The primary focus of both evolutionary and conservation biology is to have the knowledge of population genetic structure and consequently define its causes and consequences. The major determinants causing genetic variability in plant species are historical aspects, human activity, narrow habitat preferences, natural selection and gene flow among populations, drift, founder effects, geographical distribution and biological properties of a given species (especially mating system) (Karron et al. 1988; Case 1993; Case 1994; CHUNG 1994). The importance of these above mentioned factors differs between species and populations. In rare plants, such as orchids, population size and the problem of isolation are often very important in shaping the genetic structure of populations. It has been reported that species which are more continuously distributed experience more gene flow than species with discrete, isolated populations leading to relatively lower variation among the populations (Hamrick and Godt 1989; Ellstrand and Elam 1993; Chung 1996). Moreover, geographically restricted species generally have lower levels of genetic variation within populations (Loveless and Hamrick 1984; Karron 1987; Hamrick and Godt 1989) although some of them possess relatively high level of genetic variation (Gitzendanner and Soltis 2000). Dendrobium nobile Lindl., an epiphytic orchid has its distribution primarily in tropical and subtropical Asia (e.g. Northeast India, China, Japan, Malaysia, Philippines and Borneo) and North Australia usually growing at cooler climatic conditions at higher altitudes. Besides from horticultural significance, it has got a profound use in various herbal preparations. In Taiwan, its stem is used for treating night sweat, kidney... ... middle of paper ... ...t cortical neurons injured by oxygen-glucose deprivation and reperfusion. Phytomedicine 17:108–115. Xu F, Guo W, Xu W, Wang R (2008) HABITAT EFFECTS ON LEAF MORPHOLOGICAL PLASTICITY. Acta Biol Cracoviensia Ser Bot 50:19–26. Yang L, Qin L-H, Bligh SW, et al. (2006) A new phenanthrene with a spirolactone from< i> Dendrobium chrysanthum and its anti-inflammatory activities. Bioorg Med Chem 14:3496–3501. Yang LC, Deng H, Yi Y, et al. (2010) [Identification of medical Dendrobium herbs by ISSR marker]. Zhong yao cai= Zhongyaocai= J Chinese Med Mater 33:1841–1844. Yoon M-Y, Hwang J-H, Park J-H, et al. (2011) Neuroprotective effects of SG-168 against oxidative stress-induced apoptosis in PC12 cells. J Med Food 14:120–127. Zhao W, Ye Q, Tan X, et al. (2001) Three New Sesquiterpene Glycosides from Dendrobium n obile with Immunomodulatory Activity. J Nat Prod 64:1196–1200.
Some sources of error in my experiment can be found mainly in my research of the tropical trees. In the tropical zone and temperate zone, most trees were too tall to reach and examine their leaves. Furthermore, it was hard to get the entire tree within our pictures. Therefore, this caused little information about the large trees in the tropical zone, giving our information less variation. This error was also implemented throughout all the zones. Another source of error was with the light shining upon the leaves. During our experimentation, there were moments in time where the sun was hidden and the sun was shining brightly. Therefore, possibly affecting the color of our leaf color. The sunlight may cause our leaf to look lighter than they possibly are. This could cause false information to compare the leaf colors for each biome.
Carter, E., Theodorou, M., and Morris, P. 1997. Responses of lotus corniculatus to environmental Change I. effects of elevated CO2, temperature and drought on growth and plant development. New Phytologist. 136: 245-253.
Pat Willmer, Pollination and Floral Ecology (Princeton, New Jersey: Princeton University Press, 2011), 536.Dressler, L. Robert. The Orchids: Natural History and Classification. Cambridge, Massachusetts: Harvard University Press, 1981.
As a result of these factors, the flora has adapted to these conditions in a variety of ways including their shape, leaf type, root system, and color. One of the most prominent adapt...
When it comes to genetic diversity and migration, migration is known as the movement of genetic diversity within a species. Migration of genes not only happens in animals but also in plants through pollen dispersal, vegetative propagules like rhizomes and suckers among others. Migration or in other term gene flow, is said to take place both with the proceeding front of a population when it is colonizing new areas. This happens when genes of two or more populations mix through pollen and seed dispersal. In this case, migration rate is mainly related to the frequency of reproduction and the distance over which seeds and pollen usually disperse.
The communities of various native plants have been significantly minimized as a result of ...
Biodiversity is influenced by landscape fragmentation at various scales of space and time. The extinction of ecosystem types and component species may cause an increased patchiness of the landscape, resulting in lower population sizes and decreased connectivity. As a result, inhabitants may experience decreased dispersal abilities and lowered gene flows between populations.
