Underground Plant Parts Research Articles

Nutritional Evaluation of some Edible Underground Plant Parts Used by the Tribal People of South Odisha, India

The paper deals with the nutrient analysis of eleven edible underground plant parts of South Odisha, India, most of which are used by the tribal/ rural people at the time of food scarcity. The nutritive value such as crude protein, total sugar, total lipid, vitamin B and vitamin C content of the selected edible underground plant parts were analysed. The plants with edible underground parts collected for nutritional analysis are Amorphophallus paeoniifolius (Dennst.) Nicolson (Amorphophallus campanulatus Decne.), Colocasia esculenta (L. ) Schott, Curcuma angustifolia Roxb., Dioscorea alata L., D. oppositifolia L., D . wallichii Hook. f. (bulbil and rhizome), Musa × paradisiaca L., Nelumbo nucifera Gaertn., Nymphaea nouchali Burm. f., Raphanus raphanistrum subsp. sativus (L.) Domin ( Raphanus sativus L.).

Ectopic expression of miR156 represses nodulation and causes morphological and developmental changes in Lotus japonicus.

The effects of microRNA156 overexpression on general plant architecture, branching, flowering time and nodulation were investigated in the model legume, Lotus japonicus. We cloned an miR156 homolog, LjmiR156a, from L. japonicus, and investigated its SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes and its biological function at enhancing vegetative biomass yield, extending flowering time, and its impact on nodulation. Thirteen potential targets for LjmiR156 were identified in vitro and their expression profiles were determined in aerial and underground parts of mature plants, including genes coding for eight SPLs, one WD-40, one RNA-directed DNA polymerase, two transport proteins, and one histidine-phosphotransfer protein. Two SPL and one WD-40 cleavage targets for LjmiR156—TC70253, AU089191, and TC57859—were identified. Transgenic plants with ectopic expression of LjmiR156a showed enhanced branching, dramatically delayed flowering, underdeveloped roots, and reduced nodulation. We also examined the transcript levels of key genes involved in nodule organogenesis and infection thread formation to determine the role of miR156 in regulating symbiosis. Overexpression of LjmiR156a led to repression of several nodulation genes during the early stages of root development such as three ENOD genes, SymPK, POLLUX, CYCLOPS, Cerberus, and Nsp1, and the stimulation of NFR1. Our results show that miR156 regulates vegetative biomass yield, flowering time and nodulation by silencing downstream target SPLs and other genes, suggesting that the miR156 regulatory network could be modified in forage legumes (such as alfalfa and trefoils) and in leafy vegetables (like lettuce and spinach) to positively impact economically valuable crop species.Electronic supplementary materialThe online version of this article (doi:10.1007/s00438-014-0931-4) contains supplementary material, which is available to authorized users.

Acylphloroglucinol derivatives from Hypericum andinum: antidepressant-like activity of andinin A.

A new dimeric acylphloroglucinol derivative, andinin A (1), was isolated from the underground plant parts of Hypericum andinum, along with three known dimeric acylphloroglucinols, uliginosin A (2), uliginosin B (3), and isouliginosin B (4). The structure of 1 was elucidated using 1D and 2D NMR and MS experiments and by comparison with previously reported data for Hypericum dimeric acylphloroglucinols. Andinin A (1) displayed antidepressant-like activity in a mouse forced-swimming test when administered orally at doses of 3, 10, and 30 mg/kg.

