The insecticidal activity of cinnamon essential oils, cinnamon bark, cinnamon technical, cinnamon green leaf oils and their constituents and structurally related compounds against citrus flatid planthopper, Metcalfa pruinosa, was examined using a direct contact application. At 500 mg litre-1 very strong mortality (100%) was observed in cinnamon technical, cinnamon bark, cinnamon green leaf, mortality against flatid planthopper M. pruinosa. The cinnamon oils constituents were identified by GC-MS. The active principles were determined to be hydrocinnamic acid (24 h LC50, 30.66 mg/L), geranic acid (24 h LC50, 31.23 mg/L), cinnamaldehyde (24 h LC50, 32.65 mg/L), hydrocinnamaldehyde (24 h LC50, 39.11 mg/L) and trans-cinnamaldehyede (24 h LC50, 39.54 mg/L) were the most toxic against both nymph and adult of citrus flatid planthopper, M. pruinosa. The moderate activity was observed with cinnamyl acetate, dibutyl pthalate, anethole, α -cyano cinnamic acid, cinnamyl alcohol, methyl cinnamaldehyde, eugenol, 2.4-dihydrocyl cinnamic acid, bornyl acetate (24 h LC50, 53.35- 97.17 mg/L) respectively. The other constituents were showed less or no activity against adult of M. pruinosa. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the active cinnamon oils active principles act as potential insecticides for the control of M. pruinosa populations as direct spray with contact action.

Several properties related to longevity and reproduction of O. scapulalis adults were investigated on nine constant temperatures (13, 16, 19, 22, 25, 28, 31, 34 and 36℃). Thirty mating pairs on each temperature were separately prepared on the emerged days of adults, supplied with distilled water and 10% sucrose solution in small plastic cages, and observed every day. The adults could not produce fertile eggs on 13 and 36℃. The highest mating rate (ca. 47%) was observed on 19℃, and the lowest mating rate (3.3%) on 34℃. The mean longevity of mated female was observed in the range from ca. 9 to 52 days, while that of male was in the range from 10 to 31 days. The mean pre-oviposition period was longest (ca. 16 days) on 16℃ and shortest (ca. 3 days) on 31℃. The oviposition period was longest (ca. 16 days) on 19℃ and shortest (ca. 3 days) on 34℃. The low fecundity (ca. 22∼25 eggs/pair) was observed on 16 and 34℃, while 147∼416 eggs per pair were produced in other temperatures. The production pattern of fertile eggs on each temperature was analyzed. Fifty percent of production of fertile eggs was observed most rapidly on 3-day-old female at 28℃. In this study, a few properties of the mated adults were compared to those of the unmated one. Finally a few models were adopted to generalize some properties.

The insecticidal activity of 120 plant essential oils and control efficacy of six experimental spray formulations (SF) containing the oils (SF-0.25, 0.5, 1, 2.5, 5 and 10% sprays) against both nymph and adult of citrus flatid planthopper, Metcalfa pruinosa, was examined using a direct contact application. Reponses varied according to dose (1000 mg litre-1 and 500 mg litre-1). Based on 24 h exposure in leaf dipping assay at 1000 mg litre-1 strong mortality was observed in more than 19 essential oils among 130 was screened. At 500 mg litre-1 very strong mortality (100%) was observed in cinnamon technical, cinnamon green leaf, cinnamon #500, cassia tree, citronella java and penny royal followed by origanum, thyme white, grape fruit, savory, fennel sweet, aniseed and cinnamon bark (93.3- 80%) showed considerable moratality against nymphs of M. pruinosa. The moderate mortality was found in thyme red, tagette, calamus, lemoneucalptus and geranium (73.3-60%). The other oil has low or very low mortality against M. pruinosa. The oil applied as SF-10% sprays provided 100% mortality against adult M. pruinosa. In particular cinnamon technical showed very strong (>SF-0.5= 100%) effect followed by cinnamon #500 (>SF-2.5=100%), cinnamon green leaf (>SF-2.5=100%) and penny royal (>SF-2.5=100%) respectively. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the active essential oils as potential larvicides for the control of M. pruinosa populations as direct spray with contact action.

