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Marler T.E.,Pacific Western University | Lindstrom A.J.,Nong Nooch Tropical Botanical Garden
Communicative and Integrative Biology | Year: 2015

Cycad biology, ecology, and horticulture decisions are not supported by adequate research, and experiments in cycad physiology in particular have been deficient. Our recent report on free sugar content in a range of cycad taxa and tissues sets the stage for developing continued carbohydrate research. Growth and development of cycad pollen, mediation of the herbivory traits of specialist pollinators, and support of expensive strobilus behavioral traits are areas of cycad pollination biology that would benefit from a greater understanding of the role of carbohydrate relations. © Thomas E Marler and Anders J Lindstrom.

Marler T.E.,Pacific Western University | Lindstrom A.J.,Nong Nooch Tropical Botanical Garden
Frontiers in Plant Science | Year: 2014

The sugars fructose, glucose, maltose, and sucrose were quantified in seven tissues of Zamia muricata Willd. to determine their distribution throughout various organs of a model cycad species, and in lateral structural roots of 18 cycad species to determine the variation in sugar concentration and composition among species representing every cycad genus. Taproot and lateral structural roots contained more sugars than leaf, stem, female strobilus, or coralloid roots. For example, taproot sugar concentration was 6.4-fold greater than stem sugar concentration. The dominant root sugars were glucose and fructose, and the only detected stem sugar was sucrose. Sucrose also dominated the sugar profile for leaflet and coralloid root tissue, and fructose was the dominant sugar in female strobilus tissue. Maltose was a minor constituent of taproot, leaflet, and female strobilus tissue, but absent in other tissues. The concentration of total free sugars and each of the four sugars did not differ among genera or families. Stoichiometric relationships among the sugars, such as the quotient hexoses/disaccharides, differed among organs and families. Although anecdotal reports on cycad starch have been abundant due to its historical use as human food and the voluminous medical research invested into cycad neurotoxins, this is the first report on the sugar component of the non-structural carbohydrate profile of cycads. Fructose, glucose, and sucrose are abundant in cycad tissues, with their relative abundance highly contrasting among organs. Their importance as forms of carbon storage, messengers of information, or regulators of cycad metabolism have not been determined to date. © 2014 Marler and Lindström.

Chen J.,CAS South China Botanical Garden | Lindstrom A.J.,Nong Nooch Tropical Botanical Garden | Xia N.-H.,CAS South China Botanical Garden
Phytotaxa | Year: 2015

Curcuma woodii, a new species of Curcuma subg. Ecomata (Zingiberaceae) from Thailand is described and illustrated here. It differs from C. rhomba by the leaf blades abaxially pubescent, the bracts whitish green, the labellum white with orange bands at the center, the lateral staminodes white with orange dots at the apex, and the ovary nearly glabrous. © 2015 Magnolia Press.

Liu J.,CAS Kunming Institute of Botany | Liu J.,University of Chinese Academy of Sciences | Lindstrom A.J.,Nong Nooch Tropical Botanical Garden | Gong X.,CAS Kunming Institute of Botany
Phytotaxa | Year: 2016

Cycas hongheensis was firstly proposed as a distinct taxon in 1994 and formally described two years later based on vegetative materials only. Here, the reproductive organs of this species, namely, the female cone, male cone and seeds are supplemented for description as these fertile materials were found for the first time at the type locality. Furthermore, the phylogenetic position of this species as being the only endemic member of Cycas sect. Indosinenses in China was investigated. The conflicting phylogenic results between chloroplastic (cpDNA) and nuclear DNA (nDNA) are corresponded with the inconformity characters of morphology of this species. The characters of lacking indumentum on ovules and the distinct apical spine of megasporophyll are corresponding to nDNA result while the characters such as the soft and rudimentary apical spine of the microsporophyll and the absence of fibrous layer inside the sarcotesta comform to cpDNA result. For the taxonomy, we agree this species to be classified into Cycas sect. Indosinenses for the obvious morphological characters of megasporophyll and ovule as well as deeper evidence from phylogeny based on nuclear data, as biparental inherited nuclear genes could offer more comprehensive genetic information than maternal inherited cpDNA. © 2016 Magnolia Press.

Sangin P.,Kasetsart University | Lindstrom A.J.,Nong Nooch Tropical Botanical Garden | Kokubugata G.,National Museum of Nature and Science | Chaiprasongsuk M.,Kasetsart University | Mingmuang M.,Kasetsart University
Kasetsart Journal - Natural Science | Year: 2010

The intrageneric relationships among 24 species of five Cycas sections based on the combined data of three non-coding regions of chloroplast DNA: trnS-trnG, psbM-trnD and trnh-trnF, were determined using Neighbor-joining, Maximum parsimony and Maximum likelihood methods. All three methods showed similar topology, which divided Cycas into several clades. The first clade consisted of two sections, Cycas and Indosinenses, while the other clades contained Asiorientales, Wadeanae and Stangerioides, which could not be resolved. This result indicated the polyphyletic group of Cycas sections. Base substitution patterns further revealed that the subsection Rumphiae of the section Cycas could be separated into two groups (C. rumphii and C. edentata). In addition, the high bootstrap demonstrated that C. taitungensis was closely related to C. revotuta, while two other species of the section Wadeanae (C. wadei and C. curranii) were closely related, which agreed with the morphology. Data analyses suggested that the trnS-trnG sequences were more informative than the psbM-trnD and trnh-trnF regions in addressing phylogeny. Short and moderate repeated sequences detected in this region also indicated the high rate of evolution in the Cycas species. The 14 bp tandem repeats identified in this study are the first to be reported on the non-coding chloroplast DNA of Cycas.

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