Distribution of phthalic acid esters in agricultural plants and soil

The study observed the occurrence of di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) in the soil and agricultural crops (Triticum aestivum, Brassica napus, Zea mays) and their distribution to the individual parts. For the experiment were selected 4 locations in central Moravia. At two locations (L1, L2) winter wheat (Triticum aestivum) was grown, at the third location (L3) winter oilseed rape (Brassica napus), and at the fourth location (L4) flint corn (Zea mays). The soil samples (n = 72) and whole plant samples (n = 78) were collected during the vegetation. The aboveground and underground parts of plants, ears, siliques and seeds were analyzed separately.The values of DBP in soil at all areas ranged from 0.28 to 1.59 mg.kg−1 of dry matter and DEHP < 0.03 to 0.73 mg.kg−1 of dry matter. The soil at the L4 site, which was the most fertilized with organic fertilizers, especially manure, was detected significantly (P < 0.05) to show the highest values of both the PAEs (phthalic acid esters) observed (DBPL4 1.59 ± 0.07 mg.kg−1 of dry matter, DEHPL4 0.73 ± 0.18 mg.kg−1 of dry matter).Average concentrations measured in underground parts of monitored crops ranged from 1.68 to 14.26 mg.kg−1 of dry matter for DBP, and 0.12 to 10.34 mg.kg−1 of dry matter for DEHP. Values detected in aboveground parts were 0.03 to 8.84 mg.kg−1 of dry matter for DBP, and 0.25 to 4.59 mg.kg−1 of dry matter for DEHP. Average values of DBP in final products ranged from 0.05 to 0.83 mg.kg−1 of dry matter, and < 0.06 to 0.98 mg.kg−1 of dry matter for DEHP.

Factors affecting the development and control of black dot on potato tubers

Field trials were carried out over a 4 year period (2004–2007) to determine the effect of agronomic factors, specifically cultivar resistance, irrigation, crop duration and chemical control (in‐furrow application of azoxystrobin), on black dot development on potato tubers grown in fields where soilborne inoculum of Colletotrichum coccodes was present. In 2004, 2005 and 2006, two field trials were performed each year and in 2007, 19 mini‐field trials were carried out across Scotland and England. Cultivar resistance was clearly demonstrated to be an effective method of reducing black dot disease severity on tubers (described here as the percentage of unmarketable tubers, i.e. those with symptoms covering a surface area of >10%). In the four field trials carried out in 2004 and 2005, in irrigated and fungicide‐untreated plots, 43·8% of tubers of cv. Maris Piper were unmarketable, compared with 17·0% of tubers of cv. Sante. Assessments of disease development on underground plant parts (stems, stolons and roots) revealed that cultivar resistance acted only at the tuber level, as disease symptoms on other parts were often high irrespective of published disease resistance ratings. Irrigation increased the severity of disease on tubers in two trials (England 2004 and 2006), but its effect was less significant when rainfall was high. Delaying harvest by 2 weeks increased disease severity in all six trials, whilst application of azoxystrobin consistently reduced black dot severity. There were significant interactions between factors. The results clearly show how black dot disease severity can be reduced through an integrated approach to disease management.

Effects of rest grazing on organic carbon storage in Stipa Baicalensis steppe in Inner Mongolia

In order to evaluate the potential effects of rest grazing on organic carbon storage on the Stipa baicalensis steppe in Inner Mongolia, compared the S. baicalensis steppes after rest grazing for 3years, 6years, and 9years, using potassium dichromate heating method, this study analyzed the organic carbon storage of plant and soil in the steppes among different periods of rest grazing. The results indicated that as the rest grazing years prolonged, the biomass included above-ground parts, litters and underground plant parts(roots) of the plant communities all increased, meanwhile the carbon content of the biomass increased with the rest grazing years prolonged. For the zero rest grazing (RG0) steppe and the steppes after a rest grazing of 3years (RG3a), 6years (RG6a), 9years (RG9a), the carbon storage in above-ground parts of plant communities were 42.60gC/m2, 66.33gC/m2, 83.46gC/m2, 100.29gC/m2 respectively; the carbon storage of litters were 7.85gC/m2, 9.12gC/m2, 9.18gC/m2, 11.54gC/m2 separately; the carbon storage of underground plant parts (0–100cm) were 281.40gC/m2, 576.38gC/m2, 745.33gC/m2, 1279.61gC/m2 respectively; and the carbon storage in 0–100cm soil were 22991.14gC/m2, 24687.75gC/m2, 26564.86gC/m2,33041.55gC/m2. The results suggested that as the rest grazing years prolonged, the organic carbon storage in plant communities and soil increased. The carbon storage of underground plant parts and soil organic carbon mainly concentrated in 0–40cm soil. After rest grazing for 3years, 6years, and 9years, the increased soil organic carbon were as the 81.14%, 85.84%, and 89.46% of the total increased carbon; From the perspective of carbon sequestration cost, the total cost of RG3a, RG6a and RG9a were 2903.40RMB/hm2, 5806.80RMB/hm2, and 8710.20RMB/hm2. The cost reduced with the extension of rest grazing years, 0.17RMB/kgC, 0.16RMB/kgC, 0.09RMB/kgC for RG3a, RG6a and RG9a respectively. From the growth characteristics of grassland plants, the spring was one of the two avoid grazing periods, timely rest grazing could effectively restore and update grassland vegetation, and was beneficial to the sustainable use of grassland. From the available data, the organic carbon storage of RG9a was the highest, while the cost of carbon sequestration was the lowest. Therefore, spring rest grazing should be encouraged to continue for it was proved to be a very efficient grassland use measures.

