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Dado el conocido uso alimenticio de los rizomas de Canna glauca y C. indica, resulta interesante conocer si existen diferencias entre las dos especies en la acumulación de almidón en los rizomas y la posible variación estacional anual. Para su estudio se trabajó con material fresco recolectado en las cuatro estaciones del año. Mediante una observación macroscópica colorimétrica practicada sobre secciones transversales de los rizomas sobre las que se aplicó solución de ioduro de potasio iodado (lugol), se determinó la presencia de almidón en los rizomas. Este método permitió además estimar la abundancia por la intensidad de coloración. Para la determinación cuantitativa se calculó la densidad de granos de almidón por mililitro de agua destilada en cámara de Neubauer, empleando una solución acuosa de parénquima del rizoma y lugol. Desde el punto de vista cualitativo y cuantitativo, en ambas especies la acumulación de almidón alcanzó su máximo en el período otoño-invernal y comparando las dos especies, la abundancia de almidón en este período del año fue mayor en C.indica, lo cual la indica como la más promisoria para ensayar su cultivo para alimento y producción de almidón en el área rioplatense., Given the known nutritional use of the rhizomes of Canna glauca and C. indica, it is interesting to know if there are differences in the accumulation of starch in the rhizomes and the possible annual seasonal variation between the two species. For its study we worked with fresh material collected seasonally over the year. Through a macroscopic colorimetric observation carried out on cross-sections of the rhizomes the presence of starch in the rhizomes was determined through the use of iodinated potassium iodide solution (lugol). This technique also allowed estimating the abundance by the intensity of coloration. For the quantitative determination, the density of starch grains per milliliter of distilled water in Neubauer chamber was established, using an aqueous solution of parenchyma of the rhizome and lugol. From the qualitative and quantitative point of view, in both species the accumulation of starch reached the maximum in autumn-winter. Comparing the two species, the abundance of starch in this period of the year was higher in C. indica. It indicates this species as the most promising to test the crop for food and starch production in the Rio Plata area., Facultad de Ciencias Agrarias y Forestales

Taro (Colocasia esculenta (L.) Schott) is cultivated primarily for its starchy underground stem (i.e., corm). It is adapted to both upland and wetland (i.e., flooded) conditions. Although taro is exposed to hypoxia that occurs in waterlogged soil, the mechanisms of its adaptation to hypoxia were unknown. To clarify the below-ground adaptation of taro to wetland conditions, we grew five taro cultivars/landraces hydroponically for 8 days under hypoxic conditions (n = 3) and analyzed: (1) the length of the longest root that emerged from the vegetative propagule; (2) aerenchyma (i.e., tissues containing air spaces); and (3) oxidation conditions around sides of root tips. Wild taro Āweu and the Chinese cultivar Bun-long had significantly longer roots than the Hawaiian cultivars/landraces Maui Lehua, Pi‘i‘ali‘i, and Ele‘ele Naioea (P

Background Rhizome is the storage underground stem of lotus (Nelumbo nucifera), which is enlarged before winter season and could be used for asexual propagation. In addition, the enlarged rhizome is a nutritional vegetable with abundant starch, proteins, and vitamins. Enlargement of lotus rhizome is not only significance for itself to survive from the cold winter, but also important for its economic value. Results To explore the mechanism underlying its enlargement, integrative analyses of morphology, physiology and proteomics were conducted on the rhizome at stolon, middle, and enlarged stages. Morphological observation and physiological analyses showed that rhizomes were gradually enlarged during this process, in which the starch accumulation was also initiated. Quantitative proteomic analysis on the rhizomes at these three stages identified 302 stage-specific proteins (SSPs) and 172 differently expressed proteins (DEPs), based on which GO and KEGG enrichment analyses were conducted. The results indicated that light and auxin signal might be transduced through secondary messenger Ca2+, and play important roles in lotus rhizome enlargement. Conclusion These results will provide new insights into understanding the mechanism of lotus rhizome enlargement. Meanwhile, some candidate genes might be useful for further studies on this process, as well as breeding of rhizome lotus.

Astrocaryum acaule Mart. is a palm with underground stem, common in lowland forests, known in Brazil as tucuma-i. The objective of this work was to perform the description and characterization of seeds and of the seedling emergence process, revealing morphological and anatomical patterns of A. acaule. Seedlings were obtained by sowing in vermiculite. The seed is spherical, with variations in shape and size according to the number of seeds in the fruit. Germination is adjacent, with formation of a coleoptile above the cotyledonary sheath. The germinative bud is emitted within between 30 and 130 days. The proximal and distal regions differentiate with growth, forming the seedling and the haustorium that transfers reserves through the reduced apocole. The initial root system differs in the hypocotyl-radicle region, below the insertion of leaf primordia, forming a lateral root and a late primary root. The first eophyll is expanded 120 days after the protrusion of the germinative button, with aculeate petiole, amphistomatic leaf blade, papillose epidermis, homogeneous mesophyll, and vascular system covered by fibers. Morphoanatomical characters reported in this study increase our knowledge about Amazonian palms and on organogenesis in their early stages of growth.

Smilax campestris Griseb. (Smilacaceae) (“zarzaparrilla”) is a medicinal plant species widely used by traditional communities in South America. In general, the plant parts used by popular medicine are the rhizophore (underground stem) and roots, in the form of infusions or decoctions. Their main indications are: antirheumatic, antisyphilitic, diuretic, diaphoretic, anti-inflammatory, antiseptic, and to treat skin conditions (i.e. psoriasis) and gout; among others. There is lacking scientific evidence regarding the phytochemistry of such aqueous extracts, as well as their biological and pharmacological properties. Both aerial and underground organs have been described to contain polyphenolic acids, flavonoids (aglycones, glycosides and proanthocyanidin oligomers/polymers) and saponins; but no systematic research on the isolation of other families of natural products has been conducted, yet. The production of secondary metabolites (in particular flavonoids) is highly dependent on both environmental conditions (solar radiation, herbivores, etc.) of habitats and the phenological stage of the plant itself. The scientific pharmacological in vitro tests performed on S. campestris extracts have confirmed their antioxidant and anti-inflammatory activities, as well as the lack of acute toxicity. However, they have failed to demonstrate diuretic effects in in vivo models; results on the antimicrobial potential are controversial. Further research is needed to evaluate the other ethnomedicinal properties attributed to the vegetal drug. This chapter presents a critical review of the special literature on S. campestris including the most updated information available in journals, books and the internet.

