Download Plant Growth-Promoting Fungi from soils under different agricultural

Plant Growth-Promoting Fungi from soils under different agricultural crops
Potential object of agrobiotechnology is PGPF (Plant Growth-Promoting Fungi) which are
frequently used as inoculants for improving the growth and yield of agricultural crops. The
positive influence of soil fungi on plants is also related to their ability to suppress pathogenic
microorganisms, which could inhibit plant growth. The application of PGPF is an attractive
alternative to chemical fertilizers.
Objective of the present study is selection of the most active fungal strains with ability to
promote plant growth and inhibit phytopathogenic fungi.
Studies were conducted with 188 strains of fungi isolated from soils under different agricultural
crops - alfalfa (Medicago sativa), melilot (Melilotus officinalis), sainfoin (Onobrychis viciifolia),
and rapeseed (Brassica napus). To determine plant growth promoting ability the alfalfa seeds
were treated with culture filtrates of fungal isolates. The seedling emergence, shoot and root
length of treated plant seedlings were compared to nontreated ones. The antagonistic activity of
strains against phytopathogenic fungi Fusarium graminearum and Alternaria alternata was
studied by dual culture method.
Based on the phenotypic and phylogenetic characteristics it was shown that all fungal isolates
belonged to 19 species of 5 genera – Penicillium, Fusarium, Aspergillus. Trichoderma and
Acremonim. 34 strains had the plant growth-promoting ability. Seedling emergence reached
99,6%. The root length increased by 27,4-65,2 % compared to control plants. The shoot length
was higher by 19,4-64,7% compared to the control. Results of the antagonism tests showed that
21 isolates demonstrated the ability to inhibit the growth of phytopathogenic fungi. The size of
the inhibition zone was 1,5-9,5 mm. It was found that the antagonistic activity was higher against
Fusarium graminearum. The largest number of active strains was typical for soil under alfalfa.
11 of the most active strains of species Penicillium bilaiae, Trichoderma koningii, Fusarium
equiseti and Aspergillus ustus were selected for further study.