November 5, 2009, 8:42 AM CT

Making better broccoli

Carotenoidsfat-soluble plant compounds found in some vegetablesare essential to the human diet and reportedly offer important health benefits to consumers. Plant carotenoids are the most important source of vitamin A in the human diet; the carotenoids lutein and zeaxanthin, found in corn and leafy greens vegetable such as kale, broccoli, and spinach, are widely considered to be valuable antioxidants capable of protecting humans from chronic diseases including age-related macular degeneration, cancer, and cardiovascular disease.

Vegetables in the cabbage family (such as kale, cauliflower, and broccoli) have long been known as particularly good sources of dietary carotenoids. Recently, broccoli has emerged as the stand-out member of the species, providing more carotenoids to American consumers than any of its cabbage-family relatives. Yet, little has been understood about the carotenoid make-up of this popular green vegetableuntil now.

Mark W. Farnham of the U.S. Department of Agriculture, Agricultural Research Service, Charleston, South Carolina, and Dean A. Kopsell from the Plant Sciences Department, University of Tennessee, Knoxville, designed a research study aimed at finding out more about the carotenoid content of field-grown broccoli and determining the effects of genetics and the environment on carotenoid levels. The duo's research confirmed that broccoli heads contain abundant levels of lutein, an antioxidant usually thought to provide nutritional support to eyes and skin. Other carotenoids like beta-carotene, violaxanthin, neoxanthin, and antheraxanthin were also found in broccoli heads, but lutein was clearly the most significant, accounting for about half of all carotenoids measured......... Posted by: Erica      Read more         Source

November 5, 2009, 8:39 AM CT

Indoor plants to fight air pollution

Air quality in homes, offices, and other indoor spaces is becoming a major health concern, especially in developed countries where people often spend more than 90% of their time indoors. Surprisingly, indoor air has been reported to be as much as 12 times more polluted than outdoor air in some areas. Indoor air pollutants emanate from paints, varnishes, adhesives, furnishings, clothing, solvents, building materials, and even tap water. A long list of volatile organic compounds, or VOCs [including benzene, xylene, hexane, heptane, octane, decane, trichloroethylene (TCE), and methylene chloride], have been shown to cause illnesses in people who are exposed to the compounds in indoor spaces. Acute illnesses like asthma and nausea and chronic diseases including cancer, neurologic, reproductive, developmental, and respiratory disorders are all associated with exposure to VOCs. Harmful indoor pollutants represent a serious health problem that is responsible for more than 1.6 million deaths each year, as per a 2002 World Health Organization report.

Stanley J. Kays, Department of Horticulture, University of Georgia, was the lead researcher of a study published in HortScience that tested ornamental indoor plants for their ability to remove harmful VOCs from indoor air. As per Kays, some indoor plants have the ability to effectively remove harmful VOCs from the air, and not only have the ability to improve our physical health, but also have been shown to enhance our psychological health. Adding these plants to indoor spaces can reduce stress, increase task performance, and reduce symptoms of ill health......... Posted by: Erica      Read more         Source

November 5, 2009, 8:37 AM CT

Seeking flower variety

Florists and other retailers who sell flowers and plants can now add another tool to their marketing kit. A recent study of "consumption values" may help them understand what influences consumers' choices in regard to floral purchases, and how to better design marketing efforts and purchase stock that can increase customers and sales.

Li-Chun Huang from National Taiwan University and Tzu-Fang Yeh from Da-Yeh University headed a research project that reviewed the differences in floral consumption values across consumer groups (the full study appears in a recent issue of HortTechnology).

A consumer survey was conducted in cities and rural areas in Taiwan in 2006 where 677 participants were surveyed. As per responses to a survey question that asked whether they purchased flowers, participants were divided into two categories: ''users'' and ''nonusers'' of flowers.

The majority of survey participants indicated that the following values (in descending order) influenced their floral purchases: showing care to others, emotion conditioning, and "sensory hedonics", a phenomenon in which consumers perceive the value of flowers based on touching, smelling, or tasting them. Interestingly, those participants identified as "heavy users" of flowers revealed different priorities, rating "emotion conditioning" as more important than "showing care to others". The scientists note that this implies that "heavy users" make more frequent floral purchase flowers partly because they are more emotionally stimulated by flowers. Heavy users also rated "curiosity fulfillment" higher, leading to them to look for more novelty and variety when purchasing flowers......... Posted by: Erica      Read more         Source

November 4, 2009, 8:19 AM CT

Sustainably grown garlic

Consumer interest in new and diverse types of garlic is on the rise. Fueled by factors including the growth of the "local foods" movement, interest in world cuisines, and widespread reports touting its numerous health benefits, demand for high-quality, locally grown garlic is increasing throughout the U.S.

While most grocery stores in carry the familiar white, "softneck" garlic (which is most often imported), varieties of "hardneck" garlic in colorful hues of purple, magenta, pink, and white are becoming more available at local vegetable stands and through direct-marketing programs. The results of a recent study of 10 garlic cultivars can help farmers identify niche regional markets and offer new, in-demand garlic varieties to consumers.

Hundreds of garlic (Allium sativum L.) cultivars are available from seed companies, retailers, and germplasm collections. Increasingly, growers purchase bulbs from nonlocal sources and are often disappointed by unpredictable yields. Garlic bulbs resulting from seed stock purchased in other regions may not display the characteristicssuch as bulb size, shape, and colorfeatured in the catalogs.

