• 제목/요약/키워드: Ethephon

검색결과 83건 처리시간 0.017초

지베렐린이 '신고'배의 비대와 성숙촉진에 미치는 영향 (Effect of the Gibberellin Treatment on Enlargement and Mature Promotion in 'Niitaka' Pear (Pyrus pyryfolia L.))

  • 김종국;이창후
    • 농업생명과학연구
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    • 제43권2호
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    • pp.23-30
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    • 2009
  • 본 실험은 지베렐린이 '신고'배 숙기와 비대에 미치는 영향을 조사하기 위하여 실시되었다. 과실중 조사에서 모든 Gibberellic acid $A_{4+7}$ 처리구는 대조구인 지베렐린 도포제와 비등한 약효가 나타났으며, 무처리구에 비해서는 증가를 나타내었다. 횡경은 $GA_{4+7}$을 만개후 35일째에 도포한 것이, 종경은 만개후 40일째 도포한 것이 가장 효과적인 것으로 나타났으며, 과형지수는 모든 처리구에서 비슷한 수치로 나타났다. '신고'배 발달 초기에는 $GA_{4+7}$ 2.4% 처리구가 $GA_{3}+GA_{4+7}$ 2.7% 처리구나 무처리구보다 현저하게 큰 차이로 비대가 되는 것을 볼 수가 있으나, 성숙기에 들어서면 $GA_{4+7}$ 2.4% 처리구와 $GA_{3}+GA_{4+7}$ 2.7% 처리구의 크기와 가시적인 착색도가 거의 비슷해지는 것을 볼 수 있었다. $GA_{3}+GA_{4+7}$의 성숙촉진 효과를 검토하기 위하여 에테폰 액제와 비교하여 실험한 결과, $GA_{3}+GA_{4+7}$를 만개후 35일째에 어린 과실에 도포한 것이 에테폰과 비슷한 정도로 착색이 되었으며, 무처리구와 비교했을 때에는 모든 $GA_{3}+GA_{4+7}$ 처리구와 에테폰 처리 모두 착색이 6일정도 빨라 착색 속도에 현저한 차이를 보여주었다. 모든 $GA_{3}+GA_{4+7}$ 처리구는 무처리구에 비하여 당도는 증가하고 산도는 감소하였으며, 과실의 경도는 무처리구보다 낮은 것으로 나타났으나 유의한 차이는 없었다. 상기의 결과로 $GA_{3}+GA_{4+7}$ 처리구 모두가 에테폰이나 무처리구보다 과실의 비대에 있어 효과가 큰 것으로 나타났다. 특히 $GA_{3}+GA_{4+7}$를 만개후 35일째에 처리한 것이 횡경 및 종경, 과형지수 모두 가장 높게 나타났으며 착색 또한 깔끔하게 되어 상품성이 높게 평가되었다.

Enhanced fungal resistance in Arabidopsis expressing wild rice PR-3 (OgChitIVa) encoding chitinase class IV

  • Pak, Jung-Hun;Chung, Eun-Sook;Shin, Sang-Hyun;Jeon, Eun-Hee;Kim, Mi-Jin;Lee, Hye-Young;Jeung, Ji-Ung;Hyung, Nam-In;Lee, Jai-Heon;Chung, Young-Soo
    • Plant Biotechnology Reports
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    • 제3권2호
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    • pp.147-155
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    • 2009
  • Oryza grandiglumis Chitinase IVa (OgChitIVa) cDNA encoding a class IV chitinase was cloned from wild rice (Oryza grandiglumis). OgChitIVa cDNA contains an open reading frame of 867 nucleotides encoding 288 amino acid residues with a predicted molecular weight of 30.4 kDa and isoelectric point of 8.48. Deduced amino acid sequences of OgChitIVa include the signal peptide and chitin-binding domain in the N-terminal domain and conserved catalytic domain. OgChitIVa showed significant similarity at the amino acid level with related monocotyledonous rice and maize chitinase, but low similarity with dicotyledoneous chitinase. Southern blot analysis showed that OgChitIVa genes are present as two copies in the wild rice genome. It was shown that RNA expression of OgChitIVa was induced by defense/stress signaling chemicals, such as jasmonic acid, salicylic acid, and ethephon or cantharidin and endothall or wounding, and yeast extract. It was demonstrated that overexpression of OgChitIVa in Arabidopsis resulted in mild resistance against the fungal pathogen, Botrytis cinerea, by lowering disease rate and necrosis size. RT-PCR analysis showed that PR-1 and PR-2 RNA expression was induced in the transgenic lines. Here, we suggest that a novel OgChitIVa gene may play a role in signal transduction process in defense response against B. cinerea in plants.

