• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.45-49
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• 1969

The photoperiod and temperature response of Korean varieties were studied under field and greenhouse conditions. Results of the experiment indicated that all varieties tested were relatively intensitive to photoperiod. The early varieties were least affected by photoperiod while the late varieties showed the greatest response. Low temperature delays flowering either under short daylength or natural daylength. In general, temperature has a greater effect than photoperiod on the growth duration of the varieties used. The late varties had longer photoperiod-sensitive phase than the early varieties. Temperature has very little effect on the photoperiod-sensitive phase. The basic vegetative phase is longer in the early varieties than the late varieties. High temperature results shorten duration of the basic vegetative phase.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.659-664
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• 2003

The experiment was carried out to investigate the effects of sulfuric acid and nitric acid among the main components of simulated acid rain (SAR) on the growth of vegetative organs and seed germination of Arabidopsis thaliana. The Arabidopsis treated with SAR supplemented with sulfuric and nitric acids, respectively, showed 28% and 30% decrease of shoot and root growth compared to the control plants, and also many necrotic spots on leaf surfaces after SAR treatment were observed. The shoot and root length for plants grown with nitric acid rain was 14% and 17% lower, respectively, compared to the control, whereas those grown with sulfuric acid rain was 24% and 25% lower than control plants. When Arabidopsis seeds were sown in distilled water, germination rate was 100% after 7 days. However, 80% in SAR medium supplemented with sulfuric and nitric acids, 88% in sulfuric acid rain medium and 93% in nitric acid rain medium. The germination abilities of seeds harvested from SAR supplemented with sulfuric and nitric acids, sulfuric acid rain, and nitric acid rain were 73%, 73% and 94%, respectively. Consequently, sulfuric acids showed more inhibitory effects than nitric acids on the growth of vegetative organs as well as germination rates in Arabidopsis.

• Journal of Mushroom
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• v.15 no.2
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• pp.94-97
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• 2017

The choice of strain, substrate, and environmental conditions are fundamental factors that determine the ability of a fungus to develop and produce mushrooms with high quality. The objective of this study was to compare the strains of Lentinula edodes and Ganoderma lucidum originated from South Korea and Brazil in relation to their vegetative development in different culture media, to obtain isolates with high quality. The strains of the two mushroom species from Brazil and South Korea grew slowly, possibly because of abiotic factors or storage technique used. However, it may be concluded that temperature, humidity, light, pH, and nutrients from the substrate, if not regulated appropriately may affect the vegetative species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.88-92
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• 2000

Excessive soil water in paddy field induces growth losses during the vegetative stages of soybean plants. Our objectives were to know growth responses of soybean as affected by the level of ridge heights. A field experiment was conducted at the Research Farm of Korea University near Seoul in 1996. Ten cultivars of soybean (Glycine max (L.) Merrill) were planted at the ridge heights of 10, 30, and 50cm in paddy soil on 27 June. Total dry matter accumulation at the 10cm ridge height was severely decreased until the growth stage of R5 as compared to the ridge heights of 30 and 50cm, and this decrement was mainly due to both reduced leaf and stem dry weights. However, seed dry weight was not significantly decreased at the lower ridge height with the increment of harvest index. Cultivar differences were found on seed dry weight, crop growth rate from R1 to R5, and leaf/stem ratio of R5. From the above results, soybean growth responses to excessive soil water in paddy field were different between seed filling stage and late vegetative to early reproductive growth stages.

• ALGAE
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• v.25 no.3
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• pp.105-113
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• 2010

A new red algal parasite, Symphyocolax koreana M. S. Kim, gen. et sp. nov., has been found on a specimen of Symphyocladia latiuscula (Harvey) Yamada, a member of the tribe Pterosiphonieae of the Rhodomelaceae; this genus has never before been reported to host red algal parasites. Here, the new parasite from Korea is described in terms of vegetative and reproductive morphology. The thallus has a minute, colored polysiphonous upright axis with many branches attached by pseudoparenchymatous pulvinate bases. There are six pericentral cells, with many corticated cells in the lower part of the main branches. Trichoblasts occur on dioecious male and female gametophytes, but not on tetrasporophytes. Procarps develop on suprabasal cells of trichoblasts and consist of a four-celled carpogonial branch and two sterile cells attached to the supporting cell. Spermatangial branches are borne one per each successive segment on monosiphonous pedicels in spiral positions with fertile trichoblast. Tetrasporangia are formed one per segment in a straight series and are tetrahedrally divided. Features of the vegetative axes, procarp, spermatangial trichoblasts, and tetrasporangial branching show that the new genus is an alloparasite belonging to the tribe Polysiphonieae.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.53-56
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• 1999

