Effect of seeding depth on seedling growth and dry matter partitioning in American ginseng

Proctor, John T.A.,Sullivan, J. Alan The Korean Society of Ginseng 2013 Journal of Ginseng Research Vol.37 No.2

Greenhouse and field experiments with American ginseng (Panax quinquefolius L.) stratified seed sown at depths of 10 to 100 mm were carried out to determine effects of seeding depth on seedling emergence, growth and development and to calculate optimum seeding depth. The time to 50% seedling emergence ($E_{50}$) in the field increased linearly from 17 d at 20 mm seeding depth to 42.5 d at 80 mm. Seedling emergence and root weight (economic yield) at the end of the first year each increased quadratically with the increase of seeding depth. Maximum emergence and root yields were produced at sowing depths of 26.9 and 30.6 mm respectively. In a greenhouse pot experiment, increasing seeding depth from 10 to 100 mm increased partitioning of dry matter to leaves from 23.6% to 26.1%, to stems from 6.9% to 14.2%, and decreased dry matter to roots from 69.5% to 59.7%. Optimum seeding depth was 31.1 mm for a corresponding maximum root weight of 119.9 mg. A predictor equation [X (seeding depth, mm)=Y (seed weight, mg)/9.1+20.96] for seeding depth for ginseng, based on data for ten vegetable crops, their seed weights and suggested seeding depths, predicted a seeding depth of 28.3 mm for ginseng similar to that reported above for most pot and field experiments.

Low-Temperature Storage of Immature (Green) North American Ginseng Seed for Fall Planting

Proctor John T.A.,Louttit Dean The Korean Society of Ginseng 2006 Journal of Ginseng Research Vol.30 No.2

Freshly harvested, immature (green) seeds of North American ginseng (Panax quinquefolius L.) were stratified for up to 3 years in plastic pails in controlled environment rooms at $5{\pm}1^{\circ}C$ for 9 months and then $21{\pm}2^{\circ}C$ for 3 months (Trt. 1, regular stratification), or continuously at $-2{\pm}0.2^{\circ}C$ (Trt. 2), or continuously at $3{\pm}0.2^{\circ}C$ (Trt. 3). During stratification at -2 and $3^{\circ}C$ embryos did not grow. On seeding in the field embryos grew rapidly and resultant seedlings were comparable to those from regularly stratified seed. Seedling emergence rate was acceptable at the industry expected rate of 68% after one year of storage, but not after two years storage when it declined to 17.5%. Seed rot was so severe in year 3 that no planting was carried out. Seedling and second year growth were similar at the three stratification temperatures; most importantly, root dry weight (economic yield) was similar. Low-temperature storage of freshly-harvested North American ginseng seed is an acceptable method for short-term retention of propagating material.

Effect of boron nutrition on American ginseng in field and in nutrient cultures

Proctor, John T.A.,Shelp, Barry J. The Korean Society of Ginseng 2014 Journal of Ginseng Research Vol.38 No.1

Field and nutrient cultures of American ginseng (Panax quinquefolius L.) were used to establish foliar symptoms related to boron (B) concentration in leaves and soils, and to evaluate radish as a time-saving model system for B nutrition. Application of excess B, 8 kg/ha versus the recommended 1.5 kg/ha, to field plantings of 2-, 3-, and 4-yr-old American ginseng plants just prior to crop emergence caused, within 4 wk after crop emergence, leaf symptoms of chlorosis followed by necrosis starting at the tips and progressing along the margins. The B concentration in leaves of 2-4-yr-old plants receiving 1.5 kg/ha Bwas $30{\mu}g/g$ dry mass compared to $460{\mu}g/g$ dry mass where 8 kg/ha B was applied. Similarly, B concentration in soils receiving the lower B concentration was 1.8 mg/g dry mass and $2.2-2.8{\mu}g/g$ dry mass where the higher B concentration was applied. Application of 8 kg/ha B reduced the dry yield of 3rd-yr roots by 20% from 2745 kg/ha to 2196 kg/ha and 4th-yr roots by 26% from 4130 kg/ha to 3071 kg/ha. Ginseng seedlings and radish were grown under greenhouse conditions in nutrient culture with four B concentrations ranging from 0 mg/L to 10 mg/L. At 5 mg/L and 10 mg/L ginseng and radish developed typical leaf B toxicity symptoms similar to those described above for field-grown plants. Increasing B in the nutrient solution from 0.5 mg/L to 10 mg/L decreased, in a linear fashion, the root and leaf dry mass of ginseng, but not radish. Given the many similarities of ginseng and radish to B utilization, radish might be used as a timesaving model system for the study of B, and other micronutrients, in the slow-growing perennial ginseng.