The adzuki bean borer, Ostrinia scapulalis (Lepidoptera: Crambidae), is one of serious insect pests against the red bean, Vigna angularis. Adult emergence, mating and oviposition behaviors of the insect were investigated in a constant condition of 25±1℃, 15L:9D (light: dark) photoperiod, and 60±10% relative humidity, for the purpose of collecting fundamental data for elucidation of adult biology and female sex pheromone. The circadian rhythmic behaviors were observed at 30-min interval during the experiments, and the data was analyzed at one-hour interval. Adult emergence was observed for 15 hours from 2 hours before lights-off to 4 hours after lights-on in a row, and ca. 90% emerged in scotophase. Adults did not mate within the emerged scotophase and the following photophase. Mating was observed only in the scotophase, and ca. 95% of mating occurred for 5 hours from 2 hours after lights-off to 2 hours before lights-on. The result was different from the main mating time in the previous reports. Mean mating rate at 0- to 4-day-old pairs was ca. 50%. It took almost one day from mating to oviposition, but oviposition 2 days after mating was observed in 0-day-old adult pairs. Adult pairs older than 7-day-old could not mate.

본 연구에서는 팥의 꼬투리와 줄기를 가해하는 Ostrinia속 해충에 대해 종 동정 과정을 기술하였고, 사육하면서 관찰된 발육특성들을 보고 하였다. 수컷의 생식기는 3-lobed uncus 형태였으며, 가운뎃다리 종아리마디에는 털을 많이 갖는 것으로 나타났다. 미토콘드리아 cytochrome oxidase I (COI)과 II (COII) 유전자의 부분 염기서열은 콩줄기명나방(O. scapulalis), 큰섬들명나방(O. zaguliaevi), 큰조명나방(O. zealis bipatrialis)들에 대해 일본과 중국에서 보고된 서열들과 100% 일치를 보이는 종은 없었다. 기주식물 범위는 국내외 보고들 간에 일치하지 않았다. 암컷 성페로몬샘 추출물의 가스크로마토그래피 분석에서 큰섬들명나방과 큰조명나방의 성페로몬 성분인 (Z)-9-tetradecenyl acetate는 검출되지 않았다. 이상의 결과들을 종합하여 고려하였을 때, 본 연구의 팥 해충을 가해하는 곤충 종은 콩줄기명나방(O. scapulalis)일 것으로 추정되었다. 가을 야외에서 채집된 유충들을 야외조건에서 보관하였을 때, 이듬해 6월과 7월 사이에 성충들이 우화하였는데, 이 결과로부터 본 곤충 종은 말령 유충 단계에서 겨울휴면을 하는 것으로 추정되었다. 이외에 반합성 인공사료를 이용하여 실내 사육이 가능하였다.

콩과(Fabaceae) 작물 해충인 팥나방(Matsumuraeses phaseoli)과 어리팥나방(M. falcana) (나비목: 잎말이나방과)은 형태적으로 매우 유사하여 종 구별이 힘든 것으로 알려져 있다. 본 연구에서는 PCR-SSP(PCR with Sequence Specific Primers) 방법으로 두 종을 빠르고 정확하게 구별할 수 있는 판별법을 찾고자 두 종의 미토콘드리아 시토크롬 옥시다제 I(mtCOI) DNA 부분영역(439 bp)의 염기서열을 해독하였다. 그리고 다른 나방 종의 mtCOI 염기서열과 함께 나열하여 비교한 후 팥나방과 어리팥나방에서 종 특이적으로 차이가 나는 단일 뉴클레오티드를 프라이머의 3ʹ말단으로 하는 염기서열 특이 프라이머 조합을 만들었다. PCR 산물들을 전기영동 한 결과, 어리팥나방은 245 bp, 팥나방은 409 bp와 245 bp의 특이적 밴드 패턴을 보여 두 종을 구별할 수 있었다.