Fifty-three isolates of Fusarium graminearum were obtained from corn and barley samples in several provinces of Korea. Gas chromatography-mass spectrometric analysis of trichothecenes produced by these isolates revealed that 37 and 16 isolates were nivalenol (NIV)- and deoxynivalenol (DON)-chemotypes, respectively. Two hundred and seventy-five nitrate-nonutilizing (nit) mutants were obtained from the isolates. Of these mutants, 187 were identified as nit1, nit3, or NitM, but 88 could not be identified as one of these classes. The highest frequency of nit mutant was nit1 (65%), followed by nit3 (20%) and NitM (15%). Higher frequency of NitM was observed in DON-chemotypes than in NIV-chemotypes. The mutants were used for vegetative compatibility group (VCG) analysis by examining heterokaryosis using complementary mutant pairs. No heterokaryon formation was observed among all 1,248 pairwise combinations, suggesting that all isolates tested belong to different VCGs. Higher frequency of self-incompatibility was observed in NIV-chemotypes than in DON-chemotypes. These results suggest that the like-lihood of asexual genetic recombination may be very low I F. graminearum under the field condition.

• The Plant Pathology Journal
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• v.16 no.4
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• pp.227-230
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• 2000

A total of 90 isolates of Fusarium oxysporum f.sp. melonis, the causal agent of oriental melon (Cucumis melo var. makuwa) wilt, was isolated from symptomatic tissues of oriental melon from 4 provinces in Korea. These isolates were grouped into vegetative compatibility groups (VCGs) by demonstrating heterokaryosis through complementation using nitrate nonutilizing (nit) mutants. No self-incompatibility was observed in any of isolates. All isolates were grouped into 3 VCGs ; A, B, and C. iSOLATES BELONGING TO VCG A and VCG B accounted for 87% and 91% of the fungal population collected in 1991 and 1993, respectively. As the increment of cultivation period in the same field, the proportion of isolates belonging to VCG B increased whereas that of isolates belonging to VCG A decreased. Mean virulence of a total population increased as the increment of cultivation period in the same field. Isolates belonging to VCG B showed the highest increment of virulence. These data suggest that replanting of a host plant in the same field may cause increase of virulence in the pathogens. Furthermore, virulence of F. oxysporum f.sp. melonis isolates is related to the VCGs.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.79-82
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• 2012

Blossom-end rot is probably the most recognizable Ca deficiency that affects fruit production including pepper. We investigated the induction of blossom-end rot during the period of rapid vegetative growth and fruit setting, and the effect of Ca fertilization on the suppression of blossom-end rot in pepper plants grown in a plastic-film house. During the first fruit setting period, more than 60% of pepper fruits larger than 8 cm showed the symptoms of blossom-end rot. Under the condition of transpiration occurring at a much faster rate, growing leaves of pepper plants could be the greater sinks for Ca than developing fruits. The incidence of blossom-end rot was significantly decreased after two weeks of Ca fertigation. Calcium application during the rapid vegetative growth and fruit setting period could be suggested as a preventive step to overcome the local Ca deficiency inducing blossom-end rot of pepper fruits.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.5-14
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• 2006

Streptomycetes are Gram-positive microorganisms producing secondary metabolites through unique physiological differentiation [4]. The microbes show unusual morphological differentiation to form substrate mycelia, aerial mycelia, and arthrospores on solid medium [19]. Substrate mycelium growth is sustaining with sufficient nutrients in the culture medium. The concentration of a specific individual substrate in the culture environment is the most important extracellular factor allowing vegetative mycelia growth, where extracellular hydrolytic enzymes participate in the utilization of waterinsoluble substrates. However, with starvation of nutrients in the culture medium, the vegetative mycelia differentiate to aerial mycelia and spores. It has been considered that shiftdown of essential nutrients for mycelia growth is the most important factor triggering morphological and physiological differentiation in Streptomyces spp. Since proteineous macromolecule compounds are the major cellular components, these are faced to endogenously metabolize following a severe depletion of nitrogen source in culture nutrients (Fig. 1). Various proteases were identified of which production was specifically related with the phase of mycelium growth and also morphological differentiation. The involvement of proteases and protease inhibitor is reviewed as a factor explaining the mycelium differentiation in Streptomyces spp.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.417-420
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• 2002

Non-point source pollution of sediment, plant nutrients and pesticides from cropland has been identified as a significant environmental problem. Vegetative Filter Strips have been identified as one of BMPs to control nonpoint source pollution. This paper reviews the concept, functions, design criteria and management of VFS to control nonpoint source pollution.