scholarly journals Arbuscular mycorrhizal fungi associated with shade trees and Coffea arabica L. in a coffee-based agroforestry system in Bonga, Southwestern Ethiopia

Afrika Focus ◽  
2013 ◽  
Vol 26 (2) ◽  
pp. 111-131
Author(s):  
Tadesse Chanie Sewnet ◽  
Fassil Assefa Tuju

In a first step to understand the interactions between Colfea arabica L. trees and mycorrhizae in Ethiopia, an investigation of the current mycorrhizal colonization status of roots was undertaken. We sampled 14 shade tree species occurring in coffee populations in Bonga forest, Ethiopia. Milletia ferruginea, Schefflera abyssinica, Croton macrostachyus, Ficus vasta, F. sur, Albizia gummifera, Olea capensis, Cordia africana, Ehretia abyssinica, Pouteria adolfi-friederici, Pavetta oliveriana, Prunus africana, Phoenix reclinata and Polyscias fulva. Coffee trees sampled under each shade tree were all shown to be colonized by arbuscular mycorrhizal fungi (AM fungi). Four genera and 9 different species of AM fungi were found in the soils. Glomus (Sp1, Sp2, & Sp3 & Sp4), Scutellospora (Sp1 & Sp2) and Gigaspora (Sp1 & Sp2) were found under all 14 shade tree species, whereas Acaulospora (Sp1) occurred only in slightly acidic soils, within a pH range of 4.93-5.75. Generally, roots of the coffee trees were colonized by arbuscules to a greater degree than those of their shade trees, the arbuscular colonization percentage (AC%) of the former being higher than the latter (significant difference at 0.05 level). Though differences were not statistically significant, the overall hyphal colonization percentage (HC%) and mycorrhizal hyphal colonization percentage (MHC%) were shown to be slightly higher under coffee trees than under their shade trees. However, the differences were statistically significant at 0.05 level in the case of HC% values of coffee trees under Pouteria adolf-friederici and MHC% under Cordia africana. Spore density and all types of proportional root colonization parameters (HC%, MHC%, AC% and vesicular colonization percentage, VC%) for both coffee and shade trees were negatively and significantly correlated with organic soil carbon, total N, available P, EC and Zn. Correlation between arbuscular colonization for coffee (AC%) and organic carbon was not significantly positive at a 0.05 level. Incidence of specific spore morphotypes was also correlated with physical and chemical soil properties. Results indicate that AM fungi could potentially be important in aforestation and help to promote coffee production activities in Ethiopia providing an alternative to expensive chemical fertilizer use, and would offer management methods that take advantage of natural systems dynamics that could potentially preserve and enhance coffee production.

Afrika Focus ◽  
2013 ◽  
Vol 26 (2) ◽  
Author(s):  
Tadesse Chanie Sewnet ◽  
Fassil Assefa Tuju

In a first step to understand the interactions between Coffea arabica L. trees and mycorrhizae in Ethiopia, an investigation of the current mycorrhizal colonization status of roots was undertaken. We sampled 14 shade tree species occurring in coffee populations in Bonga forest, Ethiopia. Milletia ferruginea, Scheffiera abyssinica, Croton macrostachyus, Ficus vasta, F. sur, Albizia gummifera, Olea capensis, Cordia africana, Ehretia abyssinica, Pouteria adolfi-friederici, Pavetta oliveriana, Prunus africana, Phoenix reclinata and Polyscias fulva. Coffee trees sampled under each shade tree were all shown to be colonized by arbuscular mycorrhizal fungi (AM fungi). Four genera and 9 different species of AM fungi were found in the soils. Glomus (Sp1, Sp2, & Sp3 & Sp4), Scutellospora (Sp1 & Sp2) and Gigaspora (Sp1 & Sp2) were found under all 14 shade tree species, whereas Acaulospora (Sp1) occurred only in slightly acidic soils, within a pH range of 4.93-5.75. Generally, roots of the coffee trees were colonized by arbuscules to a greater degree than those of their shade trees, the arbuscular colonization percentage (AC%) of the former being higher than the latter (signifIcant difference at 0.05 level). Though differences were not statistically signifIcant, the overall hyphal colonization percentage (HC%) and mycorrhizal hyphal colonization percentage (MHC%) were shown to be slightly higher under coffee trees than under their shade trees. However, the differences were statistically significant at 0.05 level in the case of HC% values of coffee trees under Pouteria adolf-friederici and MHC% under Cordia africana. Spore density and all types of proportional root colonization parameters (HC%, MHC%, AC% and vesicular colonization percentage, VC%) for both coffee and shade trees were negatively and significantly correlated with organic soil carbon, total N, available P, EC and Zn. Correlation between arbuscular colonization for coffee (AC%) and organic carbon was not significantly positive at a 0.05 level. Incidence of specific spore morphotypes was also correlated with physical and chemical soil properties. Results indicate that AM fungi could potentially be important in aforestation and help to promote coffee production activities in Ethiopia providing an alternative to expensive chemical fertilizer use, and would offer management methods that take advantage of natural systems dynamics that could potentially preserve and enhance coffee production. Key words: aforestation; agroforestry, coffee groves, ecology, integrated production systems, rhizosphere, sustainable agriculture, symbiosis 


