Horticulture Group Newsletter - July 2011

Bristol Botanic Garden

Unlike many other well-known botanic gardens University of Bristol Botanic Garden has not enjoyed a long history on one site. Originally found in 1882, by the start of this millennium it had already been located on three sites. In 2002 it was decided to move it yet again to a new site closer to the university at The Holmes. The 1.77 hectare garden at the Holmes was relatively undeveloped, but did include a framework of mature ornamental trees to provide a backdrop to the new garden which was started in 2006.

In showing us around the new garden the curator, Nicholas Wray (pictured right), warned that the site was still 'work in progress'. The primary purpose of the garden remains as a teaching resource for the University. In addition it needs to provide an attractive and informative garden for the general public. However, the relatively small area of the site meant that the collections needed to focus on a number of specific areas and four were selected. Plants for inclusion in the garden are chosen to demonstrate either plant evolution, species from regions with a Mediterranean climate, useful plants and local plants of Somerset and the South West.

Cheddar Gorge is the home of the Cheddar Pink, Dianthus gratianopolitanus, the county flower of Somerset, and an endangered species although fortunately one that is showing good signs of recovery. The area is also well known as the unique habitat of a number of Sorbus species related to the whitebeam, Sorbus aria. These and other local plants are now being maintained in an area of gardens.

The old garden had built up a collection of plants used in Chinese herbal medicine and it was decided to relocate these to the new site as part of the 'useful plants' collection. The garden has worked closely with Dr Tony Harrison a local herbalist and leader of the Register of Chinese Herbal Medicine to collect the species and group them according to their mode of action. The collection (pictured right) provides not just a reference for those interested in herbal medicine but a valuable resource for those wishing to investigate the active principles within the plants. It also provides a valuable link with China, Chinese money and helps bring fee paying students essential to the university's financial well-being.

The move to the Holmes gave the garden a unique opportunity to reorganise parts of its collection to reflect the new classification of flowering plants established by the Angiosperm Phylogeny Group (APG III). This classification, based on analysis of the cumulative changes in DNA sequences, has shown that the traditional view where the Monocotyledons and Dicotyledons diverged from a common ancestor is invalid. The primitive Magnolids including Magnolias, Laurels and Peppers are more ancient than the monocotyledons. Three further groups are even more primitive; the Nymphales (water lilies), Austrobaileyales and the Amborellales.

The most primitive, the Amborellales, is represented by one remaining species, Amborella trichopoda from the Pacific island of New Caledonia. Although it flourishes on the island, cultivation has proved difficult and Nick Wray was proud to show off the five plants that the Botanic Garden has managed to propagate from the 12 seeds originally collected. The species' primitive vascular system makes them prone to dessication so to emulate the plant's natural environment as a tropical under-shrub the plants are currently grown in the shade of a somewhat Heath Robinson-style pile of plastic trays (pictured right). Unorthodox this may be, but it has enabled them to get both male and female plants to flower, and they now have fruit developing.

See also UK Taxonomy and Systematics Review, published in Horticulture Industry News below

Plant of the Month

Rhus typhina, staghorn sumac, Anacardiaceae

A common sight in 1970's style front gardens, this small tree is more interesting than it might at first appear! 'Rhus' was the Greek name for the species Rhus coriaria and 'typhina' means resembling Typha (bulrushes) - after the persistent inflorescence perhaps.

The Anacardiaceae (or cashew family) comprises several hundred species mainly from the tropics but also the Mediterranean region, East Asia and America. The cashew (Anacardium occidentale), mango (Mangifera indica), poison ivy (Toxicodendron radicans see 'ivy inquiry' in our Ask a Horticulture Scientist page) and smoke bush (Cotinus coggygria) are all in this family - an interesting combination of toxic and economically important plants!

The staghorn or velvet sumac (picture right by Alison Foster) is originally from Eastern North America is high in oils and polyphenols and is an important tannin source. The fruit are used to make a pink lemonade by soaking them in water. All parts of the plant except the roots can be used as a dye, indeed the North American colonists knew the tree as dyer's sumach for the yellow dye they made from it.

In the garden, it will grow in almost any conditions, but will survive on particularly dry and poor soil where other plants fail to thrive. The sumach flowers through the early part of the summer and is a dioecious tree, with male and female flowers on separate plants. On the female trees, the flowers set fruit and these are dense clusters of drupes up to 20 cm long. The leaves make for a stunning autumn display as they turn a vibrant red colour. Long after the leaves have been shed the fruits remain right through the winter and can still be seen on the tree when the next season's flowers are present.