Perennial crops have some advantages over annuals in soil erosion prevention, lower labor and water requirements, carbon sequestration, and maintenance of thriving soil ecosystems. Rhizome, a kind of root-like underground stem, is a critical component of perenniality, which allows many grass species to survive through harsh environment. Identification of rhizome-regulating genes will contribute to the development of perennial crops. There have been no reports on the cloning of such genes until now, which bring urgency for identification of genes controlling rhizomatousness. Using rhizomatous Oryza longistaminata and rhizome-free cultivated rice as male and female parents, respectively, genetic populations were developed to identify genes regulating rhizome. Both entire population genotyping and selective genotyping mapping methods were adopted to detect rhizome-regulating quantitative trait loci (QTL) in 4 years. Results showed that multiple genes regulated development of rhizomes, with over 10 loci related to rhizome growth. At last, five major-effect loci were identified including qRED1.2, qRED3.1, qRED3.3, qRED4.1, and qRED4.2. It has been found that the individual plant with well-developed rhizomes carried at least three major-effect loci and a certain number of minor-effect loci. Both major-effect and minor-effect loci worked together to control rhizome growth, while no one could work alone. These results will provide new understanding of genetic regulation on rhizome growth and reference to the subsequent gene isolation in rice. And the related research methods and results in this study will contribute to the research on rhizome of other species.

International audience; Poplar is useful in different climates for bioenergy production and carbon sequestration when planted as a single species or in agroforestry. Europe has large areas potentially suitable for poplar forestry and a bioenergy policy that would encourage poplar forestry. In this study I estimated biomass production and carbon sequestration in poplar monoculture plantation and poplar-wheat agroforestry, in the Mediterranean region of France. A single-tree harvesting method was used to estimate biomass and an empirical conversion factor was adopted to calculate sequestered carbon. Total biomass was higher in agroforestry trees (1223 kg tree(-1)) than in monoculture plantation trees (1102 kg tree(-1)). Aboveground and belowground biomass distributions were similar in both cases (89 and 88% aboveground, and 11 and 12% belowground, respectively in agroforestry and monoculture). The partitioning of total biomass in an agroforestry tree in leaves, branch, and trunk (aboveground), and fine roots, medium roots, coarse roots and underground stem (belowground) was 1, 22, and 77, and 6, 9, 44 and 40%, respectively. Except for branch and trunk, all other compartments were similarly distributed in a monoculture tree. Storage of C was higher in agroforestry trees (612 kg tree(-1)) than in monoculture trees (512 kg tree(-1)). In contrast, C storage on a per hectare basis was lower in agroforestry (85 Mg ha(-1)) than in monoculture (105 Mg ha(-1)) due to the lower density of trees per hectare in agroforestry (139 trees in agroforestry vs 204 trees in monoculture). On a per hectare basis, soil C stocks pattern were similar to per tree stocking: They were higher in agroforestry at 330 Mg ha(-1) than in monoculture 304 Mg ha(-1). Higher C accumulation by agroforestry has a direct management implication in the sense that expanding agroforestry into agriculture production areas with short rotation and fast growing trees like poplar would encourage quicker and greater C sequestration. This could simultaneously fulfil the requirement of bioenergy plantation in Europe.

The genus Azospirillum is recognized as plant growth-promoting bacteria that exert beneficial effects on the host plant and is morphologically converted into cyst-like cells (i.e., c-form) in association with poly-&beta, hydroxybutyrate (PHB) accumulation in the cells under stress conditions. We constructed Azospirillum brasilense, labeled with reporter genes (gus/gfp, mCherry) and examined the plant tissue localization along with a morphological conversion into the c-form upon its initial interaction with onion seedlings (Allium cepa L.). The PHB granules in the A. brasilense cells were easily detected under fluorescence as &ldquo, black holes&rdquo, rendering it possible to monitor the morphological conversion from vegetative to the c-form cells. The results showed that the A. brasilense cells on the surface of the roots and bulbs (underground stem) began converting at three days following inoculation and that the cell conversion was significantly advanced with time along with the cell population increase. The endophytic infection of A. brasilense into the bulb tissues was also confirmed, although these likely constituted vegetative cells. Moreover, the morphological conversion into the c-form was induced under nitrogen-restricted conditions. Analysis of the biochemical properties of the A. brasilense cells during cell conversion revealed that the acetylene reduction activity correlated positively with the PHB accumulation in the cells converting into the c-form under nitrogen-restricted conditions.

Taro [Colocasia esculenta (L.) Schott] is an ancient, tropical root crop that is morphologically diverse with over 10,000 landraces. It is the fifth most produced root crop in the world and is mainly grown in tropical Africa, China, New Guinea, and many Pacific islands. Taro typically is grown for its starchy corm (i.e., underground stem), although leaves and flowers also are eaten as vegetables. There is controversy over its geographic center of origin, but this is likely to be in the Indo-Malayan area. Evidence indicates that it was domesticated, possibly independently, across an area that ranges from northeast India to Yunnan province in China to New Guinea. Within Micronesia and Polynesia, where taro is a staple crop, the genetic base is very narrow. Genetic diversity within the taro germplasm is significantly greater in Asia and New Guinea. The exploitation of this diversity could lead to the development of cultivars with greater disease resistance, and improved yields and corm quality. Taro is a neglected crop in terms of recent advances in molecular biology, with only a limited number of studies utilizing next-generation transcriptome and genome sequencing. At present, a high-quality reference genome is lacking; however, recent genotyping-by-sequencing (GBS) approaches promise to improve our understanding of taro genetics.

The response of potato (Solanum tuberosum cv Haryeong) to mulching and different planting depths was evaluated during 2010–2013. Two different plastic mulches, black and clear polyethylene (PE) were compared with the unmulched control and seed tubers were planted at 5-, 10-, 15-, and 20-cm depths in each treatment. The objectives were to determine how mulching and planting depth affected the canopy development, underground morphology, and tuber yield. Early emergence, canopy development and tuber growth rate were improved in the mulched treatment; while delayed or decreased as the depth of planting increased. The number of stems per plant increased as seed pieces were planted closer to the soil surface in two of the four seasons, but was not affected by mulches except for 2012. Stolon length was longest in black mulches, especially on upper part of underground stem, but it was long on lower part of the stem in unmulched potatoes. Percent tuber bearing stolons were increased in the mulches and deep (10–20 cm) planted potatoes. Particularly, on the lower part of underground stem, a higher percentage of tubers were formed irrespective of mulches and planting depth. Harvest index was significantly higher in clear PE mulches in two of the four seasons while it was not affected by planting depth. Mulching potatoes produced higher total and >80 g yields, while varying the depth of planting affected the total yield which was lower in the deepest (20 cm) planted potato.