Morphological and Ginsenoside Differences among North American Ginseng Leaves

Proctor, John T.A.,Sullivan, Alan J.,Rupasinghe, Vasantha P.V.,Jackson, Chung-Ja C. The Korean Society of Ginseng 2011 Journal of Ginseng Research Vol.35 No.2

Leaf characteristics of mature 2, 3 and 4-year-old North American ginseng (Panax quinquefolius L.) leaves on fruiting and non-fruiting(NF) plants were studied. Leaflets of the 2-year-old plants had the lowest fresh and dry weight, area, volume and internal gas volume. Inflorescence removal in 3-year-old plants did not affect leaf characteristics or ginsenoside concentration but in 4-year-old plants it increased leaf fresh (38.6%) and dry (43.9%) weight, leaf area (29.1%), specific leaf mass (11.4%), leaf volume (43.1%), and leaf thickness (12.1%), and decreased leaf water content (6.2%). Cultivated ginseng, although an understorey plant, had the specific leaf mass, 35.6 g $m^{-2}$ (range, 36 to 39 g $m^{-2}$) and a chlorophyll a/b ratio of 2.40 to 2.61, both suggesting the ability to perform like a sunny habitat plant. Also, specific leaf mass of 35.6 g $m^{-2}$ is similar to that reported for perennial plants, 36.8 g $m^{-2}$, rather than that for annuals, 30.9 g $m^{-2}$.

Optimal light for greenhouse culture of American ginseng seedlings

Proctor, John T.A.,Palmer, John W. The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.3

Three greenhouse experiments with American ginseng seedlings growing under light levels from 4.8% to 68% showed a quadratic response for root dry weight, giving an optimal root dry weight of 239 mg (range 160-415 mg) at an optimal light level of 35.6% (range 30.6-43.2%).

재배미국인삼의 화서형질 변이

Proctor, J.T.A. The Korean Society of Ginseng 1986 Journal of Ginseng Research Vol.10 No.1

Variation in the inflorescence of Oriental ginseng (Panax ginseng C.A. Meyer) have been placed in 6 groups; only 2 of these groups, a complete simple hemispherical terminal umbel, and a simple umbel with several branched pedicels below it on the peduncle were found in cultivated American ginseng. Apical peduncle reflexing and associated peduncles shortening were observed in a few plants.

Evolution of structural diversity of trichothecenes, a family of toxins produced by plant pathogenic and entomopathogenic fungi

Proctor, Robert H.,McCormick, Susan P.,Kim, Hye-Seon,Cardoza, Rosa E.,Stanley, April M.,Lindo, Laura,Kelly, Amy,Brown, Daren W.,Lee, Theresa,Vaughan, Martha M.,Alexander, Nancy J.,Busman, Mark,Guti&ea Public Library of Science 2018 PLoS pathogens Vol.14 No.4

<▼1><P>Trichothecenes are a family of terpenoid toxins produced by multiple genera of fungi, including plant and insect pathogens. Some trichothecenes produced by the fungus <I>Fusarium</I> are among the mycotoxins of greatest concern to food and feed safety because of their toxicity and frequent occurrence in cereal crops, and trichothecene production contributes to pathogenesis of some <I>Fusarium</I> species on plants. Collectively, fungi produce over 150 trichothecene analogs: i.e., molecules that share the same core structure but differ in patterns of substituents attached to the core structure. Here, we carried out genomic, phylogenetic, gene-function, and analytical chemistry studies of strains from nine fungal genera to identify genetic variation responsible for trichothecene structural diversity and to gain insight into evolutionary processes that have contributed to the variation. The results indicate that structural diversity has resulted from gain, loss, and functional changes of trichothecene biosynthetic (<I>TRI</I>) genes. The results also indicate that the presence of some substituents has arisen independently in different fungi by gain of different genes with the same function. Variation in <I>TRI</I> gene duplication and number of <I>TRI</I> loci was also observed among the fungi examined, but there was no evidence that such genetic differences have contributed to trichothecene structural variation. We also inferred ancestral states of the <I>TRI</I> cluster and trichothecene biosynthetic pathway, and proposed scenarios for changes in trichothecene structures during divergence of <I>TRI</I> cluster homologs. Together, our findings provide insight into evolutionary processes responsible for structural diversification of toxins produced by pathogenic fungi.</P></▼1><▼2><P><B>Author summary</B></P><P>Toxins produced by pathogens can contribute to infection and/or colonization of hosts. Some toxins consist of a family of metabolites with similar but distinct chemical structures. This structural variation can affect biological activity, which in turn likely contributes to adaptation to different environments, including to different hosts. Trichothecene toxins consist of over 150 structurally distinct molecules produced by certain fungi, including some plant and insect pathogens. In multiple systems that have been examined, trichothecenes contribute to pathogenesis on plants. To elucidate the evolutionary processes that have given rise to trichothecene structural variation, we conducted comparative analyses of nine fungal genera, most of which produce different trichothecene structures. Using genomic, molecular biology, phylogenetic, and analytical chemistry approaches, we obtained evidence that trichothecene structural variation has arisen primarily from gain, loss, and functional changes of trichothecene biosynthetic genes. Our results also indicate that some structural changes have arisen independently in different fungi. Our findings provide insight into genetic and biochemical changes that can occur in toxin biosynthetic pathways as fungi with the pathways adapt to different environmental conditions.</P></▼2>

