Detection of Powdery Mildew Growth in Hazelnut Plant Using PCR

Powdery mildew is a serious disease of economically important hazelnut crop in Turkey. Hazelnut production has been extremely affected by the disease in terms of quality and quantity. The disease is caused by two different fungi, namely Erysiphe corylacearum and Phyllactinia guttata. E. corylacearum has been shown to be the responsible one predominantly for the recent economic damage. The fungi produce a mycelium network on hazelnut plants before they sporulate and visually detected. Early detection of these pathogens is important for management as well as understanding their spread and epidemics. In this study, a PCR assay was developed for the detection of both pathogens from hazelnut plant leaves by targeting their ribosomal DNA genes in their internal transcribed spacer (ITS) regions. Two sets of specific primers were designed for the detection of E. corylacearum and P. guttata at an early stage of infection. As a result of PCR, a specific band of 578 bp was observed. The amplicon sequencing confirmed the presence of only E. corylacearum, but not P. guttata. Therefore, this PCR-based test can identify plants that are infected with powdery mildew before they show any visual signs. From there, the infected plants can be treated or removed before the fungus has a chance to produce spores that infect neighboring plants. These results would help tackle the eradication of powdery mildew.

Electrical activity of fungi: Spikes detection and complexity analysis

Oyster fungi Pleurotus djamor generate actin potential like spikes of electrical potential. The trains of spikes might manifest propagation of growing mycelium in a substrate, transportation of nutrients and metabolites and communication processes in the mycelium network. The spiking activity of the mycelium networks is highly variable compared to neural activity and therefore can not be analysed by standard tools from neuroscience. We propose original techniques for detecting and classifying the spiking activity of fungi. Using these techniques, we analyse the information-theoretic complexity of the fungal electrical activity. The results can pave ways for future research on sensorial fusion and decision making of fungi.

Towards fungal computer

We propose that fungi Basidiomycetes can be used as computing devices: information is represented by spikes of electrical activity, a computation is implemented in a mycelium network and an interface is realized via fruit bodies. In a series of scoping experiments, we demonstrate that electrical activity recorded on fruits might act as a reliable indicator of the fungi’s response to thermal and chemical stimulation. A stimulation of a fruit is reflected in changes of electrical activity of other fruits of a cluster, i.e. there is distant information transfer between fungal fruit bodies. In an automaton model of a fungal computer, we show how to implement computation with fungi and demonstrate that a structure of logical functions computed is determined by mycelium geometry.

The Role of the external mycelial network of arbuscular mycorrhizal fungi: III. a study of nitrogen transfer between plants interconnected by a common mycelium

An experiment under greenhouse conditions was carried out to evaluate the relative contribuition of arbuscular mycorrhizal fungi (AMF) in the process of nitrogen transfer from cowpea to maize plants, using the isotope 15N. Special pots divided in three sections (A, B and C), were constructed and a nylon mesh screen of two diameters: 40µm (which allowed the AMF hyphae to pass but not the plant roots) or 1µm (which acted as a barrier to AM hyphae and plant roots) was inserted between the sections B and C. Section A had 25.5 mg of N/kg using (15NH4)2SO4 as N source. Two cowpea seedlings inoculated with Rhizobium sp. were transplanted with their root systems divided between the sections A and B. Ten days later, 2 seeds of maize were sown into the section C which was inoculated with Glomus etunicatum. Thirty-five days after transplanting, the maize plants were harvested. AMF inoculation increased dry weight and 15N and P content of maize plant shoots. Direct transfer of 15N via AMF hyphae was 21.2%; indirect transfer of 15N mediated by AMF mycelium network, was 9.6%, and indirect transfer not mediated by AM mycelium network , was 69.2%.