This study was conducted to identify an insect species in Genus Ostrinia (Lepidoptera: Crambidae) that gave serious damage to the red bean, Vigna angularis. The species has ever been described as O. zaguliaevi in the previous presentation (Jung et al., 2010). Because, however, inconsistent information has been recognized for the species, we reviewed characteristics in morphological, molecular and sex pheromone levels, and host-range. Male genitalia had 3-lobed uncus and tibia of midleg showed massive type. The morphology indicated that the species might be one of O. zaguliaevi, O. scapulalis and O. zealis. Partial nucleotide sequences of cytochrome oxidase subunit Ⅰ(COⅠ) and Ⅱ genes were not identical with those of the 3 species in GenBank, respectively. The deduced amino acid sequence of COⅠ was not identical with that of O. zealis. In the 23 analyses that sex pheromones were checked, (Z)-9-tetradecenyl acetate, which was reported in the sex pheromone components of both O. zaguliaevi and O. zealis, was not detected at all. An intensive study in Japan has reported that the feeding habit of O. scapulalis is polyphagous, while that of O. zaguliaevi is monophagous (only in Petasites japonicus) (Ishikawa et al., 1999). After considering all these information, we concluded that it is reasonable to decide that the insect species in the red bean in Korea is O. scapulalis.

Three rice planthoppers, the brown planthopper (Nilaparvata lugens), the white back planthopper (Sogatella furcifera), and the small brown planthopper (Laodelphax striatellus) and the green rice leafhopper (Nephotettix cincticeps) are major homopteran sap-sucking rice pests in Korea. These insect pests commonly have highly modified mouthparts, the stylet bundle, for piercing and sucking. Two pairs of mandibular and maxillary stylets consist of the stylet bundle by interlocking each stylet, which forms the two canals, larger one for food canal and smaller one for salivary canal. Destructive damages result from direct feeding effects (hopperburing) with heavy infestation and/or transmitting virus diseases (Rice stripe virus and Rice black-streaked dwarf virus by L. striatellus and Rice dwarf virus by N. cincticeps). Damage level is closely related to the feeding behavior of sap-sucking insects, so generally honeydew excretion amount on the resistant rice variety is smaller than that on the susceptible. Therefore, the method to measure the honeydew excretion amount has been primarily used as an indirect way to compare the feeding amount between the susceptible and the resistant. On the other hand, the electrical penetration graph (EPG) technique was firstly developed by McLean and Kinsey (1964) to measure voltage changes during piercing and sucking of insect on the plant. Since specific voltage waveforms were identified and it was known that each waveform is commonly related to salivary and feeding behavior of insect stylets in the plant tissue, EPG technique has been used to real-timely and quantitatively measure feeding behavior of piercing and sucking insects on susceptible and resistant rice variety. However, identifying each different waveform distinctly and understanding biological function of each waveform are certainly necessary to analyze feeding behavior in the plant tissue such as phloem sap ingestion. In this study, the stylet penetration behavior of N. lugens, S. furcifera, L. striatellus, and N. cincticeps on rice plants (Oryza sativa) was evaluated through the use of a direct current based electrical penetration graph (DC-EPG). To accomplish this, we classified the EPG waveforms of planthopper group into seven different patterns, np, N1, N2, N3, N4-a, N4-b, and N5, according to their shapes, voltage amplitudes, voltage levels, and frequencies. The N4-b pattern was always preceded by N3 and N4-a, in that order. Continuous honeydew excretion only occurred during the N4-b period, and the honeydew deposited on a filter paper containing ninhydrin reagent during the N4-b period were stained into violet. Based on the location of the stylets in the cross-section of rice tissue and honeydew excretion, the EPG waveforms for the stylet penetration behaviors of the three rice planthoppers were assigned to the following groups; np: non-penetration of stylets, N1: penetration initiation, N2: salivation and stylet movement, N3: an extracellular activity near the phloem region, N4-a: an intracellular activity in phloem region, N4-b: phloem sap ingestion, and N5: activity in the xylem region. Futhermore, we classified the EPG waveforms of the green rice leafhopper, N. cincticeps into seven different patterns, Nc1, Nc2, Nc3, Nc4, Nc5, Nc6, and Nc7 according to their shapes, voltage amplitudes, voltage levels, and frequencies. The Nc6 pattern was always preceded by Nc5 pattern. The Nc6 pattern of the leafhopper was carefully considered as a phloem sap feeding behavior based on regular honeydew excretion. On the other hand, the planthopper group and the leafhopper hardly showed the phloem sap feeding pattern on resistant rice varieties during an EPG-recording. In addition, the duration of the phloem sap feeding patterns was highly decreased on resistant rice varieties relative to susceptible ones. From these results, it is suggested that the phloem sap feeding related patterns are an important parameter to determine resistance of rice plant.