Botanical identification of medicinal roots collected and traded in Morocco and comparison to the existing literature

BackgroundA literature review revealed heavy reliance on a few key publications for identification of medicinal plant species from local or vernacular names and a lack of citation of voucher specimens in many publications. There is a need for more reliable and standardized data on the identity of species used for medicine, especially because local names vary from region to region. This is especially true in the case of medicinal roots, for which identification of species is difficult. This paper contributes to existing data on the species sold as medicinal roots (and other underground plant parts such as bulbs, corms, rhizomes and tubers) in Morocco.MethodsData were collected in collaboration with herbalists in Marrakech and collectors in rural regions near Marrakech where species are collected from the wild. The ethno-medicinal uses of these species were also recorded.ResultsWe identified the vernacular names for 67 medicinal roots (by free listing) used to treat a variety of human diseases. We were able to collect and identify one or more species for 39 of the recorded vernacular names. The ones we were not able to identify were either imported or no longer available in the markets. We collected more than one species for some of the vernacular names for a total of 43 species. We identified six new vernacular names and four species which had not been previously described in the literature. Our botanical identification matched at least one of the names listed in the literature 63% of the time and did not match any species listed in the literature 37% of the time. Of the three most commonly cited pieces of literature we compared to, we found the greatest overlap with the broader, more comprehensive work of Bellakhdar 1997 (as opposed to Benchâabane and Abbad 1997 which worked in a similarly focused geographical area). However there was only 63% agreement between Bellakhdar 1997 and our botanical identifications, and 29% of the time our identification didn’t match even the genus of any of the species listed in any of the 3 most commonly cited pieces of literature.ConclusionsMore rigorous methodology and reporting are needed for medicinal plant research in Morocco. This will ensure that studies are comparable, help to protect traditional medicine users from negative health effects, and, support efforts to conserve overharvested wild medicinal plants.

Antioxidant and phenolic acid profiles of tissue cultured and acclimatized Merwilla plumbea plantlets in relation to the applied cytokinins

Merwilla plumbea (Lindl.) Speta is an important medicinal plant widely used in traditional medicine. We evaluated the effect of five cytokinins [benzyladenine (BA), 2-isopentenyladenine (2iP), meta-topolin (mT), meta-topolin riboside (mTR), and meta-methoxy-9-tetrahydropyran-2-yl-topolin (MemTTHP)] on the level of phenolic acids and antioxidant activity of M. plumbea during the tissue culture and acclimatization stages. Two cytokinins (mT and mTR) significantly improved the antioxidant activity of tissue culture plantlets while the control plantlets were better after acclimatization. Using UPLC–MS/MS, the levels of hydroxybenzoic and hydroxycinnamic acid derivatives (phenolic acids) varied significantly during tissue culture and acclimatization, depending on the cytokinin and plant part analyzed. Vanillic acid (24.9μgg−1) detected in underground parts of tissue culture plants supplemented with BA was the most abundant phenolic acid detected. The current findings indicate that the phytochemicals together with the bioactivity during in vitro propagation of M. plumbea is influenced by the cytokinin type used and the stage of plant material collection.

