September 17, 2007, 5:19 AM CT

Yam bean a nearly forgotten crop

The Yam bean originated where the Andes meet the Amazon and is locally grown in South and Central America, South Asia, East Asia and the Pacific. It is produced in three species which are called the Amazonian, Mexican and Andean. Interbreeding of the bean has resulted in fertile and stable hybrids. This gives it potential to be reclassified as a single species, provide high quality food production and offer a sustainable cropping system that has been needed in Africa.

Scientists believe they have discovered a protein-rich starch staple in the yam bean in Peru. They were previously considered a root vegetable due to the high water content; however this Chuin type has lower water content. Families living in the area have been producing it as flour. The crop has extremely high seed production, but its seeds contain high concentrations of rotenone. This toxic compound has been used for reducing fish populations and parasitic mites on poultry. Seeds are never consumed since they are mildly toxic to humans and other mammals. If the rotenone was removed from the seeds, they could provide a strong protein source as well as seed oil profitable in the food industry.

Sraphin Zanklan, a scientist at Centre Songhai in Porto-Novo (Benin), has investigated the yam bean for its potential to grow and produce food under West African conditions. The study was funded by a scholarship from the German Academic Exchange Service (DAAD). Thirty-four yam genotypes were grown with and without flower removal at one droughty location and one irrigated location. Of the 33 traits that were measured, nearly all showed large genetic variation. This and the easy spreading of its seeds, make the crops very desirable to breeders. Results from the study would be reported in the July-August 2007 issue of Crop Science......... Posted by: Erica      Read more         Source

September 12, 2007, 6:50 PM CT

A small leak will sink a great ship

Flowers of higher plants are built in a similar pattern: their outermost whorl is composed of sepals, which protect the young bud, thereafter comes a whorl of often colorful petals attracting insect pollinators, followed by a whorl of stamens with pollen sacks and the innermost whorl holds carpels, which later give rise to the fruit and seeds. This basic architecture is comparable in higher plants prompting the question after common components of a genetic 'masterplan'.

Researchers in the group of Zsuzsanna Schwarz-Sommer investigated a mutant of snapdragon where stamens form instead of petals (Fig. 1). Interestingly, a strikingly similar mutant occurs in another plant species, in Petunia. 'We already suspected some ten years ago when we first looked at these mutants that in the two species a similar defect might disturb the genetic control resulting in the 'wrong organ at the wrong place' explains Mrs. Schwarz-Sommer. A similar example is well known in the fruit fly where a mutant carries a pair of legs at the head instead of the two antennae.

Indeed, experiments performed by the German and Dutch researchers showed that in the two plant species mutation in the same gene conferred altered identity to the floral organs. This gene turned out to code for a microRNA, a small ribonucleic acid consisting of little more than 20 nucleotides. MicroRNAs can recognize and bind to complementary sequences present in messenger RNAs (mRNA) and prevent thereby translation of the mRNA into a protein: the respective gene falls silent. By this interaction microRNAs can influence whole chains of control events......... Posted by: Erica      Read more         Source

September 12, 2007, 6:42 PM CT

One species, many genomes

To track down the variation in the genome of the different Arabidopsis strains, the scientists compared the genetic material of 19 wild strains with that of the genome of the lab strain, which was sequenced in the year 2000. Using a very elaborate procedure, they examined every one of the roughly 120 million building blocks of the genome. For their molecular sleuthing they used almost one billion specially designed DNA probes. "All together, these probes would have seven times the length of human genome," illustrates Weigel the extent of the project. The data were reviewed with several specially designed statistical methods, including a variant of machine learning.

The result of this painstaking analysis: on average, every 180th DNA building block is variable. And about four percent of the reference genome either looks very different in the wild varieties, or cannot be found at all. Almost every tenth gene was so defective that it could not fulfill its normal function anymore!

Results such as these raise fundamental questions. For one, they qualify the value of the model genomes sequenced so far. "There isn't such a thing as the genome of a species," says Weigel. He adds "The insight that the DNA sequence of a single individual is by far not sufficient to understand the genetic potential of a species also fuels current efforts in human genetics"......... Posted by: Erica      Read more         Source

September 6, 2007, 5:06 AM CT

Dangerous Liaisons

The new work, published in the latest edition of PLoS Biology, was based on the observation that unfit hybrids from different plant species are very similar. Their growth is retarded, the leaves become yellow and necrotic, the tissue collapses and they often do not survive to make flowers; the syndrome is generally known as hybrid necrosis. "We suspected that hybrid necrosis is always caused by the same biochemical mechanism," explains Weigel, director at the Max Planck Institute.

