• Journal of the Korean Institute of Landscape Architecture
• /
• v.32 no.2
• /
• pp.120-129
• /
• 2004

This study was carried out to develop new varieties with early maturing and large fruit size in the Korean native dogwood (Cornus kousa) for woody landscape plants from native sites or cultivated area. The results are obtained as follows; We selected strains with early maturing and large fruit. size from the habitats from 2000 to 2003. ‘SKK 2-1’ had 4.0cm of fruit size while 2.0 cm of native variety. In addition, ‘SKK 2-2’, ‘SKK 2-3’, ‘SKK 2-4’, and ‘SKK 2-5’ with large fruit and early maturing were preliminary selected from the habitats. In the preliminary selections, ‘SKK 2-1’ was finally selected as new early maturing variety with large fruits in 2003. New early maturing variety with large fruit size, C. kousa var. ‘SKK 2-1’ was selected from 200 plants of 5-year-old seedlings in C. kousa in 5-12 Nung wean ri Goo sung myun Yong In, Kyung gi do, Korea in 2000. Their fruits were colorized in September 18, 20∼25 days earlier than October 7 of native varieties. Its fruit diameter is larger than 4cm. Its fruit weight was 5 times as heavy as native cultivars grown in Korea. This useful characters were still inherited after grafting. However, characteristics of growth, leaf, flower, and flowering period were not different from those of native varieties. Therefore, it was very promising landscape woody plant, having large fruits in early fall season. The rooting rate of Korean dogwood was high by the IBA treatment. The optimum date for softwood cutting was on June 25 ∼ July 25 when the rooting rate was more than 80%. In addition. Korean dogwood was easily propagated by grafting. Therefore, new early maturing variety with large fruits, C. kousa var. ‘SKK 2-1’ is easily propagated by softwood cutting or grafting and then is a promising cultivar as a woody landscape plant.

• Molecules and Cells
• /
• v.19 no.3
• /
• pp.428-435
• /
• 2005

This study was carried out to assess the potential of SSR markers for variety identification by comparing SSR markers and morphological traits in tests of distinctiveness, uniformity, and stability (DUS) of pepper (Capsicum annuum L.) varieties. Twenty-seven SSR markers were polymorphic in 66 pepper varieties, revealing a total of 89 alleles. Average polymorphism information content (PIC) value was 0.529, ranging from 0.03 to 0.877. Cluster analysis of the band patterns separated the varieties into three groups corresponding to varietal types. Morphological trait-based clustering showed some degree of similarity to dendrogram topologies based on the SSR index. However, no significance correlation was found between the SSR and morphological data. SSR markers could be used to complement a DUS test of a candidate variety and to select complimentary varieties by pre-screening existing varieties in the context of protecting new varieties of pepper.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.12 no.3
• /
• pp.72-82
• /
• 2009

Research was initiated to investigate early establislment characteristics and germination pattern of perennial ryegrass (PR, Lolium perenne L.). Eight varieties of PR were evaluated in the study. An alternative environmental condition for a PR germination test required by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination pattern were measured and analyzed daily for 30 days. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and final germination rate. Germination rates were variable among the varieties, being 66.00 to 93.75% at the end of study. There were considerable variations in early germination characteristics and germination pattern among PR varieties. The first germination in all entries tested was initiated from 3 to 5 DAS (days after seeding) under ISTA conditions, being 2 days in differences among the varieties. It was 4 to 7 DAS in days to the 50% germination, being 1 to 3 days later from the first germination and three days were variable among them. Days to the 75% germination were 5.93 to 10.50 DAS under ISTA conditions, being 4.57 days in variety differences. Pennant II and Brightstar II were the fastest varieties. The slowest ones were Revenge GLX and Brightstar SLT. Considering days to the first germination, days to 75% germination, and germination pattern etc, Pennant II and Brightstar II were regarded as excellent varieties under ISTA conditions. From tills study, information on differences in germination characteristics and pattern would be usefully applied for golf course design and construction, when established with PR.

