• Title, Summary, Keyword: biotype

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Effective Herbicides for Control of Sulfonylurea-Resistant Monochoria vaginalis in Paddy Field

  • Kuk, Yong-In;Kwon, Oh-Do
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.4
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    • pp.286-291
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    • 2003
  • Monochoria vaginalis is one of the most troublesome resistant weeds in Korean rice culture. Thus, the objectives of this study were to evaluate the response of M. vaginalis resistant to sulfonylurea(SU) herbicides and to determine alternative herbicides for the control of resistant M. vaginalis in direct seeded and transplanted rice culture in Korea. In greenhouse studies, the resistant biotype was 31-, 38-, 3172-, and 7-fold more resistant to ben-sulfuron-methyl, cyclosulfamuron, imazosulfuron, and pyrazosulfuron-ethyl, respectively, than the susceptible biotype, indicating cross-resistance to the SU herbicides used in this study. Non-SU herbicides, butachlor, carfentrazone-ethyl, mefenacet, pretilachlor, pyrazolate, and thiobencarb, several SU herbicide-based mixtures, ethoxysulfuron plus fentrazamide, pyrazosulfuron-ethyl plus pyrazolate plus simetryn, and non-SU herbicide-based mixtures, pyrazolate plus butachlor, pyrazolate plus pretilachlor, simetryn plus molinate, carfentrazone-ethyl plus butachlor, and carfentrazone-ethyl plus thiobencarb can be used to control both the resistant and susceptible biotypes of M. vaginalis when applied before the second leaf stage. In the field experiment, the resistant biotype of M. vaginalis that survived from the paddy fields treated with a SU herbicide-based mixture could effectively be controlled by using mixtures of bentazone plus MCPA, bentazone plus mecoprop-P, and bentazone plus 2,4-D when applied at 2 or 4 main leaves. Our results suggest that the SU-resistant M. vaginalis had not developed multiple resistances to herbicides with different modes of action. In particular, bentazone plus MCPA and bentazone plus mecoprop-P were effective control measures after failure to control resistant M. vaginalis in Korean rice culture.

Variations in Leg Characters Among Three Biotypes of the Brown Planthopper, Nilaparvata lugens (Stal), in Korea (한국산 벼멸구 생태형의 계량형태적 분류)

  • ;R. C. Saxena;A. A. Barrion
    • Korean journal of applied entomology
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    • v.32 no.1
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    • pp.68-75
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    • 1993
  • Morphometric investigations of the leg characters of both sexes of brachypterous Korean N. lugens biotypes were made. Simple and multivariate statistical analyses revealed that the three N. lugens biotypes differed from one another. The amount of variation and segregation between and among the three biotype populations were approximated by the scatter plot diagrams based on the computed discriminant scores. The variables of leg characters provided the most significant segregations of three biotype populations, thus, categorizing the three biotypes as distinct intraspecific populations of N. lugens.

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Classification of the Three Korean Biotypes of the Brown Planthopper, Nilaparvata lugens(Stal), By Morphological Variation (한국산 벼멸구 생태형의 형태적 분류)

  • ;;R. C. Saxena;A. A. Barrion
    • Korean journal of applied entomology
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    • v.32 no.3
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    • pp.317-322
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    • 1993
  • Morphological investigations of the abdominal lateral lobes in females and the unguitractor p plates in the tarsi of legs in male and female N. lugens among the three Korean N. lugeηs bio-types revealed that the three biotypes varied from one another. The presence of a distinct ‘cut’ on the lateral lobes in brachypterous females distinguished Biotype 2 from Biotypes 1 and 3. The highest frequency of inserted unguitractor plates in fore-and mid-tarsal segments was exhibited by Biotype 2 in both sexes of each morphs.

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Serotype and biotypes of Salmonella strains isolated from pigeons and aquatic birds (비둘기와 수생조류(水生鳥類)에서 분리(分離)한 Salmonella속균(屬菌)의 혈청형(血淸型) 및 생물형(生物型))

  • Park, No-chan;Choi, Won-pil;Lee, Hi-suk
    • Korean Journal of Veterinary Research
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    • v.30 no.2
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    • pp.193-201
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    • 1990
  • An attempt was made to isolate Salmonella(S) organisms from a total of 4,587 fecal samples of birds during the period from May 1987 to March 1988, and serotype and biotypes of the isolates were also investigated. One hundred and sixty-six Salmonella strains were isolated from 151(3.3%) of 4,587 fecal samples of birds, and their serotype was all identified as S typhimurium var copenhagen. The positive samples of S typhimurium var copenhagen were 149 samples(5.1%) in pigeons and 2 samples (0.8%) in aquatic birds. No Salmonella was obtained from ducks, pheasant, and other birds. The isolation frequencies of S typhimurium var copenhagen from pigeons varied from 1.1 to 12.8% at 5 parks, it was higher in September and November. Biotypes of 166 S typhimurium var copenhagen strains isolated from pigeons and aquatic birds were all biotype 10 according to Brandis' method, and were biotype 25hi (78.3%), 27 hi (14.5%), 25 fhi (3.6%), 25 bhi (1.8%), 27 bhi (0.6%), 27 hiz (0.6%), and 9 hi (0.6%) according to Duguid's scheme. Appearance of different biotypes indicated the occurrence of exotic infection sources on the parks.