Gayle M. Volk of the National Center for Genetic Resources Preservation, U.S. Department of Agriculture's Agricultural Research Service in Fort Collins, and David Stern of the Garlic Seed Foundation authored a study designed to determine which garlic traits are stable and which traits vary depending on where the garlic is grown. As per the study published in a recent issue of HortScience and funded primarily by the Northeast Sustainable Agricultural Research and Education program, previous research has shown that traits such as clove number, clove skin coloration, and topset number are representative of cultivar type across growth locations, whereas "phenotypic" traits such as bulb wrapper color, bulb size, and bulb elemental composition are specific to sites......... Posted by: Erica      Read more         Source

November 4, 2009, 8:16 AM CT

Pecan trees benefit from thinning

Pecan trees, like many fruit trees, have a tendency to bear fruit in cycles, producing a large crop in one or two years, followed by one or two years with little or no crop. This cycle, called "alternate bearing", is the most profit-limiting biological problem facing pecan producers; the inconsistent production pattern creates supply and marketing challenges that can have severe negative effects on the pecan industry.

Producers have experienced success using mechanical fruit thinning as a way to minimize the effects of alternate bearing on several pecan cultivars. While the protocol for mechanical crop thinning has been established for some pecan cultivars grown in Oklahoma and Kansas, little research has been conducted regarding the economic value and potential profitability of fruit thinning of cultivars found in the southeastern United States. To address this issue, researchers at the University of Georgia's Department of Horticulture studied the effects of mechanical fruit thinning on pecan yield, nut quality, and profitability using 'Sumner' and 'Cape Fear' pecan trees, two important cultivars prevalent in areas of the southeastern U.S. The research study was published in a recent issue of HortTechnology

Ten 20-year-old trees of both 'Sumner' and 'Cape Fear' were used for the study. Trees grown in Tifton loamy sand soil in a commercial pecan orchard in Irwin County, Georgia, were used for the study. The trees were spaced 40 x 40 feet and were drip-irrigated. Treatments were replicated five times in a randomized complete-block design. Five trees of each cultivar were mechanically thinned using a tree shaker with a hydraulic shaker heada process called trunk shakingto remove 30% to 40% of the fruit on each tree, and five trees were not thinned......... Posted by: Erica      Read more         Source

November 4, 2009, 8:15 AM CT

For African violets

African violets have a mixed reputation. Their delicate, colorful flowers and furry, soft leaves make them a favorite among home gardeners and growers. But the striking plants are often regarded as temperamental: a precise recipe of light, moisture, warm temperatures, high humidity, and fertilizer is mandatory to encourage african violets to grow and flower.

A recently published study by researchers Julia C. Brotton and Janet C. Cole from the Department of Horticulture and Landscape Architecture at Oklahoma State University (in a recent issue of HortTechnology) could provide african violet enthusiasts with important care information about the finicky flower.

Because of their brightly colored flowers and hairy leaves, people are attracted to african violets and often want to touch the leaves and flowers. But how does all this attention affect the plants? The research team set out to determine the effect of "brushing" african violet leaves on plant growth and quality. Cole explained, "Because (african violet) growers work in conditions that can contribute to the development of dry, irritated skin, a number of growers use body lotions to help soothe and moisturize their dry skin. A number of consumers also use these products. Our study researched whether touching or "brushing" african violet leaves causes damage, especially when body lotion or other skin care products have been applied to hands before touching the plants"......... Posted by: Erica      Read more         Source

October 20, 2009, 10:19 PM CT

New method to help keep fruit and vegetables fresh

ATLANTA Did you know that millions of tons of fruits and vegetables in the United States end up in the trash can before being eaten, as per the U.S. Department of Agriculture?

A Georgia State University professor has developed an innovative new way to keep produce and flowers fresh for longer periods of time.

Microbiologist George Pierce's method uses a naturally occurring microorganism no larger than the width of a human hair to induce enzymes that extend the ripening time of fruits and vegetables, and keeps the blooms of flowers fresh. The process does not involve genetic engineering or pathogens, but involves microorganisms known to be linked to plants, and are considered to be helpful and beneficial to them.

"These beneficial soil microorganisms serve essentially the same function as eating yogurt as a probiotic to have beneficial organisms living in the gastrointestinal system," Pierce said.

The process works by manipulating the organism's diet so that it will over express certain enzymes and activities that work in the ripening process and keeping the flower blooms fresh. Pierce analogizes this to using diet and exercise to improve the performance of an athlete.

"We change the diet of the organism, and we can change its performance," Pierce said. "It's no different than taking a good athlete and putting them on a diet and exercise regime, and turning him or her into a world-class athlete"......... Posted by: Erica      Read more         Source

October 20, 2009, 8:48 AM CT

Carbon-offsetting and conservation

Logged rainforests can support as much plant, animal and insect life as virgin forest within 15 years if properly managed, research at the University of Leeds has found.

Because trees in tropical climates soak up large amounts of carbon dioxide, restoring logged forest through planting new trees could also be used in carbon trading, as per Dr David Edwards, from University's Faculty of Biological Sciences.