There is however, a word of caution. This tree will colonise a large area if left unchecked. It spreads by both seed and rhizomes but with a little careful tending makes a useful addition to many gardens.

Alison Foster
Oxford Botanic Garden

Medicinal Plant of the Month

Galega officinalis, goat's rue, Fabaceae

With its milky white flowers, you may be forgiven for thinking this plant was named after the colour of the petals but it was in fact named because it was thought that feeding on this plant would improve the flow of milk. It has been widely used as a forage crop for small domestic animals, such as goats, for just that reason. Flowering through the middle of the summer, this herbaceous perennial makes an excellent plant in the herbaceous border but has many uses beyond being ornamental.

Galega officinalis (picture right by H. Zell) has long been used as a treatment for diabetes. It has been found to contain galegine and guanidine, nitrogen containing molecules that have anti-diabetic activity. Modelled on these compounds is metformin - a bis-guanidine structure that is used to sensitize cells to insulin so that smaller quantities of insulin can be taken. A 20 year landmark study - the UK Prospective Diabetes Study (UKPDS) run by two Oxford academic clinicians has shown that metformin significantly improves the outcome of patients with Type II diabetes. Those taking metformin have a longer life expectancy, due to lower levels of side-effects such as vision loss, foot and such leg problems as skin ulcers, infection, necrosis and even gangrene associated with Type II diabetes.

And if all this wasn't enough, the stem pulp can be used to make paper!

Alison Foster
Oxford Botanic Garden

News from our Associates

National Horticultural Forum
The NHF is in the process of preparing a paper on 'A New Vision for Horticulture R&D'. Anyone who feels they may have views should contact our representative, Geoff Dixon.

Horticulture Industry News

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UK Taxonomy and Systematics Review published
In response to the House of Lords Science and Technology Committee report, highlighting concerns over the state of taxonomy and systematics in the UK, the Natural Environment Research Council commissioned a study on behalf of all research funders in this area. The study comprised two parts: 1) The UK Taxonomy and Systematics Review, which provides quantitative data on the current state of the subject in the UK, as requested by the Science and Technology Committee: 2) A document, Developing a National Strategy in Taxonomy and Systematics, exploring the need for a national strategy in this area and how it might be developed. A full response to the study will be published online by the end of July 2011.

Science as a public enterprise
The Royal Society is undertaking a new, major policy study on the use of scientific information as it affects scientists and society. It will ask how scientific information should be managed to support innovative and productive research that reflects public values. They welcome submissions as soon as possible, and before the 5 August 2011.

Plants clean air of formaldehyde
Formaldehyde is a major contaminant of indoor air, originating from particle board, carpet, window coverings, paper products, tobacco smoke, and other sources. Indoor volatile organic compounds (VOCs) such as formaldehyde can contribute to allergies, asthma, headaches, and a condition known as 'sick building syndrome' and could be responsible for more than 1.6 million deaths per year and 2.7% of the global burden of disease. Test have been conducted on the efficiency of volatile formaldehyde removal in 86 species of plants representing five general classes (ferns, woody foliage plants, herbaceous foliage plants, Korean native plants, and herbs).

Ferns had the highest formaldehyde removal efficiency of the five classes of plants tested, with Japanese Royal Fern, Osmunda japonica (similar to Osmunda regalis pictured right by Christian Fischer), determined to be most effective of all 86 species, coming in at 50 times more effective than the least efficient species, Dracaena deremensis. More

Foreigners are not all bad...
Conservationists and land managers should no longer use the origins of plant species as a guiding principle for policy and management decisions, argues a team of ecologists led by Marc Davis. Instead, they should focus on the function of plant species and whether they benefit or threaten biodiversity, human health, ecological services and economies. The idea of plant 'nativeness' was introduced in the mid-19th century, leading to the discipline of 'invasion biology' in the 1990s. But there is little evidence to support the claim that non-native species are the 'enemies of man and nature', say the authors. In fact, recent research suggests that alien species can be beneficial as they tend to increase the number of species in most environments, for example. More and More

... and the natives can be unfriendly
'Thugs' are plant species that bully others, take over the landscape and destroy ecosystems. While it's perhaps unexpected to hear of plants acting this way, what is really surprising is that these so-called thugs are home-grown. We usually assume that species wrecking havoc this way are exotic aliens; invasive 'outsider' species that have colonised our land and which now hold dominion over our somehow more natural, vulnerable wildlife. A new research study published by scientists in the Kew Bulletin fingers three native species of particular concern: brambles, bracken and ivy. These three species, according to the study, may do more damage to British woodlands than either rhododendron or sycamore, which are both invasives. Professor Rob Marrs of the University of Liverpool and colleagues have quantified their impact for the first time. They used mathematical analysis to work out which environmental factors, such as climate, soil, or land management, were important in controlling the composition of these species and showed that, on a nationwide scale, thugs such as bramble, bracken and ivy appear to influence what vegetation grows in our woods more than rhododendron or sycamore. They actually cause four times the variation in natural flora compared to the aliens. More