2015 ◽  
Vol 43 (2) ◽  
pp. 488-493
Author(s):  
Zhaoyong SHI ◽  
Xubin YIN ◽  
Bede MICKAN ◽  
Fayuan WANG ◽  
Ying ZHANG ◽  
...  

Arbuscular mycorrhiza (AM) fungi are considered as an important factor in predicting plants and ecosystem responses to climate changes on a global scale. The Tibetan Plateau is the highest region on Earth with abundant natural resources and one of the most sensitive region to climate changes. To evaluate the complex response of arbuscular mycorrhizal fungi colonization and spore density to climate changes, a reciprocal translocation experiment was employed in Tibetan Plateau. The reciprocal translocation of quadrats to AM colonization and spore density were dynamic. Mycorrhizal colonization frequency presented contrary changed trend with elevations of quadrat translocation. Colonization frequency reduced or increased in majority quadrats translocated from low to high or from high to low elevation. Responses of colonization intensity to translocation of quadrats were more sensitive than colonization frequency. Arbuscular colonization showed inconsistent trend in increased or decreased quadrat. Vesicle colonization decreased with changed of quadrat from low to high elevations. However, no significant trend was observed. Although spore density was dynamic with signs of decreasing or increasing in translocated quadrats, the majority enhanced and declined respectively in descent and ascent quadrat treatments. It is crucial to understand the interactions between AM fungi and prairie grasses to accurately predict effects of climate change on these diverse and sensitive ecosystems. This study provided an opportunity for understanding the effect of climate changes on AM fungi.


2021 ◽  
Vol 35 (2) ◽  
pp. 269-275
Author(s):  
Camila Abarca ◽  
Marcelo Daniel Barrera ◽  
Marta Cabello ◽  
Fabricio Valdés ◽  
María Silvana Velázquez

2004 ◽  
Vol 4 (2) ◽  
pp. 1-15 ◽  
Author(s):  
Marcos P.M. Aidar ◽  
Rosilaine Carrenho ◽  
Carlos A. Joly

Mycorrhizal colonization was assessed in roots of trees within an Atlantic Forest chronosequence, located in the southeastern of São Paulo State, Brazil, inside Tourist State Park of the High Ribeira Valley (PETAR). The phytosociological survey was carried out in three adjacent areas, all on calcareous soil, which correspond to different time intervals during which they have been left abandoned following a slash-and-burn agricultural perturbation. Early Phase (EP) with 15 years; Mid Phase (MP) with 25 years; and Late Phase (LP) with more than 36 years without clear-cut. The inventory indicated a continuum of tree species substitution, which is dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. (Mimosoideae) in the earlier successional phases. Mycorrhizal colonization, estimated by the occurrence of the mycorrhizal structures in the tree species roots, diminished during the season with less rain (winter), and showed no significant differences between successional phases in the wet season (summer). Rather, the mycorrhizal colonization was correlated with occurrence of the tree’s successional status: being positively correlated with occurrence of pioneer species, and negatively correlated with late secondary species. Mycorrhizal colonization was also correlated negatively with soil organic matter and base saturation. Twenty five species of arbuscular mycorrhizal fungi belonging to four genera were identified. Six species were only identified to generic level. The species Glomus etunicatum Becker & Gerd. represented 10% of the total number of spores and occurred in all phases and seasons, while the genus Glomus represented 57% of the total of spores found in the rhizosphere. The diversity indices evaluated for the mycohrriza community were: H’ = 2.3, J’ = 0.97 and R = 4.12. These results are a contribution to the knowledge of The Atlantic Forest biodiversity and may have implications to support programs regarding rehabilitation of degraded vegetation in one of the World’s most threatened Biomes.