Ethnobotanical appraisal and medicinal use of plants in Patriata, New Murree, evidence from Pakistan

BackgroundThis paper reflects the empirical findings of an ethnobotanical survey which was undertaken in Patriata (New Murree) of district Rawalpindi in Pakistan. The aims and objectives of the study were to document indigenous knowledge of plants particularly of medicinal, veterinary, fruit, vegetable, fodder, fuel etc.MethodsFor this purpose, the whole area was surveyed for documenting folk knowledge using a semi-structured questionnaire. A total of 93 plants species belonging to 80 genera and 56 families were found in a variety of uses by the local people for the accomplishment of their basic needs. The study further employs binary logit regression model of medicinal uses of these plants so as to identify the probability of occurrence of medicinal use of woody or non-woody plants keeping other plant characteristics in view.ResultsEthnobotanical data shows that most plants are used for medicinal and fodder purposes (27.93% each), followed by fuel (16.90%), fruit (6.55%), vegetable (5.52%) and ethno-veterinary (3.79%). There is also an established association of medicinal use of plants to the fruits use. Non-woody plants have high tendency towards medicinal use of the plants as compared to woody plants. Annual plants are less likely to be directly associated with medicinal use of plants in the surveyed vegetation. Underground plant parts are more likely to be used for medicinal purposes as revealed from the Logit expressions.ConclusionsThe study revealed that most of the plants are used for medicinal and fodder purposes. The results of Logit Model showed that the probabilities of plant species for their medicinal use are associated to the woody or non-woody, aerial or underground, perennial or annual characteristics of plants. One should be careful in completely generalizing the results as the survey findings are sensitive to the plant species and the vegetation under consideration. But it can be specified that there exists either some positive or negative association of medicinal use of plants to the various characteristics of plant species.

The impact of Trichoderma harzianum on sprouting and early development of pepper until thinning

This paper presents the results of the study on the analysis of the stimulative and biopesticide effects of the fungus Trichoderma harzianum T-22 on germination, sprouting and early development of two pepper varieties (Amfora and Buketna 1) in organic production. The results show the significant effect of the applied T-22 strain on ger?mination, sprouting, growth and early development of both aboveground and underground parts of plants, either used as soil or seed inoculum, in comparison to controls. It was concluded that T. harzianum T-22 proved its efficiency in promoting growth and development of pepper, and preventing the development of mycoses.

СОДЕРЖАНИЕ ФЛАВОНОИДОВ В НЕКОТОРЫХ ПРЕДСТАВИТЕЛЯХ СЕМЕЙСТВА ROSACEAE JUSS. ИЗ ПРИРОДНЫХ ПОПУЛЯЦИЙ ЛЕСОСТЕПНОЙ ЗОНЫ ЗАПАДНОЙ СИБИРИ

Last years more and more attention it is given to search of new herbs containing considerable percent of flavonoids and working out of preparations from the vegetative raw materials used in national medicine. The maintenance of flavonoids in vegetative raw materials is the major indicator of its biological value. The purpose of the present work – maintenance research of flavonoids in an elevated and underground part of plants of family Rosaceae. It is analysed on 16 samples of leaves and roots and 14 samples of flowers of the wild-growing plants representing to populations from a forest-steppe zone of Western Siberia. It is established that the maximum maintenance of flavonoids in leaves and flowers characterizes plants Alchemilla vulgaris (5,0 and 4,8%) and Filipendula vulgaris (3,8 and 8,3%), accordingly

Chemical Composition of Essential Oils from a Multiple Shoot Culture of Telekia speciosa and Different Plant Organs

The composition of essential oil from Telekia speciosa leaves, flowers, roots, stems and in vitro regenerated shoots was studied by GC-MS-FID leading to the determination of 112 compounds. The qualitative composition of the essential oil from the examined plant material was similar, whereas quantities of individual components of the oils varied widely depending on the kind of plant material. The most striking differences were observed between the oils produced by aerial and underground parts of the intact plant, as well as between oils produced by in vitro grown shoots and leaves of the intact plant. The main volatiles of leaf essential oil were: (E,E)-famesol (21.2%) and (E)-nerolidol (17.9%), while isoalantolactone was the predominant component of the root (62.3%) and flower oils (23.0%). Numerous thymol derivatives were also found, among them 10-isobutyryloxy-8,9-epoxythymol isobutyrate, which was one of the main components found in the flower oil (20.5%) and that from the in vitro cultures (20.2%).

