Mycelium

About: Mycelium is a research topic. Over the lifetime, 8923 publications have been published within this topic receiving 170993 citations.

Seasonal dynamics of Boletus edulis and Lactarius deliciosus extraradical mycelium in pine forests of central Spain

Abstract: The annual belowground dynamics of extraradical soil mycelium and sporocarp production of two ectomycorrhizal fungi, Boletus edulis and Lactarius deliciosus, have been studied in two different pine forests (Pinar Grande and Pinares Llanos, respectively) in Soria (central Spain). Soil samples (five per plot) were taken monthly (from September 2009 to August 2010 in Pinar Grande and from September 2010 to September 2011 in Pinares Llanos) in eight permanent plots (four for each site). B. edulis and L. deliciosus extraradical soil mycelium was quantified by real-time polymerase chain reaction, with DNA extracted from soil samples, using specific primers and TaqMan® probes. The quantities of B. edulis soil mycelium did not differ significantly between plots, but there was a significant difference over time with a maximum in February (0.1576 mg mycelium/g soil) and a minimum in October (0.0170 mg mycelium/g soil). For L. deliciosus, significant differences were detected between plots and over time. The highest amount of mycelium was found in December (1.84 mg mycelium/g soil) and the minimum in February (0.0332 mg mycelium/g soil). B. edulis mycelium quantities were positively correlated with precipitation of the current month and negatively correlated with the mean temperature of the previous month. Mycelium biomass of L. deliciosus was positively correlated with relative humidity and negatively correlated with mean temperature and radiation. No significant correlation between productivity of the plots with the soil mycelium biomass was observed for any of the two species. No correlations were found between B. edulis sporocarp production and weather parameters. Sporocarp production of L. deliciosus was positively correlated with precipitation and relative humidity and negatively correlated with maximum and minimum temperatures. Both species have similar distribution over time, presenting an annual dynamics characterized by a seasonal variability, with a clear increase on the amounts of biomass during the coldest months of the year. Soil mycelial dynamics of both species are strongly dependent on the weather.

Pathogenicity of Alternaria and Cladosporium isolates on Phaseolus

Abstract: Phaseolus leaves were inoculated with conidia of Alternaria alternata, Cladosporium cladosporioides and C. herbarum. Plants were incubated in growth rooms at high humidity. Using light microscopy and cultural techniques it was shown that several of the isolates of all three species were able to penetrate into leaves via stomata. With many isolates most infections remained localized in the substomatal cavity. In other isolates, especially of Alternaria, a more extensive, intercellular mycelium developed. A few isolates also caused host mesophyll cells to become necrotic. These parasitic activities were correlated with an accelerated loss of chlorophyll from infected leaves and an increase in their levels of ribonuclease. These data suggest that some strains of these common filamentous phylloplane fungi are able to behave as weak parasites on herbaceous tissues. The use of fungicides which restrict their activity may result in yield increases over and above those attributed to the control of other, established pathogens.

Determination and analysis of cordycepin and adenosine in the products of Cordyceps spp.

Abstract: Cordyceps sinensisis, a kind of precious natural crude drugs and edible mushrooms, were used as tonic food in East Asia area and enjoyed an extensive praise for its medicinal functions. Cordyceps militaris, as a substitute for C. sinensis, is a widely distributed species, which can be cultivated in various medium. In this study, the contents of major bioactive components, cordycepin and adenosine in fruiting bodies and mycelia from the nature C. sinensis and artificial cultural C. militaris were investigated using improved HPLC method. The results showed the mean contents of cordycepin and adenosine in the fruiting bodies of C. militaris were 2.654 ± 0.02 and 2.45 ± 0.03 mg/g, those in C. sinensis were 0.9801 ± 0.01 and 1.643 ± 0.03 mg/g, while those in the mycelium of C. militaris were 0.9040 ± 0.02 and 1.592 ± 0.03 mg/g, respectively. The concentration of cordycepin and adenosine in the fruiting bodies of C. militaris were higher than that in natural C. sinensis, while the fermented mycelium of C. militaris were similar with natural C. sinensis.

The occurrence and function of oidia in the hymenomycetes

Abstract: IN THI, latter half of the eighteenth century the early mycologists, influenced by their knowledge of higher plants, searched for sexual organs in the fungi analogous to those with which they were familiar among the phanerogams. Micheli (1729) had declared that the cystidia in the hymenium of a mushroom are apetalous flowers. Bulliard (1791) believed the cystidia to be male organs and described the manner in which their seminal fluid poured out over the basidia to fertilize the basidiospores. It has long been known that the mycelium of many fungi breaks up into short segments generally called oidia. Such commonly occurring structures as oidia did not pass unnoticed in the search for sexual organs and the questions of the significance and probable funietion of oidia engaged the attention of a number of workers. Tulasne (1851) discovered in the lichens and in many of the Ascomycetes structures in which were borne small spores usually incapable of germination. These spores he called spermatia and he considered that they are male cells. Later he discovered similar structures in the Tremellales and concluded that the pycniospores of the Uredinales are also true male cells (Tulasne, 1859). Hofmeister (1852) showed that in ferns the sex organs are developed not on the spore-bearing generation but on the prothallium which is independent of the sporophyte. This discovery provided mycologists with, a new clue and they began to search for sexual organs in the higher fungi not on the pileus but on the vegetative mycelium. Karsten (1860) described finding on the mycelium of Psalliota carmpestris reniform " female " cells which were fertilized by " male " elements. At the same time Oersted (1865) thought he saw female cells fertilized by ordinary hyphae. The suggestion that the commonly occurring oidia might be male cells was made again by Rees (1875), who germinated basidiospores of Coprinus stercorarius 2 and observed that, on the young mycelia, there were developed short branches bearing small cells which became detached from the parent filament. These cells failed to germinate and Rees believed that they must be spermatia. Seeing large vesicular cells on the same mycelium, he thought he had also found the female organs. Van Tieghem (1875a, b) reported similar spermatia and female organs in Coprinus ephemeroides and C.