Distribution and morphology Curcuma is one of the largest genera in the Zingiberaceae family. This genus is in the tribe Zingibereae, which is widely distributed in tropical Asia from India to South China, Southeast Asia, Papua New Guinea and Northern Australia. Thailand seems to be one of the areas richest in this genus (Larsen and Larsen, 2006; Sirirugsa et al., 2007). Approximately 38 species of Curcuma are now found in Thailand, separated into 5 groups, i.e., 1) the “Alismatifolia” group of eight species, C. alismatifolia, C. gracillima, C. harmandii, C. parviflora, C. rhabdota, C. sparganiifolia and two new species, found in the northeastern and eastern region; 2) the “Cochinchinensis” group of two species, C. cochinchinensis and C. pierreana, distributed in the north, southwest and eastern regions; 3) the “Ecomata” group of seven species, C. bicolor, C. ecomata, C. flaviflora, C. glans, C. singularis, C. stenochila and one new species, distributed in the northern, northeastern, eastern and southeastern regions; 4) the “Longa” group of thirteen species, C. aeruginosa, C. amada, C. angustifolia, C. aromatic, C. comosa, C. latifolia, C. leucorrhiza, C. longa, C. mangga, C. rubescens, C. viridiflora, C. zanthorrhiza and C. zedoaria, found widely in the north; and 5) the “Petiolata” group of eight species, C. aurantiaca, C. petiolata, C. roscoeana, C. rubrobracteata and four new species, found from the north to the peninsula along the western ranges (Sirirugsa et al., 2007). Unlike C. longa (tumeric), C. zedoaria, C. aromatic, etc., which are species generally used as medicinal plants (Sabu and Skornickova, 2003), C. alismatifolia Gagnep. is widely cultivated as an ornamental Curcuma for cut flowers and potted plants because the attractive inflorescence has a pink coma bract, called Siam Tulip or Patumma, with a long vase life (Figure 1). This flower clone was first selected by Dr. Pisit Woraurai from Chiang Mai University, and the famous selected clone called ‘Chiangmai Pink’ was introduced as an ornamental plant in early 1980, and nowadays is wellknown in the world market (Woraurai, 1991; Department of Agricultural Extension, 1995; Wannakrairot, 1997). The aboveground organs consisted of leaves and inflorescences. There are two types of leaves, sheath leaves are former sprouting with short and thick leaf blade and followed by foliage leaves with elliptic shape, deep green and reddish median vein. Stomata is mostly tetracyctic type, however, pentacytic and hexacytic types were found in both upper and lower surfaces. Guard cells are kidney shape and the cell size in the adaxial is longer than the abaxial site. Stomatal density in the abaxial site was about 1,000–1,200 stomata mm-2 which was higher than in adaxial site (400–500 stomata mm-2). The cuticle layer of upper leaf surface is about 10–12 μm thick and thicker than the lower leaf surface (13–15 μm thick) (Anuwong et al., 2014b). Underground organs consist of two parts, i.e., the underground stem called a stubbed German Society for Horticultural Science

The Yixian Formation (the Lower Cretaceous) of China is world famous for its fossils of early angiosperms. Although these diverse angiosperms demonstrate an unexpectedly great diversity, few are preserved as whole plants (not mention of monocots), making our understanding of them incomplete. Here, we report a fossil angiosperm, Sinoherba ningchenensis gen. et sp. nov (Sinoherbaceae fam. nov.), from the Yixian Formation of China; this fossil has a physically connected underground stem with fibrous rootlets, a stem with branches and nodes, leaves with parallel-reticulate veins, and a panicle of female flowers with an ovary surrounded by perianth. Morphological and phylogenetic analyses revealed that Sinoherba is an herbaceous monocot taxon. This newly discovered fossil underscores the great diversity of angiosperms in the Lower Cretaceous Yixian Formation.

The effect of EDTA on cadmium and zinc uptake by sugarcane (Saccarumofficinarum L.) grown in contaminated soil was investigated. Sugarcane was grown in pots for 1 month and EDTA was added at concentration levels of 0(control), 0.5, 1 and 2 millimole per 1 kilogram of soil. Plants were harvested at 2, 4, 6 and 8 months. Soil samples were analyzed to determined levels of cadmium and zinc. Plants were separated into 5 parts: Leaves, bagasses, underground stem, root and juice, including the phytotoxicity. Moreover, the plants were also analyzed for cadmium and zinc accumulation. This result shows that the concentration of EDTA at 1 millimole per 1 kilogram of soil had the highest cadmium accumulation in the root of sugarcane at 21.87, 44.68, 57.52 and 41.97 mg kg-1, at the contact time, respectively. Furthermore, the root showed the most efficient sugarcane uptake compared to the underground stem, bagasses, leaves and juice (root > undergroundstem > bagasses > leaves > juice). The EDTA concentration at 2 millimoles per 1 kilogram of soil has maximum zinc accumulation in various parts of sugarcane. The harvested time at 2 months showed zinc uptake much higher than for leaves and bagasses, while the maximum accumulation of zinc was found in roots and the underground stem at 4 months.

Zingerber offinale (ginger) is an underground stem or rhizome which is known to have originated from Asia and have been reported to have a number of medicinal properties which is used in the treatment of many ailments such as arthritis, painful menstrual periods, nausea etc. It is also used as a common specie in food and bakery industries. Due to the availability and medicinal uses of ginger, the effect of the ethanolic extract on the histology of the pancreas of adult wistar rats was investigated. Twenty five (25) adult Wistar rats weighing 125-200g were divided into five groups (A, B, C, D and E) each with five rats. The animals in group A and B served as control groups and received distilled water and olive oil respectively, the animals in groups C, D and E served as experimental groups, and received 100mg/kg, 250mg/kg and 500mg/kg body weight of the ethanolic extract of Zingiber officinale respectively. The animals received the extract for 14 days and were sacrificed 24 hours after the last administration and routinely processed histologically. The study shows that there is disintegration of the islet cells of Langerhans (IL) with pyknotic nuclei, but no visible change or alteration in the serous acini (SA) of the pancreas. It is observed that extract of ginger has adverse effect on the integrity of the islet cells of Langerhans.

Elephant foot yam probably originated from India or Sri Lanka. It is grown in Bangladesh, India, Southeast Asia and Africa. It is also found growing wild in the Philippines, Malaysia, Indonesia and Southeastern Asian countries. Elephant foot yam also known as Suran and Zamikand is a potential tropical tuber crop. Though the crop is perennial due to underground stem, it is treated as an annual with duration of 8 to 9 months. The tubers are rich in carbohydrates, starch, calcium, phosphorous, potassium and vitamin C. Tubers of elephant foot yam are mainly used as vegetable after thorough cooking. Its tubers, rich in starch, are used for making chips. Tender stem and leaves are also used as vegetables. The crop can be grown in any types of soil. However, well-drained, fertile, sandy loam soil rich in humus is ideal for the cultivation of elephant foot yam successfully.

Semiaquilegia quelpaertensis sp. nov., a new species belonging to the family Ranunculaceae, from Hallasan National Park in Jeju-do, Republic of Korea, is described and illustrated. The new species is similar to Semiaquilegia adoxoides (DC.) Makino, but can be readily distinguished by a thick underground stem, shallowly lobed leaflets, larger flowers, (4–)6 staminodes and conspicuously rugose tuberculate seed surface.

