MARIETA HRISTOZKOVA; IRA STANCHEVA; MARIA GENEVA; MADLEN BOYCHINOVA
Bulgarian Academy of Sciences, Institute of Plant Physiology and Genetics, Laboratory of Plant Soil Interactions, BG-1113 Sofi a, Bulgaria
Hristozkova, M., I. Stancheva, M. Geneva and M. Boychinova, 2017. Comparison of several arbuscular mycorrhizal fungi and sweet marjoram (Origanum majorana L.) symbiotic associations in heavy metal polluted soil. Bulg. J. Agric. Sci., 23 (3): 436–442
Mycorrhizal fungi participated in plant nutrient assimilation, root development and metal absorption from the soil depending on the resistance and stress tolerance of the involved strain. The overview of several mycorrhizal and marjoram symbiotic associations represented the effect of the studied stress over different strains and their interactions with the plants. We tested four mycorrhizal isolates, derived from various rhizospheres: Claroideoglomus claroideum (Cc1), Rhizophagus clarum, Claroideoglomus claroideum (Cc2), Funneliformis mosseae. In order to get insight into the role of mycorrhizal symbiosis in protecting Origanum majorana L. against the excess of metals (Cd and Pb), we investigated growth, uptake and distribution of heavy metals in the plant parts, mycorrhizal colonization status, glomalin- related soil proteins and acid phosphatase activity (in root and soil). Pb and Cd partitioning in non-mycorrhizal plants were soil>shoots>root while in symbiotic associations variants changed to soil>root>shoots. Bio concentration factor (BCF) and translocation factor (TF) values confi rmed by the less heavy metals shoot uptake in inoculated than control plants. The root dry weight increased in plants inoculated with C. claroideum strain (Cc1), which is isolated from industrially metal-contaminated sites. The highest shoot biomass correlated with the percentage of mycorrhization, relative mycorrhizal dependency, glomalin production and acid phosphatase activity was determined by C. claroideum (Cc2) and Funneliformis mosseae. Both strains derived from natural metalliferous sites. The fi ndings in this study are essential to get the most benefi ts of mycorrhizal association in unfavorable conditions connected with plant development and herbal products free of harmful ingredients.