• The Korean Journal of Mycology
• /
• v.49 no.4
• /
• pp.441-454
• /
• 2021

Fungal diseases including anthracnose, stem rot, blight, wilting, and root rot of crops are caused by phytopathogens such as Colletotrichum species, Sclerotinia sclerotiorum, Phytophthora species, and Fusarium oxysporum and F. solani which threaten the production of chili pepper. In this study, to identify biological control agents (BCAs) of phytopathogenic fungi, potentially useful Bacillus species were isolated from the field soils. We screened out five Bacillus strains with antagonistic capacity that are efficiently inhibiting the growth of phytopathogenic fungi. Bacillus species were characterized by the production of extracellular enzymes, siderophores, and indole-3-acetic acid (IAA). Furthermore, the influence of bacterial strains on the plant growth promoting activity and seedling vigor index were assessed using Brassica juncea as a model plant. Inoculation with Bacillus subtilis SRCM 121379 significantly increased the length of B. juncea shoots and roots by 45.6% and 52.0%, respectively. Among the bacterial isolates, Bacillus subtilis SRCM 121379 showed the superior enzyme activities, antagonistic capacity and plant growth promoting effects. Based on the experimental results, Bacillus subtilis SRCM 121379 (GenBank accession no. NR027552) was finally selected as a BCA candidate.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.3
• /
• pp.408-418
• /
• 2021

The diversity and plant growth-promoting ability of fungal endophytes that are associated with five halophytic plant species (Phragmites australis, Suaeda australis, Limonium tetragonum, Suaeda glauca Bunge, and Suaeda maritima) growing in the Buan salt marsh on the west coast of South Korea have been explored. About 188 fungal strains were isolated from these plant samples' roots and were then studied with the use of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2). The endophytic fungal strains belonged to 33 genera. Alternaria (18%) and Fusarium (12.8%), of the classes Dothideomycetes and Sordariomycetes, were most rampant in the coastal salt marsh plants. There was a higher diversity in fungal endophytes that are isolated from S. glauca Bunge than in isolates from other coastal salt marsh plants. Plant growth-promoting experiments with the use of Waito-C rice seedlings show that some of the fungal strains could encourage a more efficient growth than others. Furthermore, gibberellins (GAs) GA1, GA3, and GA9 were seen in the Sa-1-4-3 isolate (Acrostalagmus luteoalbus) culture filtrate with a gas chromatography/mass spectrometry.

• The Korean Journal of Pesticide Science
• /
• v.17 no.4
• /
• pp.388-393
• /
• 2013

It has been well documented that Bacillus vallismortis strain EXTN-1, a beneficial rhizosphere bacterium, could enhance plant growth and induce systemic resistance to diverse pathogens in plants. However, the molecular mechanisms for how the EXTN-1 promote plant growth and induce resistances to diverse pathogens. Here, we show that 3-Hydroxy-2-butanone, a volatile organic compound (VOCs) emitted from the EXTN1, is a key factor for the bacteria-mediated beneficial effects on plant growth and defense systems. We found that the presence of volatile signals of EXTN-1 resulted in growth promotion of tobacco seedlings. The identification and analysis of EXTN-1-secreted volatile signals by solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) indicated that a 3-hydroxy-2-butanone could provide not only the plant growth promotion, but also higher resistance against Pectobacterium carotovorum SCC1. These results suggest that a volatile compound released from EXTN-1 enhances the plant growth promotion and immunity of plants.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.2 no.1
• /
• pp.65-73
• /
• 1994

Earthworm cast was investigated in this study in order to domestically develop inexpensive and safe plug nursery soil. 20,30,40 and 50% of earthworm cast were added to the nursery soil as vegetable plant growth media, in which peatmoss and vermiculite constituted the rest of the soil. The effects of earthworm cast on the growth of pepper (Capsicum annuum L.) seedling were obtained as follows. 1. According to the growth stages, significant differences(p=0.001) were recorded in number of leaves, leaf area and biological dry matter yield per plant(shoor or root dry matter yield per plant). In view of mixing ratios in the nursery soil, number of leaves, leaf area and stem weight per plant showed differences significantly at 1% level and leaf weight, root weight and biological dry weight per plant at 5% level, respectively. 2. The nursery soil with earthworm cast showed increased number of leaves and leaf area per plant compared to the commercial nursery soil particularly in the later stage of this study than in the earlier stage 3. Through the total period of seedling growth, leaf weight, stem weight and root weight per plant in the nursery soil with earthworm cast were genrally higher than those in the control and this trend was apparant in the treatment of more than 40% of mixing ratio with earthworm cast. 4. Although leaf weight per plant was higher than stem weight per plant till the 3rd week, from the 4th week stem weight per plant was getting higher. In the later stage of seedling growth, the stem weight was higher in the earthworm cast mixed treatment than that in the control. 5. There was no significant difference on biological dry matter yield in the earlier stage of this study, however in the later stage, it was higher in the earthworm cast mixed treatment than that in the control.