Oenocarpus bataua var. bataua is a key species in the tropical rain forests of South America because it is one of the 10 most abundant tree species and one of most used by Amerindians. However, there is an acute lack of verifiable information about the duration of some of its ontogenic phases, the exact age of the palms, and the effect of gap formation on its spatial distribution. We employed 36 permanent plots (PP) of 0.1 ha randomly distributed in a forest of 700 ha in the Colombian Andes, in which we inventoried the stemmed palms at the establishment of the PP and after 13.4 years to study some ontogenic and demographic traits of this species. We dated underground and aboveground stems using the 14C bomb-effect and estimated the stem’s age by the rate of leaf-scar formation. We aimed at answering the following questions: (i) what are the main morphological characteristics of the underground stem and how long does it takes for its formation?; (ii) what is the pattern of its spatial distribution at the landscape level, and what factors help to explain it?; (iii) is the population structure and demography associated with the previous history of the forest?; (iv) is the first flowering a function of the vigour of the palms?. We found that the underground stem of adult palms is usually obconical and reaches 73 ± 13 cm in length (±standard deviation). The duration of the establishment phase in eleven palms was almost constant: 37.5 ± 0.7 years. The palms with smaller and larger diameters tend to flourish when the stems are 18 and 7 years old (44–55 years old from seedlings), respectively. We found that this species has a clumped spatial pattern. Several palms dated gave ages between 91 and 92 years, while others about 53 years. The bell shaped frequency distribution of the palm’s length and age suggest a lack of younger palms in this area. We interpret that both, the clumped spatial pattern and their age distribution, are a legacy from past selective loggings that induced even-aged cohorts of palms at the landscape level. This species is not in equilibrium because the population tends to be reduced through time given that its doubling time is 37.4 years and its half-life 29.3 years.

This study aims to test and compare the amount of cassava tubers which remained with underground stem after chopped with cylinder blades which had different cross-section and sizes (3x3 Treatments) by using “Kasetsart 50 cassava variety” with the age of 8 months old that planted in sandy loam in Kalasin Province. There are 30 cassava stalks per treatment were used as the sample. The implement of the test was Factorial in Completely Randomized Design. The results found that increasing of diameter of the cylinder blade from 6 – 8 cm caused the increasing amount of cassava tuber remained with underground stem, however, average tuber loss was just in range of 2.56-3.36% wt. (p-value = 0.003), but the increasing did not affect the amount of force used in cassava chopper. As for changing the cross section of cylinder blade (Square, Round and Hexagon), it caused changes in the amount of cassava tuber remained with underground stem after chopping, but there was no exact direction (p-value = 0.036). However, changing of cross section would cause changes of cassava chopper force (p-value = 0.001) that its directions were related to the length of perimeter of each cross-section.

Zamia paucifoliolata, a new cycad species from the Pacific lowlands of Valle del Cauca, Colombia, is described and illustrated. It is distinguished from other species of Zamia by having an underground stem typically bearing large solitary leaves with eighteen or fewer leaflets, villous strobilar axes, microsporangia borne on both the abaxial and adaxial side of microsporophylls, and seeds that are longer than 18 mm. It is compared to Z. pyrophylla, Z. cunaria, and Z. ipetiensis, species which it most closely resembles.

Halophila beccarii Aschers., a small monoecious seagrass with rosette leafy shoot and well-developed rhizome or underground stem that acts as anchors occurs in environment with salinity fluctuation e.g., brackish coastal water of mangrove system, lagoon and marine coastal areas. Shoots represent most of the above-ground component of the plant and in direct contact to the ever changing salinity but it is not known how they respond to such fluctuations. Therefore, this study examined the effects of salinity variations on above-ground response variables; number of leaves per shoot, leaf length, leaf width and petiole length of the seagrass Halophila beccarii. Survival and above-ground response variables to salinity were characterized in culture-experiments in which plants were exposed to increased salinity (from 25-30, 45 psu) and decreased salinities (from 25-25, 20, 15, 10, 6, 4, 2, 0.9, 0.52 and 0 psu) treatments at two-week intervals. No plants mortality and significant changes in number of leaves per shoot were observed with increased or decreased salinity treatments. Plants continued to survive even in hypotonic environment to 0 psu. Halophila beccarii was significantly affected by increased or decreased salinity altering the dimensions of leaves. Leaf length and leaf width became shorter and narrower at lower (4-0.52 psu) and higher (45 psu) salinity. These results suggest that the seagrass H. beccarii could be negatively affected by hypo- or hypersalinity conditions, although salinity changes did not alter the tolerance of this species. Halophila beccarii tolerated hyposaline conditions better than hypersaline conditions.

Cassava (M. esculenta) gives rise to unique underground stem tubers when stem cuttings are planted in an inverted orientation. The nutritional profile of the stem and root tubers were similar except for protein content which was higher in stem than in root tubers. RT-PCR revealed that several key genes (Mec1, RZF, SuSy1 and PIN2) involved in root tuberization were also expressed in these stem tubers. At five weeks post planting, these genes were expressed in roots and underground stems as in the mature tubers. However at 15 weeks post planting, they were expressed in both root and stem tubers but not in adventitious roots or in the non-tuberized stems. Expression of, the root auxin efflux carrier gene PIN2 in the stem tubers indicate a role for auxin in the stem tuberization process.

The potato tuber is a swollen underground stem that can sprout under dark conditions. Sprouting initiates in the tuber apical bud (AP), while lateral buds (LTs) are repressed by apical dominance (AD). Under conditions of lost AD, removal of tuber LTs showed that they partially inhibit AP growth only at the AD stage. Detached buds were inhibited by exogenous application of naphthaleneacetic acid (NAA), whereas 6-benzyladenine (6-BA) and gibberellic acid (GA 3 ) induced bud burst and elongation, respectively. NAA, applied after 6-BA or GA 3 , nullified the latters’ growth-stimulating effect in both the AP and LTs. GA 3 applied to the fifth-position LT was transported mainly to the tuber’s AP. GA 3 treatment also resulted in increased indole-3-acetic acid (IAA) concentration and cis-zeatin O-glucoside in the AP. In a tuber tissue strip that included two or three buds connected by the peripheral vascular system, treatment of a LT with GA 3 affected only the AP side of the strip, suggesting that the AP is the strongest sink for GA 3 , which induces its etiolated elongation. Dipping etiolated sprouts in labeled GA 3 showed specific accumulation of the signal in the AP. Transcriptome analysis of GA 3 ’s effect showed that genes related to the cell cycle, cell proliferation, and hormone transport are up-regulated in the AP as compared to the LT. Sink demand for metabolites is suggested to support AD in etiolated stem growth by inducing differential gene expression in the AP.

