American ginseng (Panax quinquefolium) is valued in traditional Asian medicine, and its use in Western countries has increased in recent years. The value of artificially-cultivated ginseng is much lower than that of woods-cultivated or wildcollected ginseng, but populations of the latter are threatened throughout its range. Our goal is to identify what factors influence the concentration of the pharmacologically active ginsenosides. Age-related increase in ginsenosides have been reported by several authors but variation among wild populations has not been considered. Ginsenoside analysis via HPLC was performed on roots collected from 8 different NY State populations. Statistical analysis of the effects of population and age on ginsenoside content indicated that there was a significant effect of both on ginsenoside Rc, a significant interaction between population and age for ginsenosides Rb1 and Rb2, and a significant three way interaction between population, age and root fresh weight for Re. Ginsenosides Rb1 and Rb2 increased with age for some populations, but not for other populations. We conclude that the prevailing generalization that ginsenosides increase with root age cannot be applied to wild North American ginseng without taking into consideration population differences. The effects of population on ginsenoside content is likely to be related not only to environmental differences among collection sites but also genetic differences since there was considerable (several fold) variation in the content of ginsenosides within single populations. It is likely therefore that selection and cloning of individual roots for higher ginsenoside content could be a useful strategy for improvement of this medicinal crop. These results also suggest that populations could be selected based on their sensitivity to age and fresh weight-related increase in ginsenosides concentration.

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Woods cultivation of North American ginseng (Panax quinquefolium L.) can generate income for forest land owners and decrease collection pressure on wild populations of this increasingly scarce forest herb. For woods cultivation, supplemental calcium by soil application of gypsum (CaSO4 2H2 O) is often recommended, but the effects of this practice on soil characteristics, plant growth and quality of American ginseng are not well characterized. In a greenhouse pot culture experiment, 3-year-old seedlings were treated with 0, 1, 2, 3, or 4 Mt/ha gypsum and grown for 12 weeks. Gypsum application decreased soil pH slightly and elevated soil electrical conductivity and available soil calcium. Tissue levels of calcium were not affected by gypsum treatment but a significant increase in both shoot and root dry weight occurred. Total ginsenosides, which are the pharmacologically active components of ginseng, were increased slightly in roots but not in shoots of plants treated with 4 Mt/ha gypsum. Rb1, the most abundant ginsenoside in roots, was elevated in roots of plants treated with 3 Mt/ha gypsum. Ginsenoside Rg1 was elevated in shoots of plants treated with 2 Mt/ha gypsum. Regardless of gypsum treatment, qualitative differences (relative concentrations of different ginsenosides) between roots and shoots were observed.

The objective of this study was to determine the feasibility of CO2 enrichment and optimal radiation level for accelerating the rooting and growth of micropropagated Kalmia latifolia cuttings during the Stage IV acclimation period. Inch long microcuttings of the Kalmia cultivars `Elf' and `Carousel' shipped from a commercial micropropagation laboratory, were stuck in flats of peat, and place in a fogging chamber constructed to allow for the simultaneous experimental variation of CO2 level and either radiation level or photoperiod. Treatments consisted of a complete factorial arrangement of 2 levels of CO2 (ambient and 1200 ppm) and 3 levels of radiation (30, 98, and 158 μmoles/m2/sec). The experiment was repeated 6 times. For `Carousel' CO2 enrichment stimulated both shoot and root growth and either the high or medium light level was optimal depending on the experiment. CO2 enrichment also stimulated growth of `Elf' but results were less consistent from experiment to experiment. Similar experiments are in progress with Amelanchier and Lilac microcuttings.

To test the hypothesis that phytohormone production is related to mycorrhizae formation 29 isolates of ectomycorrhizal fungi have been evaluated for production of ethylene and auxin in pure culture and for their ability to form ectomycorrhizae with Pinus mugo. The fungi tested included a series of monokaryotic isolates of Laccaria bicolor and dikaryotic isolates of Amanita muscaria, Hebeloma crustuliniforme, L. laccata, L. proxima, Pisolithus tinctorius, Rhizopogon ellenae, and R. vinicolor. Inoculated root systems were rated for mycorrhizae formation, root/shoot ratio and root morphology. P. tinctorius isolates which formed abundant mycorrhizae produce no ethylene in vitro, but did produce the auxin IAA. L. bicolor isolates produced ethylene as well as auxins putatively identified as IAA, and IBA. Correlations between phytohormone production and mycorrhizogenicity will be presented.