• Research in Plant Disease
• /
• v.21 no.4
• /
• pp.341-345
• /
• 2015

Virus-like symptoms including stunt, severe mosaic with malformation of leaves, fern-like leaves and abnormal petals were observed from an African impatiens (Impatiens walleriana) grown in a plant nursery in Icheon, Korea. Serological analysis using immuno-strip kits for viruses reported in African impatiens indicated that Cucumber mosaic virus (named CMV-Im) was a causal agent for the symptomatic African impatiens. Biological properties of CMV-Im were analyzed using responses of host plant species, suggesting that CMV-Im is a typical strain that belongs to CMV subgroup I. RT-PCR analysis verified CMV-Im infection from naturally infected African impatiens or mechanically inoculated some host species. Analysis of multiple alignments of CMV capsid protein (CP) sequences showed that CMV-Im shared high CP amino acids identities with other CMV strains. Phylogenetic tree analysis for the CP sequences of CMV-Im and representative CMV strains confirmed that CMV is a typical member of CMV subgroup I. To our knowledge, it is the first report of CMV in African impatiens in Korea.

• The Plant Pathology Journal
• /
• v.37 no.4
• /
• pp.375-388
• /
• 2021

Rice yellow mottle virus (RYMV) is the most harmful virus that affects irrigated and lowland rice in Africa. The RBe24 isolate of the virus is the most pathogenic strain in Benin. A total of 79 genotypes including susceptible IR64 (Oryza sativa) and the resistant TOG5681 (O. glaberrima) as checks were screened for their reactions to RBe24 isolate of RYMV and the effects of silicon on the response of host plants to the virus investigated. The experiment was a three-factor factorial consisting of genotypes, inoculation level (inoculated vs. non-inoculated), and silicon dose (0, 5, and 10 g/plant) applied as CaSiO₃ with two replications and carried out twice in the screen house. Significant differences were observed among the rice genotypes. Fifteen highly resistant and eight resistant genotypes were identified, and these were mainly O. glaberrima. Silicon application did not affect disease incidence and severity at 21 and 42 days after inoculation (DAI); it, however, significantly increased plant height of inoculated (3.6% for 5 g CaSiO₃/plant and 6.3% for 10 g CaSiO₃/plant) and non-inoculated (1.9% for 5 g CaSiO₃/plant and 4.9% for 10 g CaSiO₃/plant) plants at 42 DAI, with a reduction in the number of tillers (12.3% for both 5 and 10 g CaSiO₃/plant) and leaves (26.8% for 5 g CaSiO₃/plant and 28% for 10 g CaSiO₃/plant) under both inoculation treatments. Our results confirm O. glaberrima germplasm as an important source of resistance to RYMV, and critical in developing a comprehensive strategy for the control of RYMV in West Africa.

• Journal of Veterinary Science
• /
• v.22 no.1
• /
• pp.13.1-13.14
• /
• 2021

African swine fever (ASF) is one of the most complex infectious swine diseases and the greatest concern to the pig industry owing to its high mortality and no effective vaccines available to prevent the disease. Since the first outbreak of ASF in pig farms, ASF has been identified in 14 pig farms in four cities/counties in South Korea. The outbreak was resolved in a short period because of the immediate control measures and cooperative efforts. This paper reviews the ASF outbreak and the experience of successfully stopping ASF in pig farms in South Korea through active responses to prevent the spread of ASF. In addition, suitable changes to build a sustainable pig production system and collaborative efforts to overcome the dangerous animal disease, such as ASF, are discussed.

• Journal of Veterinary Science
• /
• v.22 no.2
• /
• pp.26.1-26.6
• /
• 2021

Fourteen African swine fever (ASF) outbreaks occurred in the pig farms in the northwestern region of South Korea, near the border with North Korea, from September 16, 2019 to October 9, 2019. Active and passive surveillance on the ASF-infected farms indicated that the infection was limited only to pigsties where the infected pigs were detected on the farm for the first time before further transmission to other pigsties and farms. This early detection could be one of the pivotal factors for the prompt eradication of ASF in domestic pig farms within 1 month in the northwestern region of South Korea.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.104-109
• /
• 1998