Three experiments were conducted with 60 germplasm accessions of yam ( Dioscorea spp.) at Plant Genetic Resources Centre of BARI for characterization and conservation of germplasm. Fifty-nine germplasm accessions of D. alata L. and one accession of D. bulbifera L. from different districts of Bangladesh were used. Clockwise twining direction was found in D. bulbifera and anti-clockwise twining direction was exhibited in all D. alata germplasm accessions. Potato like aerial tuber was found in D. bulbifera . Round, oval, elongate, flattened to irregular aerial tuber shape were found. Grayed-brown, brown to grayed-orange skin colour with yellow, yellow-orange to grayed-orange of aerial tuber flesh colour were observed among the yam germplasm accessions. Oval-oblong, cylindrical, flattened, corm, rhizome to irregular shape of underground stem or tubers were observed. Low, medium to dense types of spiniess of roots were found on the tubers. Grayed-orange, red to black tuber skin colour along with white, yellowish-white, yellow, yelloworange, red to purple tuber flesh colours were found. Significant variations were also observed in stem shape at base, colour of stem, wing and petiole wing, position of leaf, leaf shape and distance between leaf lobes. Low to high phenotypic diversity was exhibited among the germplasm accessions. The germplasm accessions produced 1 to 30 under ground tubers per plant. The main tuber length ranged from 5.4 to 66.4 cm and breadth from 2.5 to 15.5 cm. The germplasm accessions produced 0.51 kg to 16.45 kg tuber yield per plant. The maximum variability was found in tuber yield per plant (98.74%) and the minimum was found in leaf length (12.55%).The under ground tubers of yam were harvested and replanted at an interval of two to three years from 1995 at PGRC. The plants were grown on bamboo trail in the field genebank. Necessary intercultural operations are done for maintaining the yam germplasm accessions. DOI: http://dx.doi.org/10.3329/bjar.v36i4.11748 Bangladesh J. Agril. Res. 36(4): 605-621, December 2011

Potato (Solanum tuberosum) tuber, a swollen underground stem, is used as a model system for the study of dormancy release and sprouting. Natural dormancy release, at room temperature, is initiated by tuber apical bud meristem (TAB-meristem) sprouting characterized by apical dominance (AD). Dormancy is shortened by treatments such as bromoethane (BE), which mimics the phenotype of dormancy release in cold storage by inducing early sprouting of several buds simultaneously. We studied the mechanisms governing TAB-meristem dominance release. TAB-meristem decapitation resulted in the development of increasing numbers of axillary buds with time in storage, suggesting the need for autonomous dormancy release of each bud prior to control by the apical bud. Hallmarks of programmed cell death (PCD) were identified in the TAB-meristems during normal growth, and these were more extensive when AD was lost following either extended cold storage or BE treatment. Hallmarks included DNA fragmentation, induced gene expression of vacuolar processing enzyme1 (VPE1), and elevated VPE activity. VPE1 protein was semipurified from BE-treated apical buds, and its endogenous activity was fully inhibited by a cysteinyl aspartate-specific protease-1-specific inhibitor N-Acetyl-Tyr-Val-Ala-Asp-CHO (Ac-YVAD-CHO). Transmission electron microscopy further revealed PCD-related structural alterations in the TAB-meristem of BE-treated tubers: a knob-like body in the vacuole, development of cytoplasmic vesicles, and budding-like nuclear segmentations. Treatment of tubers with BE and then VPE inhibitor induced faster growth and recovered AD in detached and nondetached apical buds, respectively. We hypothesize that PCD occurrence is associated with the weakening of tuber AD, allowing early sprouting of mature lateral buds.

Mechanical control through different tillage methods is a common measure against perennial weeds. However, non-optimal tillage can potentially increase the vegetative regeneration instead of reduci...

A new anatomically preserved bennettitalean stem has been recovered from the Upper Cretaceous (Coniacian) Eden Main locality on Vancouver Island, British Columbia, Canada. The fossil, described as Saxicaulis meckertii gen. et sp. nov., is permineralized and consists of a eustelic stem with diverging nongirdling leaf traces, a narrow zone of dense wood, primary cortex, and adventitious roots. Important vegetative characters that differentiate bennettitalean stems from cycad stems are reviewed, and while the anatomy of the stem conforms to Bennettitales, it is not consistent with either the Williamsoniaceae or the Cycadeoidaceae as they are currently understood. This fossil documents greater structural diversity among Cretaceous bennettitaleans than previously known and tentatively documents an additional growth habit (underground stem). Co‐occurring fossils and plant structure suggest this plant may have inhabited an environment prone to fires. Additionally, there is evidence for two forms of plant‐animal ...

1. This account presents information on all aspects of the biology of Spiranthes spiralis (L.) Chevall. that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characteristics, herbivores and disease, history and conservation. 2. Spiranthes spiralis is a long-lived orchid species that is widely distributed in the southern part of the British Isles, southern Europe and the Mediterranean. It is native to Britain. Its most characteristic habitats are unimproved, well-grazed grasslands on dry calcareous soils, particularly chalk and limestone, cliff-tops and grassy coastal dunes. It can also be found in garden lawns and, less frequently, in slightly acidic heathland habitat. It occurs on both dry and wet soils, but it does not tolerate heavy shading. 3. Spiranthes spiralis is a non-bulbous geophyte regenerating by sexual reproduction and by vegetative spread, although the latter is limited. Vegetative reproduction involves the growth of a lateral bud on the underground stem. The new plant forms its own tubers, and eventually the connection between the mother plant and the vegetatively produced daughter plant withers away. 4. The main perennating organ is a tuberous root. In most years, the tuber generates a rosette of expanded leaves, and at the end of every year of the plant's life, the tuber is completely replaced. In some cases, however, only part of the reserves is exhausted in flowering and, when this happens, a tuber may survive for several years. Vegetative adult dormancy - the failure of above-ground parts to appear in a growing season, followed by reappearance of full-sized photosynthetic plants in subsequent seasons - has been observed. It most commonly lasts for only 1 year, but sometimes plants can remain dormant for several years. 5. The species is not autogamous and pollinators - mainly bumblebees and bees - are necessary for successful pollination and fruit set. Natural levels of fruit set are usually < 50%. Hand-pollination increases fruit set to c. 75%, indicating that reproduction is to some extent pollen-limited. Sexual reproduction comes at a cost, and few individuals flower for two or more consecutive years. Within fruits many very small seeds are produced, but most are dispersed to a distance of less than a few dm from maternal plants, leading to strongly aggregated distribution patterns and significant spatial genetic structuring within natural populations. 6. Spiranthes spiralis has suffered significant declines in distribution in Britain and other European countries. In Britain, populations were lost from many sites before 1930, when many pastures were re-sown or converted to arable land. Losses of populations due to agricultural intensification (ploughing of old fields and fertilization) still occur and are the major causes of the decline of the species. Conservation of remnant populations primarily requires the maintenance of a short turf by grazing, most often by sheep. Ideally, grazing should be suspended during flowering and seed set, allowing new recruits to become established and adult plants to flower profusely and to produce seeds.