• Journal of Crop Science and Biotechnology
• /
• v.11 no.3
• /
• pp.205-214
• /
• 2008

Blast disease caused by the fungal pathogen, Magnaporthe oryzae, is one of the most damaging diseases in rice. The use of resistant varieties is an effective measure to control the disease, however, many resistant varieties were broken down to their resistance effects by the differentiating of new virulent isolates. This study was done to analyze the haplotypes of 31 microsatellite markers linked to five major R genes and two QTLs and to identify the alleles for the putatively novel genes related to durable resistance to blast in 56 Korean japonica and four indica varieties. The 31 microsatellite markers produced 2 to 13 alleles(mean = 5.4) and had PICi values ranging from 0.065 to 0.860(mean=0.563) among the 60 rice accessions. Cluster analysis based on allele diversities of 31 microsatellite markers grouped into 60 haplotypes and ten major clusters in 0.810 genetic similarity. A subcluster IV-1 grouped of early flowering varieties harboring Piz and/or Pi9(t) on chromosome 6 and Pita/Pita-2 gene on chromosome 12. The other subcluster V-1 consisted of four stable resistance varieties Donghae, Seomjin, Palgong and Milyang20. The analysis of putative QTLs associated with seven blast resistance genes using ANOVA and linear regression showed high significance to blast resistance across regions and isolates in the markers of two genes Piz and/or Pi9(t) and Pita/Pita-2. These results illustrate the utility of microsatellite markers to identify rice varieties is likely carrying the same R genes and QTLs and rice lines with potentially novel resistant gene.

• Journal of Plant Biology
• /
• v.17 no.1
• /
• pp.22-32
• /
• 1974

In this study, phytoplanktons collected monthly at Paroho from January till April in 1968 and from May till August in 1973. The Diatom samples were identified and classified by Engler's Classification System. It resutled in 1 phyla, 1 class, 2 subclasses, 5 orders, 8 families, 18 genera, 41 species, 11 varieties and 2 forma. Of them, 8 species, 6 varieties and 2 formas are new to Korea.

• Journal of Plant Biology
• /
• v.14 no.3
• /
• pp.47-59
• /
• 1971

As a continuation of part I, this paper deals with the classification of phytoplankton species collected from Chawol-do, Soya-do Pung-do of Kyonggi-Bay. One hundred and fortythree kinds of photoplankton from this area were identified and classified by Engler's system into 17 families, 47 genera, 129 species, 10 varieties and 4 forms, blonging to 2 phyla, 3 classes, 3 subclasses, 8 orders and 1 suborder. 3 families, 7 genera, 10 species, 3 varieties and 3 forms are added. To the list published in part I. Seven species and one form described in this paper are new to Korea.

• Korean journal of applied entomology
• /
• v.22 no.2 s.55
• /
• pp.52-66
• /
• 1983

The brown planthopper, N. lugens (Stal), has become a serious pest of rice in tropical Asia during the last decade. At high pest density, its feeding damage causes 'hopperburn' or complete wilting and drying of the rice plant. It also transmits grassy and ragged stunt virus diseases. The estimated losses caused by the pest in tropical Asia exceed $US\$300$ millions. While cultivation of resistant rice varieties has proved to be highly effective against the pest, their long-term stability is threatened because of the evolution of prolific biotypes which can destroy these varieties. At present, identification of biotypes is based principally on the differential reactions of host rice varieties to the pest and on host-mediated behavioral and physiological responses of the pest. Recent findings of morphological differences in adult rostrum, legs, and antennae, body parts that possess receptors for host plant location and discrimination, and cytological differences in N. lugens populations maintained as stock cultures strongly complement other biotype studies. So far, three N. lugens biotypes have been identified in the Philippines. Biotype I can survive on and damage varieties that do not carry and genes for resistance, while Biotype 2 survives on resistant varieties carrying Bph 1 gene and Biotype 3 on varieties carrying gene bph 2. However, none of these biotypes can survive on varieties with genes Bph 3 or bph 4. Several varieties which are resistant in the Philippines are susceptible in India and Sri Lanka as the South Asian biotypes of N. lugens are more virulent than Southeast Asian biotypes. To monitor the pest biotypes in different geographical regions and to identify new sources of resistance, an International Brown Planthopper Nursery has been established in many cooperating countries. The evolution of biotypes is an exceedingly complex process which is governed by the interactions of genetic and biological factors of the pest populations and the genetic makeup of the cultivated varieties. While the strategy for sequential release of varieties with major resistance genes has been fairly successful so far, the monegenic resistance of these varieties makes them vulnerable to the development of the pest biotypes. Therefore, present breeding endeavors envisage utilizing both major and minor resistance genes for effective control of the pest.

