Overview of the microbial associations of below ground parts of Crocus sativus

Microorganisms inhabit almost every imaginable environment in the biosphere, play integral and unique roles in ecosystems. Microbiome the sum total of all the microbes associated with various plants has often been referred to as plant's second genome. Some of the microbes such as the plant growth promoting microbes (PGPM) are known to have positive interaction while microbial pathogens have negative interaction with plants. In a similar way, the microorganisms present in soil are one of the major factors affecting the production of saffron along with corm quality, soil chemistry, environment, temperature, irrigation and use of fertilizers. Here, we present a reflection of the work done on the microbial association of below ground parts i.e., corm and root of saffron using cultivation dependent and cultivation independent metagenomic approach. As a result of cultivation dependent approach, Bacilli namely Bacillus amyloliquefaciens W2 (KF663600) capable of biocontrol and biofertilizer activity were isolated, identified and evaluated in pots and fields. Similarly pathogenic Fusarium sp. was isolated, characterized at molecular level using cultivation dependent approach and identified as Fusarium oxysporum R1 that was different than commonly reported pathogenic Fusarium oxysporum. Bacteriome and mycobiome of below ground parts were studied by cultivation independent metagenomic approach. The effect of the growth stages of saffron was clearly evident on the microbiome i.e., bacteriome and mycobiome. In addition, the temporal and spatial dynamics of bacteriome during vegetative phase indicated over all similarity in the bacteriome over the period of three years but spatial variation between mother corm and daughter corm. The daughter corm bacteriome was similar to rhizosphere rather than mother, the study that needs further validation.