Arbuscular Mycorhizal Fungi Research Articles

Glomalin related soil protein, carbon, nitrogen and soil aggregate stability as affected by land use variation in the humid forest zone of south Cameroon

Arbuscular mycorhizal fungi (AMF) produce a glycoprotein (glomalin) which play an important role in the maintenance of soil structure and fertility. On the other hand, it can be used to evaluate the impact of agricultural practices on soil quality across many land use systems. We assessed land use impact on glomalin related soil proteins (GRSPs), soil quality and aggregation in the humid forest zone in southern Cameroon. Forest, short fallow and field crop production soil samples were used to determine GRSPs, carbon (C), nitrogen (N) and water stable aggregate (WSA1–2mm). Results showed that GRSPs significantly decreased from the forest to fallow and the field crop production systems. The easily extractable GRSP (EEGRSP) was 30% and 39% less under fallow and field crop production respectively, relative to the forest soils. Similarly, total GRSP (TGRSP) was 17% and 46% less under fallow and field crop production respectively, relative to the forest soils. C, N, and organic matter (OM) did not change significantly within the land use systems. The WSA1–2mm was 20% less under fallow, and 33% less under field crop production relative to the forest system. However, AMF spores augmented from forest to fallow and field crop production system. There was a positive correlation between GRSPs (EEGRSP, TGRSP) and AM fungal spore density suggesting the possible implication of these fungi to the production of the GRSP in this zone. There was also a positive correlation between C, N and EEGRSP, suggesting the implication of GRSP in stocking soil C and N in this zone. Likewise, a positive correlation between OM and TGRSP was found meaning the implication of GRSPs to OM pools in the soil of this zone. WSA1–2mm was also correlated with TGRSP, C and OM, suggesting the possible coactions of GRSP, OM to the formation of WSA1–2mm, and thereby promoting the build up of soil structure. These results highlight the view that GRSP can be used as an indicator of soil quality in this region and should be considered as a criteria when define agricultural management strategies. AM fungal and GRSP might be useful to monitor soil degradation in this zone.

Detection of species diversity of arbuscular mycorrhizal fungi (AMF) classic and molecular methods from the melon (Cucumis melo L.) plants in Van and its districts

Arbuscular-mycorhizal fungi (AMF) from melon plants grown in Van province, were studied by nestedPCR method to establish colonization ratio of related fungi in plants and to detect the fungi at species level. From 10 different locations, a total of 100 soil samples were taken from rhizosphere area of melon plants. It was also determined that 52% of these plants were colonized by arbuscular-mycorhizal fungi and were able to establish symbiotic relationship in variable ranges (4.5 to 37.8%) Glomus intraradices and Glomus mosseae were two identified AMF.

Aboveground environment type, soil nutrient content and arbuscular mycorrhizal fungi explain establishment success of Centaurea jacea on ex-arable land and in late-successional grasslands

We studied the relative importance of the aboveground and belowground environment for survival and growth of emerged seedlings of Centaurea jacea to better understand the general difficulty of establishing late-successional species at restoration sites on ex-arable land. Potted seedlings growing on soil from six late-successional grasslands and from six ex-arable (restoration) sites were reciprocally exchanged, and survival and relative growth rate of the seedlings monitored. In addition, we assessed aboveground herbivory and colonization of roots by arbuscular myccorhizal fungi of all plants, as well as nutrient availability, and microbial biomass and community composition using PLFA techniques in all twelve soils. Seedling survival was higher in restoration habitat and soil than in grassland habitat and soil, but growth did not differ between the aboveground and belowground environment types. Shoot growth rate was initially correlated with soil nutrient content, and later in the experiment with mycorrhizal colonization levels. Our results indicate that arbuscular mycorhizal fungi may be important for the successful establishment of C. jacea and that abiotic soil factors, like K availability and N:P ratio, can promote mycorrhizal colonization. Hence, the belowground environment should be considered when selecting sites for restoring species-rich grasslands.

Analysis Of Pea (Pisum Sativum L.) Source Material For Breeding Of Cultivars With High Symbiotic Potential And Choice Of Criteria For Its Evaluation

Double inoculation with arbuscular mycorhizal fungi and nodule bacteria was shown to increase seed productivity and plant dry weight in most of pea genotypes studied. Sometimes it can exceed the effect of mineral fertilizers.Seed productivity and plant dry weight were chosen as main criteria for evaluation of symbiosis effectiveness of legume crops. Expediency of legume breeding to improve symbiotic potential of legume varieties was proven and the genotypes to be used in such breeding programs were identified.

Glomus intraradices Enhances Growth and Gas Exchange of Lolium perenne Seedlings in Petroleum-contaminated Soil

Arbuscular mycorhizal fungi (AMF) have been used in phytoremediation and can increase tolerance and growth of plants in contaminated environments. However, little is known about the influence AMF on plant growth to organic contaminants in soils. A greenhouse experiment was conducted to study the response of seedlings of annual ryegrass (Lolium perenne L.) var. Passerel Plus inoculated with Glomus intraradices Schenck & Smith in soil contaminated with sweet Arabian median crude oil. Inoculated (AMF) and non-inoculated (Non-AMF) plants were established in an pasteurized and artificially contaminated sandy loam soil with 0; 3000; 15,000; or 45,000 mg of petroleum kg-1 soil (n = 20). Plants were inoculated with 500 spores of G. intraradices (Mycorise® ASP, PremierTech Biotechnologies, Canada). After 90 days, plant growth of AMF or Non-AMF plants, was drastically affected at all petroleum concentrations. However, G. intraradices enhanced plant growth, chlorophyll content, and gas exchange of plants grown at 3,000 mg kg-1 compared to Non-AMF plants. Total leaf area, chlorophyll, and net photosynthesis were also higher (+380%, +63%, and +81%, respectively) at this concentration. Water use efficiency (net photosynthesis/stomatal conductance) of AMF-plants was three times greater than Non-AMF at 3,000 mg·kg-1. At concentrations of 15,000 and 45,000 mg kg-1 AMF did not have effect, but colonization was observed (11.8% and 18.6%, respectively). These values of colonization were significantly lower than those observed in AMF-plants at 0 (42.5%) and 3,000 mg·kg-1 (55.6%). Studies are currently being conducted to understand the physiological role of AMF on plants exposed to organic contaminants.