Mycorrhizal response in wheat cultivars: relationship to phosphorus

1996 ◽  
Vol 74 (1) ◽  
pp. 19-25 ◽  
Author(s):  
B. A. D. Hetrick ◽  
G. W. T. Wilson ◽  
T. C. Todd

The effect of five mycorrhizal fungi on the growth of 10 wheat cultivars under three phosphorus regimes was assessed in a greenhouse study. Six of the cultivars responded positively, while four responded negatively or were nonresponsive to mycorrhizal inoculation. The responses of the individual cultivars were consistent regardless of inoculum source, suggesting that mycorrhizal responsiveness is an inherited trait rather than a response to individual fungi. Mycorrhizal responsiveness decreased with P fertilization for cultivars that were dependent on the symbiosis, but it was unaffected by P fertilization in cultivars that were negatively impacted by the mycorrhizae. Mycorrhizal and P responsiveness of each cultivar were highly correlated (r = 0.94), suggesting that P responsiveness may be a good predictor of the mycorrhizal dependence of selected wheat cultivars. The relationship between wheat biomass production and percentage root colonization was positive for cultivars, which responded favorably to the symbiosis, and negative for cultivars, which responded negatively or were nonresponsive to mycorrhizal inoculation. Amendment with P did not significantly affect these relationships. To determine whether differences in mycorrhizal responsiveness are related to nutrient uptake by the fungus, 32P uptake of Turkey (responsive cultivar) and Newton (nonresponsive cultivar) was controlled by severing the mycorrhizal hyphae in a split-pot experiment. Plants with intact hyphae absorbed more 32P than those with severed hyphae for both cultivars, and significantly more counts per minute of 32P were evident in Newton than in Turkey, suggesting that mycorrhizal function is not impaired even in cultivars that do not display a biomass increase in response to mycorrhizal symbiosis. Keywords: vesicular–arbuscular mycorrhizae, pathogenesis, growth response, mycorrhizal symbiosis.

1992 ◽  
Vol 70 (10) ◽  
pp. 2032-2040 ◽  
Author(s):  
B. A. D. Hetrick ◽  
G. W. T. Wilson ◽  
T. S. Cox

Using mycorrhizal fungi known to colonize wheat, the mycorrhizal dependence of various small grains including modem wheat varieties, primitive wheat lines, and wheat ancestors was studied. With the exception of the United States cultivar Newton and the German cultivars Apollo, Kanzler, and Sperber, dry weight of eight other modern wheats from the United States and Great Britain were increased by 29–100% following inoculation with mycorrhizal fungi. All landraces from Asian collections or early introduced American cultivars were also dependent on the symbiosis, with dry weight increases averaging 169 and 55%, respectively. All wheat ancestors of the AA and BB genomes (except Aegilops speltoides) benefitted significantly from the symbiosis, whereas no benefit was observed for ancestors of the DD genome, tetraploid wheats of the AABB or AAGG genomes, or in the hexaploid ancestor Triticum zhukovskyi (AAAAGG genome). These differences in mycorrhizal response of the ancestors, lines, and cultivars were highly correlated with root fibrousness ratings. When the fungi used as a combined inoculum in the previous experiment were inoculated individually onto selected plant species or cultivars, 6 of the 10 isolates stimulated growth of Andropogon gerardii, a highly dependent grass species, and 8 of the 10 stimulated the growth of 'Turkey' wheat. In contrast, none of the isolates positively affected growth of 'Newton' or 'Kanzler' wheat cultivars, and in fact several fungi decreased the biomass produced by these two cultivars. These studies have demonstrated a strong genetic basis for differences in mycorrhizal dependence among cultivars. A trend for greater reliance on the symbiosis in older cultivated wheats than iin wheat ancestors or modern wheats was also observed. The depression in growth associated with certain mycorrhizal fungi and wheat cultivars demonstrates that colonization of roots does not guarantee benefit from the symbiosis. Key words: root fibrousness, growth response, vesicular–arbuscular mycorrhizae.


