August 23, 2007, 10:20 PM CT

Emphasis on conifer forests places multiple species at risk

CORVALLIS, Ore. The traditional emphasis on dense, fast-growing, conifer-dominated forests in the Pacific Northwest raises questions about the health of dozens of animal species that depend on shrubs, herbs and broad-leaf trees, a new analysis by Oregon State University and the U.S. Geological Survey suggests.

At least 78 vertebrate species have been documented that require, in one way or another, the food or habitat provided by non-coniferous vegetation, and may be at increasing risk whenever forest management reduces the prevalence of these shrubs or trees, or specifically targets them for removal.

Wildlife species that depend on the resources provided by non-coniferous vegetation may not persist in forests where these components are scarce, the report said.

The study was just published in Forest Ecology and Management, by Joan Hagar, an affiliate faculty member of the Department of Forest Science at Oregon State University, and a wildlife biologist with the Forest and Rangeland Ecosystem Science Center of the U.S. Geological Survey, which funded the study.

Natural forests of the Pacific Northwest, Hagar said, have always been dominated by conifers. But they also provided a continuity of trees that are young and old, short and tall; diverse shrubs, particularly in the early stages of forest re-growth; gaps, snags and cavities; often a dozen or more hardwood tree species; and possibly hundreds of grass and herbacious plant species......... Posted by: Erica      Read more         Source

Tue, 21 Aug 2007 03:23:04 GMT

Momordica charantia hybrid

I couldn't resist highlighting a photograph (original via BPotD Flickr Group Pool) from the recent additions to Eric in SF@Flickr's From the Earth photo set – if you're a fan of colour and patterns, the photographs are a must-see. Thanks once again, Eric!

As Eric points out, the Wikipedia entry on bitter melon is a good starting point to learn more about this widely-grown vegetable, as it describes the plant, highlights the culinary and medicinal uses and provides common names in two dozen languages. From the common names, it is easily inferred that it is cultivated pantropically (though African common names are absent). Flora Zambesiaca, though not providing any African common names, provides the best scientific description of the plant, though: Momordica charantia.

An image search for Momordica charantia reveals a diversity of form for this vegetable (and this stamp with an illustration of the ripe fruit from the Cucurbit Network). I think the hybrid in today's photograph is one of the Indian cultivars. As always, though, I'm open to being corrected.

If you're going to search for more information on bitter melon, you'll find the search engine results cluttered with various medicinal claims, particularly in regard to diabetes. Do note that in Bitter melon (Momordica charantia): A review of efficacy and safety, Basch et al. conclude “Bitter melon may have hypoglycemic effects, but data are not sufficient to recommend its use in the absence of careful supervision and monitoring” (American Journal of Health-System Pharmacy. 60(4):356-359).

Entomology / art resource link: Trichopterae, “an unusual artistic collaboration between the French artist Hubert Duprat and a group of caddis fly larvae” in Cabinet Magazine. Posted by: Daniel Mosquin      Read more     Source

August 16, 2007, 8:53 PM CT

Ginkgo: Tools for product analysis or quality

The National Institute of Standards and Technology (NIST) has issued a suite of Standard Reference Materials (SRMs) for ginkgo biloba, one of the most popular dietary supplements in the marketplace, with annual worldwide sales estimated at $1 billion.

The NIST reference materials are designed to help scientists validate the accuracy of analytical methods for flavonoids and terpene lactones (plant constituents that may be linked to the perceived effectiveness of ginkgo) as well as toxic elements in ginkgo*. In addition to supporting measurements linked to clinical trials or verifying product label claims, the reference materials also can be used by dietary supplement manufacturers to improve product consistency.

