• Korean Journal of Organic Agriculture
• /
• v.22 no.4
• /
• pp.743-760
• /
• 2014

This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.36 no.1
• /
• pp.7-14
• /
• 2016

The objective of this study was to determine the effect of bacterial inoculation (Lactobacillus plantarum or combo inoculant mixed with Lactobacillus plantarum and Lactobacillus buchneri) and addition of fibrolytic enzyme on chemical compositions and fermentation characteristics of whole crop barley (WCB) and triticale (TRT) silage, their ruminal in vitro fermentation, and digestibility. In TRT silage, enzyme addition significantly (p<0.01) decreased NDF content compared to no enzyme addition treatment. Organic acids such as lactate and acetate contents in WCB and TRT silages were significantly (p<0.01) higher compared to those in the control. Particularly, lactate content was the highest in L. plantarum treatment. Fibrolytic enzyme treatment on both silages had relatively higher lactic acid bacteria content, while mold content was lower in both treatments compared to that in the control. In vitro dry matter digestibility was generally improved in WCB silages. It was higher (p<0.01) in TRT with mixed treatment of L. plantarum, L. buchneri, and enzyme compared to others. In vitro ruminal acetate production was relatively higher in treatments with both enzyme and inoculant additions compared to that in the control. Therefore, the quality of silage and rumen fermentation could be improved by inoculants (L. plantarum and L. buchneri) regardless whether whole crop barley (WCB) or triticale (TRT) silage was used. Although it was found that fibrolytic enzyme addition to both silages had various quality and rumen fermentation values, further study is needed.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.31 no.3
• /
• pp.295-304
• /
• 2011

This study was carried out to investigate the effect of harvest stage of Sorghum ${\times}$ Sorghum Hybrid (SSH) and manufacture methods of SSH silage on nutritive values and quality of SSH silage manufactured with SSH grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA. SSH "SS405" was harvested at two different growth stages (heading and ripen stage) and ensiled at each harvest stages. The content of crude protein in both square baled SSH silage (SBSS) and bag silage (BS) increased with delayed harvest maturity, but the contents of ADF (acid detergent fiber), NDF (neutral detergent fiber) decreased. The contents of ADF and NDF was not influenced by the inoculation of lactic bacteria. The contents of TDN (total digestible nutrient) in both stage and in vitro dry matter digestibility (IVDMD) in heading stage was not influenced by the harvest stage of SSH. The pH in all SSH silage ranged from 3.8 to 4.4 at two different harvest stages, and pH in heading stage was higher than that of ripen stage (P<0.05). The content of lactic acid of all SSH silage increased with delayed harvest maturity (P<0.05), but the content of acetic acid decreased (P<0.05). The contents of lactic acid and acetic acid in ripen stage were not influenced by manufacture method of silage. The content of lactic acid in both SBSS was higher than that of both BS and RBSS in heading and ripen stage (P<0.05), but the content of acetic acid decreased (P<0.05). The contents of lactic acid and acetic acid in BS were similar as compared to that of RBSS. Therefore, we suggest that the quality of SSH silage in both heading and ripen stage can be improved by manufacture methods of SBSS and BS.

• Journal of Korean Society of Forest Science
• /
• v.47 no.1
• /
• pp.1-15
• /
• 1980

The occurrence of witches' broom of Rhus javanica was first noticed in Korea by the author in 1979. Subsequently, studies were made on the symptomatology, etiology, and transmission of the disease, as well as the effect of some antibiotics on the disease development. The results of these studies are summarized as follows: 1. Symptoms of the infected plant were characterized by dwarfing of the tree accompanied by yellowing and brooming of the foliage. 2. Electron microscopy of witches' broom diseased Rhus javanica plant revealed the occurrence of numerous mycoplasma-like organisms (MLO's) in the phloem tissue cells (sieve tube elements and phloem parenchyma cells) of the rachis and midribs of infected leaves. 3. The MLO's were bounded by a single unit membrane and contained ribosome-like granules and strands presumed to be DNA. It also appears that the MLO multiply possibly by budding as well as binary and plurinary fission. 4. In the midrib of healthy leaves, vascular bundles were collaterally discontinuous. In the diseased leaves, however, xylems were connected to each other and phloem cells showed an atrophy. Granules, which were prominent in the normal abaxial epidermis, were not observed in the peidermis of diseased leaves. 5. Electron microscopy revealed crystals or osmopholic granules in the phloem parenchyma cells, and that normal stacks of grana were not developed in the chloroplasts of infected levels. 6. The disease was experimentally transmitted by grafting. Budding was more effective than crown grafting for transmitting the disease. The disease has been transmitted by grafting even when complete union of stocks and scions has not taken place. The disease agent was not transmitted by sap inoculation. Insect transmission has not been confirmed. 7. Dipping the roots of infected plants into the 500 ppm and 1,000 solutions of either tetracycline HCI or oxytetracycline, HCI was more effective on temporary remision of the symptoms than spraying the 100 ppm and 200 ppm solutions of the same antibiotics. A greater effect was achieved through dipping into 1,000 ppm than into 500 ppm.

