scholarly journals Arbuscular mycorrhiza and dark septate endophyte fungal associations of Oryza sativa L. under field condition: colonization features and their occurrence

2019 ◽  
Vol 6 (1) ◽  
pp. 63-70
Author(s):  
Kripamoy Chakraborty ◽  
Subam Banik ◽  
Atithi Debnath ◽  
Aparajita Roy Das ◽  
Ajay Krishna Saha ◽  
...  

The present study was aimed to study monthly colonization of arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in rice. The presence of mycorrhizal structures in the roots confirms the colonization by AM fungi. The pattern of hyphae and arbuscules denotes Arum type of AM fungal morphology. The presence of dark coloured septate hyphae running frequently on the epidermal layer and in root cortex and the occurrence of microsclerotia marks the colonization by DSE fungi. The co-occurrence of both AM and DSE fungi ensure dual colonization by two distinct fungal groups. There was significant increase in arbuscules, vesicles and hyphal percentages from first to third month in both the samples collected from two sites. In the third month, AM colonization significantly higher in both the sites. DSE colonization percentages do not differ significantly in first to third month. A total of nine AM fungal species were recovered from two sites. This study is an effort to make aware the local farmers about the usefulness of these native AM mycobiota which can be a preferable choice over chemical fertilizers leading to ecofriendly organic farming.

2004 ◽  
Vol 17 (10) ◽  
pp. 1103-1113 ◽  
Author(s):  
Ling-Ling Gao ◽  
Wolfgang Knogge ◽  
Gabriele Delp ◽  
F. Andrew Smith ◽  
Sally E. Smith

The expression of defense-related genes was analyzed in the interactions of six arbuscular mycorrhizal (AM) fungi with the roots of wild-type tomato (Lycopersicon esculentum Mill.) cv. 76R and of the near-isogenic mycorrhiza-defective mutant rmc. Depending on the fungal species, wild-type tomato forms both major morphological AM types, Arum and Paris. The mutant rmc blocks the penetration of the root surface or invasion of the root cortex by most species of AM fungi, but one fungus has been shown to develop normal mycorrhizas. In the wild-type tomato, accumulation of mRNA representing a number of defense-related genes was low in Arum-type interactions, consistent with findings for this AM morphotype in other plant species. In contrast, Paris-type colonization, particularly by members of the family Gigasporaceae, was accompanied by a substantial transient increase in expression of some defense-related genes. However, the extent of root colonization did not differ significantly in the two wild-type AM morpho-types, suggesting that accumulation of defense gene products per se does not limit mycorrhiza development. In the mutant, interactions in which the fungus failed to penetrate the root lacked significant accumulation of defense gene mRNAs. However, phenotypes in which the fungus penetrated epidermal or hypodermal cells were associated with an enhanced and more prolonged gene expression. These results are discussed in relation to the mechanisms that may underlie the specificity of the interactions between AM fungi and the rmc mutant.


2006 ◽  
Vol 33 (3) ◽  
pp. 289 ◽  
Author(s):  
Ling-Ling Gao ◽  
F. Andrew Smith ◽  
Sally E. Smith

A tomato mutant with reduced mycorrhizal colonisation, rmc, confers resistance to almost all arbuscular mycorrhizal (AM) fungal species tested, although there is variation in colonisation of different root cell layers by different fungi and one species of AM fungus can colonise this mutant relatively normally. These variations indicate a high degree of specificity in relation to AM colonisation. We explored the possibility of specificity or otherwise in interactions between rmc and three non-AM root-infecting fungi, Rhizoctonia solani anastomosis groups (AG) 4 and AG8, and binucleate Rhizoctonia (BNR). There were no differences between the wild type tomato 76R and rmc in the speed or extent to which these fungi infected roots or caused disease. Infection by R. solani induced high levels of defence-related gene expression in both tomato genotypes relative to non-infected plants. In contrast, with BNR the expression of these genes was not induced or induced to a much lower extent than with R. solani. The expression of defence-related genes with these two non-AM fungi was very similar in the two plant genotypes. It was different from effects observed during colonisation by AM fungi, which enhanced expression of defence-related genes in rmc compared with the wild type tomato. The specificity and molecular mechanisms of rmc in control of AM colonisation are discussed.