Dr Edwards is calling for the inclusion of biodiversity-friendly strategies in carbon trading schemes to ensure that carbon off-setting projects support, rather than undermine, rainforest conservation.

Currently, large plantations of one type of tree, such as Eucalpytus, are popular as carbon off-setting or sequestration projects in the tropics because they also provide commercial benefits, but they do not support tropical biodiversity.

But Dr Edwards has shown that managed restoration of logged forest which can also be used for carbon off-setting brings biodiversity virtually back to pre-logging levels within 15 years, much quicker than forest left to regenerate naturally.

"Our research shows that it is possible to have both carbon sequestration and biodiversity benefits within the same scheme," he said.

"This could act as a strong incentive to protect logged forests under threat of deforestation for oil palm and other such crops. Selectively logged rainforests are often vulnerable because they're seen as degraded, but we've shown they can support similar levels of biodiversity to unlogged forests"......... Posted by: Erica      Read more         Source

October 13, 2009, 8:18 AM CT

Rainforest Plants Then and Now

Smithsonian scientists working in Colombia's Cerrejn coal mine have unearthed the first megafossil evidence of a neotropical rainforest. Titanoboa, the world's biggest snake, lived in this forest 58 million years ago at temperatures 3-5 C warmer than in rainforests today, indicating that rainforests flourished during warm periods.

"Modern neotropical rainforests, with their palms and spectacular flowering-plant diversity, seem to have come into existence in the Paleocene epoch, shortly after the extinction of the dinosaurs 65 million years ago," said Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute. "Pollen evidence tells us that forests before the mass extinction were quite different from our fossil rainforest at Cerrejn. We find new plant families, large, smooth-margined leaves and a three-tiered structure of forest floor, understory shrubs and high canopy."

Historically, good rock exposures and concentrated efforts by paleontologists to understand the evolution of neotropical rainforestsone of the most awe-inspiring assemblages of plant and animal life on the planethave been lacking. "The Cerrejn mining operation is the first clear window we have to see back in time to the Paleocene, when the neotropical rainforest was first developing," said Scott Wing, a paleontologist from the Smithsonian's National Museum of Natural History......... Posted by: Erica      Read more         Source

Mon, 28 Sep 2009 04:06:31 GMT

Grow your own apples

Choose a location that offers 8 hours of sun per day (trees in shady areas won"t produce ample fruit).

For pollination to occur, you need to plant at least two trees within 3 o 4 m of one another.

Well-drained soil is very important since too much moisture will harm the roots of both new and established trees.

Likewise, the soil needs to be rich; abundant nutrients are essential for a bountiful crop, so when planting, work compost, bonemeal or bloodmeal into the planting holes dug for each sapling.

To maintain richness in the soil, add compost each fall or spring around the base of the trees as far out as the drip line; top up with mulch except near the trunk where excessive moisture can cause rot.

Each fall clear fallen fruits from around the base of the trees to minimize the occurrence of apple maggots and other pests that can ruin the next crop of fruit

This wraps up apple week! Check out 10 tasty ways to eat apples for more suggestions on how to make the most of the season.

Posted by: danamccauley      Read more     Source

September 20, 2009, 7:12 PM CT

Bananas Gone Bad Glow Blue in UV-Light

Nicholas Turro of Columbia University, Bernhard Krautler of the University of Innsbruck, Austria and their colleagues have observed that, as chlorophyll ages and begins to disintegrate in banana peels it does not change color in the spectrum of visible light we see. Instead, it glows blue when observed under ultraviolet light.

While the light show adds a level of exoticism to the fruit in our eyes, and serves to attract a host of potential consumers in the eyes of insects and other animals who can appreciate the UV, the display is equally exciting to chemists. Because the glowing molecules occur in close proximity to dying tissue, they promise to be a literal beacon for the further study of the way organisms cleanse themselves of dying cells, or programmed cell death. A well known and poorly understood condition in which programmed cell death malfunctions is cancer.

Turro and colleagues describe how ordinary brown spots that form on bananas as they transition from ripe to rotten, each show a glowing blue halo in UV, caused by the congregation of chlorophyll breakdown byproducts. Their research appears in the Proceedings of the National Academies of Science.

Chlorophyll is the molecule that makes much of the life on earth possible. It is the integral ingredient that allows plants to take in a mixture of carbon dioxide, water and sunlight and convert it to oxygen, sugars and starches. These are the same sugars and starches we eat every time we fix a salad, and the same oxygen that we breathe......... Posted by: Erica      Read more         Source

September 15, 2009, 9:23 PM CT

Unlocking genetic secrets of date palm

Scientists at Weill Cornell Medical College in Qatar have mapped a draft version of the date palm genome, unlocking a number of of its genetic secrets.

"We have generated a draft DNA sequence and initial assembly of the date palm using the most advanced technology," says Joel Malek, director of the Genomics Laboratory at WCMC-Q. Genetic information about the date palm is extremely valuable to scientists who are working to improve fruit yield and quality and to better understand susceptibility and resistance to disease.

"This is an important step for our biomedical research program," says Khaled Machaca, Ph.D., professor of physiology and biophysics and associate dean for basic science research. "It clearly demonstrates the feasibility and success of the most advanced genomics technologies in Qatar and represents a milestone towards establishing Qatar and Weill Cornell as a regional research center of excellence. In addition, this achievement by the WCMC-Q research team holds great promise for the application of the genomics technology to a better understanding of biomedical problems".