First Report of Peanut Cylindrocladium Black Rot Caused by Cylindrocladium parasiticum in Fujian Province, Eastern China.

During late July and early August of 2010, a serious disease of peanut (Arachis hypogaea L.) resembling Cylindrocladium black rot (CBR) was found in Longyan City, Fujian Province of Eastern China. Aboveground symptoms were chlorosis and yellowing of leaves, a black rot of the basal stem and pegs, and wilting of the vines. Underground plant parts (including pods, pegs, taproots, and hypocotyls) were blackened and rotted. Orange-to-reddish spherical fruiting bodies appeared on the lesions of the basal stems and pegs of peanut. Disease incidence was approximately 20%. A fungus was consistently isolated from the edge of lesions on potato dextrose agar (PDA) amended with streptomycin and incubated at 25°C. The fungus produced white-to-pale buff mycelia with a yellowish brown pigment. Optimum growth of the fungus on PDA was at 25 to 30°C. Conidiophores were borne laterally on a stipe that terminated in a hyaline, globose vesicle measuring 5.5 × 10.9 μm in diameter. Conidia were hyaline, cylindrical, rounded at both ends, slightly wider at the base than at the apex, with one to three septa (mostly one septa), and measured 27.3 to 70.9 × 4.1 to 8.2 μm. Orange-to-reddish perithecia were readily formed in old cultures. The perithecia were subglobose to oval or obovate and measured 215.6 to 609.4 × 309.4 to 496.9 μm. The asci were hyaline, clavate, thin walled, long stalked, with each containing eight ascospores. Ascospores were hyaline, falcate, had one septum, and measured 27.3 to 54.5 × 4.1 to 6.8 μm. The fungus was identified as Cylindrocladium parasiticum Crous, M.J. Wingfield, & Alfenas (teleomorph Calonectria ilicicola) (1,2). The beta-tubulin gene fragment was amplified using the T1/Bt2b primers (3) and sequenced. The sequences of three isolates (GenBank Accession Nos. JF343965, JF429656, and JF429657), when compared with existing sequences in GenBank, had 95 to 99% sequence identity with Calonectria ilicicola (GenBank Accession Nos. AY725643 and AY725639). Pathogenicity tests were conducted by first culturing the fungus on wheat kernels for 2 weeks. Inoculated kernels were then used as inoculum and mixed with sterilized soil in a proportion of 1:20 by weight in plastic pots (10 × 9 cm). Noninoculated wheat kernels were mixed with sterilized soil in the same proportion and served as the control. Two-week-old peanut seedlings (cv. Yueyou No. 7) were transplanted into inoculated or noninoculated pots. There were five plants per pot and each treatment was replicated four times. The plants were incubated in a greenhouse at 25 ± 2°C. All of the treated plants exhibited typical basal stem and root rot symptoms of CBR 2 weeks after inoculation, while all of the control plants remained healthy. C. parasiticum was reisolated from the diseased plants. To our knowledge, this is the first report of CBR on peanut in Fujian Province in Eastern China. The disease has been previously reported in Guangdong Province in Southern China but is not known elsewhere (4). This pathogen may pose a serious threat to peanut production in China, where peanut is an important crop.