2007 ◽  
Vol 5 (24) ◽  
pp. 773-784 ◽  
Author(s):  
A Schnepf ◽  
T Roose ◽  
P Schweiger

In order to quantify the contribution of arbuscular mycorrhizal (AM) fungi to plant phosphorus nutrition, the development and extent of the external fungal mycelium and its nutrient uptake capacity are of particular importance. We develop and analyse a model of the growth of AM fungi associated with plant roots, suitable for describing mechanistically the effects of the fungi on solute uptake by plants. The model describes the development and distribution of the fungal mycelium in soil in terms of the creation and death of hyphae, tip–tip and tip–hypha anastomosis, and the nature of the root–fungus interface. It is calibrated and corroborated using published experimental data for hyphal length densities at different distances away from root surfaces. A good agreement between measured and simulated values was found for three fungal species with different morphologies: Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders; Glomus sp.; and Acaulospora laevis Gerdemann & Trappe associated with Trifolium subterraneum L. The model and findings are expected to contribute to the quantification of the role of AM fungi in plant mineral nutrition and the interpretation of different foraging strategies among fungal species.


2003 ◽  
Vol 69 (11) ◽  
pp. 6762-6767 ◽  
Author(s):  
Ingrid M. van Aarle ◽  
Pål Axel Olsson

ABSTRACT We monitored the development of intraradical and extraradical mycelia of the arbuscular mycorrhizal (AM) fungi Scutellospora calospora and Glomus intraradices when colonizing Plantago lanceolata. The occurrence of arbuscules (branched hyphal structures) and vesicles (lipid storage organs) was compared with the amounts of signature fatty acids. The fatty acid 16:1ω5 was used as a signature for both AM fungal phospholipids (membrane constituents) and neutral lipids (energy storage) in roots (intraradical mycelium) and in soil (extraradical mycelium). The formation of arbuscules and the accumulation of AM fungal phospholipids in intraradical mycelium followed each other closely in both fungal species. In contrast, the neutral lipids of G. intraradices increased continuously in the intraradical mycelium, while vesicle occurrence decreased after initial rapid root colonization by the fungus. S. calospora does not form vesicles and accumulated more neutral lipids in extraradical than in intraradical mycelium, while the opposite pattern was found for G. intraradices. G. intraradices allocated more of its lipids to storage than did S. calospora. Thus, within a species, the fatty acid 16:1ω5 is a good indicator for AM fungal development. The phospholipid fatty acid 16:1ω5 is especially suitable for indicating the frequency of arbuscules in the symbiosis. We propose that the ratio of neutral lipids to phospholipids is more important than is the presence of vesicles in determining the storage status of AM fungi.


2012 ◽  
Vol 71 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Thangavelu Muthukumar ◽  
Kandasamy Prabha

Fungal associations in gametophytes and young sporophytic roots of the fernNephrolepis exaltataInformation is limited on the presence of endophytic fungal associations in green gametophytes and young sporophytes of extant ferns. Nothing is known about their presence in Polypodiales, the largest order among extant ferns. We screened chlorophyllous gametophytes and young sporophytes ofNephrolepis exaltata(L.) Schott., (Lomariopsidaceae, Polypodiales) growing naturally on soil, brick and coir for the presence of fungal endophytes. Gametophytes and young sporophytes growing on different substrates were invariably colonized by septate endophytic fungi. Hyaline or brown, regularly septate, inter- or intracellular hyphae with moniliform cells or microsclerotia characterized septate endophytic fungi. However, only the roots of young sporophytes growing on soil and bricks harboured arbuscular mycorrhizal (AM) fungi. The AM morphology conformed to the intermediate type with intracellular hyphal coils, arbusculate coils and intercellular hyphae. No AM fungal spores could be retrieved from the soil on which gametophytes and young sporophytes were growing. The observations in this study support the idea that the septate fungal endophytes could confer an ecological advantage on colonized individuals, especially on nutrient deficient substrates.