New approaches to underground systems in Brazilian Smilax species (Smilacaceae). Scientific studies show that the watery extract of the thickened underground stem and its adventitious roots of the genus Smilax can act as a therapeutic agent in immunoinflammatory disorders, such as rheumatic arthritis. Brazilians have used this genus of plants in folk medicine, however it is very hard to identify these species, since the morphology of the underground systems is very similar in this group. For better identification of those systems, we studied six species of Smilax L. (S. brasiliensis, S. campestris, S. cissoides, S. goyazana, S. oblongifolia and S. rufescens), collected in different regions of Brazil with different physiognomies and soil characteristics. The main purpose is to describe the morpho-anatomy of the underground systems and to analyze if their structure depends on environmental conditions. The underground stem (rhizophore) is of brown color and it is knotty, massive, slender (S. rufesce...

This study was carried out with the objective of describing the aerial and underground organs of birdsfoot trefoil [Lotus corniculatus (São Gabriel and ARS-2620 cultivars)] and big trefoil [Lotus uliginosus (Maku cultivar)]. The plants were cultivated in pots and harvested at 150 and 210 days after sowing. Stems, leaves and roots were prepared in according to conventional anatomical techniques. The anatomical structures of L. corniculatus and L. uliginosus differed in terms of pith cell integrity, starch content in the parenchyma root cell and underground stem cortex. The leaves were amphistomatic, with phenolic idioblasts, small vascular bundles and few conducting elements. The underground system was diffuse, with adventitious shoots that grew in two directions, had no cataphylls, emerged from the ground, and gave rise to aerial stems. The morphological characteristics of the shoot system of both species matched the recent descriptions of soboles.

Alternanthera philoxeroides (Mart.) Griseb. is one of many aggressive invasive plants that can grow in diverse habitats. Aquatic A. philoxeroides forms dense floating mats over the water surface. However, when water levels decrease during winter, some mats become stranded on exposed sediments and are thus exposed to air. Do the stems of these mats possess the capacity to develop new shoots during the next growing season? In this study, we examined the sprouting of sediment-stranded over-wintering mats of A. philoxeroides. Stems of the over-wintering mats were divided into three types (dry, withered, and fresh stems) depending on moisture content and were immersed in water for 4 weeks to observe the sprouting of axillary buds and roots. The results showed that withered stems yielded much more biomass than dry or fresh stems. Stem moisture content significantly affected the sprouting rate and the length growth rate of buds and roots. Dry stems lacked reproductive capacity. The sprouting rate and length growth rate of the buds and roots were higher in fresh stems than in withered stems. Furthermore, the mean values of the bud sprouting rate and the bud length growth rate were highest during the first week, i.e., most of buds sprouted within 1 week or less. Our results suggest that more than 70% (on a dry weight basis) of the stems in stranded mats possessed rapid sprouting capacity even after over-wintering on the sediment for more than 2 months. This strategy may be an adaptation to the fluctuations inherent in many aquatic habitats, and it possibly explains why A. philoxeroides can flourish even after a dry winter.

This research was to study the capacity of cadmium removal from soil by sugarcane grown in pot experiment. The experiments were designed in a Factorial Randomized Complete Block Design with three replicates. The amounts of cadmium nitrate (Cd(NO 3 ) 2 .4H 2 O) added to the pot experiments were 0, 10, 20 and 40 mg Cd kg soil (dry weight). Sugarcane samples were harvested after two growth periods, three and six months. After harvesting, the canes were botanically separated into five parts: root, underground stem, bagasse, juice, and leave. The results showed that Cd uptake capacity from soil on experimental pot was 38.96 and 31.64 mg kg in treatment of 40 mg Cd kg, at three and six months, respectively. Accumulation of cadmium in various parts of sugarcane of experimental pot was the most accumulate in roots was 96.56 mg kg following by underground stem, bagasse, leaves and juice, at the sixth month. §” ”§—≠ : °“√¥Ÿ¥¥÷s ·§¥‡i’¬i OâO¬

Summary Parasitic plants of the Orobanchaceae are known as obligate root parasites that develop haustoria that connect to roots of various host plants. This article describes, for the first time, a case where the root parasite successfully connected to potato tubers, i.e. to the swollen portion of an underground stem rather than to a root. The rhizosphere of Orobanche aegyptiaca and of its host Solanum tuberosum (potato) was carefully examined. In anatomical studies, the adventitious roots were directly connected to potato tubers. Numerous secondary haustoria, which developed along the adventitious roots in close vicinity to the potato tuber, penetrated the tuber epidermis and the perimedullary tuber parenchyma and developed xylem strands that are presumably connected to the minor xylem strands within the tuber cortex. These findings indicate that parasites of the Orobanchaceae that normally attack host roots may also parasitise underground stem tubers.

