Cabai merah (Capsicum annum L.) merupakan salah satu jenis tanaman hortikultura yang penting dan banyak dibudidayakan secara komersial. Beberapa permasalahan dalam pembudidayaan cabai merah yang dapat mengakibatkan produksi menurun salah satunya diakibatkan oleh penyakit Fusarium. Fusarium oxysporum merupakan salah satu cendawan patogen yang mampu bertahan di jaringan tanaman yang hidup atau mati. Fusarium dapat merusak tanaman sehingga mengalami kematian, untuk itu perlu dikendalikan. Salah satu pengendalian untuk mencegah penyakit ini adalah penggunaan agens hayati dengan menggunakan cendawan endofit. Penelitian ini bertujuan untuk mengetahui cendawan endofit asal tanaman cabai toraja dalam menekan pertumbuhan penyakit layu F. oxysporum secara in vitro. Penelitian ini dilaksanakan di Laboratorium Proteksi Tanaman Universitas Borneo Tarakan. Tahapan penelitian terdiri dari perbanyakan Fusarium, isolasi cendawaan endofit asal tanaman cabai Toraja, identifikasi morfologi makroskopis dan mikroskopis, uji patogenitas, uji antagonis, uji aktivitas melarutkan fosfat dan uji kemampuan mendegradasi protein. Hasil penelitian diperoleh 20 isolat cendawan endofit yang teridentifikasi hingga tingkat genus yaitu Aureobasidium, Sporisdesmium, Tricholadium, dan Chaetophaeria. Uji patogenitas menunjukkan 4 isolat cendawan endofit non patogen. Uji antagonis terhadap Fusarium oxysporum menunjukkan 2 isolat cendawan mampu menekan pertumbuhan Fusarium oxysporum pertumbuhan penyakit F. oxysporum secara in vitro. isolat D6(1) mampu menghambat sebesar 37.93% dan isolat D6(2) mampu menghambat sebesar 46.67%. Kedua isolat cendawan antagonis ini dikategorikan pengahambatan minimal dalam menekan Fusarium oxysporum.
Kata kunci: Cabai merah, Cendawan endofit, F. axysporum

Red chili (Capsicum annum L.) is one of the most important horticultural crops and is widely cultivated commercially. Several problems in the cultivation of red chili that can lead to decreased production are caused by Fusarium disease. Fusarium oxysporum is one of the fungal pathogens that survives in living or dead plant tissues. Fusarium can damage plants so that they die, so it needs to be controlled. One of the controls to prevent this disease is the use of biological agents using endophytic fungi. This study aims to determine the endophytic fungus from Toraja chili plants in suppressing the growth of F. oxysporum wilt disease in vitro. This research was conducted at the Plant Protection Laboratory of the University of Borneo Tarakan. The research stages consisted of propagation of Fusarium, isolation of endophytic fungi from Toraja chili plants, morphological and microscopic tests, pathogenicity tests, antagonist tests, phosphate solubilizing activity tests and protein degradation abilities. The results obtained were 20 endophytic fungal olates which were up to genus level, namely Aureobasidium, Sporisdesmium, Tricholadium, and Chaetophaeria. Pathogenicity test showed 4 isolates of non-pathogenic endophytic fungi. Antagonism test against Fusarium oxysporum showed 2 isolates of fungi that were able to suppress the growth of Fusarium oxysporum in vitro disease growth of F. oxysporum. isolate D6(1) was able to inhibit 37.93% and isolate D6(2) was able to inhibit 46.67%. Both isolates of these antagonist fungi were categorized as minimal inhibition in suppressing Fusarium oxysporum.