• Journal of Biosystems Engineering
• /
• 제42권3호
• /
• pp.163-169
• /
• 2017

Purpose: This study was performed to evaluate the feasibility of using an infrared thermography technique for phenotype analysis of pepper seedlings exposed to a low-temperature environment. Methods: We employed an active thermography technique to evaluate the thermal response of pepper seedlings exposed to low-temperature stress. The temperatures of pepper leaves grown in low-temperature conditions ($5^{\circ}C$, relative humidity [RH] 50%) for four periods (6, 12, 24, and 48 h) were measured in the experimental setting ($23^{\circ}C$, RH 70%) as soon as pepper seedling samples were taken out from the low-temperature environment. We also assessed the visible images of pepper seedling samples that were exposed to low-temperature stress to estimate appearance changes. Results: The greatest appearance change was observed for the low-temperature stressed pepper seedlings that were exposed for 12 h, and the temperature from these pepper seedling leaves was the highest among all samples. In addition, the thermal image of low-temperature stressed pepper seedlings for 6 h exhibited the lowest temperature. Conclusions: We demonstrated that the leaf withering owing to the water deficiency that occurred under low-temperature conditions could induce an increase in temperature in plant leaves using the infrared thermography technique. These results suggested that the time-resolved and averaged thermal signals or temperatures of plants could be significantly associated with the physiological or biochemical characteristics of plants exposed to low-temperature stress.

• Mycobiology
• /
• 제46권2호
• /
• pp.122-128
• /
• 2018

Arbuscular mycorrhizal fungi (AMF) are well-known for their ability to improve plant growth and help plants withstand abiotic stress conditions. Unlike other fungi and bacteria, AMF cannot be stored, as they are obligate biotrophs. Long-term preservation of AMF spores is challenging and may lead to the loss of viability and efficiency. This study aimed to understand the effect of prolonged subculture of AMF species on the growth and glomalin-related soil protein (GRSP) from red pepper (Capsicum annuum L.). AMF spores were mass-produced using different techniques and subcultured in pots with sorghum sudangrass as the host plant for 3 years. Experimental soil samples were collected from natural grassland. Five different AMF inocula were used in triplicate as treatments. After 70 days of growth, red pepper plants were harvested and plant dry weight, plant nutrient content, mycorrhizal colonization, AMF spore count, and soil glomalin content were determined. AMF-treated plants displayed higher dry weight than controls, with only fruit dry weight being significantly different. Similarly, significant differences in phosphorous and potassium contents of the above-ground plant parts were observed between mycorrhizal and control treatments. In addition, soil GRSP content was significantly higher in plants inoculated with Rhizophagus sp. and Gigaspora margarita. The increased plant growth and GRSP content suggest that AMF can be maintained for 3 years without losing their efficiency if subcultured regularly with different symbiotic host plants.

• Journal of Microbiology
• /
• 제43권6호
• /
• pp.510-515
• /
• 2005

The growth of red pepper plants was enhanced by treatment with the rhizobacterium, Bacillus cereus MJ-1. Red pepper shoots showed a 1.38-fold increase in fresh weight (fw) and roots showed a 1.28-fold fw gain. This plant growth-promoting rhizobacterium (PGPR) has been reported to produce gibberellins (GAs). Other GAs-producing rhizobacteria, Bacillus macroides CJ-29 and Bacillus pumilus CJ-69, also enhanced the fw of the plants. They were less effective than B. cereus MJ-1, though. The endogenous GAs content of pepper shoots inoculated with MJ-1 was also higher than in shoots inoculated with CJ-29 or CJ-69. When inoculated with MJ-1, bacterial colonization rate of the roots was higher than that of roots inoculated with CJ-29 or CJ-69. These results support the idea that the plant growth-promoting effect of the bacteria also positively related with the efficiency of root colonization by the bacteria. In addition, we identified the major endogenous GAs of the red pepper as originating from both the early C-13 hydroxylation and the early non C-13 hydroxylation pathways, with the latter being the predominant pathway of GA biosynthesis in red pepper shoots.