The date palm sequencing work was a proof of concept study, as per Malek, who established the genomics laboratory last year. The goal was to establish and validate the capabilities of the core lab for large-scale genomics projects. The lab is an integral part of a large biomedical research program launched last year by WCMC-Q with support from the Qatar Foundation that aims to make Qatar a hub for research in the Middle East......... Posted by: Erica      Read more         Source

September 15, 2009, 9:19 PM CT

Drug-free Cannabis plant

In a first step toward engineering a drug-free Cannabis plant for hemp fiber and oil, University of Minnesota scientists have identified genes producing tetrahydrocannabinol (THC), the psychoactive substance in marijuana. Studying the genes could also lead to new and better drugs for pain, nausea and other conditions.

The finding is reported in the recent issue of the Journal of Experimental Botany Main author is David Marks, a professor of plant biology in the College of Biological Sciences.

The study revealed that the genes are active in tiny hairs covering the flowers of Cannabis plants. In marijuana, the hairs accumulate high amounts of THC, whereas in hemp the hairs have little. Hemp and marijuana are difficult to distinguish apart from differences in THC.

With the genes identified, finding a way to silence themand thus produce a drug-free plant comes a step closer to reality. Another desirable step is to make drug-free plants visually recognizable. Since the hairs can be seen with a magnifying glass, this could be accomplished by engineering a hairless Cannabis plant.

The scientists are currently using the methods of the latest study to identify genes that lead to hair growth in hopes of silencing them.

"We are beginning to understand which genes control hair growth in other plants, and the resources created in our study will allow us to look for similar genes in Cannabis sativa," said Marks......... Posted by: Erica      Read more         Source

September 15, 2009, 2:45 PM CT

Exotic timber plantations use water

Ecologists have discovered that timber plantations in Hawaii use more than twice the amount of water to grow as native forests use. Particularly for island ecosystems, these findings suggest that land management decisions can place ecosystems and the people who depend on them at high risk for water shortages.

"Researchers used to believe that forests in same environments use water in the same way," says Lawren Sack of The University of California at Los Angeles, who coauthored the study with graduate student Aurora Kagawa in the recent issue of the ESA journal Ecological Applications "Our work shows that this is not the case. We need to know the water budget of our landscape, from gardens to forests to parks, because water is expensive".

Eventhough forests like these Hawaiian timber plantations can be valuable for their contributions to human society, such as fiber, fuel and carbon sequestration, they are dominated by non-native vegetation.

Kagawa, Sack and their colleagues compared the water use of trees in native forests, composed mostly of native ohia trees, with water use in timber plantations containing exotic eucalyptus and tropical ash. The team inserted heated and unheated probes into the trees' trunks and monitored the temperature differences between the two as sap flowed past them. This technique allowed them to determine the rate of sap flow through the tree. A faster flow rate means that the tree is using more water......... Posted by: Erica      Read more         Source

September 15, 2009, 2:29 PM CT

More tamarisk invasion in future

If the future warming trends that researchers have projected are realized, one of the country's most aggressive exotic plants will have the potential to invade more U.S. land area, as per a newly released study reported in the current issue of the journal Invasive Plant Science and Management The study observed that tamariskprevalent today in some parts of the region, but generally limited to warm and dry environmentscould expand its range into currently uninvaded areas.

"Results of our study suggest that a little over 20 percent of the Northwest east of the Cascade Mountains supports suitable tamarisk habitat, but less than one percent of these areas is currently occupied by the species," said Becky Kerns, a research ecologist with the Western Wildland Environmental Threat Evaluation Center (WWETAC) who led the study. "That means the remainder is highly vulnerable to invasion right now with the situation potentially getting worse as favorable conditions for tamarisk may expand under climate change".

These findings translate into a two- to ten-fold increase in highly suitable tamarisk habitat in Oregon, Washington, and Idaho by the end of the century.

Tamarisk, also known as "saltcedar," is a deciduous shrub or small tree that grows quickly, reproduces profusely, and tolerates drought and salty conditions, making it capable of easily displacing native species. It also sheds flammable leaves that serve as potential fuel, significantly increasing an area's wildfire risk. The plant was intentionally introduced to the West in the 1800s as an ornamental, windbreak, shade, and erosion control species and today can be found growing prolifically in the Northwest in the central Snake River Plain, Columbia Plateau, and Northern Basin and Range......... Posted by: Erica      Read more         Source

September 15, 2009, 7:51 AM CT

Clues into the evolution of the first flowers

Approximately 120-130 million years ago, one of the most significant events in the history of the Earth occurred: the first flowering plants, or angiosperms, arose. In the late 1800s, Darwin referred to their development as an "abominable mystery." To this day, researchers are still challenged by this "mystery" of how angiosperms originated, rapidly diversified, and rose to dominance. (See the January 2009 issue of the American Journal of Botany at www.amjbot.org/content/vol96/issue1.).

Studies of key features of angiosperm evolution, such as the evolution of the flower and development of the endosperm, have contributed to our current understanding of relationships among the early families of flowering plants. Examining the development of seeds and embryos among early angiosperms may help to improve our understanding of how flowering plants evolved from the nonflowering gymnosperms.

