Effect of three composts with active ingredients of Pseudomonas fluorescens on the development of white root disease and production of rubber plants

Damiri N, Rofiqi R, Mulawarnam, Rahim SE, Febyanti TP. 2021. Effect of three composts with active ingredients of Pseudomonas fluorescens on the development of white root disease and production of rubber plants. Biodiversitas 22: 3237-3242. White root disease (WRD) caused by Rigidoporus lignosus is a very dangerous disease and a scourge for rubber farmers because it can result in decreased production and kill rubber plants. This research was conducted to observe the impact of compost enriched with the biological agent Pseudomonas fluorescens on the development of white root disease and production in rubber plants. The results showed that the application of compost with active ingredient of P. fluorescens isolates A and B reduced the severity of white root disease in plants with mild, moderate and severe infections, 34.12%, 29.31% and 57.21% respectively. Application of compost with P. fluorescens isolates A and B, either singly or in combination, can increase latex production. The treatment of giving compost enriched with P. fluorescens isolates AR and ABR on rubber plants infected with mild WRD resulted in the highest latex production of 406 gm and 402.74 gm per plant, respectively. These two treatments did not differ from each other but were significantly different from the other treatments and controls.

In vitro Evaluation of the Fungicidal Potential of Aqueous and Methanolic Extracts of Thevetia peruviana on the Development of Rigidoporus lignosus, Causal Agent of White Root rot of Hevea brasiliensis

Aims: The objective of this work is to evaluate the effect of (aqueous (EAq) and methanolic (ME)) extracts of Thevetia peruviana on the in vitro development of Rigidoporus lignosus. Study Design: A synthetic fungicide (Onazol 100), two extracts at differents concentrations: C1 = 3.5 mg / ml; C2 = 7 mg / ml; C3 = 15 mg / ml; C4 = 30 mg / ml; C5 = 50 mg / ml and C6 = 100 mg / ml for EAq; C1 = 3.5 ml/ml; C2 = 7 ml/ml; C3 = 15 ml/ml; C4 = 30 ml/ml; C5 = 50 ml/ml for ME and a negative control (T = 0 mg / ml) were used. Place and Duration of Study: The study was conducted in pathology laboratory at University of Yaounde I and IRAD of Nkolbisson in 2018. Methodology: Daily measurements of the pathogen's development was used to evaluate the average growth (D) of the mycelium. The inhibition percentages of the different doses of EAq, ME and ONAZOL 100 were calculated after 4 to 5 days of growth of the fungus. Results: The major result obtained compared to the rate of rot showed that the treatments EAq, ME (C6) and ONAZOL 100 were closed. The disease rates at different concentrations of C1 to C6 were 13.91 to 100% for ME, 9.34 to 100% for EAq, and 100% for ONAZOL 100. Conclusion: The two extracts are promising, and on small and medium scale, could be an effective and cheap formulation for the control of Rigidoporus lignosus.

Molecular identification of endophytic fungi from torch ginger (Etlingera elatior) antagonist to phytopathogenic fungi

Lutfia A, Munir E, Yurnaliza. 2020. Molecular identification of endophytic fungi from torch ginger (Etlingera elatior) antagonist to phytopathogenic fungi. Biodiversitas 21: 2681-2689. Medicinal plants are valuable sources in exploration of endophytic microorganisms. The utilization of culturable endophytes, particularly endophytic fungi in pharmacological aspects has been reported in many literature. Zingiberaceae, being known as one of medicinal plant families, is commonly used in tropical countries, e.g Indonesia to treat health disorders and ailments. However, little information has been reported upon their associative endophytic fungi that may be used as biocontrol agents against phytopathogenic fungi. Efforts to elaborate on the symbiotic relationship between endophytic fungi and host to explain the antifungal ability from endophytes are presented in this study. Six fungal morphotypes were recovered from the rhizome fragment of torch ginger (Etlingera elatior (Jack) RM Smith) sampled from Sibayak forest, North Sumatra, Indonesia. All isolates displayed potential antifungal activities against Fusarium oxysporum, Ganoderma boninense, and Rigidoporus lignosus as representative phytopathogens in a dual culture plate assay. All fungal morphotypes were identified based on their 18S rDNA-ITS regions. Molecular identification revealed that most isolates were related to Trichoderma spp. while one isolate was identified as Pestaliotopsis sp. The endophytic assemblage of mostly Trichoderma strains in our study may reveal a mutual relationship of these soil fungi as root colonizer displaying biocontrol properties against phytopathogenic fungi to host.

