Mating type idiomorphs and sexual fertility status in Fusarium proliferatum isolates of some aquatic ecosystems

In this study, in order to identification of mating type idiomorphs and possibility of sexual fertility samples were taken from rivers, lakes, lagoons and dams of 10 provinces (Alborz, Bushehr, East Azerbaijan, Fars, Guilan, Khuzestan, Kurdistan, Lorestan, Mazandaran and South Khorasan). In each site, samples were taken from three substrates of water, sediments and foam (small bubbles on water surface). Water-agar containing antibiotic and alternating light in 25°C and peptone-PCNB-agar containing antibiotic were used for isolation of the isolates. Fifty-one isolates of F. proliferatum were recovered and maintained. Isolates were identified using morphological characteristics on carnation-leaf-agar, potato dextrose agar and SNA culture media. Then, identification of isolates was done by species-specific primers. To detect the mating type idiomorphs of the isolates, idiomorph loci were amplified by multiplex PCR using the primers designed based on corresponding MAT loci. Of 51 isolates, 28 (54.9%) were determined as MAT-1 and 23 (45.1%) as MAT-2. To test sexual fertility of the isolates, each isolate was crossed with all isolates of opposite mating type on carrot agar culture medium, and total crosses of 1288 were done between the isolates. One hundred and two crosses resulted in fertile perithecia and ascospores recovered from fertile crosses had germination rate between 70–80%. Among successful crosses, four isolates were identified as female fertile. Distribution of mating type idiomorphs and fertility status of the isolates, confirms the probability of sexual reproduction among isolates in the aquatic ecosystems.