Mycorrhizal Research

The vesicular-arbuscular mycorrhizas (AM) are very significant in the life of most plants including olive tree (Olea europaea L.), which is of great economic importance. However, due to its wide distribution, especially, in the Mediterranean, it is subject to various environmental stresses, particularly drought and aridity. This study aims to evaluate the percentage of root colonization of olive by arbuscular fungi along a climatic gradient (sub-humid, semi-arid and arid), and to estimate how this varies depending years (2010-2012) and seasons (fall, winter, spring and summer). Results showed that the roots of the olive tree are colonized by arbuscular endomycorrhizal fungi under the three types of climate, whatever the season or the study years. Mycorrhization parameters revealed a frequency of colonization (F%) of up to 83%, mycorrhizal intensity (M%) reaching 42% and a rate of arbusculars in the mycorrhizal parts of root fragments (a%) of 4%. Mycorrhizal colonization varies between bioclimatic zones. It is more frequent and intense in the sub-humid climate. Mycorrhiza also varies according to the season; it is more important in spring and slight in winter. This study allowed the characterization, for the first time, of the mycorrhizal status of olive in the northeastern Algeria, and estimate variations of that colonization depending on seasons and climate types.

This study reports on the bio-ecology of desert truffles collected from the Northern Algerian Sahara. It aims (i) the identification of desert truffle species with a morphometric characterization, (ii) the determination of their geographical distribution, and (iii) the description of the edaphic, climatic and geomorphological characteristics of their natural habitat. The harvest of 78 truffle fruiting bodies from seven different locations resulted in the identification of three species of the family Terfeziaceae: Terfezia arenaria (Moris) Trappe, Terfezia claveryi Chatin and Tirmania nivea (Desf) Trappe. These hypogeous ascomycetes live in mycorrhizal association with Helianthemum lippii (Cistaceae). Desert truffles grow in heterogeneous soils of sandy texture, moderately calcareous (10.19 ± 1.37%), slightly alkaline (7.87 ± 0.22), with low organic matter (0.86 ± 0.1%) and slight phosphorus contents. The development of desert truffles is closely linked with high rainfall amount occuring during the fall season and/or winter. The truffles colonize desert depressions "Dayas" and beds of Wadis, since these geomorphological zones accumulate rainwater, which promotes the development of both truffles and its host–plant.

In order to improve the production of olive (Olea europaea L.), plantlets of Variety Ferkani were inoculated with three arbuscular mycorrhizal fungal (AMF) spores (Glomus sp.1, Glomus sp.2, Septoglomus constrictum) isolated from a hot-arid zone in Algeria and three commercial AMF (Rhizophagus intraradices, Funneliformis mosseae, Gigaspora margarita). Mycorrhization parameters and nine growth traits were estimated in two-year-old plantlets, then the variation of growth traits following mycorrhizae parameters of various AMF inoculums was tested. The tested AMF species were all infective and effective for the mycorrhization of Ferkani variety. Glomus sp.1 gave the best results for mycorrhizal colonization and growth parameters. Indeed, the highest colonization frequency (F%) was recorded in plantlets inoculated with Glomus sp.1 (58±6.5%), whereas the highest values of colonization intensity of in the root system (M%) were obtained with Rhizophagus intraradices (2.45±1.46%) and Glomus sp.1 (2.26±0.76%). Abundances of arbuscules were low for all AMF inoculums. The controlled inoculation improved the growth of all plantlets compared to the AMF-free plantlets. AMF-inoculated plantlets showed significantly higher growth in terms shoot height, fresh and dry weights of shoot and root, and number of leaves and nodes. Statistical models revealed that all the latter growth parameters including mycorrhizal responsiveness increased significantly when mycorrhizal parameters increased, and that F% most strongly correlated with plant growth compared to other mycorrhizal parameters. Findings of this controlled inoculation research underline the importance of local AMF isolated from the rhizosphere of Ferkani variety in rapidly and extensively infecting the root system and then increasing growth of the host.