A recent study by Dr. Paula Rudall and his colleagues reported in the recent issue of the AJB (www.amjbot.org/cgi/content/full/96/9/1581) explores a piece of this mystery: the microscopic anatomy of seed development in Trithuria, a genus in the plant family Hydatellaceae, believed to be one of the earliest families of angiospermsthe so-called "basal angiosperms".

Rudall and his colleagues' observations of the development of the embryo and endosperm (tissue that surrounds the embryo and provides nutrition) in Trithuria suggest that double fertilization occurs. Double fertilization is a unique feature of flowering plants where one sperm nucleus unites with the egg, producing the embryo, while another sperm nucleus unites with a separate nucleus from the female, producing the endosperm. The endosperm is divided into two regionsthe micropylar and chalazal regions......... Posted by: Erica      Read more         Source

September 15, 2009, 7:45 AM CT

Conflict between plant and animal hormones

Cis-OPDA (12-oxophytodienoic acid) is a highly reactive plant hormone which simultaneously serves as a precursor molecule of the metabolic "master switch" jasmonic acid. Both signal herbivory in leaves and shoots of plants and activate the plants' defense reaction against caterpillars. Cis-OPDA, when reaching the hemolymph of the caterpillar, has a negative effect on the animal, leading to premature pupation and, apparently, an impaired immune system.

Paulina Dabrowska, one of the very first PhD students of the Jena International Max Planck Research School (IMPRS) who meanwhile earned her PhD, studied the whereabouts of plant hormones after they had been consumed by the caterpillars and had passed the insect gut. Are the hormones, which are known to severely influence development and metabolism of organisms even in the slightest dose, fully metabolized in the insect gut, just converted, or not influenced at all?

Studying the plant hormone cis-OPDA it became quickly evident that a conversion of the molecule must have taken place in the insect gut. The young chemist, originally from Poland, discovered that an enzyme must play a role in the chemical reaction observed: "First, we observed that cis-OPDA was not present in the insect feces anymore. Instead of cis-OPDA, our mass spectrometers suggested iso-OPDA. However, iso-OPDA is only constituted by means of enzyme catalysis." Control experiments, solely performed in strong alkaline solutions as present in the insect gut (pH approx. 10), did not cause a cis-iso conversion. The test animals were Spodoptera littoralis (cotton leaf worm) and Helicoverpa armigera (cotton bollworm) larvae; both species are major cotton pests worldwide......... Posted by: Erica      Read more         Source

September 14, 2009, 11:55 PM CT

For carnivorous plants, slow but steady wins the race

Like the man-eating plant in Little Shop of Horrors, carnivorous plants rely on animal prey for sustenance. Fortunately for humans, carnivorous plants found in nature are not dependent on a diet of human blood but rather are satisfied with the occasional fly or other insect. The existence of carnivorous plants has fascinated botanists and non-botanists alike for centuries and raises the question, "Why are some plants carnivorous?" .

A recent article by Drs. Jim Karagatzides and Aaron Ellison in the recent issue of the American Journal of Botany (www.amjbot.org/cgi/content/full/96/9/1612) addresses this question. As Ellison stated, "The general answer to this is that in environments that have few nutrients (such as bogs, where we study carnivorous plants), carnivory allows these plants to capture nutrients 'on the wing'. But if it's so good to be a carnivorous plant in these kinds of environments, why aren't there more carnivorous plants? Knowing how much it 'costs' a carnivorous plant to make a trap is a key piece of information needed to understand why there aren't more carnivorous plants".

Elllison and Karagatzides simultaneously measured both costs and benefits for traps, leaves, roots, and rhizomes of 15 different carnivorous plant species, including pitcher plants and the Venus fly trap. By measuring the construction cost of carbon needed to create these plant structures and comparing it to the payback timethe amount of time the structure takes to photosynthesize to recoup the carbon used in its constructionEllison and Karagatzides were able to determine how beneficial a trap might be to a plant......... Posted by: Erica      Read more         Source

September 11, 2009, 7:33 AM CT

As ash borer claims more trees

Mark Widrlechner may someday be known as the modern-day Johnny Appleseed for ash trees.

As the devastating insect emerald ash borer is working its way across North America destroying almost all the native ash trees it encounters, Widrlechner is rapidly collecting and storing ash tree seeds.

Like the legendary Appleseed who planted apple trees across the country, Widrlechner's seed stocks can serve as a national source for reintroducing ash trees once the devastation can be controlled.

Widrlechner, horticulturist for the United States Department of Agriculture's Agricultural Research Service (ARS) and assistant professor of agronomy and horticulture at ISU, is a curator at the North Central Regional Plant Introduction Station in Ames, Iowa, responsible for collecting and maintaining seeds for several species of trees, including ash, for the USDA's National Plant Germplasm System.

As the pest devours ash tree populations on its way across North America, there may soon be few, if any, ash trees left.

"Where these borers have been present the longest, it has basically been a total wipeout," said Widrlechner.

