Environmental Sciences and Ecology: Current Research (ESECR) How to cite this article : Garcia SSP, Suarez KF, Ortega EJP, Perez YM, Perez RP (2022) In Vitro Propagation of A Cuban Arbuscular Mycorrhizal Fungal Strain. Environ Sci Ecol: Curr Res 3: 1063 Introduction Arbuscular Mycorrhizal (AM) fungi are soil fungi that occur worldwide forming symbiotic associations with most plant families. Teir importance in natural and semi-natural ecosystems is commonly accepted and characterized by improved plant growing as well as, an increasing plant resistance against biotic and abiotic stresses [1]. In Agricultural ecosystems under less favorite growing conditions they play an important role by enhancing productivity and sustainability [2]. Te plant-AMF interaction studies are difcult due to the obligate symbiont condition of the fungi [3]. AMF cannot complete their life cycle neither grow in axenic conditions without establishing a functional symbiosis with host plants [4]. However, in vitro root cultivation techniques, as a simplifed system for the establishment of the arbuscular mycorrhizal symbiosis, have been widely used [5] and it has shed new light on their molecular biology, cytology, genetics, physiology, systematics and phylogeny [6]. Te most obvious advantage of in vitro cultivation system is the absence of undesirable microorganisms, which makes it more suitable for large-scale production of high-quality inoculum and for construct in vitro culture collections. Several AM fungi species had been cultured in root organ cultures (ROC) systems. Based on scientifc literature and culture collections, it is estimated that over 100 diferent strains are maintained in vitro [7]. However, there is evidence that many species are not able to germinate or colonize transformed roots under these conditions. Terefore, it is a challenge for many researchers to improve in vitro system by taking into account culture media composition, grows conditions, propagules and AM hosts. Although, in Cuba much progress is made in the cultivation and reproduction of AMF as well as in the production of AMF inoculum, there is less experience with in vitro culture conditions. Constructing an in vitro collection of Cuban AMF strains would be an important achievement not only for research on plant-AMF interaction but also for building up an indigenous collection for agriculture use. Te main objective of this study was to establish and characterize an in vitro culture of Rhizophagus irregularis INCAM11 based on transformed chicory (Cichorium intybus L.) hairy roots. Material and Methods Biological material Te strain INCAM 11, DAOM 711363 Rhizophagus irregularis (Walker & Schüßler) belongs to the AMF collection of the ‘Instituto Nacional de Ciencias Agrícolas, (INCA)’ from Cuba. Fungal spores were obtained from pot culture by using the wet sieving and decanting [8] technique followed by sucrose centrifugation [9]. Isolation was done under a dissecting microscope (Novel) at 10 -50 X magnifcation. Spores clusters were stored at 4˚C until their surface disinfection. Te Ri- t-DNA transformed chicory (Cichorium intybus L.) hairy roots, supplied by Montreal University, Canada, were used to establish the in vitro root-organ culture. Spores disinfection procedure INCAM 11 spores were surface disinfected according to a modifed methodology of [10]. Among 150 and 200 healthy young spores of INCAM 11 were transferred to the fltration membrane (0.44 μm), rinsed 3 times with sterile distilled water, and treated with Chloramin T 2% (with 2 drops of Tween 20) for 10 min. Ten spores were washed 3 times with sterile distillated water and treated 10 min with antibiotic solution containing Streptomycin sulphate (0.02 %) and Gentamycin sulphate (0.01 %). Te solution was flter on a disinfection apparatus through a sterile millipore flter (type HA, diameter 4.0 cm, pore 0.22 μm). Aferward, the membrane supporting the disinfected spores was gently transferred into plastic Petri plates (90 mm diam.) containing 20 mL of antibiotics solution and kept in the plates for 24 hours. Volume 3 Issue 5, 2022 Article Information Received date : May 31, 2022 Published date: June 10, 2022 *Corresponding author Kalyanne Fernández Suarez, Instituto Nacional de Ciencias Agrícolas, Department of Biofertilizers and Plant Nutrition, carretera San José-Tapaste km 3 ½, 32 700 San José de las Lajas, Mayabeque, Cuba Keywords Arbuscular Mycorrhizae; In Vitro Culture; MSR Medium Distributed under Creative Commons CC-BY 4.0 Research Article In Vitro Propagation of A Cuban Arbuscular Mycorrhizal Fungal Strain Sussy Saymara Perera Garcia 1 , Kalyanne Fernández Suarez *1 , Eduardo José Perez Ortega 1 , Yonaisy Mujica Perez 1 , Renee Perez Perez 2 and Yakelin Rodríguez Yon 1 1 Instituto Nacional de Ciencias Agrícolas, Department of Biofertilizers and Plant Nutrition, Cuba 2 Instituto Nacional de Ciencias Agrícolas, Department of Crops Physiology and Biochemestry, Cuba Abstract In vitro root cultivation techniques based on modifed root systems are ofen used in studies on Arbuscular Mycorrhizal Fungi (AMF). It is a simplifed but powerful tool to investigate AMF root colonization and development of the extraradical mycelium. Te aim of this study was to establish and characterize the in vitro culture of a Cuban strain of Rhizophagus irregularis (INCAM 11) by using transformed chicory roots. For that, superfcially disinfected propagules of R. irregularis were co-culture with the hairy transformed chicory roots on Modifed Strullu and Romand (MSR) medium during fve months. Spore germination was observed 3-5 days afer surface disinfection. Te frst contact between AMF hyphae and roots occurred 1-3 days afer germination and a signifcant production of extensive extraradical mycelium was observed. New spore formation started within 21-25 days. Afer 5 months, 2000 spores could be observed per plate which were able to germinate, colonize, establish and reproduce again spores when associated to young transformed roots of chicory. Te most frequent associated microorganism to the in vitro culture of INCAM 11 was isolated and identifed as Paenibacillus sp.