Diversity And Ecological Distribution Of Endophytic Fungi Associated With Mangroves

Mangroves are the intertidal wetlands, which play as a dynamic transition zone thatjoins the terrestrial and marine ecosystem. Mangroves are also the biodiversity hotspots formarine fungi because of their special geographical environments. Mangrove fungi are thesecond largest ecological group of marine fungi. Endophytic fungi refer to the group offungi that reside inside the living plants without causing any apparent symptoms. To someextent, they stand for the diversity of the fungi and affect the community structure anddiversity of other species. In this study, three common mangrove trees Rhizophora stylosa,Kandelia candel and Bruguiera gymnorrhiza were collected from Gaoqiao andDongzhaigang mangrove natural protection and reservation zones, aiming to investigatethe diversity and ecological distribution of endophytic fungi associated with mangroves.A total of3500isolates were recovered from4200mangrove tissues and wereclassified into107taxa by using a combination of molecular and morphological ways. Ofthese isolates,3420strains were Ascomycota (97.71%),73strains were Basidiomycota(2.09%),7strains were Zygomycota (0.2%). Two new records in china were identified anddescribed in this research. The diversity of endophtic fungi associated with mangroves wasKandelia candel (84)> Rhizophora stylosa (74)> Bruguiera gymnorrhiza (73).The total colonization rates (51.9~75.4%) of endophytic fungi associated with threemangrove trees were significantly affected by the geographical factors. The colonizationrates in stems were significantly higher than in leaves and roots. The total colonizationrates of endophytic fungi associated with the leaves of Rhizophora stylosa and Kandeliacandel were significantly higher than the roots of these two plants at Dongzhaigang;however, the reverse was true at Gaoqiao.The members of Dothideomycetes and Sordariomycetes were dominated in thesethree plants as endophytic fungi. The endophytic fungi communities were significantlydifferent among these three plants based on the analysis of NMDS and similarity index.Diaporthe phaseolorum was dominated in Rhizophora stylosa; Colletotrichum horii andDiaporthe phaseolorum were dominated in Kandelia candel, while Neofusicoccum lecanii,Diaporthe phaseolorum and Lasidioplodia theobromae were dominated in Bruguieragymnorrhiza. The diversity of endophytic fungi in stems of the three plants was higher thanin leaves and roots.Some endophytic fungi showed obvious host specificity, i.e., Phoma medicaginis wasonly revovered from Rhizophora stylosa; Botryosphaeria dothidea, Lecanicillium lecanii and Nemania bipaillata were only isolated from Kandelia candel, while Colletotrichumfragariae and Diaporthe conorum were just found in Bruguiera gymnorrhiza.Pesalotiopsis clavispora showed strong tissue specificity and was only recovered from thestems of three mangrove trees.