In the previous study, the effect of orange-eyed color on mating of BPH was not clearly occurred, and the mating preference and multiple mating of female were cautiously suggested. To understand about the BPH female mate selection in the male-male competition-free conditions and the point of time for multiple mating, we designed four different combinations of the mate choice test with one virgin orange-eyed female (org/org) and two male BPH adults, orange-eyed male (org/org) and homozygous normal-eyed male (+/+). We gave the four different mating chances to female by the order of incubation (the first male and the following second male) and the incubation time (one day and days on end) of the second male. The distribution of the eye-color phenotype in F1 progeny and their hatching-order were observed in each mating combination. In the results, fourteen females out of twenty in four combinations produced progenies in accordance with mating chance priority of the first male, while three females of one combination selected the second male as a gamete. Interestingly, in three females of one combination with the continuous incubation of the second male, after eggs fertilized by the first male were continuously produced and then egg-laying was finished, progenies of the second male were started to be produced. From these results, it was suggested that mating order determines egg-laying order of female and the second mating of female would be occurred when sperm of the first male was almost exhausted in the reproductive organ.

In the previous study, we found an orange-eyed mutant of the brown planthopper (BPH). And we confirmed that it’s orange phenotype is controlled by single recessive allele in the autosome. To understand the effect of the orange eye color on mating of BPH, we designed two different combinations of the mate choice test with three virgin female and male BPH adults. The one consisted of orange-eyed female (org/org), orange-eyed male (org/org), and homozygous normal-eyed male (+/+) (female mate choice). The other was composed of orange-eyed male (org/org), orange-eyed female (org/org), and homozygous normal-eyed female (+/+) (male mate choice). In female mate choice test, four mating types could be distinguished according to the distribution of the eye-color phenotype in F1 progeny and their hatching-order in each mating pair. Two mating types showed only one eye-color phenotype, normal and orange, respectively, and the other two produced both eye-color phenotypes in a different hatching-order. In male mate choice test, both phenotypes of offsprings were also produced in most mating pairs. From these results, the effect of eye color on mating of BPH was not clearly found, but the multiple mating in both sexes and the mating preference by female are cautiously suggested.

Ostrinia zaguliaevi (Lepidoptera: Crambidae) causes serious damage to pods and stems of the red bean, Vigna angularis, during the second half of the reproductive developmental stage. The temperature-dependent development studies of O. zaguliaevi were performed at several constant temperatures ranging from 7℃ to 36℃ in the laboratory, in the purpose of making temperature-dependent development models in the future. Eggs and larvae of O. zaguliaevi could not develop at lower temperatures of 7~13℃. As the temperature increased, the developmental period of the immature stage decreased. The number of larval instar was variable from 5 to 8, depending on temperature. The minimum number of larval instar was observed at only 25℃. Some larvae of colonies maintained at 16~22℃ showed highly longer developmental period. At relatively higher temperatures, 34℃ and 36℃, the larval developmental rates were not slowed down, and the larval survival rates was relatively high, above 60%. The egg mortality was relatively high at 36℃. Using these temperature-dependent development data of O. zaguliaevi, preliminary linear regression equations were estimated to look for a relationship between temperature and developmental rate in egg and larval stages.