1992 ◽  
Vol 28 (4) ◽  
pp. 433-442 ◽  
Author(s):  
Edwin Weber ◽  
Eckhard George ◽  
Douglas P. Beck ◽  
Mohan C. Saxena ◽  
Horst Marschner

SUMMARYInoculation with vesicular-arbuscular mycorrhizal fungi (VAMF) improved growth of chick-pea (Cicer arielinum L.) and doubled phosphorus (P) uptake at low and intermediate levels of P fertilization in a pot experiment on sterilized low-P calcareous soil. In field experiments at Tel Hadya, northern Syria, growth, shoot P concentration and seed yield of spring-sown chickpea remained unaffected by inoculation with VAMF or by P fertilization. The mycorrhizal infection of chickpea was high (approximately 75% of root length mycorrhizal at the flowering stage) irrespective of inoculation with VAMF or P fertilization and may ensure efficient P uptake under field conditions.


2012 ◽  
Vol 518-523 ◽  
pp. 5381-5384
Author(s):  
Song Mei Shi ◽  
Bo Tu ◽  
Dai Jun Liu ◽  
Xiao Hong Yang

Physic nut (Jatropha curcas Linn., Euphorbiaceae) is one of the hottest biomass energy plant studied by scientists. This paper first reviewed the symbiosis relationship between physic nut and arbuscular mycorrhizal fungi. The researches have showed that diversity of arbuscular mycorrhizal fungi (AMF) exists around the rhizosphere of physic nut. The AMF hyphae colonize root tips of physic nut to develop arbuscular mycorrhizae. The construction of mycorrhizal symbiosis relationship improves the nutritional absorption, promotes the growth and development of seedlings, and enhance the stress tolerance capacity of physic nut. This paper also displays a prospect for mycorrhizal physic nut research in the future, such as mycorrhizal system, the molecular mechanism for stress resistance and gene engineering. As an important resource of biomass energy, mycorrhizal physic nut has a huge exploitation potential and practical value.


1987 ◽  
Vol 17 (8) ◽  
pp. 970-975 ◽  
Author(s):  
G. L. Simmons ◽  
P. E. Pope

A greenhouse study was conducted to determine the influence of soil compaction on root growth of yellow poplar (Liriodendrontulipifera L.) and sweet gum (Liquidambarstyraciflua L.) seedlings grown in association with the mycorrhizal fungi Glomusmacrocarpum Tul. and Tul. or G. fasciculatum (Thaxt) Gerd. and Trappe. Seedlings were transplanted into pots that contained silt loam compacted to bulk densities of 1.25, 1.40, or 1.55 Mg m−3. Fungal chlamydospores or control filtrates were used to inoculate seedlings. Weight and length of yellow poplar roots were significantly greater at the lower bulk densities than at the highest bulk density, but fibrosity of the root system was unaffected by increasing bulk density. Weight, length, and fibrosity of the sweetgum root system decreased significantly with each increase in bulk density. Inoculated yellow poplar seedlings had greater root weight at each bulk density than noninoculated seedlings, but root length was not influenced by mycorrhizal treatments at higher bulk densities. Fibrosity of yellow poplar roots varied by mycorrhizal treatment at each bulk density. Results indicate that for yellow poplar, compaction effects may outweigh mycorrhizal benefits at higher bulk densities. At each bulk density, sweet gum seedlings inoculated with G. fasciculatum showed the greatest root growth, suggesting that effects of compaction can be alleviated for sweet gum by inoculation with this mycorrhizal fungus.


