Antifungal phytopathogens and indole acetic acid production by endophytic fungi isolated from mango mangifera indica L. Plant

Abstract

Total endophytic fungi of 239 isolates were obtained from 3 varieties of Mangifera indica L. including Okrong, Talapnak and Khiaosawoey from different parts (root, twig, leaf and fruit) of raw and ripen fruit seasons. Thirteen endophytic yeast isolates were from ripen fruit season, and endophyte filamentous fungi of 79 isolates were from raw fruit season while 147 were from ripen fruit season. A study was conducted for screening of the antifungal activity against 2 phytopathogens: Colletotrichum gloeosporioides and Lasiodiplodia theobromae by dual culture and double dishes methods. In addition, indole acetic acid (IAA) production of the isolates was also analyzed. Only the isolates containing activity were further identified. PCR-RFLP was used to group the isolates prior to ITS region DNA sequencing of the representatives from each group. Endophytic yeasts comprised Aureobasidium sp., Rhodotorula sp., Hanseniaspora sp., Candida sp. and Cryptococcus laurentii. Endophytic filamentous fungi were consisted of Aspergillus sp., Colletotrichum sp., Lasiodiplodia sp., Penicillium sp., Phyllosticta sp., and Rhytidhysteron sp. Endophytic yeast Candida sp. CY.OS 09 showed the highest growth inhibition activity against C. gleosporioides while no anti-L. theobromae activity could be detected from all 13 endophytic yeast isolates. For endophytic filamentous fungus Colletotrichum sp. CY.OS 162, and Lasidiplodia sp. CY.OS 132, showed the highest activities against C. gleosporioides and L. theobromae, respectively. The Colletotrichum sp. CY.OS 161 and Colletotrichum sp. CY.OS 33 produced the strongest antifungal volatile compound. IAA production was highest observed in endophytic yeast Aureobasidium sp. CY.OS 13, and endophytic filamentous fungus Colletotrichum sp. CY.OS 22. This study suggested a future use of isolated endophytic fungi as biocontrol agents, along with plant growth promotion capability.