• The Plant Pathology Journal
• /
• 제26권4호
• /
• pp.299-305
• /
• 2010

A half-sib family of two 4-year-old seedlings of Pinus $\times$ rigitaeda was inoculated with each of 20 Pinus thunbergii isolates of Fusarium circinatum (syn. Fusarium subglutinans f. sp. pini) from two pitch canker damaged sites in Jeju Island, South Korea. Initial symptoms of needle damages were visible on most of the seedlings at 18 days after inoculation. The 20 tested isolates were not significantly different in virulence, based on lesion lengths at the site of inoculation (P = 0.217). The most virulent isolate FT-7 showed the longest lesion length. Some seedlings began to die 46 days after inoculation. All seedlings were dead by 68 days after inoculation except two seedlings inoculated with each of isolates FS-2 and FS-13, respectively. Using the FT-7, 38-year-old 11 P. $\times$ rigitaeda trees, which were survived from a seed orchard severely damaged by pitch canker, were inoculated on branches in the seed orchard in Jeju Island to assess differences in susceptibility to pitch canker. The 11 trees differed significantly (P < 0.001) in susceptibility to F. circinatum based on average lesion lengths measured 56 days after inoculation. It is possible that induced resistance contributed to their capacity to limit lesion development. The susceptibility of natural selection P. $\times$ rigitaeda trees are more likely affected by interaction with F. circinatum rather than environmental conditions.

• The Korean Journal of Ecology
• /
• 제13권1호
• /
• pp.1-8
• /
• 1990

Effects of mycorrhizal infection on the growth of bell pepper (Capsicum annuum) and corn (Zea mays) seedlings have been studied by comparing plants grown in sterilized soil/sand mixtures to plants grown in sterilized soil/sand mixtures with topping the original non-sterile field soil. The original nonsterile field soil, which were taken from the bell pepper field, contained a high level of endmycorrhizal spores. After seven weeks, the shoot height of inoculated plants was increased by 110% in bell pepper, and 90% in corn compared with the control plants. The average above-ground biomass of inoculated plant was increased by 88% in bell pepper and 71% in corn compared with the control plants. The shoot-root ratios in bell pepper and corn were 2.7 and 1.8 for the control plants, and 4.3 and 2.7 for the treatment plants, respectively. Phosphorus level in inoculated plant was higher than that of the control plant. However, nitrogen contents were similar between the control and the treatment plants. The control plants didi not form vesicular-arbuscular mycorrhizae during the experimental period.

• Mycobiology
• /
• 제30권2호
• /
• pp.70-75
• /
• 2002

The mycelia were directly isolated from eight species of fungal basidiocarps, confirmed to the ectomycorrhiza in the roots from the fields(forestry); Suillus bovinus, Paxillus involutus, Lactarius hysginus, Russula fragilis, Lepista nuda, Lyophyllum shimeji, Tricholoma matsutake, and Russula integra. The mycelia were pure-cultured with several transferring in various agars, and inoculated to the roots of pine(Pinus densiflora) seedling by in vitro method. After ten months growth under artificially aseptic conditions, all pine seedlings inoculated were stimulated at the growth-height, whereas those not inoculated were nearly dead. Also, the ramifications of ectomycorrhizal pine roots formed in the synthetic in vitro systems and were various according to the different mycelia. Synthesis of ectomycorrhiza were clearly confirmed in ten months growth, but not distinguished at this moment. It was clearly proved that the mycelia isolated caused the ectomycorrhizae in the roots of pine seedlings.

• 한국산림과학회지
• /
• 제79권3호
• /
• pp.316-321
• /
• 1990

본(本) 실험(實驗)은 송피함량(松皮含量)을 달리한 배양토(培養土) 0, 25, 50, 75%에 균근균(菌根菌)을 접종(接種)하여 처리(處理)에 따른 균근형성(菌根形成) 및 식물생장(植物生長)에 미치는 영향(影響)을 구명(究明)코자 실시(實施)되었으며 결과(結果)는 다음과 같다. 1. 균근(菌根) 접종묘(接種苗)가 비접종묘(非接種苗)에 비(比)해 세근(細根), 균근수(菌根數), 개체생장율(個體生長率), 엽면적(葉面積) 및 묘고(苗高)가 증가(增加)하였다. 2. 송피함량(松皮含量)에 따른 균근형성율(菌根形成率)은 25%구(區)가 높았으며 50% 및 70%구(區)에서는 감소(減少)하였다. 3. 동일송피(同一松皮) 함량구(含量區)에서는 균근접종구(菌根接種區)가 무접종구(無接種區)보다 묘고(苗高) 및 엽(葉), 경(莖), 근건중(根乾重)이 증가(增加)하였다.