The relative importance of sexual reproduction (seed) and sprouting as sources for regeneration in Brazilian Atlantic Forest was evaluated in three different successional forest stages: young forest, immature forest, and late-successional forest. Young plants (10–100 cm tall) of tree species were classified into the following categories: (1) seedlings that are nonsprouting—plants that originated through sexual reproduction as seeds; (2) stem base sprouting—plants that sprouted at the base of an existing plant; and (3) underground stem sprouting—plants that sprouted from subterranean stems of an existing plant. A total of 1,030 individuals of 48 species were collected. Underground stem sprouting is the rarest form of propagation, with stem base sprouting somewhat more common and possibly associated with recovery of damaged parts. The greatest contribution to regeneration was due to seeds: 92% of the individuals counted in 67% of the plant species. However, 13 species were ‘‘facultative’’ sprouters as seedlings and sprouters were observed in this group. The three forest ages differed in the proportion of regeneration strategies; in immature forest, sprouting was more common (15%) than in young (7%) and late-successional (3%; p < 0.05) forest. In these three forest stages, germinating seeds are the major source of new plants; although sprouting as a reproductive strategy is rare, it is related to recovery after damage of an already existing plant and may be due to previous land use history (agriculture) and low soil fertility. Restoration using natural regeneration should consider these factors to understand seed arrival as seed is the main source of regeneration.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:52:28Z No. of bitstreams: 1 S0100-84042006000400005.pdf: 2155588 bytes, checksum: c652f1ca025e62a95c56f39b8bd0d72c (MD5) Made available in DSpace on 2013-08-22T18:52:28Z (GMT). No. of bitstreams: 1 S0100-84042006000400005.pdf: 2155588 bytes, checksum: c652f1ca025e62a95c56f39b8bd0d72c (MD5) Previous issue date: 2006-12-01 Made available in DSpace on 2013-09-30T19:43:41Z (GMT). No. of bitstreams: 2 S0100-84042006000400005.pdf: 2155588 bytes, checksum: c652f1ca025e62a95c56f39b8bd0d72c (MD5) S0100-84042006000400005.pdf.txt: 49834 bytes, checksum: 851ccd477360e405c5a5f8ef8b31b690 (MD5) Previous issue date: 2006-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:11:26Z No. of bitstreams: 2 S0100-84042006000400005.pdf: 2155588 bytes, checksum: c652f1ca025e62a95c56f39b8bd0d72c (MD5) S0100-84042006000400005.pdf.txt: 49834 bytes, checksum: 851ccd477360e405c5a5f8ef8b31b690 (MD5) Made available in DSpace on 2014-05-20T15:11:26Z (GMT). No. of bitstreams: 2 S0100-84042006000400005.pdf: 2155588 bytes, checksum: c652f1ca025e62a95c56f39b8bd0d72c (MD5) S0100-84042006000400005.pdf.txt: 49834 bytes, checksum: 851ccd477360e405c5a5f8ef8b31b690 (MD5) Previous issue date: 2006-12-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Smilax polyantha Griseb., conhecida como salsaparrilha, é uma espécie reconhecida como medicinal, encontrada em áreas de cerrado, especialmente na região Sudeste. O objetivo desse estudo foi descrever a morfoanatomia dos órgãos vegetativos de Smilax polyantha e verificar se os caracteres descritos na Farmacopéia Brasileira de fato permitem diferenciar esta das demais espécies denominadas salsaparrilha. Amostras dos órgãos vegetativos foram preparadas segundo técnicas usuais em microscopia de luz e eletrônica de varredura. A folha é hipoestomática e os estômatos são paracíticos. O mesofilo tende a dorsiventral, pois o parênquima adaxial é constituído por células com sinuosidades pronunciadas. O pecíolo é canaliculado, sulcado na porção abaxial, indicando torção foliar. O ramo caulinar foi estudado na porção aérea e subterrânea diferindo apenas pelo espessamento da parede das células do parênquima vascular. O rizóforo é revestido pelo córtex; entre o córtex e o cilindro vascular há o meristema de espessamento secundário; o cilindro vascular é constituído de feixes colaterais cercados por células parenquimáticas com espessamento parietal secundário. O sistema radicular adventício fibroso possui raízes brancas tenras, revestidas pela epiderme e raízes marrons rígidas revestidas pelo córtex interno esclerificado, já que a epiderme e córtex externo são eliminados ao longo do desenvolvimento. Visto que as espécies brasileiras de salsaparrilha indicadas como medicinais na Farmacopéia Brasileira são identificadas através do modo como as raízes são amarradas em feixes, do diâmetro da raiz e da sua coloração, as análises nas raízes de S. polyantha mostraram que esses parâmetros são insuficientes para diferenciar as espécies do gênero Smilax. Smilax polyantha Griseb., known as salsaparrilha, is a medicinal plant, occurring in the cerrado, in the Southeast region in Brazil. The objective of this study was to describe the morphoanatomy of the vegetative organs of Smilax polyantha and to verify whether the characters described in the Brazilian Pharmacopoeia allow to differentiate between salsaparrilha species. Samples of the vegetative organs were prepared following usual techniques using light and scanning electron microscopy. The leaf is hypostomatic and the stomata are paracytic. Mesophyll tends to dorsiventral, as the three parenchyma layers near the adaxial surface are constituted by sinuous cells. Petiole is canaliculated in the adaxial face, and striated in the abaxial face, indicating leaf twist. The stem branch was studied in the aerial and underground portion differing only by the thickening degree of vascular parenchyma cell walls. The rhizophore coat is made by cortical parenchyma; between the cortex and the vascular cylinder there is a secondary thickening meristem; the vascular cylinder has collateral bundles surrounded by parenchyma cells with thick secondary walls. The adventitious radicular system possesses white fresh roots, covered by epidermis, with large cortex, and rigid brown roots, covered by the sclerenchymatous cells of inner cortex, because the epidermis and outer cortex are eliminated along the development. The S. polyantha root analysis had shown that the parameters described in the Brazilian Pharmacopoeia, which are based on the way the roots are tied in bundles, the diameter, and colour of the roots, are insufficient to differentiate the Smilax species. Universidade Estadual Paulista Instituto de Biociências Departamento de Botânica Universidade de São Paulo Escola Superior de Agricultura Luiz de Queiroz Departamento de Ciências Biológicas Universidade Estadual Paulista Instituto de Biociências Departamento de Botânica

Ginger root( Zingiber officinal Rose) was analysed to identify its nutritional and anti- nutritional contents. The results showed that Ginger has 34.13% crude protein, 4.07% Ether Extract, 4.02% crude fibre content, 13.75% moisture content, 7.64% Ash content and 1.036% vitamin C. Furthermore, ginger contains major minerals like: Zn 64.0 mg/l , Mn 5.90 mg/l, Fe 279.7 mg/l, Cu 8.80 mg/l, Ca 280.0 mg/l and P 8068.0 mg/l. The result obtained confirmed the usefulness of ginger root as a potential functional food and could be explored further in new product and formulation. I. Introduction Ginger (Zingiber officinal rose) is an underground stem or rhizome of the plant Zingiber officinate. It has ben used as traditional medicine in China, India, Malaysia and Arabic countries since ancient times. Ginger has been used to treat stomach upset, nausea, diarrhea, colic, arthritis, heart conditions, flu- like symptoms and painful menstral periods 1 . It was found that Ginger extracts have antimicrobial properties against E.Coli, sslmonella typhi and bacillus substilis that are common cause of gastro intestinal tract infections 2 . The important active component of ginger root is the volatile oil and pungent phenol compound such as gingerol, which is a very potent anti-inflammatory compound. Mordern scientific research has revealed that ginger possesses numerous therapeutic like anti-oxidant effects, an ability to inhibit the formation of inflammatory compounds and direct anti-inflammatory effects 3 . Ginger has aso been found to reduce all symptoms associated with motion sickness like dizziness, cold sweating, nausea and vomiting 4 .

