Dinamika Populasi dan Karakter Morfologi Aktinomiset Endofit Asal 5 Varietas Tanaman Padi

Abstract

Endophytic actinomycetes lives inside plant tissues and can induce stress and pathogen tolerant of its host. The existence and role of endophytic actinomycetes on rice plants have rarely been explored. The purpose of this study was to assess the population dynamics and morphological characters of endophtic actinomycetes originated from five rice varieties, namely IR64, Inpari 9, Ciherang, Inpago 4, and Inpara2 which have different ecosystem types. The endophytic actinomycetes isolates were isolated from surface sterilized plant parts, grounded and plated in Humic Acid Vitamin-B agar (HV) medium. The purified isolates were grown on Yeast Starch Agar (YSA) supplemented with cyclohexamide, nalidixid acid, and griseovulvin. The total of 137 isolates were successfully isolated both from plant extract and plant parts. The highest number of endohytic actinomycetes colony was found in 4 weeks old of irrigated rice (IR64, Inpari 9 dan Ciherang) and upland rice (Inpago 4) , while for the endophytic actinomycetes originated from wetland rice (Inpara 2) growth peak was obtained at 2 weeks old plant. The highest total population of endophytic actinomycetes was found from root parts. Meanwhile, the morphological characters of endophytic actinomycetes was found diversed and most commonly found on shoot and leaves that are dominated by brown-colored aerial mycelia. This study shows that the population dynamics and diversity of rice endophytic actinomycetes are influenced by age, varieties, and ecosystem type of rice plants. Further study to assess the potential of endophytic actinomycetes in rice plants is required.

Aktinomiset endofit hidup di dalam jaringan tanaman dan dapat membantu inangnya dalam menekan stress serta tahan terhadap patogen. Keberadaan dan peran biologi aktinomiset endofit pada tanaman padi belum banyak diketahui. Tujuan dari penelitian ini adalah untuk mengkaji dinamika populasi dan karakter morfologi aktinomiset endofit asal lima varietas tanaman padi, yaitu IR64, Inpari 9, Ciherang, Inpago 4, dan Inpara 2 dengan beragam tipe ekosistem. Aktinomiset endofit padi diisolasi dengan sterilisasi permukaan dan ditumbuhkan pada media Humic Acid Vitamin-B Agar (HV agar). Purifikasi aktinomiset endofit menggunakan media Yeast Starch Agar (YSA) dengan antibiotik cyclohexamide, nalidixid acid, dan griseovulvin. Sebanyak 137 isolat berhasil diisolasi dari lima varietas dan bagian tanaman yang berbeda. Puncak pertumbuhan koloni aktinomiset berada pada tanaman padi irigasi (IR64, Inpari 9 dan Ciherang) dan padi gogo (Inpago 4) yang berumur 4 minggu, sedangkan pada padi rawa (Inpara 2), populasi aktinomiset endofit tertinggi ditemukan pada tanaman padi umur 2 minggu. Total populasi aktinomiset endofit diperoleh dari bagian akar. Keragaman karakter morfologi aktinomiset endofit paling banyak ditemukan pada batang dan daun yang didominasi oleh miselia aerial berwarna coklat. Penelitian ini menunjukkan bahwa keragaman aktinomiset endofit dipengaruhi oleh umur, varietas, dan tipe ekosistem tanaman padi sehingga perlu dikaji lebih lanjut potensi aktinomiset endofit pada beragam varietas tanaman padi.