea, and Acaulospora
morrowiae to determine differences among AMF isolates for mineral acquisition. Shoots of mycorrhizal (AM) plants had 6.2-fold P concentration
differences when grown in pHCa 4 soil and 2.9-fold in pHCa 5 soil. Acquisition trends for the other mineral nutrients essential for plant growth were similar for AM plants grown in
pHCa 4 and 5 soil, and differences among AMF isolates were generally higher for plants grown in pHCa 4 than in pHCa 5 soil. Both declines and increases in shoot concentrations of N, S, K, Ca, Mg, Zn, Cu, and Mn relative to nonmycorrhizal
(nonAM) plants were noted for many AM plants. Differences among AM plants for N and Mg concentrations were relatively small
(<2-fold) and were large (2- to 9-fold) for the other minerals. Shoot concentrations of mineral nutrients did not relate well
to dry matter produced or to percentage root colonization. Except for Mn and one AMF isolate, shoot concentrations of Mn,
Fe, B, and Al in AM plants were lower than in nonAM plants, and differences among AM plants for these minerals ranged from
a low of 1.8-fold for Fe to as high as 6.9-fold for Mn. Some AMF isolates were effective in overcoming acidic soil mineral
deficiency and toxicity problems that commonly occur with plants grown in acidic soil.
Accepted: 14 June 1999 相似文献
16.
A pot-culture experiment was carried out to investigate the effect of arbuscular mycorrhizal (AM) fungus (Glomus macrocarpum Tul. and Tul.) on plant growth and Cd2+uptake by Apium graveolens L. in soil with different levels of Cd2+. Mycorrhizal (M) and non-mycorrhizal (NM) plants were grown in soil with 0, 5, 10, 40 and 80 Cd2+ mg kg−1soil. The infectivity of the fungus was not affected by the presence of Cd2+ in the soil. M plants showed better growth and less Cd2+ toxicity symptoms. Cd2+ root : shoot ratio was higher in M plants than in NM plants. These differences were more evident at highest Cd2+ level (80 mg kg−1 soil). Chlorophyll a and chlorophyll b concentrations were significantly higher in AM-inoculated celery leaves. The dilution effect due to increased biomass, immobilization
of Cd2+ in root and enhanced P-uptake in M plants may be related to attenuation of Cd2+toxicity in celery. 相似文献
17.
The arbuscular mycorrhizal (AM) non-host plants mustard, sugar beet, lupin and the AM host plant cucumber were used as test plants. Cucumber plants were grown either in the absence of the AM fungus (AMF) Glomus mosseae or in a split-root system, with one side mycorrhizal and one side non-mycorrhizal. Root exudates of the AM non-host plants, the non-mycorrhizal cucumber plants and the mycorrhizal and the non-mycorrhizal side of the split-root system of mycorrhizal cucumber plants were collected and applied to cucumber plants inoculated with the AMF. Root exudates of non-mycorrhizal cucumber plants showed a significant stimulatory effect on root colonization, whereas root exudates from the mycorrhizal and the non-mycorrhizal sides of a split-root system of a mycorrhizal cucumber plant did not show this stimulatory effect and were even slightly inhibitory. Root exudates of the two AM non-host plants mustard and sugar beet significantly reduced root colonization in cucumber plants, whereas no such effect was observed when root exudates of the AM non-host plant lupin were applied. 相似文献
18.
Most terrestrial plants live in symbiosis with arbuscular mycorrhizal (AM) fungi. Studies on the direct interaction between
plants and mycorrhizal fungi are numerous whereas studies on the indirect interaction between such fungi and herbivores feeding
on aboveground plant parts are scarce. We studied the impact of AM symbiosis on host plant choice and life history of an acarine
surface piercing-sucking herbivore, the polyphagous two-spotted spider mite Tetranychus urticae. Experiments were performed on detached leaflets taken from common bean plants (Phaseolus vulgaris) colonized or not colonized by the AM fungus Glomus mosseae. T. urticae females were subjected to choice tests between leaves from mycorrhizal and non-mycorrhizal plants. Juvenile survival and
development, adult female survival, oviposition rate and offspring sex ratio were measured in order to estimate the population
growth parameters of T. urticae on either substrate. Moreover, we analyzed the macro- and micronutrient concentration of the aboveground plant parts. Adult
T. urticae females preferentially resided and oviposited on mycorrhizal versus non-mycorrhizal leaflets. AM symbiosis significantly
decreased embryonic development time and increased the overall oviposition rate as well as the proportion of female offspring
produced during peak oviposition. Altogether, the improved life history parameters resulted in significant changes in net
reproductive rate, intrinsic rate of increase, doubling time and finite rate of increase. Aboveground parts of colonized plants
showed higher concentrations of P and K whereas Mn and Zn were both found at lower levels. This is the first study documenting
the effect of AM symbiosis on the population growth rates of a herbivore, tracking the changes in life history characteristics
throughout the life cycle. We discuss the AM-plant-herbivore interaction in relation to plant quality, herbivore feeding type
and site and the evolutionary implications in a multi-trophic context. 相似文献
19.