The bark of the underground stem of Tontelea micrantha (Mart. ex. Schult.) A. C. Sm., a native Brazilian Cerrado species, is used in folk medicine for treating kidney ailments. The structures of the underground and the aerial stems were examined and their barks were analyzed for the presence of secondary metabolites. Bark fragments were processed according to conventional techniques in plant anatomy and their chemical compositions examined using histochemical and phytochemical tests, thin layer chromatography, and high-efficiency liquid chromatography. The underground stem is a sobol with unusual cambial activity. Laticifers that secrete terpenoids were present in the cortex and phloem of both organs and can contribute to the identification of the species in field. Druses were present in both barks, but mono-crystals were only observed in the sobol. Tannins, flavonoids, alkaloids, and terpenoids occurred in both types of bark, but carotenoids were only detected in the sobol. The similarities between these two organs indicate that the aerial stem bark has potential medicinal use and represents a plausible alternative to harvesting the sobol, which could contribute to the preservation of natural populations of this species. Tontelea micrantha (Mart. Ex. Schult.) A. C. Sm. é uma espécie nativa do Cerrado brasileiro cuja casca do caule subterrâneo é utilizada como medicinal no tratamento de doenças renais. As estruturas dos caules subterrâneo e aéreo foram estudadas e suas cascas avaliadas para a presença de classes de metabólitos secundários. Fragmentos das cascas foram processados de acordo com metodologias usuais em anatomia vegetal e submetidos às análises fitoquímicas colorimétricas, cromatografia em camada delgada e identificação química por cromatografia líquida de alta eficiência. O caule subterrâneo é um sóbole e apresenta atividade cambial não usual. Laticíferos que secretam terpenóides estavam presentes no córtex e floema de ambos os órgãos e podem contribuir para a identificação da espécie no campo. Drusas estão presentes em ambas as cascas, mas mono-cristais são observados apenas no sóbole. Taninos, flavonóides, alcalóides e terpenóides ocorrem em ambas as cascas, mas carotenóides são detectados apenas no sóbole. As semelhanças entre estes dois órgãos indicam que a casca do caule aéreo tem potencial para uso medicinal, representando uma alternativa plausível para o uso do sóbole, o que pode contribuir para a preservação de populações naturais da espécie.

A method has been developed for rapid multiplication of Curculigo orchioides (Hypoxidaceae) through direct organogenesis and bulbil formation in vitro. Leaf and underground stem explants produced maximum number of shoots (four and 10 per explant, respectively) on B5 medium supplemented with 4.4 μM BAP. Higher concentrations of BAP (≥22 μM) in the medium completely inhibited the growth and shoot proliferation from the leaf explants. Stem-disc-derived callus produced numerous bulbils on the medium containing BAP (8.8–35.2 μM) and sucrose (0.12–0.23 M). Maximum number of bulbils (10 per explant, 0.19 g fresh weight per bulbil) were recorded on the medium supplemented with 35.2 μM BAP and 0.18 M sucrose. Isolated bulbils increased in size (maximum growth index 36.4) and produced secondary bulbils on transfer to medium of the same composition. A maximum number of secondary bulbils (six per bulbil) were produced on the medium containing 35.2 μM BAP and 0.23 M sucrose. Growth of in vitro produced bulbils into plantlets and rhizogenesis from isolated shoots was achieved on the medium devoid of plant growth regulators. Small plantlets developed in vitro were successfully (90% survival) transferred to the soil. Plantlets sprouted in the next season (June 1997) after over-wintering.

Quantitative and qualitative data on wood and bark are offered for 11 species of lianoid Indomalesian and Asiatic species ofGnetumsectionCylindrostachys. Material of roots was studied for two species, material of an underground stem for one species, and stem material was studied for all species; wood from inside and outside of a large stem ofG. montanumwas analysed (quantitative data do not change with age in this species). Roots have shorter, narrower vessel elements, more numerous per mm2, compared with those of stems; these trends run counter to those in dicotyledons. Roots and underground stems have more abundant parenchyma and less abundant sclerenchyma than do stems. Parenchyma of both roots and stems is rich in starch. All of the species studied here have both fibre-tracheids and tracheids, but tracheids are not distributed vasicentrically as they are in dicotyledons. Tori are reported for tracheary elements of three species studied here. Vasicentric axial parenchyma (which usually is thick–walled) is present in all species; thick or thin-walled diffuse or diffuse-in-aggregates apotracheal parenchyma is present in almost all of the species studied. Rays are mostly dimorphic in size, but show various conditions with respect to wall thickness, sclerenchyma presence, and crystal presence. As in other lianoid species ofGnetum, the species of the present study show origin of lateral meristem activity in parenchyma of the innermost cortex. Cortex and bark of the species studied here are relatively uniform in distribution of gelatinous fibres, nests of sclereids, the cylinder of brachysclereids that extends around the stem, and sclerenchymatous phelloderm. Laticifers were observed in bark of only two species studied. Although a few species characters are evident, the species that comprise SectionCylindrostachysdiffer from each other mostly in degree rather than in presence or absence character state distributions. Secretory cavities are newly reported for the genus.

A new Cyperus (C. sharonensis) belonging to section Arenarii (Kunth) Jaub. et Spach basal, from the Sharon Plain of Israel, is described. It has a tuberous brachyblastic basal part terminating the underground stem, and scapous inflorescence on 70–130-cm-long leafless culm, and grows on shallow dunes of the coastal plain of northern Israel between Tel Aviv and the coast of Galilee. The leaves are wider and longer and the rhizome thicker than those of its few relatives which share the sandy habitats of coastal or desert areas of Israel. The longer nutlets, specific morphology of the nearly smooth surface, and roots that are not woolly, all differentiate the new species from its closest relative, C. capitatus Vandelli.

The effect of plant to plant variation and root size, weight, and location on storage root surface terpene chemistry of Centennial sweetpotato was investigated under field conditions. In plants grown in pots, the magnitude of the variation in concentration of boehmerol and boehmeryl acetate between plants in different pots, plants within pots, roots from a single plant, and location on individual roots was evaluated. Significant differences in boehmerol or boehmeryl acetate due to storage root location order along the axis of the underground stem were found for some individual plants, but the trend was not consistent among plants. A similar response was found for the distance down the underground stem at which the storage root was attached. Differences in surface chemistry between roots from a single plant appeared to be controlled by factors other than location along the main axis. Storage root length to diameter ratio accounted for 42% of the variation in boehmerol. The inverse of root density ...

L'Orobanche cumana Wallr., plante parasite racinaire, provoque de nombreux dégâts sur les cultures de tournesol (Helianthus annuus L.) dans toute l'Europe. Jusqu'à aujourd'hui, la seule méthode de lutte efficace reste l'utilisation de génotypes résistants. Cependant, les mécanismes de résistance à l'orobanche restent encore méconnus, bien que des études précédentes aient démontré l'existence de plusieurs mécanismes. L'étude de génotypes de tournesol sensible (2603) et résistant (LR1) en culture hydroponique a permis de mettre en évidence que la concentration du milieu de culture modifie le niveau d'infestation du tournesol par l'orobanche. Pour le génotype sensible (2603), le nombre de parasites nécrosés augmente avec la concentration du milieu de culture. Pour le génotype résistant (LR1), l'augmentation de la concentration du milieu de culture diminue l'infestation en diminuant le nombre d'orobanches fixées sur les racines et en limitant leur développement ultérieur. Lorsque l'on cultive les tournesols dans le milieu non dilué, l'allocation de radiocarbone dans la plante se modifie avec un accroissement de la force puits de l'apex caulinaire, alors que l'incorporation de 14C est réduite dans les orobanches. Notre étude démontre qu'en milieu contrôlé, la concentration en nutriments influe directement sur le potentiel de résistance du tournesol à l'orobanche.