Rice phyllosphere bacteria producing antifungal compounds as biological control agents of blast disease

Abstract

Abstract. Wiraswati SM, Nawangsih AA, Rusmana I, Wahyudi AT. 2020. Rice phyllosphere bacteria producing antifungal compounds as biological control agents of blast disease. Biodiversitas 21: 1273-1278. In vitro analysis of rice phyllosphere bacteria can be developed as biocontrol agents of blast disease using their antifungal activity. To prove the efficacy of bacterial isolates in reducing the severity of blast disease, a greenhouse experiment was conducted. Furthermore, antifungal compounds produced by potential bacterial isolate were also identified using Thin Layer Chromatography (TLC) and Liquid Chromatography-Mass Spectrometry/ Mass Spectrometry (LC-MS/MS) analysis. The application of seven rice phyllosphere bacterial isolates significantly reduced the severity of blast disease in rice (var: Ciherang). Surprisingly, the isolate STGG 14 is the most effective with 70.83% of blast disease reduction. Isolate STGG 14 has been identified as Bacillus subtilis subsp. subtilis which is known as various bioactive compounds producer. It was confirmed through identification of antifungal compounds produced by isolate STGG 14. The bioautography test shows that crude bioactive compounds from isolate STGG 14 could inhibit P. oryzae race 173. On the further analysis using LC-MS/MS, four bioactive compounds isolated from isolate STGG 14 were identified as moracin C, psoralen, 4,6-dimethyl-3 (4’-hydroxyphenyl) coumarin and xanthotoxin. All identified compounds except moracin C, belong to the coumarin group. According to the previous studies, among all compounds, psoralen and xanthotoxin displayed antifungal activity against several fungal pathogens.

Isolation and Characterization of Phosphate Solubilizing Bacteria from Upland Rice Cultivation Areas in Bangka Regency

“…Isolation of PSB from rice crops has been carried out by (Putriani et al 2019;Hartanti 2020;Wiraswati et al 2020;Damo et al 2022). Enterobacter asburiae is PSB isolated from the planting of paddy in the Aceh region (Putriani et al 2019).…”

“…Basil sp., Enterobacter sp., and Brachybacterium sp. bacteria are also isolated from the paddy plant philosopher originating in West Java (Wiraswati et al 2020). Furthermore, Acidovorax sp., Pseudomonas sp., Burkholderia sp., Sphingomonas sp., Mycolicibacterium sp., and Variovorax sp.…”

Ketahanan Enam Varietas Padi Terhadap Penyakit Blas (Pyricularia oryzea Cav.) pada Lahan Sawah Irigasi dan Sawah Tadah Hujan

“…Pengendalian penyakit blas telah dilakukan melalui beberapa cara yaitu: penggunaan fungisida dan varietas tahan, praktek agronomi, agens hayati, teknik budidaya dan perbaikan tanaman melalui pendekatan bioteknologi (Kongcharoen, 2020;Ribot et al, 2008;Wiraswati, 2020;Srivastava et al, 2017;Wiyono, 2020;Suriani, 2019). Salah satu teknik pengendalian penyakit Blas yang efektif, terjangkau dan ramah lingkungan yaitu penggunaan varietas tahan (Yulianto, 2017;Mustikarini, 2020;Vales, 2018).…”