Endemic populations of Abies religiosa (fir, oyamel) have great economic, ecological and social importance; in addition, they form different interactions with edaphic microorganisms, mainly with ectomycorrhizal fungi. Currently, isolated populations (i. e. fir) are threatened by deforestation, agricultural expansion and global warming; therefore, it is urgent to understand the ecological and evolutionary interactions with ectomycorrhizal fungi. The objective of the present research was to analyze the use of molecular ecology, taxonomy and biology of ectomycorrhizal
fungi to understand the role that these fungi play in A. religiosa trees in Mexico. Areas of research are presented as well as the main information gaps in the morphological/molecular characterization, taxonomy and evolution of the ectomycorrhizal symbiosis in A. religiosa. For the above, we collected information of 108 taxa of potentially ectomycorrhizal fungi obtained from different fir populations. The taxa with high potential to inoculate A. religiosa are Sebacina dimitica, Clavulina cf. cinerea, Membranomyces sp., Thelephoraceae, Russula spp., Ramaria spp., Lactarius spp. e Inocybe spp. Finally, we discuss issues that remain unresolved to determine their potential for use, management and conservation of A. religiosa in temperate areas of Mexico. This problem can be solved by combining molecular tools with the morphological and histological description of ectomycorrhizal morphotypes. In addition, methodologies are required to standardize results to come to more robust conclusions about mycorrhizal interactions.
Las poblaciones endémicas de Abies religiosa (abeto, oyamel) poseen gran importancia económica, ecológica y social; además, forman distintas interacciones con microorganismos edáficos, principalmente con hongos ectomicorrizógenos. Actualmente, las poblaciones aisladas (i. e. oyamel) están amenazadas por la deforestación, la expansión agrícola y el calentamiento global; por lo cual, es urgente entender las interacciones ecológicas y evolutivas con hongos ectomicorrizógenos. El objetivo de la presente investigación fue analizar el uso de la ecología, taxonomía y biología molecular de ectomicorrizas para comprender el papel que juegan estos hongos en árboles de A. religiosa en México. Se presentan áreas de oportunidad de investigación, así como los principales vacíos de información de la caracterización morfoanatómica/molecular, taxonomía y evolución de la simbiosis ectomicorrízica en bosques de A. religiosa. Para lo anterior, se reunió información de 108 taxones de hongos potencialmente ectomicorrizógenos, colectados en diferentes poblaciones de abetos. Los taxones con potencial alto para inocular A. religiosa son Sebacina dimitica, Clavulina cf. cinerea, Membranomyces sp., Thelephoraceae, Russula spp., Ramaria spp., Lactarius spp. e Inocybe spp. Finalmente, se discuten aspectos que faltan por resolver para determinar el potencial de uso, manejo, conservación y aprovechamiento de A. religiosa
en zonas templadas de México. Este problema puede resolverse combinando herramientas moleculares con la descripción morfológica e histológica de morfotipos ectomicorrizógenos. Adicionalmente, se requieren metodologías que permitan estandarizar resultados para llegar a conclusiones más sólidas sobre las interacciones micorrízicas.

Arbuscular mycorrhizal fungi (AMF) regarded as ubiquitous soil fungi which help in improving plant growth under
harsh conditions. Petunia hybrida is one of the most favorite ornamental plants growing all over the Riyadh city of Saudi
Arabia. In the present study, we would like to highlight the Petunia as a mycotrophic plant for the management of
mycorrhizal fungi under field conditions. Roots along with rhizosphere soils of P. hybrida were collected from various
sites in Riyadh, Saudi Arabia to study AM colonization and biodiversity of AMF. The data obtained in this study indicated
that P. hybrida is a very highly mycotrophic plants, and all the samples produced very high colonization with mycelium,
vesicles, coiled hyphae and arbuscules. The significant variation was found with the occurrence of mycelium and vesicles
among the locations but in case of arbuscules more or less same range of occurrence was found. Only different species of
Glomus were observed in all the locations. Glomus showed diversity in all the locations as indicated by the Shanon Diversity
Index. As the P. hybrida is a highly mycotrophic plant, so this plant may be grown under harsh condition of Saudi Arabia to
manage the plant growth under different stresses viz., water stress, saline soils and heavy metal toxicity conditions.