• Korean journal of applied entomology
• /
• v.31 no.3
• /
• pp.205-240
• /
• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• Korean Journal of Plant Resources
• /
• v.35 no.4
• /
• pp.464-470
• /
• 2022

In this study, the morphological characteristics of flower and fruit in five varieties (Hancho 915ho, 930ho, 10ho, 1020ho, 1030ho) from Zanthoxylum schinifolium were investigated as new varieties with different fruiting seasons. Qualitative and quantitative characteristics were investigated, spectively. For quantitative characteristics can be measured numerically, such as size and number, the varieties were identified using ANOVA and Scheffe's multiple range test. In addition, the validity of whether the quantitative characteristics of five varieties can be explained by factor analysis was reviewed. Using UPGMA, the relationship between the five varieties was confirmed by dendrogram. As a result of ANOVA and Scheffe's multiple range test there was significant difference in inflorescence width and female flower length. It had a high contribution to distinguishing varieties, which was similar to the PCA results using factor analysis. As a result of dendrogram using cluster analysis, Hancho 915ho, 1020ho and 1030ho were similar, but there was a distinct difference in the characteristics of different flowering and fruiting periods, confirming that they were different varieties.

• Korean Journal of Agricultural Science
• /
• v.43 no.5
• /
• pp.734-741
• /
• 2016

Lily (Lilium davidii) is a high-yielding flowering plant. Besides roses and chrysanthemums, lily bulbs have long been used as food and in oriental medicine. However, the usage and value of cut lily bulbs has not been recognized. A bulb whose yield has been decreased is called a waste bulb, and a large amount of such bulbs is discarded every year. In this study, the functionality of waste bulbs from cut lilies was investigated to explore their potential use as a value-added product. We divided lily bulbs into two groups, one group with six varieties of new bulbs (Medusa, Siberia, Woori Tower, Yelloween, Le Reve, and Morning Star) used for cultivation and the other group with six varieties of waste bulbs (Medusa, Siberia, Woori Tower, Yelloween, Sorbonne, and Sheila). Physiological activities (${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl: DPPH) and 3-ethlbenzthiazolne-6-sulfonic acid (ABTS) radical scavenging capability and tyrosinase inhibiting activity), the amount of total as well as eight individual phenolic compounds (chlorogenic acid, epicatechin, rutin hydrate, p-coumaric acid, kaempferol 3-O-${\beta}$-rutinoside, phloridzin dihydrate, myricetin, and quercetin), and total flavonoid content were measured in the bulbs by high performance liquid chromatography. We detected high amounts of total phenol and total flavonoid as well as high DPPH and ABTS radical scavenging ability. More tyrosinase inhibiting activity was detected in the new bulbs than in the waste bulbs. However, both the new and waste bulbs showed a higher inhibitory activity than the standard (100 ppm ascorbic acid). Although the content of phenolic compounds differed among varieties, under the conditions of the experiment, the most abundant phenolics were epicatechins, followed by chlorogenic acid, and rutins. Overall, the waste bulbs had a higher content of these compounds than the new bulbs. Based on these results, we concluded that bulbs from cut lilies could be used as functional foods in the future and farmers could expect economic gain from the hitherto neglected waste bulbs.