2013 ◽  
Vol 281 ◽  
pp. 664-669
Author(s):  
En Wu ◽  
Guo Rong Xin ◽  
Kazuo Sugawara

With the aggravation of volcanic ash Andosol acidification, artificial forage grass Dactylis glomerata L. gradual degradation, replaced by weed plant Anthoxanthum odoratum L., but the mechanism is unclear. In order to reveal the mechanism, this study used Andosol soil as matrix, explored the effects of arbuscular mycorrhizal fungi on D. glomerata and A. odoratum at different pH gradients in acidic Andosol by glasshouse experiment. The results show that the mycorrhizal colonization of D. glomerata strongly affected by soil pH, but the A. odoratum was not yet. The mycorrhizal symbiosis led to a positive effect on growth and P uptake of D. glomerata and A. odoratum. Consider to invasion and expansion of A. odoratum in severity acidic pasture is origin of this specificity on arbuscular mycorrhizal symbiosis in acidic soil other than D. glomerata.


2001 ◽  
Vol 79 (10) ◽  
pp. 1175-1180 ◽  
Author(s):  
R Azcón ◽  
J M Ruiz-Lozano ◽  
R Rodríguez

The objective of this study was to determine how the uptake and transport of nitrate by two species of arbuscular mycorrhizal (AM) fungi is affected by its concentration in the medium and by the age of the AM symbiosis. Tracer amounts of15N nitrate were applied at two plant growth periods to mycorrhizal or nonmycorrhizal lettuce plants, which had been grown in soil supplied with nitrate to provide a total of 84, 168, or 252 mg N/kg. At both injection times, Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe and Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe reached the highest values of nitrogen derived from the fertilizer (NdfF) at 84 mg N/kg. Glomus mosseae also reached the highest values of labeled fertilizer N utilization at 84 mg N/kg, whereas G. fasciculatum reached the highest values at 168 mg N/kg in the medium. The highest N level in the medium (252 mg N/kg) had a negative effect on % NdfF and % labeled fertilizer utilization for all mycorrhizal plants. Regarding the time of15N fertilizer application, G. fasciculatum-colonized plants had a minimum change in % NdfF and % labeled fertilizer utilization during the growth period (60 days application vs. 30 days application). In contrast, G. mosseae-colonized plants growing at 168 mg N/kg in the medium, decreased these two values in the latest application. The present results confirm that mycorrhizal symbiosis may be particularly important for nitrogen nutrition in plants growing in neutral-alkaline soils.Key words: arbuscular mycorrhizae, nitrate assimilation, nitrate uptake,15N-labeled fertilizer.


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 400 ◽  
Author(s):  
Torres ◽  
Hilbert ◽  
Antolín ◽  
Goicoechea

(1) Background: Vitis vinifera L. cv. Tempranillo is cultivated over the world for its wine of high quality. The association of Tempranillo with arbuscular mycorrhizal fungi (AMF) induced the accumulation of phenolics and carotenoids in leaves, affected the metabolism of abscisic acid (ABA) during berry ripening, and modulated some characteristics and quality aspects of grapes. The objective of this study was to elucidate if AMF influenced the profiles and the content of primary and secondary metabolites determinants for berry quality in Tempranillo. (2) Methods: Fruit-bearing cuttings inoculated with AMF or uninoculated were cultivated under controlled conditions. (3) Results: Mycorrhizal symbiosis modified the profile of metabolites in Tempranillo berries, especially those of the primary compounds. The levels of glucose and amino acids clearly increased in berries of mycorrhized Tempranillo grapevines, including those of the aromatic precursor amino acids. However, mycorrhizal inoculation barely influenced the total amount and the profiles of anthocyanins and flavonols in berries. (4) Conclusions: Mycorrhizal inoculation of Tempranillo grapevines may be an alternative to the exogenous application of nitrogen compounds in order to enhance the contents of amino acids in grapes, which may affect the aromatic characteristics of wines.