Morphological and Genetic Characteristics of Colletotrichum gloeosporioides Isolated from Newly Emerging Static-Symptom Anthracnose in Apple

  • Jeon, Yongho;Cheon, Wonsu
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2014년도 추계학술대회 및 정기총회
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    • pp.34-34
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    • 2014
  • Filamentous fungi of the genus Colletotrichum (teleomorph, Glomerella) are considered major plant pathogens worldwide. Cereals, legumes, vegetables, and fruit trees may be seriously affected by this pathogen (1). Colletotrichum species cause typical disease symptoms known as anthracnoses, characterized by sunken necrotic tissue, where orange conidial masses are produced. Anthracnose appears in both developing and mature plant tissues (2). We investigated disease occurrence in apple orchards from 2013 to 2014 in northern Gyeongbuk province, Korea. Typical anthracnose with advanced symptoms was observed in all apple orchards studied. Of late, static fruit spot symptoms are being observed in apple orchards. A small lesion, which does not expand further and remains static until the harvesting season, is observed at the beginning of fruit growth period. In our study, static symptoms, together with the typical symptoms, were observed on apples. The isolated fungus was tested for pathogenicity on cv. 'Fuji apple' (fully ripe fruits, unripe fruits, and cross-section of fruits) by inoculating the fruits with a conidial suspension ($10^5$ conidia/ml). In apple inoculated with typical anthracnose fungus, the anthracnose symptoms progressed, and dark lesions with salmon-colored masses of conidia were observed on fruit, which were also soft and sunken. However, in apple inoculated with fungi causing static symptoms, the size of the spots did not increase. Interestingly, the shape and size of the conidia and the shape of the appressoria of both types of fungi were found to be similar. The conidia of the two types of fungi were straight and cylindrical, with an obtuse apex. The culture and morphological characteristics of the conidia were similar to those of C. gloeosporioides (5). The conidia of C. gloeosporioides germinate and form appressoria in response to chemical signals such as host surface wax and the fruitripening hormone ethylene (3). In this study, the spores started to germinate 4 h after incubation with an ethephon suspension. Then, the germ tubes began to swell, and subsequently, differentiation into appressoria with dark thick walls was completed by 8 h. In advanced symptoms, fungal spores of virtually all the appressoria formed primary hyphae within 16 h. However, in the static-symptom fungus spores, no primary hyphae formed by 16 h. The two types of isolates exhibited different growth rates on medium containing apple pectin, Na polypectate, or glucose as the sole carbon. Static-symptom fungi had a >10% reduction in growth (apple pectin, 14.9%; Na polypectate, 27.7%; glucose, 10.4%). The fungal isolates were also genetically characterized by sequencing. ITS regions of rDNA, chitin synthase 1 (CHS1), actin (ACT), and ${\beta}$-tubulin (${\beta}t$) were amplified from isolates using primer pairs ITS 1 and ITS 4 (4), CHS-79F and CHS-354R, ACT-512F and ACT-783R, and T1 and ${\beta}t2$ (5), respectively. The resulting sequences showed 100% identity with sequences of C. gloeosporioides at KC493156, and the sequence of the ${\beta}$t gene showed 100% identity with C. gloeosporioides at JX009557.1. Therefore, sequence data from the four loci studied proves that the isolated pathogen is C. gloeosporioides. We also performed random amplified polymorphic DNA-PCR, which showed clearly differentiated subgroups of C. gloeosporioides genotypes. The clustering of these groups was highly related to the symptom types of the individual strains.

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