Biocontrol potential of <i>Aspergillus terreus</i>, endophytic fungus against <i>Rigidoporus microporus</i> and <i>Corynespora cassiicola,</i> pathogens of rubber tree

The pathogenic fungi, <i>Rigidoporus microporus</i> and <i>Corynespora cassiicola</i> are among the major agents of root and leaf disease of rubber tree (<i>Hevea brasiliensis</i>). In this study, endophytic fungi were isolated from seeds of <i>H. brasiliensis</i> obtained from different regions of Malaysia to determine the diversity of endophytes inhabiting the seeds and to select a potential biocontrol agent against selected <i>Hevea</i> pathogens. Through morphological observation and molecular identification, six genera were identified namely <i>Aspergillus, Colletotrichum, Diaporthe, Lasiodiplodia, Mucor</i> and <i>Pseudofusicoccum</i>. Isolate PN3 which showed 99.82% identity to <i>Aspergillus terreus</i> was selected as a candidate to evaluate its biocontrol potential against <i>R. microporus</i> and <i>C. cassiicola</i> as it displayed promising inhibitory potential in preliminary experiments. <i>A. terreus</i> showed inhibition of 81.24%, 70.35% and 64.19% against <i>R. microporus</i> and two races of <i>C. cassiicola</i> namely CLN 16 and CSB 16 respectively in dual culture assay. In dipped stick inhibition assay, <i>A. terreus</i> showed 100% inhibition to the growth of <i>R. microporus. A. terreus</i> also reduced infection of leaves cultured with <i>C. cassiicola</i> CLN 16 and CSB 16 by 93.33% and 86.67% respectively. This study has identified some of the fungal species inhabiting the seeds of <i>H. brasiliensis</i> which may have potential as biocontrol agents.