The legume pod borer, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae) causes serious damage to some legume crops of genus Vigna and Sesbania in Korea. In the current study, laboratory studies on the temperature-dependent development of the insect were performed at 8 constant temperatures ranging from 13℃ to 34℃ at 3℃ intervals. Lower developmental threshold (LDT) for eggs, larvae, and pupae were calculated as 10.0, 12.5 and 13.3℃, respectively, using the linear-regression equations of the developmental rates. Degree-days required to complete a stage were estimated as 48, 187, and 94, for egg, larval, and pupal stages, respectively. The larvae couldn't survive at 13 and 16℃, and the larval survival rate was the highest at 28℃. The egg hatching rate was the lowest at 13℃. In the adult stage, the pre-oviposition period was the shortest at 22℃, and the total egg number was the most with ca. 500 at 25℃. Degree-days for the stages of 1st-4th larval instars, egg, and adult emergence-50% oviposition were calculated during the reproductive development season of red bean using single sine method and Suwon weather station data based on LDTs, respectively. Finally, the adult occurrence time was estimated after the degree-days were cumulated reversely from the distribution data of larval stages observed in a red bean field

An expression of adult wing form in reaction to rearing density during nymphal stage was investigated in the brown planthopper, Nilaparvata lugens. Under mass rearing condition, the S-BPH and the 2007-BPH population predominantly showed a short-winged, brachypterous, form and a long-winged, macropterous, form, respectively. At rearing density of less than 5 nymphs in the 2007-BPH, 90% of females showed brachypterous form, but all males became macropterous form. The ratio of macropterous form in the 2007-BPH males decreased by 75% in 10 to 15 rearing density, but increased by more than 95% again at 20 to 30 rearing density. In the case of the 2007-BPH females, the ratio of macropterous form gradually grew from 31% at 10 nymphal density to 92% at 20 nymphal density. All females originated from the S-BPH showed brachypterous form, regardless of nymphal density. The ratio of macropterous males in the S-BPH rapidly went down from 74% at 1 nymphal density to 10% at 10 nymphal density. At 20 nymphal rearing density, all males of the S-BPH showed brachypterous form. On the other hand, other brachypterous (OJ67-BPH) and macropterous (2006-BPH) population produced similar results with above the two populations at 1 nymphal rearing density. In summary, these results demonstrate that wing form dimorphism in N. lugens is largely influenced by nymphal density and the wing form at a specific density (low or high) can be different by sex or N. lugens populations.

Previous studies indicated that Matsumuraeses phaseoli and M. falcana (Lepidoptera: Tortricidae) are separate species since a few differences were observed in genitalia morphology and female sex pheromone composition. A clear difference was detected in the DNA sequences of cytochrome oxidase I of the two species separately collected in different plants and regions. A hybridization test also showed that a post-zygotic reproductive isolation occurred between the species. In field monitoring, however, both species have been caught simultaneously and together in the separate sex pheromone traps installed for the two species around neighboring soybean and red bean fields. Molecular marker-assisted identification with several adults sampled from the trapped insects showed that only ca. 40% of M. phaseoli adults identified as the species by genitalia morphology was the M. phaseoli, while ca. 97% of M. falcana adults identified as the species was the M. falcana. The result indicated that the observation of genitalia did not make a decisive criterion for classification of the insects. Conclusively, it suggested that the sex pheromones of the two species should be studied more precisely although there is a possibility that the two species are hybridized in fields as in laboratory, and speciation is under process.