• 한국산림과학회지
• /
• 제99권3호
• /
• pp.337-343
• /
• 2010

소나무재선충을 접종한 소나무묘목에서 잎의 수분포텐셜 변화를 식물수분시스템으로 측정하였다. 소나무재선충 접종 후 35일째 12시경에 소나무의 잎 수분포텐셜은 소나무소나무재선충 접종묘에서 -1.04 MPa, 비접종묘에서 -0.94 MPa로 소나무재선충 접종묘가 비접종묘보다 더 낮았다. 접종 후 56일째에는 해뜨기 직전 잎 수분포텐셜은 소나무재선충 접종묘가 -0.71 MPa, 비접종묘가 -0.26 MPa로 소나무재선충 접종묘가 더 낮았다. 접종 후 63일째에는 소나무소나무재선충 접종묘의 1년생 잎이 옅은 황색으로 되었다. 이때 접종묘의 근원부 단면에서는 수지가 나오지 않았다. 소나무재선충의 밀도는 접종 후 28일째에 최대가 되었다가 68일째에 급감하였다. 접종묘의 체관부와 수조직은 갈변되었으며 수지 유출은 접종 후 계속 감소하였다. 결론적으로 소나무재선충은 접종 1개월부터 소나무묘목에 수분 스트레스를 일으켰다.

• 한국균학회지
• /
• 제50권4호
• /
• pp.357-360
• /
• 2022

In July 2021, we surveyed diseases affecting wild vegetables grown in Hongcheon, Gangwon Province, Korea. During this survey, we observed severe seedling rot symptoms in Kamchatka goatsbeard (Aruncus dioicus) grown in a vinyl greenhouse. The incidence of the disease in the plant seedlings was 1-10%. Diseased seedlings from this population were collected, and fungi were isolated from leaf and petiole lesions. Rhizoctonia sp. was consistently isolated from the lesions. We examined the morphological and cultural characteristics and anastomosis groups of nine Rhizoctonia sp. isolates obtained from the lesions. The results revealed that all isolates corresponded to Rhizoctonia solani AG-1(IB). Three isolates of R. solani AG-1( IB) were evaluated to determine their pathogenicity towards Kamchatka goatsbeard seedlings through artificial inoculation. The tested isolates caused rot symptoms on the inoculated plant seedlings. The symptoms were similar to those observed in plant seedlings from the vinyl greenhouse. We found that R. solani AG-1(IB) caused seedling rot of Kamchatka goatsbeard.

• 한국환경생태학회지
• /
• 제29권1호
• /
• pp.88-94
• /
• 2015

An investigation was conducted on the effects of arbuscular mycorrhizal fungus, Glomus etunicatum on the formation of soil aggregate and mycorhizal development in the roots of Robinia pseudoacacia seedlings in coal mine tailings and forest soil. G. etunicatum formed mycorrhizas by 35.1 % in coal mine tailings and by 48.9 % in forest soil. Its infection was the typical Arum-type forming inter-cellular hyphae and intra-cellular arbuscules. Ergosterol contents were 3.20 ppm in forest soil and 1.92 ppm in coal mine tailings. The formation of soil aggregate per 50 g pot soil was 19.6 g and 9.5 g in inoculated and noninoculated forest soil and 16.5 g and 11.0 g in inoculated and non-inoculated coal min tailings, respectively. In conclusion, G. etunicatum inoculation increased the formation of soil aggregate both in forest soil and coal mine tailings, but was less effective in the latter.

• The Plant Pathology Journal
• /
• 제23권2호
• /
• pp.103-105
• /
• 2007

Mechanical transmission of barley seedlings with barley yellow mosaic virus (BaYMV) is generally inefficient and is the major constraint for testing cultivar resistance to the virus. To explore mechanical transmission, BaYMV-infected barley plants were grown at different conditions and used as inoculum sources to seedlings of susceptible barley cultivar Baegdong. Extracts prepared from BaYMV-infected Baegdong plants at 47, 53, 74, and 90 days after symptom appearance (DASA) and grown at 10 and $12^{\circ}C$ gave 10, 30, 68 and 76% infection, respectively on inoculated susceptible barley cv. Baegdong seedlings. While Jinyangbori, another susceptible cultivar obtained 95% infection rate inoculated with extracts from 90 DASA disease source and grown at $10/12^{\circ}C$. However, low infection rates were obtained when the virus sources were grown in a greenhouse at $15-18^{\circ}C$. Our results indicate that longer incubation period and lower temperature are required for virus accumulation and stability.

• Mycobiology
• /
• 제42권2호
• /
• pp.210-214
• /
• 2014

In Korea, mass mortality of Quercus mongolica trees has become obvious since 2004. Raffaelea quercus-mongolicae is believed to be a causal fungus contributing the mortality. To evaluate the pathogenicity of the fungus to the trees, the fungus was multiple- and single-inoculated to the seedlings and twigs of the mature trees, respectively. In both the inoculations, the fungus was reisolated from more than 50% of inoculated twigs and seedlings. In the single inoculations, proportions of the transverse area of non-conductive sapwood at inoculation points and vertical lengths of discoloration expanded from the points were significantly different between the inoculation treatment and the control. In the multiple inoculations, no mortality was confirmed among the seedlings examined. These results showed that R. quercus-mongolicae can colonize sapwood, contribute to sapwood discoloration and disrupt sap flows around inoculation sites of Q. mongolica, although the pathogenicity of the fungus was not proven.

• 농업과학연구
• /
• 제44권2호
• /
• pp.196-210
• /
• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.