2017 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Nasir S. A. Malik ◽  
Alberto Nuñez ◽  
Lindsay C. McKeever

This study was conducted to investigate the effect of mycorrhizal symbiosis on the levels of polyphenols in olive saplings. Rooted stem cuttings of olive cultivar, ‘Arbequina’, were inoculated with AM fungus Rhizophagus intraradices. The inoculated plants showed more robust growth after six months, and after nine months the increase in the mycorrhizal plant’s height was 146%, and the increase in number of leaves was 117% when compared to uninoculated controls. Polyphenols in the methanol extracts of leaves were separated by HPLC and the peaks identified by using commercially available standard compounds and comparing retention time and the mass obtained with the mass spectrometer. Oleuropein, which is a major component of the olive leaf polyphenols, increased in mycorrhizal plants compared to uninoculated plants by 42%, and its derivatives, oleuroside and ligstroside, increased by 68% and 48%, respectively. The highest increase was found in the levels of luteolin-7’-O-glucoside (107% increase), while its sister compound luteolin-4’-O-glucoside increased by 43%. Only verbascoside levels were lower in mycorrhizal plants versus non-mycorrhizal plants declining to below detectable limits. Thus, inoculation of olive saplings with mycorrhizal fungi produces very positive effects on the levels of olive leaf polyphenols. Higher levels polyphenols mean better quality of leaf material for use as herbal medicine.


1983 ◽  
Vol 61 (3) ◽  
pp. 944-963 ◽  
Author(s):  
D. S. Hayman

The enhanced growth of plants infected by vesicular–arbuscular (VA) mycorrhizal fungi results primarily from improved uptake of soil phosphate. Extra phosphate reaches the root through the fungal hyphae, which tap the soluble P in soil beyond the phosphate-depletion zone near the root surface. This mechanism can explain the many corrrelations between root geometry and mycotrophy and other nutritional effects of VA mycorrhizae such as increased uptake of zinc and copper ions. Recently VA mycorrhizae have been shown to increase the levels of chlorophyll and some hormones in plants and to alleviate water stress. Legumes are now receiving considerable attention because VA mycorrhiza affects nitrogen fixation in them indirectly by its action on P uptake. In this review the physiology of the VA mycorrhizal symbiosis is discussed in categories reflecting successive stages in its formation and function: (i) activation of the VA mycorrhizal propagules; (ii) penetration and initial infection of the host plant; (iii) spread of infection in roots; (iv) response of the plant; the components and mechanisms of VA mycorrhizal systems; (v) benefits to the fungus; carbon sinks; and (vi) imbalances in the symbiosis. It is suggested that studies on the physiological complexities of VA mycorrhizal associations should take more account of the biological diversity of VA mycorrhizal fungi and the wide range of host–endophyte–soil specificities.


2012 ◽  
Vol 36 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Elcio Liborio Balota ◽  
Oswaldo Machineski ◽  
Alexandra Scherer

In recent years, physic nut (Jatropha curcas L.) has attracted attention because of its potential for biofuel production. Although it is adapted to low-fertility soils, physic nut requires soil acidity corrections and addition of a considerable amount of fertilizer for high productivity. The objective of this research was to evaluate the effectiveness of arbuscular mycorrhizal fungi (AMF) (control without AMF inoculation, Gigaspora margarita inoculation or Glomus clarum inoculation) on increasing growth and yield of physic nut seedlings under different rates of P fertilization (0, 25, 50, 100, 200, and 400 mg kg-1 P soil) in greenhouse. The experiment was arranged in a completely randomized, block in a factorial scheme design with four replications. The physic nut plants were harvested 180 days after the beginning of the experiment. Mycorrhizal inoculation increased physic nut growth, plant P concentration and root P uptake efficiency at low soil P concentrations. The P use quotient of the plants decreased as the amount of P applied increased, and the P use efficiency index increased at low P levels and decreased at high P levels. Mycorrhizal root colonization and AMF sporulation were negatively affected by P addition. The highest mycorrhizal efficiency was observed when the soil contained between 7.8 and 25 mgkg-1 of P. The physic nut plants responded strongly to P application, independent of mycorrhizal inoculation.


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