• Korean Journal of Breeding Science
• /
• v.41 no.3
• /
• pp.292-298
• /
• 2009

A new rice cultivar "Keumo 3" was developed for adopting under double cropping system with after or before cash crop cultivation. It was selected from the cross-combination between YR17202 $F_2$/Shinkeumobyeo//YR15727-B-B-B-102. The parent, YR17202 $F_2$ individual plant, was used for tolerance to lodging, it derived from a cross between Nonganbyeo/Shinkeumobyeo. Nonganbyeo is well known to lodging tolerance cultivar, as well as biotic stress, because it was developed by crossing with Tongil type. And the YR15727-B-B-B-102 line used as another parent with short growth duration, likewise highly resistance to rice blast disease. The pedigree derived from the cross-combination YR17202 $F_2$/Shinkeumobyeo//YR15727-B-B-B-102 were generated to $F_7$, and a best line among them named as Milyang 201. After a series of yield trials, including local adaptability test conducted throughout the peninsular of Korea, Milyang 201 was registered with the name of "Keumo 3" in 2005. The cultivar belongs to a early maturing group and heads 4 days earlier than Keumobyeo, a standard cultivar. It has short culm, and less spikelet number per panicle than Keumobyeo. However, its milled rice yield grown under extremely late transplanting time, 10. July, over the 3 local sites for 2003-2005 years, averaged 4,48 MT/ha, which is 6% higher than the standard, Keumobyeo. "Keumo 3" has showed a durable resistance to leaf blast disease during fourteen blast nurseries screening covered from south to north in Korea for 2003-2007 years. And it was confirmed harbours pi-zt, a durable blast resistance gene. Moreover it was incompatible with 19 blast isolates under artificial inoculation, except one isolate, K1101. Additionally, "Keumo 3" exhibits resistance to $K_1$, $K_2$ and $K_3$ of bacterial blight pathogen, as well as strip virus disease resistance, and moderate resistance to dwarf virus disease. Consequently, the new rice cultivar "Keumo 3" would be well adopted where a bio stress makes a big problem annually.

• Journal of Sericultural and Entomological Science
• /
• v.28 no.1
• /
• pp.1-14
• /
• 1986

