BIODIVERSITAS ISSN: 1412-033X Volume 19, Number 6, November 2018 E-ISSN: 2085-4722 Pages: 2028-2034 DOI: 10.13057/biodiv/d190607 The diversity of endophytic fungi associated with Piper nigrum in the tropical areas: A recent study from Kutai Kartanegara, Indonesia SOPIALENA 1,♥ , SUYADI 1 , MUHAMAD SAHIL 1 , JULI NURDIANA 2,♥♥ 1 Program of Plant Pests and Disease Science, Faculty of Agriculture, Universitas Mulawarman. Jl. Pasir Belengkong, Kampus Gunung Kelua, Samarinda 75119, East Kalimantan, Indonesia. Tel.: +62-541-749161, Fax.: +62-541-738341. ♥ email: sopialena88@gmail.com 2 Program of Environmental Study, Faculty of Engineering, Universitas Mulawarman. Jl. Sambaliung No. 9, Kampus Gunung Kelua, Samarinda 75117, East Kalimantan, Indonesia. Tel.: +62-541-749315, Fax.: +62-541-736834. ♥♥ email: julinurdiana@gmail.com Manuscript received: 1 July 2018. Revision accepted: 18 October 2018. Abstract. Sopialena, Suyadi, Sahil M, Nurdiana J. 2018. The diversity of endophytic fungi associated with Piper nigrum in the tropical areas: a recent study from Kutai Kartanegara, Indonesia. Biodiversitas 19: 2028-2034. This research aimed to identify the diversity of endophytes fungal in the root and leaves of Piper nigrum Linn. This research contributes to the knowledge gaps by focusing the discussion on the Endophytic fungal communities of Piper nigrum Linn in tropical areas at Kutai Kartanegara, Indonesia. Two certain plots within the study area were selected based on the different characteristics of topographic contours. The locations, named Plot A was characterized by ramps area, while plot B was sloping or hilly area. A total of 55 isolates were obtained from the root and the leaves of healthy plants, 35 isolates were from Plot A and the other 20 isolates were from plot B. Based on Shannon index (H’), both of the plots corresponded to the same genus; namely Aspergillus sp., Fusarium sp., Nigrospora sp., and Trichoderma sp, and categorized as medium diversity. In this regards, this study confirms that the genus Aspergillus sp. and Fusarium sp. represent a large part of the diversity of Endophytes fungi. As the study indicates that plot B has higher diversity of endophytic fungi compared to plot A, it shows that the hilly area turns out to be a better location for Piper nigrum Linn. Keywords. Pepper, Endophytic fungi, diversity index, dominance index. INTRODUCTION Pepper (Piper nigrum L) is a type of plant which is widely used as a spice and pepper oil. In Indonesia, pepper becomes the fifth largest foreign exchange earner in the spice group and the fifth after rubber, tea, oil palm, and coffee. Indonesia is one of the world's second largest exporter of pepper. The largest pepper producing provinces in Indonesia included Lampung, Bangka Belitung, South Sumatera and East Kalimantan (Directorate General of Plantations GOI 2011). In the cultivating process; either modern or conventional, many plant-disturbing organisms such as pests or diseases get in the way and cause cropping disturbances. The diseases may be caused by viruses, bacteria or fungi, which are pathogenic to pepper plants and could result inthe reduced crop production. Nevertheless, some fungi have mutualism interaction properties to the host called endophytic fungi. Endophytic fungi are known to live in plant tissues such as leaves, flowers, fruits or plant roots over a period and can live by forming colonies in plant tissues without harming the host (Clay 1988). According to Azevedo et al. (2000) and Khastini et al. (2014), endophytic fungi have an important role in host tissue which exhibits a mutualistic interaction, i.e., positive interaction with the host and negative interaction with plant pest organisms. Endophytic fungi can produce secondary metabolites from their host plants by adopting some genetic information from its host (Strobel and Daisy 2003; Rubini et al 2005). Meanwhile, Worcher et al (2013) stated that endophytic fungi would benefit from the supply of nutrients, and can endure the unfavorable environmental pressures. On the other hand, host plants can benefit from the induction of resistance to various pressures, both by biotic and abiotic factors, and can also increase their growth, through the production of phytohormones, increased access to minerals and nutrients, and synthesis of antagonistic metabolites (Labeda 1990; Tejesvi et al. 2010; Drigo et al. 2010). Associated endophytic fungi in host plants may vary (Azevedo et al. 2000; Rodriguez 2009; Saunders et al. 2010; Suyadi et al. 2017). In tomato plants, for instance, there are several genera of endophytic fungi such as Acremonium sp., Aspergillus sp., Cephalosporium sp., Fusarium sp., Helicocephalum sp., Penicillium sp., and Rhizopus sp. (Wulandari et al. 2014). Whereas fungi found in leaf tissues, stems and roots of potato plants consisted of 12 genera (Tirtana et al. 2013). Further, Puspita et al. (2013) found that endophytic fungi within the genus Colletotrichum was dominant in citrus plants. More number of endophytic fungi were isolated from plant parts of clove, i.e., Curvularia sp., Colletotrichum sp., Mucor sp., Gonatobotryum sp., Aspergillus sp., Beltrania sp., and Aspergillus sp. (Shofiana et al. 2015). Moreover, Mandyam et al. (2013) and Wang et al. (2014) also mentioned that the presence of endophytic species always associated with the host’ microhabitat conditions and genotype of the host plants and the endophytic fungi. Thus it affects the