• The Plant Pathology Journal
• /
• 제22권2호
• /
• pp.155-160
• /
• 2006

A strain of Pepper mottle virus (PepMov) was isolated from chili pepper plants in Korea. In host range study, this virus, designated PepMoV-SNU1, shared most characteristics with PepMoV isolates reported previously. Thermal inactivation point ($45^{\circ}C\;to\;75^{\circ}C$) and dilution end point ($10^{-1}\;to\;10^{-4}$) of PepMoV-SNU1 showed differences depending on the propagation hosts. Cylindrical and pinwheel-shaped inclusions were always observed in pepper leaf tissues infected with the virus alone. Unexpectedly, a special structure of pinwheel shaped inclusion surrounded with unknown small spots was also observed in the leaf section when co-infected with a strain of pepper mild mottle virus. The partial sequence of coat protein gene and 3' untranslated region of PepMoV-SNU1 showed 98% identity with those of other PepMoV isolates. A primer pair derived from 3' end of the coat protein gene and poly A tail regions were designed. Optimal detection condition of PepMoV-SNU1 by RT-PCR was tested to determine appropriate annealing temperature and additional volumes of oligo-dT (18-mer), dNTP, and Taq polymerase. Under the optimized condition, an expected 500 Up PCR-product was detected in pepper leaves infected with PepMoV-SNU1 but not in healthy plants.

• 식물병연구
• /
• 제25권3호
• /
• pp.136-142
• /
• 2019

식물 근권과 내생에서 분리한 447 균주 중 식물 생장 촉진특성과 건조 내성이 있는 28 균주를 일차적으로 스크리닝 하였으며, PEG에 의한 인위적 건조 스트레스 조건에서 잎의 상대수분함량과 MDA를 기반으로 GLC02와 KJ40을 선발하였다. 이 두 균주의 효과를 검증하기 위해 밭흙을 사용한 자연 건조에서 식물 포트 검정을 하였으며, 기공전도도와 지상부(줄기와 잎) 무게가 유의하게 증가한 반면 MDA가 감소하였다. 병 억제 효과에서는 GLC02를 처리할 경우 역병의 병진전도가 감소하였으며, KJ40을 처리할 경우 세균성 점무늬병에 대한 억제효과가 있었다. 이를 토대로, GLC02와 KJ40을 처리할 경우 건조 스트레스를 경감시켜주며 식물생장의 증진, 병 억제효과를 유도하여 생물비료의 소재로 사용할 수 있을 것으로 생각된다.

• 농약과학회지
• /
• 제12권3호
• /
• pp.270-276
• /
• 2008

전국 고추재배 포장에서 2005년부터 2007년까지 3년간 분리한 151개의 고추 역병균을 가지고 연도별 metalaxyl에 대한 감수성 정도를 조사하였다. 그 결과 Phytophthora capsici에 대한 metalaxyl의 평균 $EC_{50}$ 값은 역병균을 채집한 3년 동안 2005, 2006, 2007년의 균주들이 1.454, 0.830, $0.323{\mu}g\;mL^{-1}$로 그 값이 감소하고 있었으며, 2007년에 채집한 균주에서는 저항성 병원균을 전혀 분리하지 못하였다. Metalaxyl에 저항성인 고추 역병균이 mandiproramid와 dimethomorph에 대해서 교차 저항성을 보이는 지를 조사한 결과, metalaxyl과 다른 두 약제 mandipropamid와 diinethomorph의 사이에는 전혀 상관관계가 없었다. 또한 metalaxyl에 대한 저항성은, 역병균의 균사 생장 속도와 고추에 대한 병원성과도 상관관계가 없었다.

• 식물병연구
• /
• 제13권1호
• /
• pp.24-29
• /
• 2007

풋마름병징을 나타내는 고추와 토마토 식물체로부터 35개의 풋마름병균 계통들을 분리하여 생리.생화학 실험, 병원성 실험, 유전학적 실험을 통해 유전적 다양성을 연구하였다. 생리 생화학 실험과 종특이적 polymerase chain reaction(PCR)을 실시한 결과 풋마름병균 계통들은 모두 Ralstonia solanacerum biovar 4로 동정되었다. 분리균은 고추와 토마토 유묘를 이용해 병원성이 확인되었다. Repetitive sequence-based PCR(rep-PCR) 결과를 토대로 계통도 분석을 한 결과 고추와 토마토 분리균은 6개의 group으로 나뉘었으며, 유전적 다양성은 높게 나타났다. 풋마름병균 계통들의 그룹간에는 지역별, 기주별 특이성은 관찰되지 않았다.