Matsumuraeses phaseoli and M. falcana cannot be classified with the external morphological characters. Although differences in the morphology of male genitalia and in the mitochondrial DNA sequence of cytochrome oxidase I between the two species have been found, there is no information that the two species are biologically different species till now. We, therefore in this study, tried to cross the two species to observe postzygotic incompatibility in the next hybrid generations and to know whether the two species are 'biological species' or not. In crossing between the parents, two kinds of F1 hybrids were produced successfully. In inter- and intra-breeding between F1 hybrids, two lines crossed with females of F1 hybrid produced by females of M. phaseoli could not produce F2 adults to show inviability of larvae. The other two lines produced F2 adults successfully and the F2 adults produced F3 larvae in inbreeding. In back-crossing between parents and F1 hybrids, the two lines of 8 breeding lines, in which females of F1 hybrid were produced by females of M. phaseoli, could not produce the next generation of larvae. The other six lines produced F2 adults successfully. The results indicated that maternal factors of F1 hybrid produced by M. phaseoli females contributed to create the incompatibility between the F1 females and other lines. In conclusion, the results showed a postzygotic reproductive isolation between M. phaseoli and M. falcana in part.

The Asian corn borer, Ostrinia furnacalis, over-winters as the last instar larva in Suwon and undergoes diapause during the over-wintering, and it has been postulated that most of the over-wintering larvae be originated from the larvae of 2nd and 3rd generation (Jung et al., 2008). The over-wintered larvae pupate next year and 50% of emerged adults occur by the early June. In order to know whether the emergence has synchronism among over-wintering larvae regardless of the time entering into diapause or not, neonate larvae were reared on artificial diet at two-week intervals from May 28 to Sep. 28, 2008 in an outside condition and their emergence dates were recorded. The over-wintering larvae occurred from the colony treated at Jul. 20, 2007, and totally emerged from May 11 to Jul. 6, 2008. The 50% date of cumulative emergence was June 3, 2008. The maximum success of over-wintering occurred in the colony treated at Aug. 17, whereas any non-over-wintering larvae were not observed from the following colonies. Although the durations of emergence overlapped partially among the colonies treated at different times in the previous year to show a synchronism at some extent, the first and last colonies treated in the previous year showed a pattern of fast emergence. This result suggested that the duration necessary for diapause termination be different according to the time entering into diapause.

(E,E)-8,10-dodecadienyl acetate (E8E10-12:Ac) and (E)-8-dodecaenyl acetate (E8-12:Ac) have been selected as the candidate chemicals for sex pheromone components of the M. phaseoli, female through GC-EAD tests, whereas the two compounds and an additional candidate, (E,Z)-7,9-dodecadienyl acetate (E7Z9-12:Ac), have been found at a ratio of 7:1:1 in the abdominal tip extract (Yum et al., 2008). In order to determine the actual composition of sex pheromone, therefore, several blends using the three chemicals were evaluated for attractiveness to males of M. phaseoli around red bean and soybean fields. Individual components as well as two blends consisted of E8E10-12:Ac/E7Z9-12:Ac and E8-12:Ac/E7Z9-12:Ac did not show attractiveness, whereas the blend of E8E10-12:Ac/E8-12:Ac showed an increased effect in male capture. Of the tested blends with all three chemicals, the 7:1:2 composition of E8E10-12:Ac, E8-12:Ac and E7Z9-12:Ac attracted the most number of males. The results suggested that E7Z9-12:Ac is one of the sex pheromone components and may act as a synergist.

