European spruce bark beetle Ips typographus is an important driver of ecological processes in spruce stands, with severe effects on forestry economies. To prevent bark beetle outbreaks, early detection of infestations is a crucial step in forest management. It is expected that bark beetle infestation modifies biochemical composition of wood and needles, alters physiological responses in the early stage of infestation, which results in the reduction of tree growth and ultimately a tree death. Therefore, we studied the differences in biochemical composition of wood, content of photosynthesis-related pigments, shoot morphology, and growth between the healthy Siberian spruce trees (Picea obovata) and trees which were infested by I. typographus. The study was performed in five experimental plots established in the south of the Udmurt Republic in the European part of the Russian Federation. Three infested and three non-infested trees were chosen on each plot. Our results showed no significant effect of bark beetle infestation on the content of main structural components of wood – holocellulose (cellulose and hemicellulose) and lignin. On the other hand, we found differences in the content of extractive substances in the wood. Specifically, we found a higher tannin content in the non-infested trees. The content of photosynthesis-related pigments differed between the non-infested and infested trees as well. Unexpectedly, bark beetle infestation caused the overproduction of both pigment types rather than their degradation. Moreover, we observed that a higher amount of total extractive substances positively affected the incremental growth, whereas tannins supported the growth of shoots and needles.

В статье приведены результаты экспериментов по исследованию влияния инокуляции эндотрофным микромицетом Cylindrocarpon magnusianum на физиологобиохимические показатели тестовых растений томата. Схема эксперимента включала инокуляцию культурой гриба (контрольная популяция) и популяциями этого гриба, предварительно выращенными на агаризированных средах с внесением разных концентраций тяжелых металлов. Инокулированные растения выращивались на контрольном субстрате (без внесения тяжелых металлов) и на субстратах с внесением разных концентраций тяжелых металлов (цинка, меди, свинца и хрома). Минимальные различия с контролем по физиологическим и морфологическим показателям растений наблюдались лишь при инокуляции растений популяциями Cylindrocarpon magnusianum, адаптированными к разным концентрациям солей тяжелых металлов, и при выращивании инокулированных растений в условиях высокого содержания солей тяжелых металлов в субстрате. The results of experiments on the effect of inoculation with the endotrophic fungus Cylindrocarpon magnusianum on the physiological and biochemical parameters of tomato are presented in the article. The scheme of the experiment included inoculation with the fungal culture (control) and the populations of this fungus, previously grown on agar media with the different concentrations of heavy metals. Inoculated plants were grown on a control substrate (without heavy metals) and on substrates with various concentrations of heavy metals (zinc, copper, lead and chromium). Minimal differences with the control of physiological and morphological parameters of plants were observed only when the plants were inoculated with Cylindrocarpon magnusianum populations adapted to different concentrations of heavy metal salts and when inoculated plants were grown under conditions of high content of heavy metal salts in the substrate.

The effect of inoculation of Cylindrocarpon magnusianum on plants under the action of heavy metal salts was studied. Effective partnership of the fungus and plants was revealed in the conditions most extreme for the life of plants.

No abstract

The aim of this research was to study the effect of inoculation with the Cylindrocarpon magnusianum endotrophic micromycete on the physiological and biochemical parameters of tomato test plants under the action of heavy metal salts. The plants were inoculated with the fungus culture (control population) and populations of this fungus preliminarily adapted to the action of the stress factor. Then, inoculated plants were grown under control conditions and on substrates with different concentrations of heavy metal salts (zinc, copper, lead and chromium). After the plants were inoculated with the control population of the C. magnusianum fungus, a stimulating effect increasing the plants’ resistance to the action of the heavy metal salts was not detected. When the plants were inoculated with adapted populations of the C. magnusianum fungus, adaptive reactions of the plants associated with the content of photosynthetic pigments in the leaves and the formation of plant biomass were significantly manifested. Under these conditions, a more intense development of fungal infection in plant roots was observed in contrast to the use of the control fungal population. These findings therefore demonstrated an effective partnership between the C. magnusianum fungus and the root system of plants under extreme conditions for plant life. Keywords: Cylindrocarpon magnusianum, micromycetes, heavy metals, inoculation, biochemical indicators