• The Plant Pathology Journal
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• 제28권3호
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• pp.239-247
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• 2012

Phytoplasmas have been associated with more than 46 plant species in Korea. Several vegetables, ornamentals, fruit trees and other crop species are affected by phytoplasma diseases. Six 16Sr groups of phytoplasmas have been identified and these phytoplasmas are associated with 63 phytoplasma diseases. Aster yellows phytoplasmas are the most prevalent group and has been associated with more than 25 diseases in Korea. Jujube witches' broom, paulownia witches' broom and mulberry dwarf diseases cause economic losses to host trees throughout the country. So far, Korean phytoplasmas belong to six species of 'Candidatus Phytoplasma'; 'Ca. P. asteris', 'Ca. P. pruni$^*$', 'Ca. P. ziziphi', 'Ca. P. trifolii', 'Ca. P. solani$^*$' and 'Ca. P. castaneae'. The diseases are distributed throughout the country and most of them were observed in Gyeongbuk and Chonbuk provinces. At least four insect vectors; Cyrtopeltis tenuis, Hishimonus sellatus, Macrosteles striifrons and Ophiola flavopicta have been identified for phytoplasma transmission.

• 미생물학회지
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• 제3권1호
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• pp.1-6
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• 1965

Over a period of 1962-64, a transmission-experiment of witchess' broom of jujube tree by stem-grafting was conducted. When stem-grafting of sound scions upon diseased roots or diseased scions upon sound roots were carried out, disease transmission of high rate was witnessed; 99% in the former and, in the latter, 62% of the stocks which saw union by callussing and had new shoots. Even when the diseased scions by stem-grafting or the diseased buds by budding upon sound stock died away, the transmission rate was 21% in stem-grafting and 14% in budding which seems to show that, when tissues of diseased plants and stocks are kept contacted over a certain period, the disease transmission occurs. And when the recovered scions taken from once diseased tree were grafted upon diseased roots, the transmission rate was 100 % and therefore it is presumed that the immunity could not be acquired even under the assumption of complete recovery from the disease. In stem-grafting of the diseased scions upon sound roots, 98% of the scions which were stored in the cellar, overwintered and grafted in spring was diseased, whereas the disease rate of the scions which were cut and grafted in spring was only 33%. It was particularly noteworthy that 90% of the scions in the former case and only 3% in the latter case were diseased as of June 18th approximately 2 months after the actual grafting and then the latter advanced to 33% with the passage of time. It appears that the pathogen in branches and shoots of the diseased trees standing outdoors become inactivated or diminished during winter. Through its symptom, pathological change in tissue, and easy transmission of the disease via stem-grafting, it seems certain that the pathogen of the witches broom disease in jujube tree is a virus.

• 한국산림과학회지
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• 제82권1호
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• pp.12-16
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• 1993

대추를 수확(收穫)한 직후(直後)에 oxytetracycline-HCl(OTC)용액(溶液)를 수간주입(樹幹注入)하여 대추나무 빗자루병(病)에 대(對)한 방제효과(防除效果)를 조사(調査)하였다. 빗자루병(病)에 결린 대추나무(흉고직경(胸高直徑) 9-16cm)에 크기에 따라 약량(藥量)을 늘리면서 주당(株當) OTC 2g 내지 6g을 물 0.51 및 1.01에 녹여 9월(月)에서 10월(月) 사이에 중력식(重力式) 수간주입(樹幹注入)을 실시(實施)한 결과(結果), 2년간(年間) 병징(病徵)이 억제(抑制)되고 건전(健全)한 모습으로 회복(回復)되었다. 0.51와 1.01수용액간(水溶液間)에 방제효과(防除效果)의 차이(差異)가 없었으며, 이와 같이 비교적(比較的) 고농도(高濃度)의 OTC를 주입(注入)하였을 경우(境遇) 우려(憂慮)되는 약해(藥害)가 이듬해 새로 나온 잎에서 관찰(觀察)되지 않았다. 한편 회복(回復)된 나무의 사부조직(篩部組織)을 DAPI(4'-6-diamidino-2-phenylindole.2HCl)로 염색(染色)하여 형광현미경(螢光顯微鏡)으로 검경(檢鏡)하여 보았던 바 마이코플라스마-특이(特異) 형광반응(螢光反應)이 나타나지 않음으로써 조직내(組織內)의 마이코플라스마가 소멸(消滅)되었음을 알 수 있었다.