This study was carried out to acguire some basic information on nutritional and lhysiological effects of vesicular arbuscular mycorrhizae(VAM) on mulberry trees inoculated with Glomus mosseae, Gerd. & Trap. grown in clay for 65 days and treated with 5 different levels of phosphorus, ie 30, 60, 120, 240, 480 ppm as (NH4)2 HPO4. At the End of the expermental period the levels of fixed phosphate in the soil was measared. And the native VAM fungi were collected to select the most effective VAM species on mulberry tree. The nutritional and biochemical effects of VA mycorrhizae on the mulberry leaves were also studied. Those results are as follow. 1. The mulberry trees grown in clay and inoculated with VAM were heavier in shoot dry weight as much as 197% than uninoculated plants. But in vermioulite, uninoculated mulberry trees were heavier as much as 135% than inoculated. 2. The rates of endo mycorrhizal formation in clay was highest at 60 ppm level of phosphorus, and vesicles in roots were formed in 240ppm and 480ppm level of phosphorus, but not in 30ppm, 60ppm and 120ppm. 3. The greatest growth responses of VAM inoculation was found at 60ppm level of hosphorus, and the optimum phosphorus level for VAM responese appeared to be 60ppm. 4. VAM was also to absorb soil-fixed phosphate. VAM abosrbed Fe-bound phosphate most efficiently and Ca-bound phosphate with ease but not Al-bound phosphate and Al-Fe occluded phosphate. 5. Three species of Gigaspora and one species of Glamus growing naturally in mulberry plantations were collected and tested for the growth responses. Gigaspora tricalipta and Gigaspora calospora revealed the greatest growth responses on mulberry tree among tested VAM fungi. 6. Mulberry leaves inoculated with VA mycorrhizal fungi contained 9.8% more phosphate and 15.2% more nitrogen, 22.2% more water-soluble carbohydrates and 15.2% more proteins than uninoculated plants. 7. The electrophoretic pattern of mulberry leaf protein inoculated with VAM fungi has 19 bands. 8. The patterns of peroxidase zymogram and Amulase zymogram were different between the mulberry leaves inoculated and uninoculated with VA mycorrhizal fungi. The peroxidase zymogram of inoculated leaves has 1 less majour band than unioculated leaves The amylase zymogram of inoculated leaves has 2 bands near the +pole, but that of uninoculated leaves has 1 band near the $pole.

• Korean Journal of Breeding Science
• /
• v.40 no.4
• /
• pp.408-413
• /
• 2008

Rice blast resistance is considered one of the most important traits in rice breeding and the disease, caused by Magnaporthe grisea Barr, has brought significant crop losses annually. Moreover, breakdown of resistance normally occurs in two to five years after cultivar release, thus a more durable resistance is needed for better control of this disease. We developed a new variety, Keumo3, which showed strong resistance to leaf blast. It was tested in 2003 to 2007 at fourteen blast nursery sites covering entire rice-growing regions of South Korea. It showed resistance reactions in 12 regions and moderate in 2 regions without showing susceptible reactions. Durability test by sequential planting method indicated that this variety had better resistance. Results showed that Keumo3 was incompatible against 19 blast isolates with the exception of KI101 by artificial inoculation. To understand the genetic control of blast resistance in rice cultivar Keumo3 and facilitate its utilization, recombinant inbred lines (RIL) consisting of 290 F5 lines derived from Akidagomachi/Keumo3 were analyzed and genotyped with Pizt InDel marker zt56591. The recombination value between the marker allele of zt56591 and bioassay data of blast nursery test was 1.1%. These results indicated that MAS can be applied in selecting breeding populations for blast resistance using zt56591 as DNA marker.

• Journal of agriculture & life science
• /
• v.52 no.6
• /
• pp.49-60
• /
• 2018

Here, we reported 159 varieties of major cultivars using grapevine genetic resources to identify the resistant grape ripe rot cultivars. To do this, we performed pathogenicity assays from these grape cultivars by inoculating Colletotrichum acutatum and Colletotrichum gloeosporioides. Genotyping-by-sequencing(GBS) method was also used to compare genetic diversity among grape varieties. As a result, leaves inoculated with C. acutatum showed that 58 cultivars were susceptible, while 17 cultivars were resistant. In the case of C. gloeosporioides, 34 cultivars were found to be susceptible, while 25 cultivars were resistant. The 8 cultivars that showed resistance to both species were 'Agawan', 'Huangguan', 'Xiangfei', and 5 other cultivars from the hybrids of European and American species. Most of the varieties such as 'Emerald Seedless', 'Tano Red', and 'Rem 46-77(Aestivalis GVIT 0970)' originated in European species were identified as susceptible. These results can be used in the effective management of grape disease. In addition, these findings provide information for the development and cultivation of resistant to grape ripe rot disease cultivars.