The fruits and seeds of the female ginkgo are used for a variety of purposes in traditional Chinese medicine. In the West, dietary supplements are more usually formulated from ginkgo leaves and standardized leaf extracts. They are used in the therapy of asthma, bronchitis, fatigue and tinnitus (ringing in the ears); for memory improvement and for the prevention and therapy of Alzheimers disease, eventhough these uses have not been backed by rigorous clinical trials. Ginkgo biloba contains a family of chemical constituents known as ginkgolides which have been linked to reduced platelet aggregation. The National Institute of Healths (NIH) National Center for Complementary and Alternative Medicine (NCCAM) notes promising results in many areas, but says larger, well-designed research studies are needed......... Posted by: Erica      Read more         Source

August 15, 2007, 9:13 PM CT

First all-African GM crop is resistant to maize streak virus

The first all-African genetically modified crop plant with resistance to the severe maize streak virus (MSV), which seriously reduces the continents maize yield, has been developed by researchers from the University of Cape Town and PANNAR PTY Ltd, a South African seed company. The research, published in Plant Biotechnology Journal represents a significant advance in African agricultural biotechnology, and will play an important role in alleviating Africas food shortages and famine.

Dr Dionne Shepherd, lead researcher explains, MSV is transmitted to maize by small insects called leafhoppers. The disease is therefore a result of a complex interplay between the plant, the virus and insect. Factors that can influence the severity of the disease include the age at which the plant is infected (the younger the plant, the more severe the infection), the maize variety (some are more susceptible than others), and environmental conditions.

We have created an MSV-resistant maize variety by genetic engineering, using an approach known as pathogen-derived resistance. This means that a gene from the viral pathogen is used to protect the plant from that pathogen. We mutated a viral gene that under normal circumstances produces a protein that is essential for the virus to replicate itself and inserted it into the maize plants genome, creating genetically modified maize. When the virus infects one of these transgenic maize plants, it displays a significant delay in symptom development, a decrease in symptom severity and higher survival rates than non-transgenic plants......... Posted by: Erica      Read more         Source

August 15, 2007, 8:19 PM CT

Humans fostering forest-destroying disease

Enjoying your August vacation? Well, (as they say in the summer movies) theres a killer in the woods. Its strike has been consistently quiet, sudden, and deadly. Unknowingly, we have all been playing into its hands But put down that rock -- you personally are not in any danger. Its the woods themselves that are getting axed and you may be an accomplice.

Melodrama aside, the threat is very serious the killer is an invasive, forest-destroying plant disease known as Sudden Oak Death. Caused by an (apparently) non-native water mold (Phytophthora ramorum), the disease affects a broad range of woody plants, and is especially lethal to our native oaks. In the last few years, it has infected and killed large stands of western oaks with alarming suddenness (hence the name). From its initial California appearance sometime in the mid-1990s, the disease has been spreading rapidly, changing the landscape as it goes.

People tend to not care about plants and forests as much as we do about humans and animals, but sudden oak death could be a bird flu of the plant world waiting to happen, said Ross Meentemeyer, a landscape ecologist at the University of North Carolina at Charlotte. This may be even worse than chestnut blight in its impact on our forests, since it is affecting multiple keystone species......... Posted by: Erica      Read more         Source

August 7, 2007, 10:30 PM CT

tracing genetic history of coconut

The coconut has been popular in lore and on palates for centuries, yet little is known about the history of coconut's domestication and dispersal around the world.

Now, a biologist at Washington University in St. Louis is embarking on the task of understanding the plant's history by exploring the genetics of the coconut (Cocos nucifera L.).

Kenneth Olsen, Ph.D., Washington University assistant professor of biology in Arts & Sciences, has received a $20,000 grant from the National Geographic Society to study the DNA of the plant, which can be used to infer historical relationships among populations. The work will be done in collaboration with Bee Gunn, a research specialist at the Missouri Botanical Garden.

"The coconut played a crucial role in the history of human exploration and dispersal across the tropics, and it continues to play a fundamental role in human societies today," said Olsen. "As a portable source of nutrition and water, the coconut was critical for humans to be able to voyage, establish trade routes, and colonize lands in the Pacific Rim, coastal India, Africa and South America.