GM Aphid resistant wheat for trialling?
Rothamsted Research have submitted an application to the Advisory Committee on Releases to the Environment (ACRE) for permission to carry out a GM field trial in 2012 and 2013. The purpose of this trial is to test whether GM wheat plants capable of making an aphid pheromone alarm are better able to resist aphids under field conditions. They expect to hear from ACRE in 3 to 6 months time. The aphid resistance gene has been synthesized but is similar to a gene found in peppermint (Mentha x piperita) and hops (Humulus) and over 300 varieties of plants. It enables the plant to produce the sesquiterpine, (E)-beta-farnesene (EBF), the chemical aphids produce to warn others to keep away. More and More

Heavy snow alters ecological balance
Heavy and prolonged snowfall can bring about unexpected conditions that encourage fungal growth, leading to the death of plants in the Arctic. An international study confirms that whilst snow has an insulating effect which helps plants to grow bigger, heavy and prolonged snow can, in certain circumstances, also encourage the rapid and extensive growth of killer fungal strains. Extensive damage to a pervasive species under snowier conditions would leave gaps for another plant to take its place over time but could also alter the whole food-web. Researchers used snow fences to maintain increased snow conditions, and found that the fungus, Arwidssonia empetri, increased under heavier and prolonged snow cover killing the majority of the shoots of one of the dominant plant species in that area - the dwarf shrub Mountain Crowberry, Empetrum hermaphroditum (pictured right by Ante Aikio). More

Faster DNA analysis
An international team of researchers has developed a new DNA technology which makes it possible to perform reliable analyses on DNA quantities that are a thousand times smaller than was previously the case. The method can be used, for example, to study small quantities of stem cells, starting tumour tissue, parts of plant and animal tissue, and archaeological samples. The new method is published in Nature Methods under the name LinDA. The main difference between LinDA and commonly used methods is how DNA molecules are copied to make them identifiable in analysis equipment. With existing PCR based methods, DNA fragments are amplified exponentially while LinDA DNA is amplified linearly. The latter is in particular attractive for the identification and quantification of low abundant DNA (or RNA) fragments. More

Resistant plant pumps glyphosate into cell vacuole
Conyza canadensis (Pictured right by Rasbak), variously called Canadian fleabane, mare's tail or horseweed, a fibrous biennial plant that can grow to be six feet tall is one of the most serious glyphosate resistant weeds in the US. In a soybean field, it can reduce yields by more than 80 percent. Researchers sprayed Conyza plants with glyphosate and then examined living leaf tissue in a Nuclear Magnetic Resonance (NMR) instrument. They found that they could distinguish the glyphosate signal from those of other phosphorus-bearing plant metabolites, including the ubiquitous energy-storing molecule adenosine triphosphate (ATP) but found two glyphosate signals at slightly different resonance frequencies. The first signal was coming from glyphosate in the cell cytoplasm and the second from glyphosate in the plant vacuole. Within 24 hours, resistant Conyza had managed to shuttle 85 percent of the glyphosate into the vacuole. Sensitive Conyza, on the other hand, had disposed of only 15 percent of the glyphosate in this way. The researchers believe resistant horseweed has a pump in the tonoplast (the membrane surrounding the vacuole) that actively shuttles glyphosate into this storage compartment where it can no longer interfere with the critical biological reactions taking place in the chloroplast. More

Growing point decides which way to bend...
The process of phototropism by which plants grow towards light, is well-documented in grasses, but has been difficult to resolve in 'dicotyledons' (see Bristol Botanic Garden above). Research in the model plant Arabidopsis thaliana now shows that the hormones that cause phototropism are distributed from the tip of the plant rather than where the plant's stem bends as had been thought. The bending is known to be controlled by the plant hormone auxin. For the past decade, it had been thought that auxin was transported down the stem of dicot plants and then moved laterally to epidermal areas to cause bending. A team from the Universities of Glasgow and Purdue, have found that the auxin instead is redistributed laterally at the plant tip and then moves down to the bending point, as is the case in grasses. More

...while enzyme control their stretch
Researchers have found that an enzyme called protein phosphatase 2A, or PP2A, regulates ethylene production. PP2A is a relatively common enzyme that removes phosphoryl groups from proteins to control which proteins are active in the cell. PP2A also removes phosphoryl groups from different versions, or isozymes, of the plant protein acetyl-CoA synthetase (ACS), a key enzyme involved in regulating ethylene production. They found that dephosphorylation of several isozymes of ACS was necessary to reduce the production of ethylene in embryonic plants, but dephosphorylation of at least one isozyme positively regulated ethylene production. When embryonic plants produced less ethylene, their cells elongated, a necessary process for the plants to break through the soil and reach sunlight.

