Horticulture Group Newsletter May 2016

6 May 2016

This year we had 15 applications for the David Miller Travel Bursary Award. These are currently being reviewed by the panel of judges and the winners will be annnounced by mid-May. Thanks to continuing support from Vitacress , The Eden Project and the help of a new sponsor, The Eric Gardener Memorial Fund, we are able to offer two awards of £500 each this year.

This month on 10 May we will be visiting Leigh Court Farm and Tyning Climbers in association with the Professional Horticulture Group South West.

On 12 May the Agrisciences Group will be holding their annual Young Researchers in Agri-Food event entitled Food Quality and Sustainability from Plough to Plate at Reading University.

On 26 - 28 May all those interested in viticultue will be heading to Brighton for the International Cool Climate Wine Symposium.

Peter Grimbly


From Tin & Copper to China
Plant of the Month
News from our Associates
Horticulture Industry News
Events Calendar
Horticulture Group contact details
Related Links

From Tin & Copper to China

Lying half way between the china clay quarry that is now the Eden Project and the well-known and much filmed harbour of Charleston, Pinetum Park and Pine Lodge Gardens were developed by Ray and Shirley Clemo who travelled the world collecting seeds and plants to establish their Garden. As a result, it is what is described as a plantsman’s garden with a wide variety of exotic species arranged as often in many ‘English’ gardens into separate areas or rooms each with its own planting and character. Ray Clemo is a locally bred Cornishman, son of an acrobat, and related to the Cornish poet Jack Clemo while his wife, Surrey born Shirley, moved to Cornwall when her father developed his local hotel business.

The site on which they developed their garden is yet another piece of Cornish industrial history having been the location of a tin and copper mine. They had planned to incorporate some full-scale relic of this industry in the garden but the planners refused and they had to make do with the small models of Cornish mines which can still be seen around the centre of the garden.

Chiang LiThe Clemos have now moved on and the garden bought by Chinese businessman, Mr Chang Li (pictured right). He showed us round the twelve ‘rooms’ or gardens that make up the whole with such familiar names as sunken-, cottage-, water- and woodland-garden as well as more unusual names like the slave garden, so called because of the figure which forms the centrepiece of the garden holding a sundial above his head.

As the property's name implies there are also larger areas of arboretum (pictured below) and a relatively newly planted pinetum. There is a small Japanese garden but as yet no Chinese garden, an omission Mr Chang intends to rectify. However, as he explained, it will be a number of smaller Chinese features rather than a single garden.

He described the different philosophy and long history behind the traditional Chinese garden. The first ‘gardens’ of the emperors before 1100BC were similar to the hunting parks of medieval England; semi-wild areas like the New Forest and Richmond Park. During the first millennium AD smaller enclosed gardens referred to as ‘Scholars Gardens’ were created by government officials. These gardens were inspired by classic legends and poetry.

arboretumMr Chang described a typical Chinese garden as 40% architecture, 40% landscape and 20% plants. Furthermore he said, the plants would usually be native plants from the locality rather than many imported species we are familiar with. However, bearing in mind the number of Chinese species that have become part of our normal plantings, perhaps they did not have to look so far.

This usual balance of hard and soft features has led at least one author to describe the traditional Chinese garden as 'confusing and dense, dominated by huge rock-piles and a great number of buildings all squeezed into innumerable, often very small spaces'. It may explain why Mr Chang plans to separate these small spaces rather than jumble them all together in a manner that western tastes will find confusing.

Like the ‘rooms’ of many English Gardens such as Hidcote and Sissingshurst a Chinese garden is not meant to be viewed all at once. Instead it should be a journey through the architecture with pleasant views and glimpses of different parts of the garden and above all it should avoid symmetry. The plants, although a minor element, are still regarded as important not just for their beauty and tranquillity but also for their symbolism. Thus the orchid represents nobility, the peony opulence and the lotus integrity and balance.

It will be interesting to return in a few years and see what Mr Chang has created.

Peter Grimbly


Plant of the Month

Rhododendron spp., Ericaceae

rhododendronThe genus Rhododendron (including azaleas) is well known to gardeners for its stunning displays of colourful flowers. At this time of year, there are gardens across the country glowing with a multitude of colours from yellow through orange and red to vivid purples and lilacs – and all down to rhododendrons.