• The Plant Pathology Journal
• /
• 제28권1호
• /
• pp.81-86
• /
• 2012

We developed a reassortant RNA virus vector derived from $Cucumber$ $mosaic$ $virus$ (CMV), which has advantages of very wide host range and can efficiently induce gene silencing in a few model plants. Certain CMV isolates, however, show limited host ranges presumably because they naturally co-evolved with their own hosts. We used a reassortant comprised of two strains of CMV, Y-CMV and Gn-CMV, to broaden the host range and to develop a virus vector for virus-induced gene silencing (VIGS). Gn-CMV could infect chili pepper and tomato more efficiently than Y-CMV. Gn-CMV RNA1, 3 and Y-CMV RNA2-A1 vector were newly reconstructed, and the transcript mixture of RNA1 and 3 genomes of Gn-CMV and RNA2 genome of Y-CMV RNA2 containing portions of the endogenous phytoene desaturase (PDS) gene (CMV2A1::PDSs) was inoculated onto chili pepper (cv. Chung-yang), tomato (cvs. Bloody butcher, Tigerella, Silvery fir tree, and Czech bush) and $Nicotiana$ $benthamiana$. All the tested plants infected by the reassortant CMV vector showed typical photo-bleaching phenotypes and reduced expression levels of $PDS$ mRNA. These results suggest that the reassortant CMV vector would be a useful tool for the rapid induction of the RNA silencing of endogenous genes in chili pepper and tomato plants.

• 한국유기농업학회지
• /
• 제30권3호
• /
• pp.409-422
• /
• 2022

본 연구에서는 흰비단병에 대한 길항 미생물과 유기농업자재를 선발하여 혼합 처리 시 방제 효과를 확인하고자 하였다. 토양에서 분리한 39균주 중 균사 생장 억제력이 가장 높은 JJ2-01 균주를 길항 미생물로 선발하였다. 또한, 유기농업자재의 흰비단병 발병도를 확인하여 병 억제 효과가 있는 유기농업자재로 마늘 오일을 선발하였다. 선발 미생물과 마늘 오일을 혼합하거나 마늘 오일을 단독으로 사용할 경우 병 억제 효과는 유사하게 나타났지만, 마늘 오일을 단독으로 사용할 경우 토양의 acid phosphatase의 활성이 감소하였다. 반면, 마늘 오일과 선발 미생물 JJ2-01 균주를 혼합 처리하였을 때 urease 활성이 증가하였다. 본 실험의 결과를 종합하면, 선발 미생물 JJ2-01 균주와 마늘 오일을 혼합하여 사용하면 고추 흰비단병을 효과적으로 억제하고 토양의 질과 건전성을 유지 또는 향상하는데 도움이 될 수 있을 것이라 판단된다.

• 한국자원식물학회지
• /
• 제22권6호
• /
• pp.506-512
• /
• 2009

To study the effect of genotype of donor plants on anther culture, anthers of nine hybrid cultivars (Derby, Special, Bossanova, Minipaprika, Fiesta, Boogie, Phenlene, Kufrah, and Clarity) of sweet pepper (Capsicum annuum L.) were cultured in a petridish containing C medium (Sibi, Dumas De Vaulx medium) supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin, 3% sucrose and 0.32% Phytagel. The cultures were incubated in the dark at $35^{\circ}C$ for seven days, and then cultured at $25^{\circ}C$ with a photoperiod of 16 hr. daylength for 40 days. Frequency of callus formation and plant regeneration was varied among cultivars. Callus formation was ranged from 6% in Phenlene to 69.8% in Kufrah. The highest percentage of regenerated plantlets was obtained in cv. Phenlene (2.67%) followed by Bossanova (2.41%). Result of ploidy analysis; chromosome number observation and flowcytometry analysis, showed that haploid plants could be developed from all of these hybrid cultivars except cv. Fiesta, where highest percentage of haploid plants were obtained in Minipaprika (40%) followed by cv. Bossanova (36.1%). Haploid plants derived from these hybrid cultivars contained single set of chromosome (12 in numbers), higher stomata density (numbers), and smaller sized stomata as compare to diploid plants. The mean length of stomata was 26.9 ${\mu}m$ in haploid plants and 35.7 ${\mu}m$ in diploids.