Growth, Dry Matter Partitioning and Photosynthesis in North American Ginseng Seedlings

Proctor, John T.A.,Palmer, John W.,Follett, John M. The Korean Society of Ginseng 2010 Journal of Ginseng Research Vol.34 No.3

North American ginseng seedlings (Panax quinquefolius L.) were grown in pots in heated greenhouses, in a cool greenhouse, or in the field, in 11 experiments at various times over 16 years. Crop establishment, dry matter partitioning, photosynthesis, radiation use efficiency and carbon budget were measured and/or calculated in some years. Once the seedling canopy, of about $20\;cm^2$ per seedling, and a leaf area index of 0.37, was established, about 40 days after germination, full canopy display lasted about 87 days. Only 16.6% of the incoming solar radiation was intercepted by the crop, the remainder falling on the mulched soil surface. Total and root dry matter accumulations in the cool greenhouse and in the field were about double that in the heated greenhouses. Partitioning of dry matter to roots (economic yield or harvest index) in the cool greenhouse and in the field was 73% whereas it was 62.5% in the heated greenhouses. The relationship between root dry matter and radiation interception during the full canopy period was linear with growth efficiencies of $2.92\;mg\;MJ^{-1}$ at 4.8% of incoming radiation and $0.30\;mg\;MJ^{-1}$ at 68% of incoming radiation. A photosynthetic rate of $0.39\;g\;m^{-2}\;h^{-1}$ was attained at light saturation of about $150\;{\mu}mol\;m^{-2}\;s^{-1}$ (7.5% of full sunlight); dark respiration was $0.03\;g\;m^{-2}\;h^{-1}$, about 8.5% of maximum assimilation rate. Estimates of dry matter accumulation by growth analysis and by $CO_2$ uptake were similar, 6.21 vs. 7.62 mg $CO_2$, despite several assumptions in $CO_2$ uptake calculations.

Labour of Love: Fan Labour, BTS, and South Korean Soft Power

Jasmine Proctor 한국마케팅학회 2021 ASIA MARKETING JOURNAL Vol.22 No.4

With the steady rise in global popularity of the Korean music group BTS, the South Korean government and surrounding industries have swiftly begun utilizing their image and international recognition for specific nation branding purposes. While K-pop soft power strategies are not novel to the South Korean state, what is new is the rapid speed at which BTS have become a beacon for South Korean culture, language, and symbolism in the international arena. However, few scholarly works have sought to investigate the role fans have played in this heightened position for the group as state representatives, with minimal research conducted into the work fans do within the framework of ARMY fan culture. This paper will thus aim to fill the gap in scholarship on ARMY as an organized labour network, focusing on the role fans play as labourers in online spaces that work to promote, disseminate, and cultivate wider recognition for BTS as artists. Through the conjunct engagement of a political economy framework and theories of participatory culture, this paper will explore the manner through which the free labour of ARMY, premised on affect, has constructed the fandom as active agents of soft power alongside BTS themselves.

Low-Temperature Storage of Immature (Green) North American Ginseng Seed for Fall Planting

John T.A. Proctor,Dean Louttit 고려인삼학회 2006 Journal of Ginseng Research Vol.30 No.2

Freshly harvested, immature (green) seeds of North American ginseng (Panax quinquefolius L.) were stratified for up to 3 years in plastic pails in controlled environment rooms at 5±1℃ for 9 months and then 21± 2℃ for 3 months (Trt. 1, regular stratification), or continuously at -2±0.2℃ (Trt. 2), or continuously at 3±0.2℃ (Trt.3). During stratification at -2 and 3℃ embryos did not grow. On seeding in the field embryos grew rapidly and resultant seedlings were comparable to those from regularly stratified seed. Seedling emergence rate was acceptable at the industry expected rate of 68% after one year of storage, but not after two years storage when it declined to 17.5%. Seed rot was so severe in year 3 that no planting was carried out. Seedling and second year growth were similar at the three stratification temperatures; most importantly, root dry weight (economic yield) was similar. Low-temperature storage of freshly-harvested North American ginseng seed is an acceptable method for short-term retention of propagating material.