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Manual removal of inflorescences from mature (3- and 4-year-old) American ginseng plants (Panax quinquefolium L.) at commercial timing (early July, ≈25% flowers open) increased root yield at harvest. Consecutive inflorescence removal for 2 years (third and fourth) increased yield 55.6%. Inflorescence removal in 4-year-old plants increased yield by 34.7% compared with 26.1% in 3-year-old plants. Analysis showed that the largest portion of roots (≈40%) was in the medium category (10-20 g), and inflorescence removal did not influence root size distribution. Root yield for 3-year-old plants increased quadratically with plant density, with plants lacking inflorescences having an estimated yield increase of 25%. Maximum yields of 2.4 kg·m-2 for deflowered plants were achieved at a plant density of 170 plants/m2. To maximize ginseng root yield, all plants except those needed to provide seed for future plantings should have inflorescences removed.

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Genetic differences among eleven cultivated and eight wild-type populations of North American ginseng (Panax quinquefolium L.) and four cultivated populations of South Korean ginseng (P. ginseng C.A. Meyer) were estimated using RAPD markers. Cultivated P. ginseng population samples were collected from four regions of S. Korea. Cultivated P. quinquefolium population samples were collected from three regions in North America: Wisconsin, the Southeastern Appalachian region of the United States, and Canada. Wild-type P. quinquefolium was collected from three states in the United States: Pennsylvania, Tennessee, and Wisconsin. Evaluation of germplasm with 10 decamer primers resulted in 100 polymorphic bands. Genetic differences among populations indicate heterogeneity. The genetic distance among individuals was estimated using the ratio of discordant bands to total bands scored. Multidimensional scaling of the relationship matrix showed independent clusters corresponding to the distinction of species, geographical region, and wild versus cultivated types. The integrity of the clusters was confirmed using pooled chi-square tests for fragment homogeneity.

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We determined the effect of moderate water stress on the growth of american ginseng (Panax quinquefolium), and on concentrations of six major ginsenosides (Rg1, Re, Rb1, Rc, Rb2, and Rd). Two-year-old “rootlets” (dormant rhizome and storage root) were cultivated in pots, in a cool greenhouse (18.3 ± 2 °C). Pots were watered either every 5 days (control) or every 10 days (stress), repeatedly for 8 days. Soil volumetric water content was measured during the last 10 days of the experiment for both treatments. Leaf water potential, measured on the last day of the experiment, was -0.43 MPa for the control and -0.83 MPa for the stress treatment. Drought stress did not affect above-ground shoot or root dry weight. Initial rootlet fresh weight (covariate) had a significant effect on the concentration of ginsenosides Re, Rb1, Rc, and Rb2. Drought stress increased the concentration of ginsenosides Re, Rb1, and total ginsenoside concentration.

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Four-year-old American ginseng (Panax quinquefolium L.) plants and soil samples were collected from nine ginseng gardens. Soil and leaf mineral contents were determined and six major ginsenosides, Rb1, Rb2, Rc, Rd, Re, and Rg1, were extracted from leaves and roots and quantified by high-performance liquid chromatography (HPLC). Correlation coefficients were more significant for soil nutrient levels vs. ginsenoside contents of leaves than of roots, suggesting that soil nutrient levels may play a major role in the synthesis of leaf ginsenosides. Minor elements in the leaf were also better correlated with ginsenoside contents of the root than that of the leaf. Iron content in the leaves exhibited highly significant correlations with the levels of Rb1, Rb2, Rc, and Rd, but calcium and copper contents were negatively correlated with Rg1 in the roots.

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Cryopreservation of pollen from two ginseng species —Panax ginseng L. and P. quinquefolium L.—was studied. Freezing anthers that served as pollen carriers to –40C before liquid N storage affected pollen viability little after liquid N storage. Anther moisture content affected pollen viability significantly when stored in liquid N. The ideal anther moisture content to carry pollen for liquid N storage was 32% to 26% for P. ginseng and 27% to 17% for P. quinquefolium. Viability of pollen from P. quinquefolium anthers with 25.3% moisture content changed little after 11 months of liquid N storage.