EKSPLORASI DAN IDENTIFIKASI CENDAWAN ANTAGONIS TERHADAP JAMUR AKAR PUTIH (Rigidoporus lignosus) PADA TANAMAN PALA (Myristica fragrans Houtt)

Nutmeg (Myristica fragrans Houtt) is a multipurpose plantation commodity crop that almost all parts of the plant have strategic economic value to be cultivated. In Indonesia there are the largest nutmeg commodity centers, including the Maluku islands, North Sulawesi and Aceh. The biggest problem with nutmeg plants is the attack of pests and diseases. One of the most severe diseases in nutmeg is white root mushroom (Rigidoporus lignosus). This study aims to 1) determine the fungus of white root fungus antagonists (Rigodoporus lignosus) from the Aceh nutmeg rhizosphere (Myristica fragrans Houtt), 2) identify the content of antibiotic fungus JAP antagonist compounds in Aceh nutmeg plants. The study was conducted by taking soil samples from nutmeg plants at three nutmeg plantations in South Aceh. The antagonist fungus isolation activity uses a dilution method. Isolation of JAP from infected roots using direct planting method. Furthermore, it is identified macroscopically and microscopically. The antagonist test was carried out using the dual culture method with RAL. From the rhizosphere in the nutmeg area, 5 candidate antagonist isolates were obtained, having high in vitro antagonism ability to the pathogen R. lignosus. Identification results showed that isolates 1, 2 and 3 were Trichoderma spp, and isolates 4 and 5 were Gliocladium virens. Keywords: In vitro, the content of antibiotic compounds, Aceh nutmeg, Rigidoporus lignosus, antagonistic test

EFEKTIVITAS BIOFUNGISIDA Trichoderma koningii TERHADAP PENCEGAHAN PENYAKIT JAMUR AKAR PUTIH DI PEMBIBITAN BATANG BAWAH TANAMAN KARET (Hevea brasiliensis)

One of the main obstacles in rubber cultivation is the white root fungus (JAP) attack which caused by Rigidophorus ligonosus. This pathogen infects rubber plants from the nursery until the mature plants. Efforts to control the disease have been carried out by chemical, technical culture and use of biological agencies. This research was conducted at the STIP-AP Medan in January 2017 to June 2017, this study used a non-factorial Randomized Block Design (RBD) with four replications and four treatments. Using Trichoderma koningii with somes doses were 20 grams, 30 grams, and 40 grams/seedling. The results of this study indicate that the biofungicide application of Trichoderma koningii 30 g/seedling produces the greatest inhibition of the rubber plants seedling nursery against the growth of pathogens Rigidoporus lignosus.

Antagonism of Pseudomonas fluorescens from plant roots to Rigidoporus lignosus pathogen of rubber white roots in vitro

Damiri N, Mulawarman, Effendi RS. 2019. Antagonism of Pseudomonas fluorescens from plant roots to Rigidoporus lignosus pathogen of rubber white roots in vitro. Biodiversitas 20: 1549-1554. Indonesia's rubber productivity is still relatively low. This low productivity of rubber can be caused by many factors such as the attack of Rigidoporus lignosus. This study aims to explore antagonistic bacteria from the plant roots and test their antagonism ability to R. lignosus at the laboratory level. This research was conducted at the Laboratory at the Faculty of Agriculture, Sriwijaya University, Indralaya Ogan Ilir District, South Sumatra, Indonesia. Corporate and bacterial isolations are carried out by serial dilution method. In-vitro testing of antagonistic bacteria was carried out using the dual-culture technique method on sterile PDA media by direct opposition between R. lignosus culture and antagonistic bacteria explored. Results of the study showed that a number of bacterial isolates existed there, namely 11 bacterial isolates belonging to Pseudomonas fluorescens, four from turmeric roots, three from the roots of rubber seedlings, two from galangal roots and two from the roots of yielding rubber plants. P. fluorescens from roots of turmeric, rubber seedlings, rubber, and galangal was able and had the potential to be developed as biopesticide to control R. lignosus. The best isolate in suppressing the growth and development of R. ligonosus is P. fluorescens isolates from the roots of turmeric and those of rubber seedlings (isolates of C, B, and G).