"That is something we rarely see in nature," he said. "It's uncommon for a pest to come in and just clean something out. It doesn't just attack sick trees. Emerald ash borer attacks healthy trees. It attacks small trees. So you don't have just big, old trees falling to this, you've got 2 to 3 inch saplings falling to this."........ Posted by: Erica      Read more         Source

September 10, 2009, 7:06 AM CT

Getting plants to rid themselves of pesticide residues

Researchers in China are reporting the "intriguing" discovery that a natural plant hormone, applied to crops, can help plants eliminate residues of certain pesticides. The study is scheduled for the Sept. 23 issue of ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication.

Jing Quan Yu and his colleagues note that pesticides are essential for sustaining food production for the world's growing population. Farmers worldwide use about 2.5 million tons of pesticides each year. Researchers have been seeking new ways of minimizing pesticide residues that remain in food crops after harvest with little success. Prior research suggested that plant hormones called brassinosteroids (BRs) might be an answer to the problem.

The researchers treated cucumber plants with one type of BR then treated the plants with various pesticides, including chloropyrifos (CPF), a broad-spectrum commercial insecticide. BR significantly reduced their toxicity and residues in the plants, they say. BRs appears to be "promising, environmentally friendly, natural substances suitable for wide application to reduce the risks of human and environmental exposure to pesticides," the researchers note. The substances do not appear to be harmful to people or other animals, they add......... Posted by: Erica      Read more         Source

August 28, 2009, 7:01 AM CT

DNA from Linnaeus' botanical collections

Scientists at Uppsala University has succeeded in extracting long DNA fragments from dried, pressed plant material collected in the 1700s by Linnaeus' apprentice Adam Afzelius. It is hoped that the study, led by Associate Professor Katarina Andreasen, will shed light on whether plants growing today at Linnaeus' Hammarby estate outside Uppsala reflect the species cultivated by Linnaeus himself.

A large number of plants of uncertain provenance grow at Carl Linnaeus' Hammarby estate, a museum and popular tourist destination. Have they been present since Linnaeus' time? In addition to probing this question, the current study will test the limits of DNA-sequencing methods with regard to old plant material and has already demonstrated that it is possible to sequence plant material more than 200 years old. The study is now reported in the scientific journal Taxon

"This opens up many exciting research possibilities in connection with material from herbaria throughout the world", says Katarina Andreasen.

The scientists hopes to initiate corresponding DNA investigations of plant material from the garden at Hammarby as soon as possible.

"It would be fun, if we can show that the old material is genetically identical with the plants currently growing at Hammarby, to create a living herbarium for summer visitors to the garden", says Katarina Andreasen......... Posted by: Erica      Read more         Source

August 16, 2009, 9:14 PM CT

Rare healing substances in the endangered Devil's claw plant

Deep in Africa's Kalahari Desert lies the "Devil's claw," a plant that may hold the key to effective therapys for arthritis, tendonitis and other illnesses that affect millions each year. Unfortunately, years of drought have pushed the Devil's claw toward extinction, so researchers are scrambling to devise new ways to produce the valuable medicinal chemicals of the Devil's claw and other rare plants.

One group of researchers reported a major advance toward that goal here today at the 238th National Meeting of the American Chemical Society (ACS). They described the first successful method of producing the active ingredients in Devil's claw ingredients that have made the Devil's claw a sensation in alternative medicine in Europe. Their technique may eventually lead to the development of "biofactories" that could produce huge quantities of rare plant extracts quickly and at little cost.

Milen I. Georgiev, Ph.D., who delivered the report, pointed out that for thousands of years, native populations in Southern Africa have used the Devil's claw as a remedy for a huge number of ailments, including fever, diarrhea and blood diseases. Today, there are dozens of medicinal and herbal products around the world that are based on chemicals derived from the Devil's claw.

In particular, studies suggest that two chemicals the so-called iridoid glycosides harpagoside and harpagide may have beneficial effects in the therapy of degenerative rheumatoid arthritis, osteoarthritis, tendonitis, and other conditions, Georgiev said......... Posted by: Erica      Read more         Source

August 6, 2009, 11:31 PM CT

A plant's arsenal of crystalline darts and sand

Pet owners have heard the warnings to keep certain poisonous houseplants away from their pets, such as Dieffenbachia (dumbcane), Philodendron, peace lily, and pothos. For houseplants like these and others, the problem may not just be a poison, but the presence of tiny crystals throughout the plant.

A discussion of plants may not bring to mind crystals; however, crystals are found in hundreds of plant families. Despite this, their purpose is not well-understood. Hypotheses include acting as a deterrent to herbivory, serving as a long-term storage depot for calcium, or providing extra support to various plant tissues.

To help elucidate the role of crystals in plants and determine whether this role may actually be to prevent animals from munching on the plant, Dr. Gary Cot studied the variety and locations of crystals found in the houseplant Dieffenbachia seguine. His findings have just been reported in the July 2009 issue of the American Journal of Botany

Three common types of crystals are found in plants: druses (spherical crystal aggregates), raphides (long pointed needles found in bundles), and prisms. Cot found all three of these in Dieffenbachia. He discovered that each type of tissue within the plant, as well as different portions of the same organ in some instances, had their own specific crystals. And, despite the variety of crystal structures found throughout the plant, all crystals were found to contain calcium oxalate, the same substance comprising kidney stones......... Posted by: Erica      Read more         Source

August 4, 2009, 8:10 AM CT

Agricultural research key to food security

Boosting agricultural research in the developing world is the key to ensuring food security for the world's poorest, says Adel el-Beltagy, Chair of the Global Form on Agricultural Research (GFAR), writing in the latest issue of the TWAS Newsletter, published last week.

