Clones of Trees Will Help Restore Forests: Russian Scientists Increase the Survival Rate of Seedlings for After-Fire Reforestation

Scientists from the National University of Science and Technology MISIS (NUST MISIS) and Tambov State University (TSU) presented a new technology to increase the survival rate of microclonal seedlings planted for reforestation after massive fires. The use of nanopreparations allowed obtaining seedlings of deciduous and coniferous trees with an increased survival rate (10-28% higher) in the open ground. They have already been used to create experimental forest plantations in the Central Black Earth Region of Russia.

According to the Federal Forestry Agency (FFA, Russia), in 2019 economic damage from forest fires in Russia is 14.4 billion rubles. During the fire season in a number of Russian regions, the fire covered more than 10 million hectares of forest. One of Australia’s largest banks, Westpac, has estimated that direct losses to the Australian economy after the wildfires will be about $ 3.5 billion.

To restore forest resources, burned areas are sown with seedlings grown in special laboratory conditions using the method of microclonal reproduction. The method is based on the ability of a plant cell to give rise to an entire plant organism under favorable conditions. Tree microclones can be reproduced 3-4 times faster than conventional seedlings, while they are genetically homogeneous.

However, during adaptation to the soil, there is a high probability of their death, which reduces the effectiveness of the technology as a whole. To solve this problem, a team of scientists from NUST MISIS and TSU obtained experimental samples of unique nanopreparations for microclonal reproduction of trees based on colloidal solutions of nanoparticles.

“The obtained nanopreparations are the basis of the nutrient medium. They protect the microclonal seedlings of trees from infections. These are mostly microscopic phytopathogenic fungi, which at this stage kill about 30% of seedlings, — said the Project Manager, Director of the TSU Ecology and Biotechnology Research Institute, Associate Professor of the NUST MISIS Department of Functional Nanosystems and High-Temperature Materials Alexander Gusev. — Infections are especially dangerous when sprouts are transferred from laboratory test tubes to the non-sterile environment of the greenhouse, where they grow to become seedlings that can be planted in open ground”.

The experiments in the framework of the project have shown that nanopreparations in a nutrient medium ensure the death of about 90-95% of pathogenic microorganisms. The nanopreparation is used to sterilize the explant (the initial piece of a plant tissue, which is then cloned) before being introduced into the culture, and is also added to the cultivation medium, where microsprouts grow. Besides, plants are treated with a suspension of a nanopreparation through watering the soil after transplanting from test tubes into containers with soil.

“The active substance of the preparations is nanocomposites of the graphene oxide-silver and graphene oxide-copper oxide composition. In this case, silver or copper oxide nanoparticles are located on the surface of the graphene oxide sheets, — said the representative of the nanocomposite developers and the Head of the NUST MISIS Department of Functional Nanosystems and High-Temperature Materials Denis Kuznetsov. Graphene oxide serves as a bioactive nanoparticles carrier and a colloidal systems stabilizer, and silver and copper oxide act as non-toxic wide spectrum of action fungicides for plants (substances that inhibit the growth of pathogenic microscopic fungi). It should be noted that copper oxide nanoparticles contributed to an increase in the formation of additional shoots in seedlings in vitro. This corresponds to the data obtained by the staff of our department during many years of research — nanoparticles of metals and metal oxides often exhibit stimulating effects in relation to a number of plant crops”.

As a result of the project, stimulators of growth and phytoimmunity of tree crops, which have no analogs, were created. They are intended for use as components of cultivation media for microclonal sprouts and for treating plants in a greenhouse during growing in the closed ground.

The development of Russian scientists has export potential since it can be in demand in countries where the majority of planting material is produced by microclonal propagation laboratories — the USA, Canada, Spain, Italy, Portugal, Poland, Germany, Latvia, Belgium, and Holland.