Efektivitas Fungisida Berbahan Aktif Heksakonazol terhadap Penyakit Jamur Akar Putih Bibit Tanaman Karet (Hevea brasiliensis)

<p class="KataKunciInggris">White Root Fungus Disease (JAP) is the biggest threat in rubber. The attack can result in a significant reduction in number, especially in plants lasting 0-3 years. The pathogen that causes white fungus is Rigidoporus lignosus. In JAP endemic areas, decreased tree density 40-50%. In rubber seedlings, symptoms of JAP attack with yellowing color leaves, then dry and fall. This study was conducted at STIP-AP Medan from January 2017 to June 2017. The aim of the study was to determine the effectiveness of several doses of hexaconazole. This study uses a non-factorial Randomized Block Design (RBD) with four replications. Hexaconazole fungicides are active with treatment of A0, A1, A2, A3 and A4 (0, 5, 10, 15 and 20 ml / l air). The results of this study indicate that A2 application of hexaconazole-active fungicides (10 ml / l air) has been effective in controlling JAP disease in rubber seedlings.</p>

EKSPLORASI DAN IDENTIFIKASI Trichoderma spp. DI UNIVERSITAS TEUKU UMAR

<Trichoderma sp. is land microorganisms which saprophyte and naturally strike pathogens and beneficial for the plant. Trichoderma sp. could hinder the growth of some plant diseases such as Rigidoporus lignosus, Fusarium oxysporum, Rhizoctonia solani, Sclerotium rolfsi. In addition, as the ability to control pathogen, Trichoderma sp. give positive effect on rhizosfer, the growth of plants, and plants production. This research aimed to identifying Trichoderma spp. in University of Teuku Umar. The methodology are exploration, isolation, and macroscopic and microscopic observation. The research showed that the similarity of Trichoderma spp. at FKM, FP, FT, and Rectorat were Trichoderma sp. 1 and Trichoderma sp. 2. On UF of peat and alluvial land only had Trichoderma sp. 1. Keywords: Different location, exploration and identification, Trichoderma spp.

Kemampuan Mikrob Endofit dan Rizosfer Tanaman Karet dalam Mengendalikan Rigidoporus lignosus

Rigidoporus lignosus is the most important pathogen of rubber tree which causes white root rot disease. The use of antagonistic microbe is recommended to control this pathogen. This research was conducted to isolate endophytic and rhizospheric microbes, and to study their ability to inhibit growth of R. lignosus. Research consisted of isolation of endophytic and rhizospheric microbes, pathogenicity test, in vitro and in vivo assays, growth promotion assays, and identification. There were 99 isolates of bacteria and 18 isolates of fungi isolated from the root and rhizosphere of rubber trees. In vitro and in vivo assay showed that 2 bacterial isolates, i.e. endophytic bacteria ME8, and rhizospheric bacteria MR3; and 3 fungal isolates, i.e. endophytic fungi CB8, CB6, and CL3 were able to inhibit the growth of R. lignosus. Endophytic bacteria ME8 showed the ability of solibilizing phosphate and fixing nitrogen. Rhizospheric bacteria MR3 showed the ability of solubilizing phosphate. The isolates CB6 and CL3 were very similar with Chaetomium sp. and Penicillium sp., respectively based on morphological characters; while CB8 was identified as mycelial sterile. Based on 16S rRNA sequences, endophytic bacterium ME8 and rhizospheric bacteria ME3 were identified as Bacillus siamensis B268 and B. amylolyquefaciens BCRh10, respectively. Endophytic and rhizospheric microbes isolated from rubber trees has the potency as biocontrol agents of R. lignosus.