Methanol extracts from 84 Indian plant samples (50 species in 31 families) and 27 African plant samples (20 species in 12 families) in vitro were tested for their growth-inhibitory activities against Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus acidophilus, Clostridium perfringens, and Escherichia coli, using a paper disc agar diffusion method under $O_2-free$ conditions. The responses varied with bacterial strain, plant species and plant part. Extracts from Cymbopogon citratus whole plants, Ocimum basilicum whole plant, Madhuca indica flowers, and Aegle marmelos leaves among Indian plant samples moderately or strongly inhibited the growth of Cl, perfringens whereas moderate growth-inhibitory activity against E. coli was obtained from extract of Indian O. basilicum whole plants. These plant extracts did not affect the growth of the lactic acid forming bacteria tested. These results may be an indication of at least one of the pharmacological actions of these tropical plants.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.4
• /
• pp.382-389
• /
• 2011

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

• Korean journal of applied entomology
• /
• v.34 no.3
• /
• pp.200-205
• /
• 1995

Total 31 samples from 21 African plant species in 13 families were tested for their insecticidal and acaricidal activities against Nilaparvata lugens (Stal) and Tetranychus urticae (Koch) adults through topical application an leaf-dipping methods, respectively. The insecticidal and acaricidal activities were both plant parts and species dependent. The methanol extracts from whole plants of Casia occidental is and Cassia tora (Caesalpinaceae), an stem of Prosopis chinensis (Mimosaceae) revealed potent insecticidal activity against N. lugens. Potnet acaricidal activity against T. urticae was obtained from the methanol extracts from whole plants of Celosia trigyna (Amaranthaceae) and Combretum micronthum (Combretaceeae), leaves of Combretm glutinotum, and leaves and fruits of prosopis chinensis.

• Korean Journal of Environmental Biology
• /
• v.39 no.3
• /
• pp.329-335
• /
• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• Journal of Fashion Business
• /
• v.11 no.1
• /
• pp.136-148
• /
• 2007

African marigold is a common plant easily available in many flower beds. It has been reported as a practical and prospective resource of dyes since the dyes can be extracted from their bodies as well as petals. In this research, cotton and ramie fabrics which are made from natural cellulose were dyed using the extract of the African Marigold which is a variety of marigold. Dyeing tests were carried out under different pH of the dye solution and mordants. Dyeability was evaluated by examining and measuring surface color, K/S value, and the changes in the maximum absorption wavelength. The probability of improving dyeability was investigated by pre-mordanting with pre-treated chitosan. For the dyeing with marigold extract, the color tone did not differ by pre-mordanting and non-mordanting. Reaction with post-mordanting was excellent, which was colored in various yellow series. The best dyeability was achieved in dye solution of pH 6.5-7.0 which is not conditioned. The largest K/S value and color difference were obtained in tin mordanting. The dye uptake was greatly increased in chitosan pre-treated mordanting compared with the post-mordanting without chitosan pre-treatment. Due to its high heat resistance, African Marigold extract is easy for dye extraction and dyeing, and its dyeability is excellent for natural cellulose fibers. Also, colorfastness was proved to be practically usable.

• Journal of Forest and Environmental Science
• /
• v.36 no.4
• /
• pp.267-273
• /
• 2020

Diospyros mespiliformis is a highly valued and threatened tree species within the Sahelo-Sudanian zone of Africa, but its seed germination requirements under cultivation are not well researched. In a first experiment which aimed at determining germination response of seeds to dehydration, fresh seeds were dried at room temperature for 26 days during which their moisture content, their germinability, and their viability were monitored at two-day intervals. In the second experiment, 14 pre-germination treatments were tested for their effect on the germination of dried seeds. Results showed that fresh seeds had 52.7% moisture and achieved 97.7% germination. As seeds were dried, percentage germination gradually decreased with decreasing moisture content and reached 0% when moisture content had dropped to 18%. Meanwhile, seed viability remained at 100% over drying duration. Seeds that were not germinated after air dry also recorded 100% viability. The most effective treatment for inducing germination of dried seeds was scarification using 98% sulfuric acid for 30 min which resulted in 96.6% germination. This study reports for the first time in D. mespiliformis seeds a desiccation-induced dormancy which can be efficiently alleviated by acid scarification. This study provides useful information that will contribute to efficient management of D. mespiliformis seed resources for propagation.