Strychnine is a poisonous alkaloid, C21H22N2O2, obtained in colorless or white rhombic crystals. These have a bitter taste and melt at around 290( C (4 p.1). Alkaloids are any class of naturally occurring organic nitrogen containing bases, usually containing one or more of these nitrogen atoms in a ring of atoms called a cyclic system. Alkaloids are primarily found in plants and are predominant in flowering plant species. The function of alkaloids in plants is thought to be simply a waste product of the plants metabolic processes, but current research may suggest a specific biological function. This is evident in some plants as the levels of alkaloid increase just prior to seed formation and then drops off after the seed is ripe. This evidence suggests possible mechanisms of maturation and possible defense, against certain insect species (5 p.2). Strychnine, being an alkaloid, is slightly soluble in water, but is more soluble in alcohol and is released from its salts by alkalis. Many of the commercial alkaloids are found in the genus Strychnos.
7. Stevens, J., et al. Chemistry and biology of hop flavonoids. J. Am. Soc. Brew. Chem.
It is known that one of the active constituents of the medicinal plant Couroupita guianensis, namely isatin, is known to exert cytotoxic activity against certain cancer cell lines, being a potential source of new chemotherapeutic agents (Gousia et al., 2013). Isatin is an endogenous compound identified in humans. Biological properties of isatin include the brain and offer protection against certain types of infections. Isatin constitutes an important class of bioactive compounds exhibiting caspase inhibitor, antibacterial and antiproliferative activity (Kiran et al., 2013).
Kuddus , Mohammed, Ibrahim A. M. Ginawi, and Awdah Al-Hazimi. “Cannabis sativa: An Ancient Wild Edible Plant of India.” Emirates Journal of Food & Agriculture 25.10 (2013) : 736-745. Print.
Summary: Herbs have been used for centuries in medical history containing their names and the benefits of the plants being used more than its beauty. Plants are prime targets in making new clinical trials with their bioactive components. Valerian also known as, Valeriana Officinalis, is a perennial plant native to Europe and Asia and naturalized in the United States. It has a distinctive odor that many find unpleasant [2,3]. Other names include setwall (English), Valerianae radix (Latin), Baldrianwurzel (German), and phu (Greek). The genus Valerian includes over 250 species, but V. officinalis is the species most often used in the United States and Europe and is the only species discussed in this fact sheet (Health Professions 2013). In addition, the Valerian genome-sequencing project (VBGP) will benefit medicine in human health in understanding why certain sequences in plants help people’s pains and disorders. Valerian contains many biological activities derived from a larger chemical known as sesquiterpenes. Joe Chappell professor of plant chemistry at the University of Kentucky says ““Chemicals like you find in Valeriana, especially the sesquiterpene molecules, have represented a conceptual challenge ... because they’re very
Common names for Datura are numerous, some of the most common ones being raving nightshade, thorn apple, stinkweed, Devil's apple, Jimson weed, and angel's trumpet (Heiser 1969:140 and Avery 1959:19). Datura can be found throughout Asia, Europe, and the Americas as either native or adventive plants, and some have also been found in Africa and Australia (Conklin 1976:5). The epicenter of diversity of this plant is in the New World, specifically in Andean South America and in the southwestern United States/Mexico region (Lewis 1977:423-4). This data correlates with the generally agreed upon origin of Datura, although this topic was debated for some time. Researchers now believe the plant originated and evolved in Mexico and the American Southwest, followed by adaptive radiation into new desert environments (Conklin 1976:5).
...mpounds in Dendrobium plants include a group of sesquiterpene alkaloids and phenols (Okomoto et al., 1966; Elander et al., 1973; Tang and Eisenbrand, 1992). Moscatilin (Fig. 1) is a bibenzyl phenol derived from Dendrobium species. It is also known as dendrophenol, Phenol, 4-(2-(4-hydroxy-3-methoxyphenyl) ethyl)-2,6-dimethoxy-. In the year 1987, moscatilin was first extracted from Dendrobium moscatum (Mazumdar and Sen, 1987) and it was later isolated from several other species such as Dendrobium loddigesii (Chen et al., 1994), Dendrobium amoenum (Mazumdar et al., 1999), Dendrobium nobile (Miyazawa et al., 1999), Dendrobium densiflorum (Fan et al., 2001), Cymbidium aloifolium (Juneja et al., 1987) and Agrostophyllum khasiyanum (Mazumdar et al., 1996). Studies have proved the anti-cancer activity of moscatilin in stomach and lung cancer cell lines (Ho et al., 2003).
Dandelions grow in our backyards every year, but all we see are small yellow weeds that take control of the grass and cause a nuisance. What many are unaware of is their actual uses and how helpful they were throughout history. Dandelion is grown in Europe, Asia, North America, and South America. It grows in many places such as in gardens, on mountains, and it is sometimes found in some health food markets, or as a freeze-dried herb. Part of the reason they grow in many places is because they aren’t very picky. They grow in sunlight or shade, and will accept most climates even though they prefer to be grown in warmer climates. However, they will not tolerate a hot-dry wind, meaning that they need protection in harsh, hot climates, or they can grow poorly which can affect its taste. Dandelions are harvested for best results in the middle of spring and sometimes the summer. What is unique about dandelions is that they have a very deep root which stay alive and spread during the winter. We wouldn’t know as much about the weed without knowing its history.