2007 ◽  
Vol 64 (4) ◽  
pp. 393-399 ◽  
Author(s):  
Milene Moreira ◽  
Dilmar Baretta ◽  
Siu Mui Tsai ◽  
Sandra Maria Gomes-da-Costa ◽  
Elke Jurandy Bran Nogueira Cardoso

Araucaria angustifolia (Bert.) O. Ktze. is an endangered Brazilian coniferous tree that has been almost exterminated in the native areas because of uncontrolled wood exploitation. This tree has been shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) and, therefore, AMF may be essential for forest sustainability and biological diversity. Root colonization, density and diversity of AMF spores were assessed in two Araucaria forest stands at the State Park of Alto Ribeira (PETAR), at two sampling dates: May and October. A comparison was made between a mature native stand composed of Araucaria trees mixed into a variety of tropical trees and shrubs, without any sign of anthropogenic interference (FN) and an Araucaria stand planted in 1987 (R), which has been used as a pasture. Assessments included percent root colonization, AMF spore numbers and species richness, Simpson's dominance index (Is), and Shannon's diversity index (H). Mycorrhizal root colonization did not differ between ecosystems in May. In October, however, the native stand (FN) presented a higher colonization than the planted forest (R), and the root colonization was more intense than in May. When considering both sampling periods and forests, 27 species of AM fungi, with higher numbers of spores in FN than in R were found. Canonical discriminant analysis (CDA) indicated Shannon's diversity index as the ecological attribute that contributed the most to distinguish between forest ecosystems, with higher value of H in FN in relation to R. CDA showed to be a useful tool for the study of ecological attributes.


2012 ◽  
Vol 77 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Anna Lisek ◽  
Lidia Sas Paszt ◽  
Beata Sumorok

Summary In organic farming, mineral fertilizers are replaced by various preparations to stimulate plant growth and development. Introduction of new biopreparations into horticultural production requires an assessment of their effects on the growth and yielding of plants. Among the important indicators of the impact on plants of beneficial microorganisms contained in bioproducts is determination of their effectiveness in stimulating the growth and yielding of plants. Moreover, confirmation of the presence of arbuscular mycorrhizal (AM) fungi in the roots and plant growth promoting rhizobacteria (PGPR) in the rhizosphere is also necessary. In addition to conventional methods, molecular biology techniques are increasingly used to allow detection and identification of AM fungi in plant roots. The aim of this study was identification and initial taxonomic classification of AM fungi in the roots of ‘Elkat’ strawberry plants fertilized with various biopreparations using the technique of nested PCR. Tests were performed on DNA obtained from the roots of ‘Elkat’ strawberry plants: not fertilized, treated with 10 different biopreparations, or fertilized with NPK. Amplification of the large subunit of ribosomal gene (LSU rDNA) was carried out using universal primers, and then, in the nested PCR reaction, primers specific for the fungi of the genera Glomus, Acaulospora, and Scutellospora were used. Colonization of strawberry roots by arbuscular mycorrhizal fungi was determined on the basis of the presence of DNA fragments of a size corresponding to the types of the fungi tested for. As a result of the analyses, the most reaction products characterizing AM fungi were found in the roots of plants treated with the preparation Florovit Eko. The least fragments characteristic of AM fungi were detected in the roots of plants fertilized with NPK, which confirms the negative impact of mineral fertilizers on the occurrence of mycorrhizal fungi in the roots of strawberry plants. The roots of plants fertilized with Tytanit differed from the control plants by the presence of one of the clusters of fungi of the genus Glomus and by the absence of a cluster of fungi of the genus Scutellospora. In the roots of plants treated with other biopreparations there were reaction products indicating the presence of fungi of the genera Glomus, Scutellospora and Acaulospora, like in the roots of the control plants. The results will be used to assess the suitability of microbiologically enriched biopreparations in horticultural production.


