The effect of IAA producing Bacillus sp. Q3 strain on marshmallow seed germination

Abstract

Marshmallow (Althea officinalis) is one of the important medicinal plants in Serbia. One of the bigest problem in growing of marshmallow is poor seeds germination. Rhyzospheric bacteria able to produced plant growth stimulating hormones can inpruve seed germinations and decreace seed infections with patogens. IAA production by Bacillus sp. Q3 strain estimate in this investigation ranged from 3.76-10.62 μgml-1. The application of soil bacteria as the antagonists to the growth of pathogenic fungi, indicated that IAA producing Bacillus sp. strain Q3 demonstrated not only a high level of antagonism towards the seed mycoflora, but significantly increased the germination rate of the marshmallow seeds. Soaking marshmarrow seeds for 24 h in the 105 CFU ml-1 of investigated strain Bacillus sp. strain Q3 increased the 55.1% germination and decreased the percentage of the seed infection by the fungus Alternaria alternata, compared to the control (32%). Strong increasing percent germination of marshmallow's seeds from 26.9-55.1% and decreasing seed infection with phytopathogen Alternaria alternate, as predominant marshmallow seeds pathogen, can recommend this strain for seed protection and as PGPR.