Questions: How are ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) traits related to other plant traits at the community level? Which abiotic factors drive the variability of these ECM and AM traits? What is the relative importance of plant species turnover and plant intraspecific differences on mycorrhizal trait variability among communities? Location: Nine Mediterranean woody communities, Sierra Morena Mountains, C ordoba, south Spain.
Methods: Mycorrhizal and plant traits were weighted by the abundance of con-stitutive plant species to calculate community-weighted means (CWM). Maximum likelihood techniques were used to analyse how variation in these functional community traits was driven by soil abiotic factors.
Results: The degree of ECM colonization was positively related to the abundance of evergreen species and to tissue dry matter content (in leaves and roots), but negatively to specific root length and specific leaf area. The best abiotic pre-dictor of ECM colonization was soil moisture, with higher ECM colonization in drier sites. However, AM colonization was not related to any of the plant traits studied, and was positively related to soil Cu and other physico-chemical soil properties. Changes in community mycorrhization of both types were primarily due to plant species turnover (mainly species occurrence), with a remarkable importance of plant intraspecific variability in the case of AM colonization (especially in the percentage of vesicles).
Conclusions: The degrees of colonization by ECM and AM at the community level exhibited different patterns, influenced by both biotic factors (plant functional structure) and abiotic conditions (soil moisture and chemical composition). The proposed mycorrhizal trait-based approach can help to better understand the role of these symbioses on plant community functioning.

The Olive (Olea europaea L) was introduced in Kingdom of Saudi Arabia
(KSA) in 1980. The cultivation of olive in KSA increased rapidly because of suitable
climatic conditions, increasing demand for olive oil, domestic use in different diets and
its importance in the social life and economy of the country. The present status of available
literatures on the role of Arbuscular Mycorrhizal Fungi (AMF) and Plant Growth Promoting
Rhizobacteria (PGPR) as Microbial Inoculants (MI), on growth improvement of olive
plants were surveyed and presented here. It was found from the literatures that MI was
used in many different olive growing countries of the World and it improved plant
growth both in green house and field conditions. We also highlighted the need of research
for olive plantations in KSA in relation to their availability in the soils, inoculum
production, growth under green house and field conditions, role on improved water
relation, tolerance to salinity and heavy metals, use of green manure and natural fertilizers
under organic cultivation etc. Although AMF and PGPR are regarded as important MI,
and are commonly associated with many terrestrial plants, but they have been utilized
recently for the growth improvement of olive plants throughout the olive growing areas
of the world and no research activities was found in KSA until now.

Abies religiosa (abeto, oyamel) tiene importancia económica por su madera y porque es usada como árbol de navidad. En los inventarios micológicos de bosque de Abies se han encontrado unas 50 especies que pueden formar ectomicorriza con A. religiosa, sin embargo, no se había estudiado específicamente este aspecto. En este trabajo se estudiaron los hongos ectomicorrízicos asociados con individuos adultos de A. religiosa en el bosque y se realizó un seguimiento de la presencia de micorriza en raíces de plántulas en el campo a través de un año. También se evaluó el efecto de cuatro tratamientos de inducción de micorriza con suelo rizosférico como inóculo sobre las variables: presencia y tipo de micorriza, altura total, diámetro a la altura de la base (Db), biomasa (B) y área foliar (Af). Se registraron 25 taxa de hongos ectomicorrízicos (24 Basidiomycota y 1 Ascomycota). Ocho fueron registrados exclusivamente en sitios con dosel y 15 en área abierta. Amanita muscaria y Russula olivacea se recolectaron en ambas condiciones. Los géneros con mayor número de taxa fueron Cortinarius (5) y Russula (4). Las especies más abundantes fueron Lycoperdon perlatum y A. muscaria. La diversidad fue significativamente mayor (p<0.001) en área abierta (H´= 3. 97) que bajo el dosel (H´= 2.8). Se encontraron estructuras micorrízicas en plántulas de A. religiosa aún cuando no se encontraron esporomas. En cuanto al experimento, la mayor tasa de crecimiento en altura (2.215 ± 0.092 cm), Db (0.825 ± 0.042 mm), B (0.446 ± 0.397 g), y Af (29.027 cm2 ± 8.947)(p < 0.01), se obtuvo en el tratamiento de suelo de A. religiosa (SA). No obstante, después de siete meses el suelo rizosférico mostró ser poco eficaz para inducir la formación de micorriza en plántulas de A. religiosa. Las diferencias en las tasas de crecimiento son atribuibles al mayor contenido de materia orgánica en el tratamiento SA. Se requiere hacer estudios en campo sobre plántulas inoculadas en invernadero para evaluar el efecto de la inoculación en la supervivencia y el desempeño de dichas plántulas.