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Development of the Brown Planthopper, Nilaparvata lungens Sta$\{aa}$l, Biotypes and Their Hybrid Progenies Fed on Different Cultivars of Rice with Various Resistance Gene and Damage of Different Rice Cultivars (벼멸구 생태형의 교잡종별 발육 및 수도 품종별 피해)

  • 최주수;박영도
    • Journal of Life Science
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    • v.7 no.4
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    • pp.347-354
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    • 1997
  • Some attempts were made to investigate the gentic characteristics of the brown planthopper(BPH), Nilaparvata lugens Sta${\aa}$l, biotypes. In terms of egg and nymphal periods, egg hatcgability, emergence ratio, and population change of BPH and plant damage of rice cultivars by the infestation of BPH biotypes and their hybrid progenies in field conditions. The egg and nymphal periods of the three of BPH biotypes and their hybrid progenies on Dongjinbyeo with no resistance gene were shorter than on rice cultivars with resistance gene. But the periods of biotype-2(♀) X 2(♂) (E) on Samgangbyeo with Bph-1 gene and biotype-3(♀) X 3(♂)(I) on Mirying 63 with bph-2 gene were as short as on Dongjinbyeo. The egg hatchability and emergence ratio of the three Bph biotypes and their hybrid progenies on Dongjinbyeo were higher than on the other rice cultivars, and those of E on Samgangbyeo and I on Miryang 63 were as high as on Dongjinbyeo. In rice paddy field, biotype-1(♀) X 1(♂)(A)$\sim$I infested on Dongjinbyeo, E onSamgangbyeo, and I on Miryang 63 were increased their population densities remarkably in next generation. Dongjinbyeo infested by A$\sim$I, and Myryang 63 infested by I were hopperburned at 60 days after infestation and had a damage rating of 0.9. But Samgangbyeo infested by E was no hopperburn(damage rating: 7.3) though it showed high BPH population at 60 days after infestation.

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Variation in Demography of Taraxacum officinale Seeds Harvested from Different Seasons

  • Yang, Hyo-Sik;Oh, Man-Ho
    • The Korean Journal of Ecology
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    • v.26 no.2
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    • pp.82-86
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    • 2003
  • We investigated the variation in adaptation to growth for four ecotypically-differentiated population of Taraxacum officinale found naturally in temporal environmental heterogeneity. Seeds collected from the four seasons were germinated in incubators and were grown for four months in greenhouse to test genetic variation among biotypes. Biotypes, segregated by seeds collected seasonally, were the part of natural population in Mokpo, South Korea. Each biotype was different in total dry weight of seeds, biomass, and leaf area, confirming previous finding. Differences between biotypes grown under a common environment indicated a genetic basis to their distinct demographic rates. Therefore, biotypes with similar annual rates of growth and contrasting seasonal rates should persist in the population. This differential response suggests that temporal variation in environment may be responsible, in part, for the maintenance of genetic variation within populations.

Characterization of a salicylate-degrading strain of pseudomonas putida (Salicylate를 생분해하는 pseudomonas putida의 특성)

  • 홍순우;하영칠;이계준;배경숙
    • Korean Journal of Microbiology
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    • v.24 no.1
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    • pp.51-56
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    • 1986
  • Eight strains of the bacteria capable of growing on salicylate as the sole carbon source were isolated form soil and river water. Three of these isolates were identified as Acinetobacter calcoaceticus (AcBl), Pseuomonas putida biotype B (PpB2), and P. putida biotype A (PpB3). Effects of temperature, pH and C source concentration on biodegradation of salicylate by PpB3 were wxamined. The optimum conditions were as follows; $30^{\circ}C$ for temperature, 7.0 for pH, and 10mM for C source concentration. Ultraviolet scanning spectrum of the salicylate was measured. The spectrum has two peaks at 225nm and 292nm. The spectra of the culture filtrates indicate that ring degradation of salicylate is accomplished.

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Isolation of Staphylococcus Aureus from the Tonsils of Healthy Pigs (돼지편도로부터 STAPHYLOCOCCUS AUREUS균의 분리)

  • 이재봉;고주영;조영보;정승기
    • Korean Journal of Veterinary Service
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    • v.14 no.2
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    • pp.143-147
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    • 1991
  • Between June and August 1990, the tonsils of 86 healthy pigs were examined for the presence of staphylococci. All of the pigs examined harboured Staphylococci in the tonsils, the most predominant Staphylococcus species was Staphylococcus aureus(45.3%) followed by Staph hyicus subsp chromogenes (20.9%), Staph hyicus subsp hyicus (16.3%), Staph hominis(4.7%), Staph simulans(2.3%) and Staph xylosus(1.2%), Unidentifiable species were isolated from 3(3.5%) of the 86 tonsils examined. Thirty-nine strains of Staph aureus were subjected to the biotyping scheme of Hajek & Marsalek all the strains were classified as biotype B.

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