Endophytic fungus is a fungus that is associated with healthy host tissues without causing disease symptoms. T h i s f u n g u s can be developed as the biological control agent of chilli pests. This study i s aimed a t isolating, selecting and evaluating the potency of endophytic fungi from chilli crops (Capsicum annuum L.) as bioinsecticides. Endophytic fungi were isolated from leaves, trunk, branches and roots of chilli. Screening endophytic fungal isolates pathogenic to insect were conducted using fifth instar larvae of Tenebrio molitor. The isolates with the highest mortality were further assayed against Spodoptera litura larvae. The results of the research showed that of the 46 isolates of endophytic fungi that were successfully isolated from chilli, 22 isolates were pathogenic (47.82%) and 24 isolates not pathogenic in insects. Mortality of T. molitor larvae ranged from 15- 30% and the percentage of sporulation ranged from 11.11- 100%. Endophytic fungi werealso able to infect S. litura larvae. Mortality of second instar S. litura larvae ranged from 23.34-64.99%, depending up on the conidial concentrations. Endophytic fungi from chilli were pathogenic in insect and can be developed as bioinsecticides identified as Aspergillus flavus.

Abstract. Rahma H, Nurbailis, Kristina N. 2019. Characterization and potential of plant growth-promoting rhizobacteria on rice seedling growth and the effect on Xanthomonas oryzae pv. oryzae. Biodiversitas 20: 3654-3661. Xanthomonas oryzae pv. oryzae (Xoo), a major limiting factor in rice production, and the use of resistant Xoo varieties have failed to control the bacterial pathogens as well as increased yield. It is due to the diversity in pathotypes, caused by environmental factors, the nature of resistant variety used, and gene mutation. The aims of this study were to select rhizobacterial strains with the potential of suppressing Xoo growth and promoting the growth of rice seedlings. This experiment was conducted in a completely randomized design (CRD) using seven rhizobacterial isolates selected through a dual culture test, with four replications. There were four isolates that potential in inhibiting the growth of Xoo, namely KJKB5.4, LMTSA5.4, Bacillus cereus AJ34, and Alcaligenes faecalis AJ14, with inhibition diameters greater than 11.50 mm. Rhizobacterial supernatant of 4 potential isolates has a zone of inhibition ranging from 12.25 to 24.00 mm. Four potential isolates were also able to solubilize phosphate, produce indole acetic acid (IAA) growth hormone, and siderophore, as well as enhance the growth of rice seedlings. Based on the nucleic acid sequencing of LMTSA5.4, KJKB5.4, and RK12 isolates were identified as Stenotrophomonas malthopilia strain LMG 958 (99.13%) accession NR 119220.1, Stenotrophomonas pavanii strain LMG 25348 (95.84%) accession NR 118008.1 and Ochrobactrum ciceri strain ca-34 (92.91%) accession NR115819.1.

Disease incidence of Stewart’s wilt on the seed and response of several maize varieties to Pantoea stewartii subp. stewartii. Stewart’s wilt disease of maize is caused by Pantoea stewartii subsp. stewartii.  This bacterium is seed-borne pathogens, when attacked maize caused yield lost 40-100%.  The objective of this research was to detemine the incidence level of stewart’s wilt disease, growth of some varieties of maize and their response to stewart’s wilt pathogens Pantoea stewartii subsp. stewartii.  The research was conducted in the Laboratory of Bacteriology and Greenhouse Cikabayan IPB from November 2011 to March 2012. In experiment I, nineteen samples of maize were used for symptom test  in the maize seedling stage, using Randomized Block Design with three replications. Experiment II used a Randomized Block Design with 2 factors: maize varieties (8 hybrids varieties, 3 open pollinated varieties, and 7 sweet corn varieties) and bacteria isolates  (BGR 2, BGR 4, BGR 28, BGR7 and PSM 27), with three replications. The results showed in experiment I, the incidence of stewart’s wilt disease ranged 2.00 – 15.33%, germination and vigor index of maize seed were 68.00 – 95.33% and 55.33 – 90.67% respectively.  While in experiment II, hybrid and open pollinated of maize varieties were resistant to moderately susceptible   while all sweet corn varieties were susceptible to infection of Pantoea stewartii subsp. stewartii.

Abstract. Nurbailis, Djamaan A, Rahma H, Liswarni Y. 2019. Potential of culture filtrate from Trichoderma spp. as biofungicide to Colletotrichum gloeosporioides causing anthracnose disease in chili. Biodiversitas 20: 2915-2920. Trichoderma spp. have the potential to be used for controlling the airborne pathogenic fungi such as C. gloeosporioides. The purpose of this study was to evaluate the antifungal activity of the culture filtrate of five isolates of Trichoderma spp. (T. harzianum, T. viride, T. koningii, Trichoderma PP2, Trichoderma PP3) against C. gloeosporoides causing anthracnose disease in chili. Culture filtrate of Trichoderma spp. was produced from single culture and dual culture techniques. The design was a Completely Randomized Design with six treatments and four replications. The treatments were culture filtrate from T. harzianum, T. viride, T. koningii, Trichoderma PP2, Trichoderma PP3, and negative control (without culture filtrate from Trichoderma spp.). Parameters observed were: the diameter of the colony, colony coverage, conidial germination, and conidial density. The results of this research showed all the culture filtrate from Trichoderma spp. produced by single and dual culture techniques can inhibit the growth of C. gloeosporioides. The culture filtrate from Trichoderma PP2 and T. koningii were the most potential in inhibiting the growth, conidial density, and conidial germination of C. gloeosporioides.

Abstract. Rahma H, Nurbailis, Busniah M, Kristina N, Larasati Y. 2021. The potential of endophytic bacteria to suppress bacterial leaf blight in rice plants. Biodiversitas 23: 775-782. Endophytic bacteria are potential as biocontrol agents against bacterial leaf blight (BLB) disease caused by Xanthomonas oryzae pv. oryzae in rice to support sustainable agriculture. This study aimed to select and characterize 22 endophytic bacteria isolated from healthy rice, determine their ability to promote plant growth and suppress bacterial leaf blight disease in rice and also identify potential endophytic bacterial isolates. The study was arranged in a Completely Randomized Design with 24 treatments and three repetitions. The treatments used in the current study consisted of Xanthomonas oryzae infected plants and treated with endophytic bacterial isolates; infected plants without endophytic bacteria treatment (positive control), non-infected plants (negative control). Identification of potential endophytic bacteria was performed based on 16S rRNA sequences. Three out of 22 bacterial isolates, i.e., LmB1, LmA6, and LmB2 were able to suppress bacterial leaf blight disease with severity levels of 35.82%, 23.78%, and 23.78%, respectively. Based on the rice plant growth parameters, three bacterial isolates (LmA6, LmB1, and LmB35) were able to increase the growth of rice plants with an average value of 69.56%, 56.51%, and 47.82%, respectively. Two bacterial isolates, i.e., LmB 1 and LmA6 suppress the development of bacterial leaf blight disease and increase the growth of rice plants. Based on DNA sequence comparisons of DNA fragments amplified by 16S rRNA related marker of the selected bacterial isolates and database, then LmA6, LmB2, LmB1, and LmB35 had similarities with Bacillus cereus MD152 (96.87%), Bacillus thuringiensis ATCC 10792 (98.20%), Ochrobactrum intermedium strain OI1 (97.52%), and Stenotrophomonas maltophilia strain A1w2 (97.92%), respectively. Our study revealed that the indigenous endophytic bacteria from rice plants could be potential biological agents for controlling bacterial leaf blight disease and increasing plant growth.