2016 ◽  
Vol 70 (2) ◽  
Author(s):  
Happy WIDIASTUTI ◽  
Edi GUHARDJA ◽  
Nampiah SOEKARNO ◽  
L K DARUSMAN ◽  
Didiek Hadjar GOENADI ◽  
...  

SummaryAM fungal symbiosis increase the uptake of P in oil palm seedlings. However the optimum condition of symbiosis has to be determined to get higher benefit of AM fungal symbiosis. Optimization of the symbiosis Acaulospora tuberculata and Gigaspora margarita with oil palm seedling in acid soil was determined. An experiment was conducted in polybag sized 40 x 60 cm contained sterilized Cikopomayak soil. Three factors studied were AM fungal species (A. tuberculata, G. margarita), inoculant dose (0.0; 12.5; 25.0; and 37.5% w/w), and fertilizer rate (0; 25; 50; and 100% recommended dose) and each treatment replicated three times. The result showed that optimum growth reached on the inoculant addition of 36% (w/w) in the form of infected roots, hypha, and spores and fertilizer dose of 25% for A. tuberculata, while for G. margarita was 40% (w/w) inoculant and 26% fertilizer. Efectivity of fertilizer and P uptake of oil palm seedling were significantly increased with AM fungi inoculation. P uptake of oil palm seedling inoculated with A. tuberculata increase. RingkasanSimbiosis cendawan mikoriza arbuskula (CMA) dapat meningkatkan serapan P pada pembibitan kelapa sawit. Namun, untuk mendapatkan keuntungan simbiosis yang tinggi perlu diketahui kondisi optimum simbiosis. Simbiosis CMA dengan tanaman sangat dipengaruhi tingkat hara dan dosis inokulum. Percobaan dilakukan dalam polibag berukuran 40 x 60 cm berisi tanah Cikopomayak steril. Tiga faktor yang diuji ialah spesies CMA (A. tuberculata, G. margarita), dosis inokulum campuran (0,0; 12,5; 25,0; dan 37,5% b/b), dosis pupuk (0; 25; 50; dan 100% dosis rekomendasi) dan masing masing perlakuan diulang tiga kali. Hasil percobaan menunjukkan bahwa pertumbuhan optimum dicapai pada pemberian inokulum berupa akar terinfeksi, hifa, dan spora 36% (b/b) dan pupuk 25% untuk A. tuberculata, sedangkan untuk G. margarita ialah 40% (b/b) inokulum dan pupuk 26%. Keefektifan pupuk dan serapan P meningkat secara nyata dengan inokulasi CMA


2020 ◽  
Vol 16 (4) ◽  
pp. 697-703
Author(s):  
Hoang Kim Chi ◽  
Tran Thi Nhu Hang ◽  
Tran Thi Hong Ha ◽  
Le Huu Cuong ◽  
Tran Ho Quang ◽  
...  

Arbuscular mycorrhizal (AM) fungi are soil eukaryotes that belong to phylum Glomeromycota and have symbiosis with the vast majority of higher plants’ roots. AM fungi are believed to be coevolved with terrestrial plants, the abundance and diversity of AM fungal communities as a result are host plant dependent. A survey of AM fungi from the rhizospheres of medicinal plants in Northern Vietnam including gurma Gymnema sylvestre and turmeric Curcuma longa was carried out. From the extracted total DNAs of the medicinal plants’ rhizosphere soil samples, 35 mycorrhizal fungal species were identified by analyzing small subunit rRNA gene sequences. Result revealed that genus Glomus is the most abundant in the AM communities of G. sylvestre and C. longa, followed by Gigaspora and Acaulospora. Besides, AM species belonging to genera Scutellospora, Diversispora and Rhizophagus were observed in almost all rhizosphere soil samples. The spore counting by wet sieving and decanting method uncovered a variation in AM spore density of gurma and turmeric rhizosphere. In general, AM species were found more abundantly and more diverse in collected rhizome soil samples of C. longa (27 species belonging to 10 genera) than of G. sylvestre (17 species found belonging to 7 genera). The observed difference in AM communities of G. sylvestre and C. longa supports evidence for the dependence of AM fungal species on host plants, and indicates that AM fungi may have relation to the host plants’ secondary metabolite production.