Testing the air to avoid pesticide overuse
A testing kit has been developed so that growers can detect airborne diseases before they infect crops. Produced by the National Pollen and Aerobiology Research Unit (NPARU) based at the University of Worcester. Professor Roy Kennedy, director of the NPARU, said 'It means farmers no longer have to waste time and money spraying crops when there is no disease in the air'. Growers can check online when the crop is at risk from infection and on days when there is a high reading they can use the testing kit in their fields to determine whether disease is in the air. Fred Tyler, a spokesman for a co-operative of small growers, said: 'The kits show great promise in reducing the amount of pesticides required to control disease in crops.' More

Quotes of the Month

'Ignorance more frequently begets confidence than does knowledge'.

Charles Darwin

Events Calendar

Other Events of Interest

Medicinal, Aromatic and Nutraceutical Plants from Mountainous Areas
6 - 9 July, International Society for Horticultural Science
Saas-Fee, Switzerland

Bee ecology and pollination in the agricultural landscape
7 July, Society of Biology
Hatfield UK

Ohio Short Course
9 - 12 July, Ohio Florist Association
Columbus, USA

The co-evolution of bees and flowers
11 July, Society of Biology
Farnborough, Kent, UK

The Woking Show
13 July, The Woking Nurseries
Worplesdon, UK

Quality Management of Fresh Cut Produce: Convenience Food for a Tasteful Life
17 - 21 July, International Society for Horticultural Science
Turin, Italy

Fruit Focus
20 July, Haymarket Media Group
East Malling, UK

Eastgro Horticultural Trade Show
3 Aug
Diss, UK

Medicinal and Aromatic Plants
16 - 19 Aug, International Society for Horticultural Science
Petén, Guatemala

Keeping Pesticides out of Water Workshop
17 - 18 Aug, Association of Applied Biologists
Wageningen, The Netherlands

Plantarium
24 - 27 Aug,
Boskoop, The Netherlands

Four Oaks Trade Show
4 - 6 Sep
Lower Withington, UK

Spoga Gafa Trade Fair
4 - 6 Sep, Koelnmesse
Cologne, UK

Saltex
6 - 8 Sep, Institute of Groundsmanship
Windsor, UK

Mycotoxins in Nuts and Dried Fruits
10 - 12 Sep, International Society for Horticultural Science
Damghan, Iran

Fruit Breeding and Genetics
11 - 15 Sep, International Society for Horticultural Science
Warsaw, Poland

Genetically Modified Organisms in Horticulture Symposium
11 - 15 Sep, Eucarpia
Mpumalanga, South Africa

European Whitefly Symposium
11 - 16 Sep, The Hebrew University of Jerusalem, Tel Aviv University and Volcani Center
Rehovot, Israel

Flormart
15 - 17 Sep, PadovaFiere
Padova, Italy

Naivasha Horticultural Fair
16 - 17 Sep, see also Commercial Horticultural Association
Naivasha, Kenya

Integrated Control in Protected Crops, Temperate Climate
18 - 22 Sep, Association of Applied Biologists
Sutton Scotney, UK

In Vitro Culture and Horticultural Breeding
18 - 22 Sep, International Society for Horticultural Science
Ghent, Belgium

Exocytosis in animals, fungi and plants
19 - 21 Sep, Society of Experimental Biology
London, UK

Biomass and Energy Crops
21 - 23 Sep, Association of Applied Biologists
Champaign, USA

IPM Dubai
26 - 26 Sep, Messe Essen
Dubai, UAE

If you would like to advertise a forthcoming event please contact. zoe.daniel@soci.org

Horticulture Group Contact Details

For submitting ideas or to volunteer to be part of a committee or a group, please contact:

Chairman - Peter Grimbly
Meetings Secretary - Marion Stainton
Minutes Secretary - Margaret Waddy
Newsletter Co-ordinator - Sue Grimbly, E: scihortigroup@btinternet.com
Group Coordinator - Zoe Daniel zoe.daniel@soci.org T: +44 (0)20 7598 1594