Aris Tri Wahyudi
Department of Biology, Faculty of Mathematics and Natural Sciences, Institut Pertanian Bogor. Jl. Agatis, Dramaga, Bogor 16680, West Java, Indonesia

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

Screening and characterization of actinomycetes isolated from soybean rhizosphere for promoting plant growth UMI FATMAWATI; ANJA MERYANDINI; ABDJAD ASIH NAWANGSIH; Aris Tri Wahyudi
Biodiversitas Journal of Biological Diversity Vol. 20 No. 10 (2019)
Publisher : Society for Indonesian Biodiversity

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/biodiv/d201027

Abstract

Abstract. Fatmawati U, Meryandini A, Nawangsih AA, Wahyudi AT. 2019. Screening and characterization of actinomycetes isolated from soybean rhizosphere for promoting plant growth. Biodiversitas 20: 2970-2977. Actinomycetes which colonized plant rhizosphere has a vital role in improving plant growth by producing Indole-3-Acetic Acid (IAA). The aim of this study was to evaluate the potency of actinomycetes isolated from soybean rhizosphere as promoter agents for plant growth in vitro. Fifty actinomycetes isolates were successfully isolated from soybean rhizosphere. Based on the colorimetric methods, 35 isolates can produce IAA in various concentration, in the range of 0.46-30.6 mg/L. Seed germination assay using Ragdoll methods revealed that 26 isolates significantly promoted germination parameters, including the hypocotyl and the radicular length, the number of the lateral roots, and dry weight of the plant. Also, 14 from 26 isolates showed phosphate solubilizing activity in different phosphate-solubilizing index ranging from 1.25-2.62. Eight isolates were able to grow in N-free medium, indicating that these isolates have the ability in fixing nitrogen. Out of 23 from 26 isolates were detected to produce siderophore. All the tested isolates show chitinase production except ASR 55. Based on the observed parameters, it showed that there are four potential isolates (ASR 46, ASR 58, ASR 75 and ASR 76) as promising plant-growth promoters, phosphate solubilizer, nitrogen fixer, siderophore and chitinase producer. Based on the result of 16S rRNA sequence analysis, four potential isolates were identified as Streptomyces spp. in different taxa of strains and species.
Rice phyllosphere bacteria producing antifungal compounds as biological control agents of blast disease SRI MARTINA WIRASWATI; ABDJAD ASIH NAWANGSIH; IMAN RUSMANA; Aris Tri Wahyudi
Biodiversitas Journal of Biological Diversity Vol. 21 No. 4 (2020)
Publisher : Society for Indonesian Biodiversity

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/biodiv/d210401

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.