• 식물병연구
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• 제24권2호
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• pp.138-144
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• 2018

In December 2016, stem rot symptoms were observed on Persian buttercup (Ranunculus asiaticus) plants in Chilgok, Gyeongbuk, Korea. In the early stage of the disease, several black spots appeared on the stem of infected plants. As the disease progressed, the infected stem cleaved and wilted. The causal agent was isolated from a lesion and incubated on Reasoner's 2A (R2A) agar at $25^{\circ}C$. Total genomic DNA was extracted for phylogenetic analysis. Based on the 16S rRNA gene analysis, the isolated strain was found to belong to the genus Pseudomonas. To identify the isolated bacterial strain at the species level, the nucleotide sequences of the gyrase B (gyrB) and RNA polymerase D (rpoD) genes were obtained and compared with the sequences in the GenBank database. As the result, the causal agent of the stem rot disease was identified as Pseudomonas marginalis. To determine the pathogenicity of the isolated bacterial strain, it was inoculated into the stem of healthy R. asiaticus plant, the inoculated plant showed a lesion with the same characteristics as the naturally infected plant. Based on these results, this is the first report of bacterial stem rot on R. asiaticus caused by P. marginalis in Korea.

• 화훼연구
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• 제26권4호
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• pp.179-186
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• 2018

Ranunculus asiaticus characterizes colorful and attractive flower shapes that are related with the ornamental value of bulbous plants. Improving ornamental value of bulbous flowers has been the general goal of floricultural market. Gibberellic acid ($GA_3$) and benzyladenine (BA) play an important role in growth and developmental processes in floriculture. Combinational treatments of these two hormones have been used in floriculture to improve flower quality. We assessed the effects of combined $GA_3$ and BA, as well as the individual effects of each hormone, on growth characteristics using soil drench application to eight R. asiaticus cultivars, 'Giallo Millepetali', 'Bianco Millepetali', 'Arancio Millepetali', 'Rosa SC', 'Arancio Pratolino', 'Giallo Pratolino', 'Bianco Pratolino', and 'Rosa Ch Pratolino'. $GA_3$ treatments increased plant height and first flower size of R. asiaticus cultivars. Moreover, about 5 to 9 days to flowering were averagely shortened by $GA_3$ treatments compared to controls. On the other hand, the opposites, including first flower size and days to flowering, were observed for cultivars treated with BA, compared with controls. Treatments of $GA_3$ + BA generally affected growth traits, such as plant height, flower size, and the timing of flowering on some R. asiaticus cultivars. In particular, about 5 to 6 days to flowering were reduced on average by Treatments of $GA_3$ + BA. Our results showed positive growth effects, including plant height, days to flowering, first flower height, number of flowers from the application of individual and combined hormones to R. asiaticus cultivars and demonstrate a role for these hormones in future bulbous floriculture.

• 화훼연구
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• 제16권1호
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• pp.76-84
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• 2008

황색 꽃의 압화 후의 변색의 원인이 무엇인지를 모색하기 위해 나리, 온시디움, 장미, 튤립, 금어초, 카네이션, 프리지아, 칼라, 거베라, 해바라기와 라넌큘러스 황색 절화 11종을 식물재료로 사용하였다. 이들 식물 재료의 꽃잎의 특성과 화색소를 분석하고 압화 후의 변색 정도와의 상호 관련성을 검토하였다. 꽃잎 두께, 꽃잎의 장폭비, 그리고 꽃잎의 수분함량은 압화의 변색에 크게 영향을 미치지 않았다. 카로티노이드에 의해 황색이 발현되는 종은 나리, 온시디움, 장미와 튤립이었으며, 플라보노이드에 의해 황색이 발현되는 종은 금어초, 카네이션, 프리지아와 칼라였으며, 카로티노이드와 플라보노이드가 공존하면서 황색이 발현되는 종은 거베라, 해바라기와 라넌큘러스였다. 카로티노이드가 단독이거나 플라보노이드와 공존하거나 상관없이 카로티노이드에 의해 황색이 발현되는 경우는 압화의 변색 정도가 심했다. 그러나 플라보노이드에 의해 황색이 발현되는 종은 거의 변색 되지 않았다. 암처리 한 압화는 거의 변색되지 않았으나 광처리 한 것은 변색의 정도가 심했다.