Nematodes as a Limiting Factor in Potato Production in Scandinavia

Plant parasitic nematodes associated with potato feed on roots and/or tubers. About 70 species, representing 24 genera, have been reported from potato. Since nematodes attack underground plant parts, there are no reliable foliar symptoms to show that nematodes may be the major cause of poor growth and reduced tuber yields. Potato roots damaged by nematodes may show lesions, abnormal proliferation of lateral roots, emerging white females and brown cysts. Nematode attacks may render plants vulnerable to other pathogens, so disease caused by microorganisms may have nematodes as an etiological component. Therefore, nematode damage may often have been attributed to other factors. In Scandinavia, potato cyst nematodes (Globodera rostochiensis and Globodera pallida) are by far the most important nematodes on potato. In Norway, the cost of compensations schemes due to imposed statutory regulations of potato cyst nematodes may some years exceed the compensation for any other pests or diseases organism in agriculture. Other important nematodes include root lesion nematodes (Pratylenchus spp.), stubby root nematodes (Trichodorus spp. and Paratrichodorus spp.), and potato rot and stem nematodes (Ditylenchus spp.). Root knot nematode Meloidogyne hapla is considered less important. Meloidogyne chitwoodi and Meloidogyne fallax are not known to be present in Nordic countries. In the control, crop rotations using non-host crops, alternating susceptible and resistant potato cultivars, are an important control measure. However, the use of resistant potato cultivars requires knowledge of the species and pathotypes present in the field.

Особенности аккумуляции тяжелых металлов растениями на черноземе южном

В статье рассмотрены особенности аккумуляции тяжелых металлов растениями, произрастающими на черноземе южном, выявлены закономерности распределения этих токсикантов в надземных (вегетативных и генеративных) и подземных органах растений.

Involvement of salicylic acid and nitric oxide in protective reactions of wheat under the influence of heavy metals

This article studies the effect of salicylic acid (SA) and nitric oxide (NO) on Triticum aestivum L. wheat plants exposed to the influence of high concentrations of copper and zinc compounds. It is shown that heavy metals (HMs) caused a decrease in the growth parameters in the overground and underground plant parts and contributed to a sharp deterioration in the energy balance and the situation regarding oxidative stress. SA and NO exerted a protective effect, which was expressed in the increased ability to accumulate shoot and root mass, stabilize the energy balance, and reduced lipid peroxidation.

Triterpene Functional Genomics in Licorice for Identification of CYP72A154 Involved in the Biosynthesis of Glycyrrhizin

Glycyrrhizin, a triterpenoid saponin derived from the underground parts of Glycyrrhiza plants (licorice), has several pharmacological activities and is also used worldwide as a natural sweetener. The biosynthesis of glycyrrhizin involves the initial cyclization of 2,3-oxidosqualene to the triterpene skeleton β-amyrin, followed by a series of oxidative reactions at positions C-11 and C-30, and glycosyl transfers to the C-3 hydroxyl group. We previously reported the identification of a cytochrome P450 monooxygenase (P450) gene encoding β-amyrin 11-oxidase (CYP88D6) as the initial P450 gene in glycyrrhizin biosynthesis. In this study, a second relevant P450 (CYP72A154) was identified and shown to be responsible for C-30 oxidation in the glycyrrhizin pathway. CYP72A154 expressed in an engineered yeast strain that endogenously produces 11-oxo-β-amyrin (a possible biosynthetic intermediate between β-amyrin and glycyrrhizin) catalyzed three sequential oxidation steps at C-30 of 11-oxo-β-amyrin supplied in situ to produce glycyrrhetinic acid, a glycyrrhizin aglycone. Furthermore, CYP72A63 of Medicago truncatula, which has high sequence similarity to CYP72A154, was able to catalyze C-30 oxidation of β-amyrin. These results reveal a function of CYP72A subfamily proteins as triterpene-oxidizing enzymes and provide a genetic tool for engineering the production of glycyrrhizin.