To test this hypothesis, the researchers took 280 genetically different strains of Arabidopsis from all over the world, which they crossed in 861 different combinations. Most of the hybrid plants were strong and grew normally, but 20 - or two percent - of the crosses produced only small necrotic and unhealthy plants. Genomics-based experiments showed that these hybrids all had a comparable profile of gene activity: A common group of some 1000 genes were either more strongly or more weakly active in the hybrids than in their healthy parents. Moreover, this pattern was very similar to what is seen with a strong immune response mounted against pathogens during a normal infection. The plant immune response typically involves the sacrifice of a few cells at and around the infection site. But in the wimpy hybrids, healthy tissue also suffered - without pathogen infection. The hybrid plants apparently mistook their own cells for dangerous germs......... Posted by: Erica      Read more         Source

Thu, 06 Sep 2007 01:35:09 GMT

Native plant resource

Do other gardeners have the same problem that I do of finding specific plants? I’ll hear about a particularly cool native plant, fall in love with it, must have it…..and then I can’t find it anywhere. This is very annoying. I do not like spending a million dollars for a bareroot plant in a fancy catalog. And I intensely dislike driving all over New England to look for plants or randomly calling nurseries in the phone book.

But I found a cool tool while doing some research recently for a garden that I’m creating for a client. It’ll be very useful for those of you (in the northeast part of the country) that wants to to find native plants at a nursery near you.

American Beauties is “a collection of native plants that makes it easy to use trees, shrubs, vines, grasses and wildflowers that are beautiful and good for wildlife.” Two nurseries, Prides Corner Farms of Lebanon, Conn. and North Creek Nurseries of Landenberg, Penn. created American Beauties to promote the use of native plants in home gardens. The nurseries teamed up to create four native plant gardens “guaranteed to bring life to your landscape by providing food and habitat for a variety of desirable critters.”

Plants in the American Beauties Collection have a special identification tag, and are sold by participating garden centers. The website includes a tool that allows you to type in your zip code and tells you which garden centers near you carry the plants. Each nursery won’t have all of the plants on hand, but at least you have a specific nursery to call–they may be able to special order certain plants.

The best part is that American Beautifies donates 25 cents, 50 cents, or $1 of each plant sold (depending on the plant) to the National Wildlife Federation (NWF) to fund their home habitat work and outreach programs. NWF is well-known for its efforts to help home gardeners create wildlife-friendly outdoor spaces.

American Beauties includes four collections of plants for bird, butterfly, dry/shade, and moist/sun gardens. You can also search by type, such as ferns, grass, deciduous trees, etc. Or if you want to find out about a specific plant, you can search by common or botanical name.

If you live in the northeast, check out the American Beauties website and start shopping for native plants. If not, the good news is that they hope to expand the program to other regions in the near future, so stay tuned.

Photos & graphics courtesy of American Beauties LLC. Posted by: Caroline Brown      Read more     Source

Wed, 05 Sep 2007 03:22:50 GMT

Plants that are poisonous for pets

In general I’ve lately been trying to blog more gardening about topics that are related to ecology and nature, not about strict gardening subjects or how-to’s. However, I couldn’t help but post a link to this important information from the ASPCA about plants that are poisonous to pets. I always thought that poinsettias were really dangerous but they don’t even make the top 10, according to the ASPCA’s Animal Poison Control Center.

The ASPCA says the ten most poisonous plants are marijuana (duh), sago palm, lilies, tulip & narcissus (daffodil) bulbs, azalea & rhododendron, oleander, castor bean, cyclamen, kalanchoe, and yew. The only one of these that I knew was poisonous already was oleander. We have tons of the other stuff in the yard and in the house from time to time, so I was surprised and a little embarrassed that I didn’t know about lilies, tulips, & daffodils. I have some lilies in a vase right now! And one of my cats loves to eat plants.

If your plants and pets share the same outdoor or indoor space, please make sure to read the ASPCA’s website. You can also find out the symptoms of poisoning for different plants and learn which plants are non-toxic. Posted by: Caroline Brown      Read more     Source

September 4, 2007, 6:54 PM CT

Want To Know More About Cotton Fleahoppers

Inquiring Texas research minds want to know more about cotton fleahoppers - a tiny, sometimes obscure pest that can damage plants during their early growth.