With nearly a billion people suffering from chronic hunger, global food security remains a major concern, despite being a key goal of the UN Millennium Development Goals (MDGs). Extreme weather events due to climate change and the recent trend to convert croplands to biofuels both threaten to put even more people who are at risk.

The solution, says el-Beltagy a member of TWAS, the Academy of Sciences for the Developing World must involve a renewed concentration on agricultural research in the South.

Writing in the spring issue of the TWAS Newsletter, el-Beltagy outlines the steps that will be needed to ensure that developing countries can take advantage of cutting-edge agricultural technologies, such as genomics and nanotechnology, that have the potential to increase crop yields without unduly stressing the environment.

Building such capacity will depend upon overcoming.

two obstacles: The North-South gap, which delays the transfer of technologies to the developing world, and the gap between developing world research communities and farmers working in the field......... Posted by: Erica      Read more         Source

July 28, 2009, 11:17 PM CT

Forest response project FACEs the end

After 12 years, an experiment focused on forest growth and climate change comes to an end, and scientists at Oak Ridge National Laboratory are eager to collect and analyze data to see if their predictions match results.

With the Department of Energy-sponsored free air carbon dioxide enrichment experiment, known as FACE, three plots of sweetgum trees were the control sites and two plots of sweetgums were exposed to increased carbon dioxide levels in the atmosphere at 550 parts per million, the concentration that is projected to occur in about 2050 if current trends continue. The atmospheric carbon dioxide concentration has been rising steadily because of the burning of fossil fuels and global land use change.

Project leader Rich Norby of the Environmental Sciences Division describes the end of the experiment as bittersweet.

"In one sense, a project that I have been heavily involved in will no longer be an active experiment site," Norby said. "Conversely, I am looking forward to gathering the evidence and analyzing the materials to see if our hypotheses prove to be true."

Already, scientists and students are sifting through the soil to measure the amount of fine roots and to examine them further. Smaller roots are significant points of study because they take up the majority of the water and nutrients and provide important clues to how forests will respond to higher carbon dioxide in the future......... Posted by: Erica      Read more         Source

July 20, 2009, 11:15 PM CT

DNA of ancient lost barley could help modern crops

Scientists at the University of Warwick have recovered significant DNA information from a lost form of ancient barley that triumphed for over 3000 years seeing off: 5 changes in civilisation, water shortages and a much more popular form of barley that produces more grains. This discovery offers a real insight into the couture of ancient farming and could assist the development of new varieties of crops to face today's climate change challenges.

The researchers, led by Dr Robin Allaby from the University of Warwick's plant research arm Warwick HRI, examined Archaeobotanical remains of ancient barley at Qasr Ibrim in Egypt's Upper Nile. This is a site that was occupied for over 3000 years by 5 successive cultures: Napatan, Roman, Meoitic, Christian and Islamic.

The first surprise for the scientists was that throughout that period every culture seemed to be growing a two rowed form of barley. While natural wild barley tends to be two rowed most farmers prefer to grow a much higher yield 6 row version which produces up to 3 times as a number of grains. That 6 row version has grown for over 8000 years and that was certainly grown in the lower Nile over the same period as Qasr Ibrim was occupied. It was thought that despite the fact that the rest of Egypt used 6 row barley that the farmers of Qasr Ibrim were perhaps deliberately choosing to import 2 rowed barley but the scientists could not understand why that would be so......... Posted by: Erica      Read more         Source

July 4, 2009, 10:50 PM CT

Plants' internal clock can improve climate-change models

The ability of plants to tell the time, a mechanism common to all living beings, enables them to survive, grow and reproduce. As per a research findings reported in the latest issue of the prestigious journal Ecology Letters, an international team has studied this circadian clock from a molecular viewpoint and has found an ecological implication: it makes climate change scenarios and CO2 level figures more accurate.

The international team of scientists led by the University of Castilla-La-Mancha (UCLM) has compiled the research carried out to date on this topic in order to understand the implications of the so-called "circadian clock" as regards the survival and ecology of a wide range of plant species. The plants of the model species Arabidopsis thaliana, created in a laboratory environment without this ability, found it difficult to survive and reproduced less frequently.

"One hour before the sun comes out, a plant with a circadian clock already knows that it is time to wake up and all the genes associated to photosynthesis begin to activate," Vctor Resco de Dios, lead author of the study and a researcher in the Environmental Science Department of the UCLM explained to SINC.

The study, which has been reported in the latest issue of Ecology Letters, reveals the ecological implications of plants' ability to "tell the time". Scientists have studied the genes involved in photosynthesis and adapting to the climate......... Posted by: Erica      Read more         Source

June 25, 2009, 7:29 PM CT

Long-term apple scab resistance remains elusive

There are hundreds of choices when picking a crabapple tree from the nursery, but a Purdue University expert says only a handful are resistant to a widespread fungus or other serious diseases.

After reviewing 33 years of data, Janna Beckerman, a Purdue assistant professor of botany and plant pathology, observed that only five of 287 crabapple varieties had durable resistance to a serious disease of crabapple trees. The results of her study were reported in the recent issue of the journal HortScience

Beckerman said data on crabapple trees and apple scab had only been done on a year-by-year basis until now. Looking over a prolonged period gives scientists a better idea of which trees have historically maintained or lost apple scab resistance.

