• The Plant Pathology Journal
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• 제26권2호
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• pp.178-184
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• 2010

Four major diseases of chili pepper including two fungal diseases, anthracnose (Colletotrichum acutatum) and Phytophthora blight (Phytophthora capsici), and two bacterial diseases, bacterial wilt (Ralstonia solanacearum) and bacterial spot (Xanthomonas campestris pv. vesicatoria), were investigated under future climate-change condition treatments in growth chambers. Treatments with elevated $CO_2$ and temperature were maintained at $720ppm{\pm}20ppm$ $CO_2$ and $30^{\circ}C{\pm}0.5^{\circ}C$, whereas ambient conditions were maintained at $420ppm{\pm}20ppm$ $CO_2$ and $25^{\circ}C{\pm}0.5^{\circ}C$. Pepper seedlings or fruits were infected with each pathogen, and then the disease progress was evaluated in the growth chambers. According to paired t-test analyses, bacterial wilt and spot diseases significantly increased by 24% (p=0.008) and 25% (p=0.016), respectively, with elevated $CO_2$ and temperature conditions. On the other hand, neither Phytophthora blight (p=0.906) nor anthracnose (p=0.125) was statistically significant. The elevated $CO_2$ and temperature accelerated the progress of bacterial wilt by two days and bacterial spot by one day compared to the ambient treatment. Temperature regime studies of the diseases without changes in $CO_2$ confirmed that the accelerated bacterial disease progress was mainly due to the increased temperature rather than the elevated $CO_2$ conditions.

• Mycobiology
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• 제37권1호
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• pp.28-30
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• 2009

This study was aimed at evaluating the growth promoting effect of symbiotic algal polyol (ribitol) and plant hormones on the lichen-forming fungi (LFF), Ramalina farinacea (CH050010 and 40403) and Ramalina fastigiata. The addition of ribitol to basal (malt-yeast extract) medium enhanced the relative growth rates of all three LFF. R. farinacea (CH050010), R. farinacea (40403) and R. fastigiata (H06127) showed 35.3%, 29.0% and 29.3% higher growth rates, respectively, compared to the control. IBA (indole-3-butyric acid) and TIBA (2,3,5-tridobenzoic acid) also increased growth rates of the LFF by 34 to 64% and 7 to 28%, respectively, compared to the control. The combination of ribitol with IBA or TIBA synergistically increased the growth of all LFF. For example, ribitol and IBA treatments increased growth rates of R. farinacea (CH050010), R. farinacea (40403) and R. fastigiata (H06127) by 79.4%, 40.3% and 72.8% in, respectively, compared to those grown on the basal medium. The stimulating effect of ribitol and IBA on the LFF growth induced vertical development of the fungal mass in culture. We suggest that lichen-forming fungal growth of Ramalina lichens can be stimulated aposymbiotically by supplementing polyols and plant hormones to the basal medium in the mass production of lichen secondary metabolites under large scale culture conditions.

• 한국환경과학회지
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• 제28권3호
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• pp.321-328
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• 2019

This study aimed to analyze the growth and physical responsees of Dracaena braunii in response salt accumulation in ornamental water culture and to examine the effect of activated carbon on this growth response. The experiment was conducted in a plant growth chamber and the indoor environmental conditions of the chamber were set at $23{\pm}1^{\circ}C$ temperature, $70{\pm}3%$ humidity, and 1,000 lux brightness. The observation of the growth response of plants in the presence of activated carbon showed that the pH with activated carbon maintained sub-acidic to neutral (6.27~7.32) conditions and showed decreased electric conductivity in the media. As the treatment with added activated carbon showed good growth and physical responses, this indicated that absorption effect of activated carbon had a positive influence on the growth of plants. However, as the absorption effect of activated carbon may decrease over time and the use of high concentrations of activated carbon might cause nutrition shortage, various concentration of activated carbon and their absorption effects need to be investigated in the future.

• 한국작물학회지
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• 제69권1호
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• pp.15-24
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• 2024

Environmental factors play an important role in crop growth and development. In recent years, climate change has become a challenge that limits environmental factors. Light is an important environmental factor for photosynthesis in rice. In addition, temperature is one of the most important factors for rice production; thus, a 1℃ increase in temperature because of climate change can affect rice growth and development. Therefore, we investigated the effect of shading on the growth characteristics of rice under different temperature conditions from the vegetative stage to the flowering stage. Plants were grown at three different temperatures: 26℃/16℃ for 21℃, 29℃/19℃ for 24℃, and 22℃/32℃ for 27℃ in a phytotron. A 55% shade treatment was applied after 10 days of transplanting until the flowering stage. Plant height was not affected by the shading treatment. In the maximum tiller number response to shading, a lower tiller number and growth speed of tiller was found in the 27℃ condition. Among leaf characteristics, shading increased the flag leaf area, length, width, and effective leaf area; however, it decreased the leaf number on the main stem, especially at 27℃. In terms of stem characteristics, shading affected culm wall thickness in both varieties. Finally, regarding the panicle characteristics, lower panicle numbers, spikelet numbers per panicle, primary numbers, and secondary numbers per panicle were found under the shading treatment. Most of the desirable characteristics were affected by the shading treatment at 27℃. Overall, these results indicated that shading had a greater effect on rice plant growth at high temperature.