Status and ethno-medicinal usage of invasive plants in traditional health care practices: a case study from northeastern Bangladesh

Species diversity and ethno-medicinal usage of 39 species of invasive plants were explored in and around two protected areas, Khadimnagar National Park (KNP) and Rema-Kalenga Wildlife Sanctuary (RKWS), of northeastern Bangladesh,. Status of invasive plants were investigated in 60 sample plots with 5 different habitat types, including forest, roadside, homestead, fallow land and others (ponds, canals, water logged areas, agricultural land, etc.). Data about the usage of invasive plants in traditional health care were collected through interviewing 110 households. Among the five habitat types, fallow land (28 species) possessed the highest number of species, followed by roadside (25 species), forest (23 species), homestead (22 species) and others (13 species). Based on the survey, invasive plants of study areas were also categorized into five degrees of invasiveness e.g., naturalized, introduced, possibly invasive, moderately invasive and highly invasive. Additionally, there is the linear trend between degrees of invasiveness and use percentage of invasive plants. Total 39 species of invasive plants belonging to 29 families were recorded, which are generally used to treat 37 diseases, ranging from simple headache to highly complicated eye and heart diseases. The majority of the species used by the local inhabitants were herbs (16 species), followed by some shrubs (11 species), climbers (5 species), trees (5 species) and grasses (2 species). The use percentage of aboveground plant parts were higher (70.58%) than that of underground plant parts (16.18%).

Variation in podophyllotoxin concentration in leaves and rhizomes of American mayapple ( Podophyllum peltatum L.)

Podophyllotoxin is a precursor for compounds used in the synthesis of commercially available anticancer drugs and their precursors etoposide, teniposide, and etopophos. Podophyllotoxin is currently obtained from the underground plant parts (roots and rhizomes) of Himalayan mayapple ( Podophyllum emodii Wall.) but is also found in several other species, including American mayapple. There is no information in the literature on podophyllotoxin concentration in the roots or rhizomes of the American mayapple, and it was not clear if podophyllotoxin concentration in underground plant parts is correlated with the concentration in aboveground plant parts. The objective of this study was to estimate podophyllotoxin concentration in the leaves and rhizomes of 28 accessions of American mayapple under natural conditions (wild) and compare this to podophyllotoxin concentrations of the same accessions in the leaves when cultivated. Podophyllotoxin concentration in the rhizomes was positively correlated to soil organic matter content and to the concentrations of soil-available P and Na. Podophyllotoxin in the leaves was negatively correlated to soil-available Mg concentrations. The concentration of podophyllotoxin in the leaves varied from undetectable amounts to 2.52%, whereas podophyllotoxin in rhizomes varied from 0.14% to 0.42%. Most of the accessions had greater than 0.45% podophyllotoxin concentration in the leaves under both wild and cultivated conditions. There was no significant correlation between the podophyllotoxin concentrations in rhizomes and leaves; nine accessions had the highest podophyllotoxin concentration in leaves under natural environment. Another nine accessions had the highest podophyllotoxin in the leaves under cultivated conditions, and an additional eight accessions had greater podophyllotoxin concentrations in roots than in leaves irrespective of the environment. The results from this study may contribute toward developing American mayapple into a new cash crop for U.S. farmers.

Downward Vascular Translocation of a Green Fluorescent Protein-Tagged Strain of Dickeya sp. (Biovar 3) from Stem and Leaf Inoculation Sites on Potato

Translocation of a green fluorescent protein (GFP)-tagged Dickeya sp. from stems or from leaves to underground parts of potato plants was studied in greenhouse experiments. Thirty days after stem inoculation, 90% of plants expressed symptoms at the stem base and 95% of plants showed browning of internal stem tissue. The GFP-tagged Dickeya sp. was detected by dilution plating in extracts of the stem interiors (100%), stem bases (90%), roots (80%), stolons (55%), and progeny tubers (24%). In roots, the GFP-tagged Dickeya sp. was found inside and between parenchyma cells whereas, in stems and stolons, the GFP-tagged Dickeya sp. was found in the xylem vessels and protoxylem cells. In progeny tubers, this strain was detected in the stolon end. Thirty days after leaf inoculation, the GFP-tagged Dickeya sp. was detected in extracts of 75% of the leaves, 88% of the petioles, 63% of the axils, and inside 25% of the stems taken 15 cm above the ground level. UV microscopy confirmed the presence of the GFP-tagged Dickeya sp. inside petioles and in the main leaf veins. No blackleg or aerial stem rot and no translocation of the GFP-tagged Dickeya sp. to underground plant parts was observed. The implications for contamination of progeny tubers are discussed.