"Whenever new plants are released, they are often touted as disease-resistant, but they have only been tested for a few years," Beckerman said. "That isn't enough time. From this data, you could see that varieties that did well for the first few years after planting often developed scab within 10 years".

The Venturia inaequalis fungus produces black scab-like lesions on the fruit and leaves. Crabapple trees with scab tend to defoliate, or lose all their leaves, in early summer, a condition that can weaken and eventually kill the trees......... Posted by: Erica      Read more         Source

June 23, 2009, 5:00 PM CT

Prairie dogs and plants?

Prairie dogs may seem like harmless little creatures, but they can inflict serious injury on plants simply by snacking on them. Plants cannot flee from their furry predators, so how do they avoid becoming a prairie dog's lunch?.

Dr. John Freeman and his colleagues explore the role of metal hyperaccumulation in plant defense in the June 2009 issue of the American Journal of Botany Certain plants species growing on soils with high metal content (such as arsenic, copper, selenium, and lead) accumulate large quantities of metals in their leaves and stems. The purpose of this metal hyperaccumulation is not fully known, but metal hyperaccumulation may increase a plant's ability to respond to drought, compete with other plants, or provide a defense against bacteria, viruses, and animals.

"It is interesting to think about the effect of the prairie dog, which was an amazing ecosystem engineer on a very large scale here in North America," said Dr. Freeman, Colorado State University. "From their prehistoric ancestors the ground squirrel to the modern prairie dog, these animals may have driven the evolution of selenium hyperaccumulation as an elemental defense against herbivory in a number of different plant species".

Dr. Freeman's research focused on the role of selenium hyperaccumulation in Stanleya pinnata (prince's plume), a wildflower correlation to mustard plants. Eventhough low levels of selenium are essential for a number of animals, consumption of high levels is toxic. But just because an overdose of selenium is toxic to animals does not mean that the presence of high levels in leaves deters animals from eating the plants; prairie dogs may not know to avoid S. pinnata until it is too late. Few studies have addressed this question and whether metal hyperaccumulation actually acts as a deterrent......... Posted by: Kelly      Read more         Source

June 21, 2009, 8:56 PM CT

Domestication of Capsicum annuum chile pepper

Without the process of domestication, humans would still be hunters and gatherers, and modern civilization would look very different. Fortunately, for all of us who do not relish the thought of spending our days searching for nuts and berries, early civilizations successfully cultivated a number of species of animals and plants found in their surroundings. Current studies of the domestication of various species provide a fascinating glimpse into the past.

A recent article by Dr. Seung-Chul Kim and his colleagues in the June 2009 issue of the American Journal of Botany explores the domestication of chiles. These hot peppers, found in everything from hot chocolate to salsa, have long played an important role in the diets of Mesoamerican people, possibly since as early as ~8000 B.C. Capsicum annuum is one of five domesticated species of chiles and is notable as one of the primary components, along with maize, of the diet of Mesoamerican peoples. However, little has been known regarding the original location of domestication of C. annuum, the number of times it was domesticated, and the genetic diversity present in wild relatives.

To answer these questions, Dr. Kim and his team examined DNA sequence variation and patterns at three nuclear loci in a broad selection of semiwild and domesticated individuals. Dr. Kim et al. found a large amount of diversity in individuals from the Yucatan Peninsula, making this a center of diversity for chiles and possibly a location of C. annuum domestication. Previously, the eastern part of central Mexico had been considered to be the primary center of domestication of C. annuum On the basis of patterns in the sequence data, Dr. Kim et al. hypothesize that chiles were independently domesticated several times from geographically distant wild progenitors by different prehistoric cultures in Mexico, in contrast to maize and beans which appear to have been domesticated only once......... Posted by: Erica      Read more         Source

June 21, 2009, 8:52 PM CT

Plant Communication

-"To thine own self be true" may take on a new meaning-not with people or animal behavior but with plant behavior.

Plants engage in self-recognition and can communicate danger to their "clones" or genetically identical cuttings planted nearby, says professor Richard Karban of the Department of Entomology, University of California, Davis, in groundbreaking research reported in the current edition of Ecology Letters.

Karban and fellow scientist Kaori Shiojiri of the Center for Ecological Research, Kyoto University, Japan, observed that sagebrush responded to cues of self and non-self without physical contact.

The sagebrush communicated and cooperated with other branches of themselves to avoid being eaten by grasshoppers, Karban said. Eventhough the research is in its early stages, the researchers suspect that the plants warn their own kind of impending danger by emitting volatile cues. This may involve secreting chemicals that deter herbivores or make the plant less profitable for herbivores to eat, he said.

What this research means is that plants are "capable of more sophisticated behavior than we imagined," said Karban, who researches the interactions between herbivores (plant-eating organisms) and their host plants.

"Plants are capable of responding to complex cues that involve multiple stimuli," Karban said. "Plants not only respond to reliable cues in their environments but also produce cues that communicate with other plants and with other organisms, such as pollinators, seed disperses, herbivores and enemies of those herbivores"......... Posted by: Erica      Read more         Source