ZOOTEC ◽  
2017 ◽  
Vol 37 (1) ◽  
pp. 167
Author(s):  
Rifa E. Ansiga ◽  
A. Rumambi ◽  
D. A. Kaligis ◽  
I. Mansur ◽  
W. Kaunang

EXPLORATION OF ARBUSCULAR MYCORRHIZAL (AM) FUNGI IN FORAGE RHIZOSPHERES. This study aimed to determine the diversity of Arbuscular Mycorrhizal Fungi (AMF) in several kinds of hybrid forages Rhizospheres, either in grasses or legumes. Soil samples were taken from three different locations, consisted of: Mapanget (forages type: Leucaena leucocepala, Sorghum varieties numbu, Penicettum purpureum cv. Mott), Tateli (forages type: calothyrsus Calliandra, Gliricidia sepium) and Campus of UNSRAT, Manado (forage type: King grass). The soil samples which taken from forages rhizospheres were sieved using Brundrett method and then centrifuged.  Thereafter, isolation and identification of spore were carried out based on spore morphology character, involves: shape, size, color, hyphae attachment, and ornament. Extraction and identification of spores on six types of rhizosphere were found 34 different types of AMF spores in shape and color. In grass, it was found three types of spores, i.e.: Glomus, Acaulospora, and Sclerocystis, meanwhile in leguminous just one type of spore was found, i.e.: Glomus. The difference of rhizosphere in grass and leguminosae resulted in different types of spores, where Sclerocystis and Acaulospora are found in grasses, on the contrary Sclerocystis and Acaulospora are not found in leguminosae. Based on the number of spores of AMF, it seemed that Glomus types found to have the most number, while Sclerocystis and Acaulospora had the lowest number of spores found. Key words: Exploration, Arbuscular Mycorrhizal Fungi (AMF), Grass, Legume, Spores


2021 ◽  
Author(s):  
Soibam Helena Devi ◽  
Ingudam Bhupenchandra ◽  
Soibam Sinyorita ◽  
S.K. Chongtham ◽  
E. Lamalakshmi Devi

The 20thcentury witnessed an augmentation in agricultural production, mainly through the progress and use of pesticides, fertilizers containing nitrogen and phosphorus, and developments in plant breeding and genetic skills. In the naturally existing ecology, rhizospheric soils have innumerable biological living beings to favor the plant development, nutrient assimilation, stress tolerance, disease deterrence, carbon seizing and others. These organisms include mycorrhizal fungi, bacteria, actinomycetes, etc. which solubilize nutrients and assist the plants in up taking by roots. Amongst them, arbuscular mycorrhizal (AM) fungi have key importance in natural ecosystem, but high rate of chemical fertilizer in agricultural fields is diminishing its importance. The majority of the terrestrial plants form association with Vesicular Arbuscular Mycorrhiza (VAM) or Arbuscular Mycorrhizal fungi (AMF). This symbiosis confers benefits directly to the host plant’s growth and development through the acquisition of Phosphorus (P) and other mineral nutrients from the soil by the AMF. They may also enhance the protection of plants against pathogens and increases the plant diversity. This is achieved by the growth of AMF mycelium within the host root (intra radical) and out into the soil (extra radical) beyond. Proper management of Arbuscular Mycorrhizal fungi has the potential to improve the profitability and sustainability of agricultural systems. AM fungi are especially important for sustainable farming systems because AM fungi are efficient when nutrient availability is low and when nutrients are bound to organic matter and soil particles.


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