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Abstract

In a study of nutrient requirements of American ginseng (Panax quinquefolium L.) foliar deficiency symptoms of Ca occurred first, followed by those for Mg and P. N-deficiency symptoms occurred very gradually, and S-deficiency symptoms never appeared. Root fresh weight gain was most restricted by omission of either Ca, P, or Mg from the nutrient solution. Omission of S resulted in a root fresh weight gain equal to that obtained with complete nutrient solution.

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Dormant one-year-old roots of American ginseng (Panax quinquefolium L.) were exposed to a range of stratification temperatures and times to define limits for these parameters and to quantify their effect on terminating rest when placed in a growing environment. Effective storage temperatures tested ranged from 0° to 9°C. A low percentage of roots produced tops with as few as 30 days of stratification; however, 60 to 90 days were required for 100% emergence. The number of days to emergence, after planting, decreased with increased time in stratification through the maximum storage time of 120 days. The number of days of dormancy (days in stratification + days to emergence) averaged 126 and was relatively constant over the range of effective temperatures and periods of stratification. The minimum predicted period of dormancy was 116 days and was associated with a derived 70 days in storage (1680 hr) at 3.1°. Root growth rate, after emergence, was greatest following 105 days of stratification.

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Siberian ginseng [Eleutherococcus senticosus (Rupr. ex. Maxim.) Maxim] is currently a popular medicinal plant in Eurasia and North America. It has been used by the Chinese for over 2000 years. Recently, imported products of this plant have become available in North America, with a market share of 3.1% of the medicinal herbal industry. Siberian ginseng is harvested from its natural habitat in Russia and northeast China. Overharvesting has resulted in this popular herb approaching endangered species status. Cultivation is the only way to avoid its extinction, and to ensure the correct identity. Siberian ginseng is not a true ginseng (Panax quinquefolium L. or P. ginseng C.A. Meyer), but it has its own bioactive ingredients with unique and proven medicinal values. However, standardization and quality control of the active ingredients in the marketed products, which are mainly imported from China, are needed to avoid mislabeling or adulteration with other herbs.

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Abstract

Oriental ginseng (Panax ginseng C.A. Meyer) to the Chinese “… is the medicine par excellence: the dernier resort when all other drugs fail; reserved for the use of the Emperor and his household, and conferred by Imperial favour upon high and useful officials whenever they have a serious breakdown that does not yield to ordinary treatment, and which threatens to put a period to their lives and usefulness” (14). Although written in 1578, these claims are still held by traditional Chinese healers. Westerners do not hold ginseng in such high esteem (9). However, the discovery of American ginseng (Panax quinquefolium L.) growing in Canada in the early 1700s lead to the establishment of trade in ginseng between North America and the Orient, which continues today (3, 4, 8).

Open Access

Abstract

American ginseng (Panax quinquefolium L.) roots have a dormancy period which can be satisfied by exposure to low temperatures of 0° to 10°C for about 100 days. Three-year-old roots of ginseng were weighed, given variable periods (≥ 50 days) of low temperature (5°C), planted in vermiculite in pots, and grown in light or dark at 5°, 10°, 15°, or 20°. After 50 to 100 days of storage at 5°, stem growth occurred at all temperatures except 20°. At this temperature, a minimum of 75 days at 5° was required to satisfy dormancy. Stem growth rate was relatively constant at 5° and 10° but increased with storage time when grown at 15° or 20°; leaf growth rate was affected similarly, except that no leaf growth occurred at 5°. If optimum cold storage and growth requirements were not met, the plants appeared abnormal and had reduced root dry weights. After 100 days of storage, the greatest growth rate was observed at 15° and 10°. Plant growth rate was the least at 5° and 20°.

Open Access