• 한국자원식물학회지
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• 제18권3호
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• pp.410-416
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• 2005

백두산에 자생하는 홍경천의 종자를 기내에서 발아시켜 잎 절편으로부터 캘러스를 유도 할 수 있었으며, 식물생장조절제의 처리로 기관분화도 시킬 수 있었다. 토양순화는 약 8주후면 멸균되지 않은 토양에서도 홍경천의 뿌리활착이 활발함을 알 수 있었다. 캘러스의 유도율은 Kinetin 1 mg/L와 NAA 2 mg/L를 첨가한 배지에서 가장 높은 $98\%$의 캘러스 형성률을 보였다. 캘러스에서 부정아의 유도는 BA가 1 mg/L 첨가된 MS배지에서 $96.6\%$의 높은 부정아형성률을 보였으며 뿌리와 신초의 신장은 옥신은 첨가되지 않은 배지에서 다량으로 유도됨을 관찰할 수 있었다. 토양순화는 $100\%$ 성공적 이었다.

• 식물병연구
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• 제15권3호
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• pp.248-253
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• 2009

항균활성을 가진 키토산은 우리나라 포장에서 다양한 식물 방제와 식물 생장을 위해 넓게 사용하고 있다. 고분자와 저분자(키토올리고당)의 키토산 화합물을 혼합한 2가지 제제(SH-1, SH-2)에 대한 병 방제 효과를 Fulvia fulva에 의해 발생하는 토마토 잎곰팡이병에 대하여 비닐하우스에서 조사하였다. 두 제제(SH-1, SH-2)는 두 번의 포장 시험에서 병 방제에 대한 활성을 나타내었다. 두 제제의 예방적인 병 방제에 대한 활성은 합성농약인 thiophanate-M과 비교하여 수행하였다. 병 방제를 위한 제형의 활성유지는 살포 후 21일까지 지속되었다. 병 방제를 위한 키토산의 효과적인 농도는 1,200 mg a.i/L였다. 포트시험에서 키토산 제제는 600 mg a.i/L 농도에서 식물생장이 증진되었다. 결과적으로 키토산 제제는 토마토 잎곰팡이병방제를 위한 친환경제제로서 활력을 가지며 식물생장도 촉진하였다.

• Journal of Plant Biotechnology
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• 제7권3호
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• pp.161-167
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• 2005

Brassinosteroids are steroidal plant hormones and are known to modulate physiological and cellular response in a wide range of plant species. Considerable insights has been achieved of the physiological role of brassinosteroid in Brassica species in the past few years, but their effect on direct organogenesis has not been extensively studied. In this sense, under optimal basal media and growth conditions we tested the cellular and organogenic response of 24-epibrassinolide (EBL) in a variable concentration (0.1 to $5.0\;{\mu}M$) and Zeatin (Z) (1.0 to $100\;{\mu}M$) and their synergic effect on hypocotyl explants of cauliflower and broccoli. The isolated EBL accelerated cell elongation and promotes direct organogenesis. One micromolar EBL + $10\;{\mu}M$ of Z was the most efficient combination for cell elongation, cell differentiation as well as for organogenesis. A suppressing effect on root induction was confirmed for all the tested hormone levels. The general results indicate a synergic effect of EBL-Z and EBL potentates Zeatin activity, at least in certain tissues. Besides de genetic factors, we can speculate that the natural hormone concentration in the explants might affect the responses by application of exogenous growth regulators. Experiments with new plant growth regulators, like brassinolide, are important aiming to maximize or accelerate plant regeneration for in vitro multiplication or for genetic transformation.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.539-544
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• 2013

The effects of culture depth (2-10 cm) and cell density on the growth rate and biomass productivity of Chlorella sp. XQ-200419 were investigated through the use of a self-designed open circular pond photobioreactor-imitation system. With increases in culture depths from 2 to 10 cm, the growth rate decreased significantly from 1.08 /d to 0.39 /d. However, the biomass productivity only increased slightly from 8.41 to 11.22 $g/m^2/d$. The biomass productivity (11.08 $g/m^2/d$) achieved in 4 cm culture with an initial $OD_{540}$ of 0.95 was similar to that achieved in 10 cm culture with an initial $OD_{540}$ of 0.5. In addition, the duration of maximal areal productivity at a 4 cm depth was prolonged from 1 to 4 days, a finding that was also similar to that of the culture at a 10 cm depth. In both cases, the initial areal biomass densities were identical. Based on these results and previous studies, it can be concluded that the influence of culture depth and cell density on areal biomass productivity is actually due to different areal biomass densities. Under suitable conditions, there are a range of optimal biomass densities, and areal biomass productivity reaches its maximum when the biomass density is within these optimal ranges. Otherwise, biomass productivity will decrease. Therefore, a key factor for high biomass productivity is to maintain an optimal biomass density.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1045-1059
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• 2021

Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.

• Journal of Plant Biotechnology
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• 제49권3호
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• pp.213-221
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• 2022

Wild garlic (Allium victorialis var. platyphyllum, AVVP) is a nontimber forest product used as an edible and medicinal vegetable. AVVP is usually propagated form offspring bulbs but it takes a long time to harvest. Using tissue culture technology could overcome this problem. This study investigated the optimal conditions for shoot multiplication, root growth, and plant growth by scooping AVVP bulbs. AVVP bulbs harvested from Ulleung Island, Korea, the main producer of AVVP, were surface-sterilized and used for in vitro propagation. Shoot multiplication was performed by the scooping method. More than five multiple shoots were induced from scooped tissue in Quoirin and Lepoivre (QL) medium containing plant growth regulators (PGRs); the maximum number of multiple shoots were induced from scooped tissue in QL medium containing 0.45 μM thidiazuron (TDZ) after 16 weeks of culture. Roots were induced directly at the base of the shoots in all treatments. In vitro rooting depended on the type of PGRs, and the best root-inducing treatment was QL medium containing 9.84 μM indole-3-butyric acid (IBA). Plants with in vitro roots were transferred to pots containing artificial soil and successfully acclimatized for 4 weeks. The acclimatized plants showed a survival rate of 80% after 20 weeks and gradually promoted growth depending on the acclimatization period. The results of this study will be of great help to AVVP dissemination through sustainable mass propagation.