Mycorrhizal fungi are an essential component to consider for better management of soil fertility, particularly in degraded rangelands of drylands. The present article presents a field survey of colonization and intensity of arbuscular mycorrhizal fungi (AMF) on prickly pear (Opuntia ficus-indica) roots from young (5 years old) and old (more than 20 years) plantations. The results observed were explained by seasonality and edaphic factors. Prickly pear roots showed a mycorrhizal frequency (F%) up to 100% of colonization and a mycorrhizal intensity (M%) that may exceed 70%. According to ANOVAs, both F% and M% varied significantly between Prickly pear plantation ages, but only M% between seasons. The Generalized linear model showed that edaphic factors have no effect on the variation of F%. However the statistical model revealed that M% were significantly influenced by active CaCO3, organic matter, carbon, nitrogen, phosphorus contents, and C/N. Our findings highlight the importance of mycorrhization in rehabilitation programs of degraded rangelands by prickly pear plantations in semiarid and arid lands, particularly during early plant ages and under environmental abiotic stresses such as climate and soil type.

Micorriza arbuscular, Mucoromycotina y hongos septados oscuros en helechos y licófitas con distribución en México: una revisión global Abstract: Arbuscular mycorrhizal, Mucoromycotina and dark septate fungi in ferns and lycophytes with distribution in Mexico: a global review. Ferns and lycophytes are a group of vascular plants of interest to understand the evolution of mycorrhizal interactions; their preservation is of relevance for their multiple ecological relations. The record of different taxonomic groups of fungi associated with ferns and lycophytes is fragmentary , and the criteria for it identification is inconsistent, which hinders the understanding and determination of mycorrhizal status. The aim of this study was to determine the percentage of the species of ferns and lycophytes with distribution in Mexico, and with information of fungal interactions. A checklist of the presence of arbuscular mycorrhizal fungi (AMF), Mucoromycotina and dark septate fungi (DSF) associated with ferns and lycophytes was integrated through an exhaustive global literature search. In this study, mycorrhizal species was considered by the presence of arbuscules to differentiate with hyphal, vesicular and coils colonization. The study gathered a checklist of mycorrhizal occurrences of 27 families, 61 genus and 137 species of ferns and lycophytes, which covers 13.4 % of the species, 91 % of the genus and 77 % of the families distributed in Mexico. The 78.1 % of the species showed colonization, 56.2 % by AMF, 29.9 % by DSF and 0.72 % by Mucoromycotina fungi. From the total of the species, the higher presences of colonization were in terrestrial, epiphytic, saxicolous, and aquatic plants with 76.6 %, 33.3 %, 20 %, and 6.3 %, respectively. The families of ferns and lycophytes with the higher number of species colonized were Pteridaceae, Polypodiaceae, Aspleniaceae and Dryopteridaceae. The present study showed the widespread associations of AMF and DSF in ferns and lycophytes of Mexico. It is urgently needed to include ferns and lycophytes in studies focused on endomycorhizal interactions, since only 28 species (28 %) were studied in Mexican ecosystems. The majority of studies were focused on sporophytic face (80 %). Nonetheless, to understand the role that plays the mycorrhiza in the establishment of ferns and lycophytes, it is necessary to include the gametophytic face in ecological, molecular and physiological experimental studies. This information is important to implement conservation strategies, because a considerable number of ferns and lycophytes species, depend on these mycorrhizal associations for their growth and survival. Rev. Biol. Trop. 65 (3): 1062-1081. Epub 2017 September 01.