• Korean Journal of Plant Resources
• /
• v.1 no.1
• /
• pp.88-92
• /
• 1988

The study was conducted to determine the optimal basal media and the concentration of plant growth regulator for germination of seeds and growth of plantlet from Dendrobium monile. The results obtained were summarized as follows. Germination was similar in light and dark condition, but the growth of plantlet after germination was better under dark than under light condition in several media. Germination was best in Hyponex and Kyoto solution medium among the 9 media tested. The number of roots/shoot was most in the Hyponex medium containing 0,1ppm NAA and 1.Oppm BA.

• Mycobiology
• /
• v.34 no.1
• /
• pp.34-37
• /
• 2006

Growth responses of Zea mays and Glycine max to colonization by mixture of combination of three species of arbuscular mycorrhizal (AM) fungi, two species of Glomus and a species of Scutellospora were compared. In Zea mays, plants inoculated with single species of AM fungi showed significantly higher in dry weight than non-mycorrhizal plant for all three AM fungal species. Also, growth of plants inoculated with spores of two species of AM fungi was significantly higher than nonmycorrhizal control except for plants inoculated with two Glomus species. When three species of AM fungi were inoculated, the plants showed the highest growth. In Glycine max, plants with single AM fungal species inoculation were not significantly different in plant growth from nonmycorrhizal plants. When the plants were inoculated with combination of two or more AM fungal species, their growth significantly increased compared to nonmycorrhizal plants. In both plant species, mycorrhizal root colonization by Scutellospora species was significantly lower than by Glomus species.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.4
• /
• pp.87-92
• /
• 2019

In this paper, a closed hydroponics device was designed and fabricated to grow and harvest plants in a small space for safe consumption, which enables horticultural activities that are difficult to perform due to space constraints from urbanization. This device also aimed to minimize the air pollution of crops. To obtain data for the optimal growth conditions for crops in this intelligent plant-growing system, sensors were used to measure and control the growth conditions. To investigate the optimal growth conditions, blue lettuce and crown daisy were selected as representative crops. The growth rates were comparatively analyzed through four experiments for each plant. This hydroponics device was used to collect data on growth rates that are altered depending on cultivation conditions, which can then be used to study methods to control the growth rate of crops.

• The Plant Pathology Journal
• /
• v.38 no.5
• /
• pp.425-431
• /
• 2022

Plant microbiota has influenced plant growth and physiology significantly. Plant and plant-associated microbes have flexible interactions that respond to changes in environmental conditions. These interactions can be adjusted to suit the requirements of the microbial community or the host physiology. In addition, it can be modified to suit microbiota structure or fixed by the host condition. However, no technology is realized yet to control mechanically manipulated plant microbiota structure. Here, we review step-by-step plant-associated microbial partnership from plant growth-promoting rhizobacteria to the microbiota structural modulation. Glutamic acid enriched the population of Streptomyces, a specific taxon in anthosphere microbiota community. Additionally, the population density of the microbes in the rhizosphere was also a positive response to glutamic acid treatment. Although many types of research are conducted on the structural revealing of plant microbiota, these concepts need to be further understood as to how the plant microbiota clusters are controlled or modulated at the community level. This review suggests that the intrinsic level of glutamic acid in planta is associated with the microbiota composition that the external supply of the biostimulant can modulate.

• The Plant Pathology Journal
• /
• v.23 no.3
• /
• pp.223-225
• /
• 2007

Many plant growth-promoting rhizobacteria (PGPRs) have been known for beneficial effects on plants including biological control of soilborne pathogens, induced systemic resistance to plant pathogens, phytohormone production, and improvement of nutrient and water uptake of plants. We developed a simple and rapid method for screening potential PGPR, especially phytohormone producing rhizobacteria, or for analyzing their functions in plant growth using cucumber seedling cuttings. Surface-sterilized cucumber seeds were grown in a plastic pot containing steamed vermiculite. After 7 days of cultivation, the upper part 2 cm in length of cucumber seedling, was cut and used as cucumber cuttings. The base of cutting stem was then dipped in a microcentrifuge tube containing 1.5ml of a bacterial suspension and incubated at $25^{\circ}C$ with a fluorescent light for 10 days. Number and length of developed adventitious roots from cucumber cuttings were examined. The seedling cuttings showed various responses to the isolates tested. Some isolates resulted in withering at the day of examination or in reduced number of roots developed. Several isolates stimulated initial development of adventitious roots showing more adventitious root hair number than that of untreated cuttings, while some isolate had more adventitious root hair number and longer adventitious roots than that of untreated control. Similar results were obtained from the trial with rose cuttings. Our results suggest that this bioassay method may provide a useful way for differentiating PGPR's functions involved in the development of root system.

• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.4
• /
• pp.223-231
• /
• 2002

A phosphate-solubilizing bacterium, Enterobacter intermedium 60-2G, was examined for plant growth-promotion and induction of systemic resistance using a model system of cucumber and scab disease, caused by Cladosporium cucumerinum. Compared with a nonbacterized control, treatment of cucumber with E. intermedium significantly reduced the severity of scab disease after challenge-inoculation with C. cucumerinum. Treatment of cucumber with E. intermedium also enhanced cucumber growth. The 60-2G strain showed a strong antimicrobial activity against several plant pathogenic fungi including Fusarium soysporum and Magnaporthe grisea. These results suggest the E. intermedium 60-2G is a promising candidate as a biological control agent displaying multiple beneficial properties to promote plant health.