"Our preliminary DNA sequence data show genetic variation within the coconut, and this is key to delineating historical relationships among different populations......... Posted by: Erica      Read more         Source

August 1, 2007, 9:28 PM CT

Plants and stress

Our crops are not doing well these days: too much water, too little sunlight. In short, they are suffering from stress. Researchers from VIB, linked to the Katholieke Universiteit Leuven (K.U.Leuven), have revealed a new mechanism demonstrating the intricate ways in which plants deal with stress. The newly discovered control system has a remarkable way of orchestrating the activity of hundreds of genes, forcing the plant into safety mode; the consumption of energy is contained while the organism is stimulated to mobilize reserves. This may have a negative impact on growth, but it allows the plant to temporarily safeguard itself against pernicious stress conditions. These findings also may prove to be useful beyond the case of plants, for the results are likely to be valuable in understanding disorders such as cancer and diabetes.



Life thanks to plants

Plants catch sunlight and use it as an energy source to produce sugars from CO2 and water. In doing so, they are at the very basis of the food chain. Ultimately, all life on earth depends upon this biochemical process: photosynthesis. Without plants, life as we know it today would simply not be possible. But what if things go wrong" When there is too little sunlight, for example" And what with other stressful conditions for plants" Environmental changes can compromise photosynthesis and exhaust energy supplies......... Posted by: Erica      Read more         Source

Fri, 27 Jul 2007 01:13:58 GMT

Rubus Tayberry Group

Following the convention of the Royal Horticultural Society, I've used the name Rubus Tayberry Group for this hybrid. The original tayberry, a cross between the early-ripening Rubus 'Aurora' (a blackberry) and a large-fruited tetraploid raspberry (tetraploids have 4 sets of chromosomes instead of the usual two and tend to be more robust), was hybridized at the Scottish Crops Research Institute in Invergowrie, Scotland (sources: Plants for a Future and Wikipedia). In efforts to improve it (e.g., a longer fruiting season or improving hardiness or thornlessness), other plant breeders would attempt similar crosses but with slight variations (e.g., a different blackberry cultivar as one parent) — the end results would be something closely resembling the original tayberry, but genetically different. Since a cultivar name should, in theory, represent only one distinct genotype, a different naming convention is required when an aggregate of (often) closely-related genotypes are known to exist, though it may be exceedingly difficult to tell them apart. Hence, Tayberry Group. Similar examples include Colorado blue spruce (Picea pungens Glauca Group), purple New Zealand flax (Phormium tenax Purpureum Group) and pendulous ginkgo (Ginkgo biloba Pendula Group).

The Oregon Raspberry and Blackberry Commission describes the flavour of tayberry as clean, tangy and tart. I find them to have a slight overtone of soap which isn't altogether pleasant, but perhaps that's just me. Posted by: Daniel Mosquin      Read more     Source

Tue, 24 Jul 2007 19:44:19 GMT

Dierama galpinii

I think this is the first plant on BPotD named after a banker; Ernest Galpin (also see Wikipedia) was a South African born banker who had a life-long interest in plants due to his mother's influence. Dierama galpinii is actually one of several species named in honour of this meticulous collector of South African flora. In fact, two genera are named in relation to him: Galpinia and Mosdenia (named after his farm!).

Dierama galpinii is one of the later-flowering African harebells or fairywands (Dierama pulcherrimum is long-finished). The appearance of the flowers seems to coincide with the African section of the alpine garden starting to decline from the peak colour display of only a week ago. Posted by: Daniel Mosquin      Read more     Source

Tue, 24 Jul 2007 09:22:09 GMT

Proboscidea louisianica subsp. fragrans

Today's image is again courtesy of our “BPotD correspondent in Mexico”, David Tarrant.

This plant was growing along the roadside in the freshly disturbed earth near a building site, a typical locale for this plant of weedy areas, cattle pens and other degraded sites in Texas and Mexico. In Mexico, the common name is toritos or “little bulls”, while in Texas it is variously known as unicorn plant, common devil's claw, ram's horn, cow-catcher or mule-grab. Some common names refer to the paired upright bractlets that subtend the flower, while others refer to the fruit (a series of images including dried fruit and flowers can be seen here, but the site is only working intermittently this morning).

The Plants For a Future database provides references on the human uses of the fruits, including food (when immature), ornamentation, and sewing withes (for the latter, also see the section on “Coiled Baskets for Household Use” in By the Prophet of the Earth: Ethnobotany of the Pima). Posted by: Daniel Mosquin      Read more     Source