2016 ◽  
Vol 82 (16) ◽  
pp. 4921-4930 ◽  
Author(s):  
Geoffrey L. House ◽  
Saliya Ekanayake ◽  
Yang Ruan ◽  
Ursel M. E. Schütte ◽  
Wittaya Kaonongbua ◽  
...  

ABSTRACTArbuscular mycorrhizal (AM) fungi form mutualisms with plant roots that increase plant growth and shape plant communities. Each AM fungal cell contains a large amount of genetic diversity, but it is unclear if this diversity varies across evolutionary lineages. We found that sequence variation in the nuclear large-subunit (LSU) rRNA gene from 29 isolates representing 21 AM fungal species generally assorted into genus- and species-level clades, with the exception of species of the generaClaroideoglomusandEntrophospora. However, there were significant differences in the levels of sequence variation across the phylogeny and between genera, indicating that it is an evolutionarily constrained trait in AM fungi. These consistent patterns of sequence variation across both phylogenetic and taxonomic groups pose challenges to interpreting operational taxonomic units (OTUs) as approximations of species-level groups of AM fungi. We demonstrate that the OTUs produced by five sequence clustering methods using 97% or equivalent sequence similarity thresholds failed to match the expected species of AM fungi, although OTUs from AbundantOTU, CD-HIT-OTU, and CROP corresponded better to species than did OTUs from mothur or UPARSE. This lack of OTU-to-species correspondence resulted both from sequences of one species being split into multiple OTUs and from sequences of multiple species being lumped into the same OTU. The OTU richness therefore will not reliably correspond to the AM fungal species richness in environmental samples. Conservatively, this error can overestimate species richness by 4-fold or underestimate richness by one-half, and the direction of this error will depend on the genera represented in the sample.IMPORTANCEArbuscular mycorrhizal (AM) fungi form important mutualisms with the roots of most plant species. Individual AM fungi are genetically diverse, but it is unclear whether the level of this diversity differs among evolutionary lineages. We found that the amount of sequence variation in an rRNA gene that is commonly used to identify AM fungal species varied significantly between evolutionary groups that correspond to different genera, with the exception of two genera that are genetically indistinguishable from each other. When we clustered groups of similar sequences into operational taxonomic units (OTUs) using five different clustering methods, these patterns of sequence variation caused the number of OTUs to either over- or underestimate the actual number of AM fungal species, depending on the genus. Our results indicate that OTU-based inferences about AM fungal species composition from environmental sequences can be improved if they take these taxonomically structured patterns of sequence variation into account.


1998 ◽  
Vol 130 (2) ◽  
pp. 125-133 ◽  
Author(s):  
V. S. MEHROTRA

A survey of soil and root samples collected beneath some pioneering plants colonizing reclaimed mine spoil at an opencast coal mine site at Chandrapur, Maharashtra State, India, was conducted in October 1994 to examine the possible host and edaphic influence on the occurrence of arbuscular mycorrhizal (AM) fungi. Thirteen plant species were sampled to determine the mycorrhizal root colonization and the number of spores of individual AM fungal species in the rhizosphere.Typical AM fungal infection was observed in roots of all the plant species examined. Mycorrhizal infection ranged from 20 to 95%. Sampled soils contained six spore-forming species of AM fungi (Acaulospora scrobiculata, Entrophospora colombiana, Glomus aggregatum, Glomus ambisporum, Scutellospora calospora and a previously undescribed species of Glomus). Fungal spore densities were not related to the mycorrhizal infection levels. E. colombiana and G. ambisporum were the leading species in terms of spore densities and frequencies. Phenotypic variations in spores of AM fungi were possibly related to the physical and chemical properties of the mine spoil.It is concluded that the pioneering plant species on mine spoils can cause the development of different populations of AM fungi. The study also indicates that certain species of AM fungi have broad environmental requirements.


Sign in / Sign up

Export Citation Format

Share Document