• Korean Journal of Environmental Biology
• /
• v.36 no.3
• /
• pp.359-369
• /
• 2018

Harmful algal blooms (HABs) are a serious problem for public health and fisheries industries, thus there exists a need to investigate the possible ways for effective control of HABs. In the present study, we investigated the algicidal effects of a newly developed GreenTD against the HABs (Chattonella marina, Heterosigma akashiwo, Cochlodinium polykriokides, and Heterocapsa circularisquama) and non-HABs (Chaetoceros simplex, Skeletonema sp. and Tetraselmis sp.), which is focused on the different population density and concentration gradients of algicidal substances. The time series viability of target alga was assessed based on the activity of Chl. a photosynthetic efficiency in terms of $F_v/F_m$, and in vivo fluorescence (FSU). Effective control of Raphidophyta, C. marina and H. akashiwo was achieved at a GreenTD concentration of $0.5{\mu}gL^{-1}$ and $0.2{\mu}gL^{-1}$, respectively, and regrowth of both the species was not observed even after 14 days. The inhibitory ratio of the dinoflagellate, C. polykriokides was more than 80% at $0.2{\mu}gL^{-1}$ of GreenTD. H. circularisquama was constantly affected in the presence of $0.2{\mu}gL^{-1}$ of GreenTD in the high- and low-population density experimental groups. On the other hand, diatoms, C. simplex, and Skeletonema sp. were not significantly affected even in the presence of $0.2{\mu}gL^{-1}$ of GreenTD and exhibited re-growth activity with the passage of incubation time. In particular, green alga Tetraselmis sp. remained unaffected even in the presence of the highest concentration of GreenTD ($1.0{\mu}gL^{-1}$), implying that non-HABs were not greatly influenced by the algicidal substances. As a result, the algicidal activity of GreenTD on the harmful and nonharmful algae was as follows: raphidophyte>dinoflagellates>diatoms>green alga. Consequently, our results indicate that inoculation of GreenTD substances into natural blooms at a threshold concentration ($0.2{\mu}gL^{-1}$) can maximize the algicidal activity against HABs species. If we consider the dilution and diffusion rate in the field application, it is hypothesized that GreenTD will demonstrate economic efficiency, thus leading to effective control against the target HABs in the closed bay.

• Journal of Mushroom
• /
• v.18 no.4
• /
• pp.331-338
• /
• 2020

This study was conducted to cultivate new Lepista nuda varieties with shorter cultivation period and better fruiting body compared to that of wild strains, for mass production and commercial application. Eighteen genetic resources of L. nuda were collected and grown in boxes using rice straw-fermented growth medium. Four lines with fruiting bodies were formed and selected as cross-breeding lines. Although 657 combinations were crossed through monospore crossing, only 17 combinations were bred between the 'CBMLN-19' line and the 'CBMLN-30' line. Among them, 8 lines with fast mycelial growth and high density were selected. After inoculating the rice straw-fermented growth medium with 14 genetic resources and 8 cross-breeding lines, their incubation period was investigated. Six of the cross-breeding lines completed their incubation in 20 days, while 7 of the 14 genetic resources took more than 40 days to complete their incubation, reducing the incubation period by more than 20 days in most cross-breeding lines. After the incubations were completed, the clay loam soil was covered with for post-cultivation, and when the mycelial cultivation was complete, the formation of fruiting bodies was induced after scraping the mycelial bodies under these environmental conditions: 14℃, 95% relative humidity or higher, and 1,500 to 2,000 ppm CO2 concentration. The temperature was reduced to 6℃ at night, resulting in a low temperature shock. Thus, 4 lines of fruiting bodies occurred from two genetic resources 'CBMLN-31' and 'CBMLN-44' and two cross-bred lines 'CBMLN-96' and 'CBMLN-103'. After inoculation, the longest period for fruiting bodies to occur was 100 days for the control:, the genetic resource 'CBMLN-31', and the shortest period (45 days) was observed for the cross-breeding line 'CBMLN-103'. The result of the investigation of the fruiting body characteristics shows that the cross-bred line 'CBMLN-103' showed a small form with 1.9 g of individual weight and 123validstipes per box, which was the highest incidence among the four lines. Another cross-bred line, 'CBMLN-96', had an individual weight of 5.5 g, which is larger than that of 'CBMLN-103'; however, the number of valid stipes per box was 30 less than that of 'CBMLN-103'. Quantity analysis showed that the control, 'CBMLN-31', had the highest quantity of 783 g per box, followed by the cross-bred line, 'CBMLN-96' with 165 g per box, and then the 'CBMLN-103' with 232 g. The quantity of the two crossbred lines was lower than that of the control 'CBMLN-31'; however, the amount of fruiting bodies was higher, and the cultivation period was shortened by 32 to 33 days. Therefore, these two lines would be selected as superior lines.