"Fleahoppers are a threat to young cotton for about four weeks," said Dr. Megha Parajulee, Texas Agricultural Experiment Station entomologist based at Lubbock. "They feed on new plant growth, primarily the first small squares. This damage can delay plant maturity, leaving the crop open to damage from other pests later in the growing season."

But these tiny pests aren't all bad. After cotton reaches peak bloom, this tiny critter is considered a beneficial insect - living out its relatively short life as both a predator and prey species.

"Fleahoppers prey on bollworm eggs after peak bloom," Parajulee said. "They also serve as a food source for other predatory beneficial insects as the growing season progresses. But we really don't know much about this pest. We know it is only a cotton pest in Texas and Arkansas, but there is more we don't know."

For instance:.

- Can cotton plants compensate for fruit/square loss caused by fleahoppers and still produce acceptable yields?.

- What threshold of fleahopper numbers or feeding damage should trigger a chemical control?.

- What pesticides work best against fleahoppers without damaging beneficial insects?......... Posted by: Erica      Read more         Source

Sat, 01 Sep 2007 12:18:05 GMT

Gladiolus papilio

Butterfly gladiolus or goldblotch gladiolus is one of the approximately one hundred and sixty species of gladiolus endemic to South Africa. Unlike the genus Watsonia (featured on BPotD a couple days ago), the genus Gladiolus extends beyond the borders of South Africa; it can be found throughout much of sub-Saharan Africa and parts of Eurasia, though its centre of diversity remains in South Africa.

Within the globally widespread family Iridaceae, Gladiolus belongs to the Old World subfamily Crocoideae, along with Watsonia, Crocosmia, Dierama, Crocus and Babiana. Iridaceous plants not belonging to the Crocoideae featured on BPotD to-date include Cypella, Iris, Olsynium, Sisyrinchium and Diplarrena, all belonging to the subfamily Iridoideae.

The Angiosperm Phylogeny Group goes into taxonomic detail on the Iridaceae and its subfamilies.

Paghat writes about Gladiolus papilio from a horticultural perspective. Posted by: Daniel Mosquin      Read more     Source

August 31, 2007, 5:03 AM CT

Sustainability Of The Bioeconomy

This spring farmers responded to the ethanol industry's demand for grain by increasing their corn acreage by 19 percent over last year, as per U.S. Department of Agriculture estimates.

What if that happens again next year?

What if farmers decide against crop rotations and plant corn on the same fields, year after year? Or, what if farmers begin growing biomass crops such as switchgrass for the production of ethanol from plant fiber?.

Will soil lose fertility? Will erosion increase? Will the amount of energy needed to produce biofuels go up or down? Will farm income increase or decrease?.

Will the bioeconomy be sustainable?

Robert Anex, an Iowa State associate professor of agricultural and biosystems engineering and associate director of Iowa State's Office of Biorenewables Programs, is working to answer those and other questions about the transition to an agriculture that produces biomass as well as food and fiber.

One answer is that American agriculture is likely to change.

"It may well be that the development of biomass-based crops production systems can have as profound an impact on agriculture and its environmental footprint as it does on energy security and the global climate," Anex and co-authors Andrew Heggenstaller and Matt Liebman of Iowa State's agronomy department and Lee Lynd and Mark Laser of Dartmouth College wrote in a recent paper. "Whether this is a positive impact or a negative impact will depend largely on how biomass feedstocks are produced and converted, and the extent to which these two activities are integrated"......... Posted by: Erica      Read more         Source

Sun, 26 Aug 2007 17:52:58 GMT

Magnolia delavayi

This is a follow-up photograph to last year's BPotD on Magnolia delavayi (or Delavay's magnolia). Peter Wharton described the plant in a comment accompanying that entry, so I'll direct you there if you'd like to read more.

Last week, the garden received a paper-copy of the Red List of Magnoliaceae, published jointly by Fauna & Flora International and Botanic Gardens Conservation International. From a global list of 245 magnolia species, over half are identified as being in danger of extinction in the wild (including Magnolia delavayi). The list makes for very sobering reading, particularly as it is difficult to imagine a scenario whereby changes are made to prevent the loss of many of these species. Posted by: Daniel Mosquin      Read more     Source