Galván GA Kuyper TW Burger K Keizer LC Hoekstra RF Kik C Scholten OE 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(5):947-960
The response of Allium
cepa, A. roylei, A. fistulosum, and the hybrid A. fistulosum × A. roylei to the arbuscular mycorrhizal fungus (AMF) Glomus intraradices was studied. The genetic basis for response to AMF was analyzed in a tri-hybrid A. cepa × (A. roylei × A. fistulosum) population. Plant response to mycorrhizal symbiosis was expressed as relative mycorrhizal responsiveness (R′) and absolute
responsiveness (R). In addition, the average performance (AP) of genotypes under mycorrhizal and non-mycorrhizal conditions
was determined. Experiments were executed in 2 years, and comprised clonally propagated plants of each genotype grown in sterile
soil, inoculated with G. intraradices or non-inoculated. Results were significantly correlated between both years. Biomass of non-mycorrhizal and mycorrhizal plants
was significantly positively correlated. R′ was negatively correlated with biomass of non-mycorrhizal plants and hence unsuitable
as a breeding criterion. R and AP were positively correlated with biomass of mycorrhizal and non-mycorrhizal plants. QTLs
contributing to mycorrhizal response were located on a linkage map of the A. roylei × A. fistulosum parental genotype. Two QTLs from A. roylei were detected on chromosomes 2 and 3 for R, AP, and biomass of mycorrhizal plants. A QTL from A. fistulosum was detected on linkage group 9 for AP (but not R), biomass of mycorrhizal and non-mycorrhizal plants, and the number of
stem-borne roots. Co-segregating QTLs for plant biomass, R and AP indicate that selection for plant biomass also selects for
enhanced R and AP. Moreover, our findings suggest that modern onion breeding did not select against the response to AMF, as
was suggested before for other cultivated species. Positive correlation between high number of roots, biomass and large response
to AMF in close relatives of onion opens prospects to combine these traits for the development of more robust onion cultivars. 相似文献
20.
Two pot experiments were conducted to examine three-level interactions between host plants, mycorrhizal fungi and parasitic
plants. In a greenhouse experiment, Poa annua plants were grown in the presence or absence of an AM fungus (either Glomus lamellosum V43a or G. mosseae BEG29) and in the presence or absence of a root hemiparasitic plant (Odontites vulgaris). In a laboratory experiment, mycorrhizal infection (Glomus claroideum BEG31) of Trifolium pratense host plants (mycorrhizal versus non-mycorrhizal) was combined with hemiparasite infection (Rhinanthus serotinus) of the host (parasitized versus non-parasitized). Infection with the two species of Glomus had no significant effect on the growth of P. annua, while hemiparasite infection caused a significant reduction in host biomass. Mycorrhizal status of P. annua hosts (i.e. presence/absence of AM fungus) affected neither the biomass nor the number of flowers produced by the attached O. vulgaris plants. Infection with G. claroideum BEG31 greatly increased the biomass of T. pratense, but hemiparasite infection had no effect. The hemiparasitic R. serotinus plants attached to mycorrhizal hosts had higher biomass and produced more flowers than plants growing with non-mycorrhizal
hosts. Roots of T. pratense were colonized by the AM fungus to an extent independent of the presence or absence of the hemiparasite. Our results confirm
earlier findings that the mycorrhizal status of a host plant can affect the performance of an attached root hemiparasite.
However, improvement of the performance of the parasitic plant following attachment to a mycorrhizal host depends on the extent
to which the AM fungi is able to enhance the growth of the host.
Accepted: 23 February 2001 相似文献