Resistance-breaking ability of wild brown planthopper (BPH), Nilaparvata lugens, on resistant rice cultivars has been reported in many Asian countries. To understand the development of resistance-breaking ability of wild BPH in Korea, we conducted the nymphal survivorship test and the electrical penetration graph (EPG) on susceptible and resistant rice cultivars with four different BPH populations, which were collected in the early 1980s (S-BPH), 2005, 2006, and 2007, respectively. The S-BPH showed low survival rates on resistant rice cultivars carrying Bph1 and bph2, respectively. On the other hand, recent(2005~2007) wild BPH populations seemed to have high resistance-breaking ability because they maintained elevated survival rates on most other resistant rice cultivars except Gayabyeo (Bph1 and bph2) and Rathu Heenati (Bph3). In the EPG monitoring, however, wild BPHs could not easily feed on the phloem sap of resistant rice cultivars, Cheongcheongbyeo (Bph1), ASD7 (bph2), and Gayabyeo. Wild BPHs spent more time on reaching the phloem sieve elements of resistant cultivars. Ph waveform duration and honeydew excretion amount of wild BPHs also decreased. From the results, we suggest that though recent wild BPHs collected in Korea have high resistance-breaking ability simultaneously on rice cultivars carrying Bph1 and bph2 through the increase of survivorship, they still have to pay some cost to feed on the phloem sap of resistant rice cultivars.

As a first step of mapping genes conferring resistance to the brown planthopper, Nilaparvata lugens Stål, in Gayabyeo using a population derived from a cross between Gayabyeo and Taebaegbyeo, we performed the whole genome resequencing of these two Tongil-type rice varieties. The amount of raw sequence data was about 18.5X109 bp and 17.9X109 bp in Gayabyeo and Taebaegbyeo, respectively. After quality trimming and read mapping onto Nipponbare reference genome sequence, 9.3X109 bp was mapped in Gayabyeo with mapping depth of 25.0X, and 9.5X109 bp was mapped in Taebaegbyeo with mapping depth of 25.5X. Between Gayabyeo and Nipponbare, 1,585,880 SNPs were detected, while 1,416,898 SNPs were detected between Taebaegbyeo and Nipponbare. Between Gayabyeo and Taebaegbyeo, 284,501 SNPs were detected. Among the SNPs between Gayabyeo and Taebaegbyeo, 21.2% were in genic region and 78.8% were in intergenic region. In CDS region, 15,924 SNPs were detected, among which synonymous SNPs covered 47.3% and non-synonymous SNPs covered 52.7%. We designed Cleaved Amplified Polymorphic Sequences (CAPS) markers with SNPs in the restriction enzyme recognition sites, and 20 CAPS markers were tested. Of the 20 markers, 19 markers showed polymorphism and one marker showed monomorphism between Gayabyeo and Taebaegbyeo. It is expected that sufficient DNA markers for mapping genes with a population derived from a cross between Gayabyeo and Taebaegbyeo can be developed based on the results of the study.

Brachypodium distachyon is a temperate annual grass that has a short life cycle, a small genome size, self fertility, and a small physical stature. The relationship with major cereal crop including wheat, Brachypodium is considered as a monocot model plant. Recently, the cell wall composition of Brachypodium is reported closely related with maize and Miscanthus giganteus. Therefore, Brachypodium is emrging as a powerful model plant for bioethanol production. Here, Brachypodium was chronically irradiated with the doses of 50 Gy, 100 Gy, 150 Gy, 200Gy, 250Gy, and 300 Gy. Plant height and fresh weight were observed dosage-dependent negative effect. However, tiller number and internode diameter were found to be increased their value as compared to control. The cell wall yield showed a decreased tendency with dosage-dependent negative, but cell wall yield of 50 Gy and 200 Gy were detected higher than control. The lignin content of irradiated Brachypodium stem was reduced with dosage incease The ratios of lignin content to control were 97.6% (50 Gy), 91.9 (100 Gy), 87.3% (150 Gy), 89.4% (200 Gy), 81.6% (250 Gy), 85.2% (300 Gy). SEM image analysis demonstrated that cell size of 300 Gy plant was decreased by 45% of control. RT-PCR was performed to analyze transcript accumulation of lignin pathway related genes with irradiated Brachypodium stem. CCR, PAL, C4H, and 4CL were detected at least 2 times higher expression than control at 150 Gy, 200 Gy, 250 Gy. The preteatment and enzyme hydrolysis will be discussed for bioethanol production.