Perakitan teknik pengendalian penyakit tanaman padi Ramah lingkungan berbasis bakteri agen hayati dan Metabolit sekundernya

Abstract

Penyakit tanaman padi merupakan salah satu kendala dalam upaya mencapai dan mempertahankan swasembada beras. Pengendalian hayati merupakan salah satu teknik pengendalian penyakit padi yang banyak dikembangkan karena ramah lingkungan dan bersifat berkelanjutan. Penelitian ini bertujuan menemukan agens hayati dari golongan bakteri yang dapat dikembangkan sebagai biopestisida terhadap 3 penyakit penting tanaman padi yaitu penyakit hawar daun, hawar pelepah dan busuk leher yang disebabkan oleh patogen Xanthomonas oryzae pv oryzae, Rhizoctonia solani, dan Pyricularia oryzae.. Sebanyak 30 isolat bakteri berpotensi sebagai agens hayati (tidak menunjukkan reaksi hipersensitif pada tanaman indikator (tembakau). Pengujian uji potensi antagonisme in vitro dan uji fitotoksisitas dan pemicu pertumbuhan terhadap benih padi in vivo didapatkan 3 isolat bakteri yaitu ATS6 (Aktinomiset), TTS47 (bakteri non fluorescens) dan P12 (Pseudomonas kel fluorescens) yang efektif mengendalikan X. oryzae pv oryzae, R. solani dan P. oryzae. Karakterisasi lebih lanjut terhadap ketiga isolat menunjukkan aktivitas kitinase (ATS6, TTS47), produksi siderofore (ATS4, TTS47, dan P12), phospatase ((ATS6, TTS47, dan P12), and indole acetic acid (TTS47 and P12). Identifikasi berdasarkan sekuensing gen 16S rRNA menunjukkan isolat ATS6 memiliki kemiripan 99% terhadap Streptomyces sp dan TTS47 memiliki tingkat kemiripan 98% terhadap Ralstonia picketsii.

Rice plant diseases is the most important problem under humid and high fertilizer input condition. Biological control of rice diseases is one of the control measure that has advantages i.e. environmental friendly . The objective of this research is to find biological control agents from bacteria groups to control 3 important rice diseases: bacterial leaf blight, sheat blight, and neck rot caused by Xanthomonas oryzae pv oryzae, Rhizoctonia solani, and Pyricularia oryzae, respectively. We found 30 isolates bacteria which indicated non-plant pathogenic bacteria (shown negative result of hypersensitive reaction test on indicator plant) were potential as biological control agents. Further test on antagonistic , phytotoxicity, and planth growth effect both in vitro nd in vivo test were found 3 isolates of bacteria with high potency to control of X. oryzae pv oryzae, R. solani, and P. oryzae. Those of 3 isolates are ATS6 (actinomycetes), TTS47 (non-fluorescens bacteria) and P12 (fluorescens pseudomonas). Characterization of these isolates indicated that its produced chitinase (ATS6, TTS47), siderofore (ATS6, TTS47, and P12), phospatase (ATS6, TTS47, and P12), and indole acetic acid (TTS47 and P12). Identification by sequencing of 16S rRNA nucleotides indicated that ATS6 had high similarity to Streptomyces sp (99%), and TTS47 to Ralstonia picketsii (98%), while P12 not been analyzed yet.