• The Plant Pathology Journal
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• 제18권2호
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• pp.98-101
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• 2002

Using phytoplasma universal primer pair Pl and P7, a fragment of about 1.8 kb nucleotide sequences of 16S rRNA gene and 16S-23S rRNA intergenic spacer region, and a portion of 23S rRNA gene of jujube witches'broom (JWB) and mulberry dwarf(MD) phytoplasmas were determined. The nucleotide sequences of JWB and MD were 1,850 bp and 1,831 bp long, respectively. The JWB phytoplasma sequence was aligned with the homologous sequence of MD phytoplasma. Twenty-eight base insertions and nine base deletions were found in the JWB phytoplasma sequence compared with that of MD phytoplasma. The similarity of the aligned sequences of JWB and MD was 84.8%. The near-complete 16S rRNA gene DNA sequences of JWB and MD were 1,529 bp and 1,530 bp in length, respectively, and revealed 89.0% homology. The 16S-23S rRNA intergenic spacer region DNA sequences were 263 bp and 243 bp in lengths respectively, while homology was only 70% and the conserved tRNA-lle gene of JWB and MD was located into the intergenic space region between 16S-23S rRNA gene. The nucleotide sequences were 77 bp long in both JWB and MD, and showed 97.4% sequence homology. Based on the phylogenetic analysis of the two phytoplasmas, the JWB phytoplasma belongs to the Elm yellow phytoplasma group (16S rV), whereas, the MD phytoplasma belongs to the Aster yellow group (16S rI).

• 원예과학기술지
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• 제33권3호
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• pp.396-402
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• 2015

This study identified a new male-sterile germplasm of Chinese jujube, named male-sterile No. 2 (JMS2), and achieved controlled hybridization using that germplasm as the female parent. The anthers of JMS2 before flower bud opening became shrunken, dingy yellow and much smaller than normal ones, and they changed to brown after anthesis. No pollen was observed in anthers of JMS2 and its male-sterile trait remained stable over different years. A total of 1,642 fruits were obtained from ten intra- and interspecific cross combinations via controlled hybridization from 2008 to 2012 using JMS2 as the female parent. Of those, 27.3% produced seeds, on average (0-72.6%). The rate of fruit with seed (RFS) was significantly different between cross combinations or years. Compared to other cross combinations, the RFS in the combination of JMS2 ${\times}$ 'Xingguang' (a Chinese jujube cultivar with high resistance to jujube witches' broom disease) and JMS2 ${\times}$ 'Xing16' (a sour jujube genotype) remained high in different years and reached means of 48.7 and 58.1%, respectively. Finally, 150 plantlets were regenerated from immature embryos, and 51 of them were randomly selected and identified to be authentic hybrids using amplified fragment length polymorphism (AFLP) markers. This is the first report of hybrids obtained from a cross between Chinese jujube and sour jujube.

• 한국응용곤충학회지
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• 제32권3호
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• pp.338-347
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• 1993

대추나무빗자루병 매개충인 마름무늬매미충(Hish[monus sellatus Uhler)의 생태, 혼식 및 산란 호성, 기주이동, 월동태를 조사한 결과 남부지방에서 연 5세대가 경과되었고, 제 1세대 6월 중 ~하순, 2세대 7월 중~8월 상순, 3세대 8월 중~하순, 4세대 9월 상~중순, 5세대 10월 상~중순이었고, 최대 발생기는 3화기인 8월 중~하순이었다. 계절에 따른 한 세대에 요하는 기간은 춘계 80, 하계 69, 추계 77.8일이었으며, 각 단계별 크기는 란 0.8 mm, 1령충 0.9mm, 2령충 l.4mm. 3령충 2.1mm, 4령충2.5mm, 5령충 3.2 mm 이었으며 성충 암컷 4.1mm, 수컷 3.8mm였다. 년중을 통한 기주식물의 이동을 보면 주로 뽕나무, 환삼덩굴, 대추나무에서 란으로 월동하며, 5월 중~하순경까지 뽕나무와 환삼덩굴의 신호를 계속 증가하면서 일부가 6월 하순~7월초순경에 대추나무로 이동하며 가해하는데 이들 란이 10월 중~하순 경부터 월동태로 들어간다. 산란부위는 신초, 엽병, 엽통 등이며 1마리의 암컷 산란수는 32~62개였다. 파식선호성에서는 환삼덩굴, 대추나무, 쥐똥나무, 뽕나무에서 높은 선호성(38.2S-21.64 %)을 보였고 닥나무, 개머루, 구기자나무, 구지뽕나무, 모시풀, 벼, 골담초, 일일초, 차풀 등이 4.65~2.48%였다, 산란이호성에서는 식이호성이 높은 환삼덩굴, 뽕나무, 대추나무에서 24~12개 정도였으며 성충의 생명에서는 환삼덩굴, 뽕나무, 대추나무에서 41.4~44.4일, 개멀, 차풀, 쥐똥나무, 일일초, 자운영, 샐러리에서 25일 이상이었고 기지 기주식물에서는 20일 이하이었다.