We describe the morpho-anatomical features of the ectomycorrhizas (ECMs) formed by Lactifluus rugatus on Cistus, a genus of about 20 species of woody shrubs typical of the Mediterranean maquis. The description of L. rugatus mycorrhizas on Cistus is the first ECM
description of a species belonging to Lactifluus subgen.  Pseudogymnocarpi. The ECM identity was verified through molecular tools. Anatomically, the characteristic of L. rugatus mycorrhiza is the
presence of abundant, long “bottle-shaped” cystidia on mantle surface. Indeed, the overwhelming majority of milkcap mycorrhizas are acystidiate. This is the third Lactarius/Lactifluus mycorrhiza
to have been described associated with Cistus, the others being Lactarius cistophilus and L. tesquorum. The phylogenetic distance between all these taxa is reflected by the diversity of the
principal features of their ECMs, which share host-depending ECM features known for Cistus, but are otherwise distinguishable on the host roots. Comparison of Lactifluus rugatus ECM with those formed by L. vellereus and L. piperatus on Fagus reveals elevated intrageneric diversity of mycorrhizal structures. Such a diversity is supported by analysis of ITS sequences of relevant species within European Lactifluus species. Our study extends knowledge of Cistus mycorrhizal
biology and confirms the informative value of mycorrhizal structures in understanding phylogenetic relationships in ECM fungi.

Regarding effects of water stress on plant, many research reports have been release during recent years, but, studies on effects of this stress on biochemical parameters and mineral content at an early stage are scarce. This study investigated drought stress effects on some biochemical parameters and mineral content of mycorrhizal Vigna subterranea plant, in a randomized block design. The microbial material comprised of a mixture of locally selected arbuscular fungi. The four levels of watering expressed in % of field capacity were: 90, 60, 30 and 15; with or without mycorrhizal inoculation. Experiment was carried out on a sterilize substrate during 31days of water stress. Results showed that with increasing level of water stress, mycorhization increased: mineral content, both soluble sugars and acid phosphatase, but lessened proline content. Arbuscular mycorrhizal fungi (AMF) could thus be an effective tool in the alleviation of harmful effects of drought stress on plants, by improving their tolerance to this abiotic stress and consequently contributing to a better growth of V.subterranea. Get more articles at: http://www.innspub.net/volume-7-number-2-august-2015-ijaar/

Alsophila firma is a deciduous tree fern considered as an emblematic species of Mexican tropical montane cloud forest (TMCF). We studied spores diversity, structure and colonization by arbuscular mycorrhizal fungi (AMF) within the roots of the Alsophila firma in rainy and dry season. Eighteen species of the genera Acaulospora (5), Gigaspora (4), Glomus (4), Funneliformis (2), Sclerocystis (2) and Scutellospora (1) were identified. The species F. constrictum, F. geosporum, Gigaspora albida, G. decipiens, Glomus microaggregatum and Sclerocystis coremioides are reported for the first time in TMCF. The dominant genera were Funneliformis and Acaulospora. In rainy season, a higher richness (H′ t0.005(2)9 = 4.78) and evenness (E) of AMF spores was recorded, compared to the dry season. However, the degree of colonization was statistically significant higher in the dry season. This study is the first to estimate the species richness of AMF associated with the rhizosphere of a fern in Mexico as well as for A. firma.

Present experiments were conducted to assess the response of Panicum turgidum to salinity and possible role of arbuscular mycorrhizal fungi (AMF) in enhancing the salt tolerance. The activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione reductase (GR) and compatible solutes were increased by salt stress and were further enhanced by AMF inoculation. Hydrogen peroxide and malonaldehyde content increased in salt-stressed plants while a reduction was observed due to AMF inoculation. Salt-stressed plants showed higher activities of pyruvate orthophosphate dikinase (PPDK), phosphoenolpyruvate carboxylase (PEPC) and malate dehydrogenase as compared to control and AMF-inoculated plants. Salt stress caused significant decrease in phosphorous, potassium and calcium uptake but an increase in sodium uptake was observed. AMF alleviate salinityinduced negative impact on the plant growth and nutrient uptake by reducing the oxidative damage through strengthening of the antioxidant system. Abdel Latef AAH, Chaoxing H. 2011. Effect of arbuscular mycorrhizal fungi on growth, mineral nutrition, antioxidant enzymes activity and fruit yield of tomato grown under salinity stress. Sci. Hort. 127:228-233. Ahanger MA, Hashem A, Abd Allah EF, Ahmad P. 2014a. Arbuscular mycorrhiza in crop improvement under environmental stress. In: Ahmad P, Rasool S, editors. Emerging technologies and management of crop stress tolerance; Vol. 2. Waltham, MA: Elsevier; p. 69-95. Available from: http://dx.