The genus consists of about 1,000 species, although there is ongoing taxonomic debate about the exact number. The main centres of diversity for this genus are in the Himalayas and in South East Asia, although there are representatives from across the temperate areas of the northern hemisphere, including Europe and North America.

‘What is the difference between a rhododendron and an azalea?’ must be the key question for gardeners concerning this groups of plants. Azaleas are a horticultural subgroup of the genus Rhododendron, thus making all azaleas actually Rhododendron. Azaleas can be distinguished by having five stamen rather than the ten or more in the other members of the genus. They are all small to medium shrubs and, although there are evergreen azalea, the majority of cultivars developed are deciduous.

Rhododendron_ponticaWhile a quarter of Rhododendron species are under threat in the wild, Rhododendron ponticum (picture right by Karduelis) is a species of concern for an altogether different reason. Originally introduced into cultivation by Kew in 1763 from a collection in the Gibraltar region, this plant is now considered an invasive and aggressive weed. It was initially planted as an ornamental itself and was later used as a rootstock for less hardy species and cultivars. With its abundant flowering in late spring, Rhododendron ponticum could provide a copious nectar resource for native pollinators. However, the nectar of some plants contains specialised metabolites usually associated with defence against herbivores. The impacts of these compounds on pollinators are often unknown. Kew scientists are studying these toxic nectar compounds, called grayanotoxins, in Rhododendron ponticum and looking at the levels in both native and non-native populations. They have shown that there is a substance in the nectar that is toxic to honeybees but not to bumblebees. However, the levels are lower in the non-native populations than in plants growing in the native range.


The general structure of the grayanotoxins

Read more at:
Arnold, S. E. J., Arnold, S. E. J., Peralta Idrovo, M. E., Lomas Arias, L. J., Belmain, S. R. & Stevenson, P. C. (2014). Herbivore defence compounds occur in pollen and reduce bumblebee colony fitness. Journal of Chemical Ecology 40: 878–881.

Teideken, E-J, Stout, J. C, Egan, P., Stevenson, P. C. & Wright, G. A. (2014). Bumblebees are not deterred by ecologically relevant concentrations of nectar toxins. Journal of Experimental Biology 217: 1620–1635.

For more on Rhododendrons at Kew see: Plant of the Month Tour May 2016

Alison Foster
Royal Botanic Gardens Kew


Medicinal Plant of the Month

Ledum palustre, Labrador tea, Ericaceae

Rhododendron_tomentosumOne of the three closely related species that are all commonly known as Labrador tea, Ledum palustre, is just one of the botanical names that this plant has been known by. Others include Rhododendron tomentosum and Rhododendron palustre.

This species originates from the very northern-most parts of North America, Europe and Asia growing in peaty soils with other shrubs, lichen and moss. All parts of the plant, including the leaves are reported to contain bioactive substances that affect the central nervous system. Symptoms range from headache (just from the smell), through to dizziness, spasms, nausea and unconsciousness. The substances the plant contains are terpenes and the major component is called ledol, with ascaridole present in smaller amounts.

Traditionally, the leaves were made into a tea which was used in herbal medicine to treat a range of conditions but also in shamanistic practices.


Further reading:
Natural Product Research, Volume 29, Issue 11, 2015, pp999-1005.
Sameh Baananou, Edita Bagdonaite, Bruno Marongiu, Alessandra Piras, Silvia Porcedda, Danilo Falconieri & Naceur A. Boughattas.

Note on naming:
The Plant List has Ledum palustre as the currently accepted name, with other names as synonyms.

Alison Foster
Royal Botanic Gardens Kew


News from our Associates

CHACommercial Horticultural Association
This October (26 - 27) CHA are launching GrowQuip, a major new international conference and exhibition for the commercial horticultural industry. To be held at the Stratford Manor Hotel, Stratford on Avon, GrowQuip will feature a one day conference followed by a trade exhibiton. On 27 October the trade exhibition will be open to all growers free of charge. For details of the conference, exhibitor packages and sponsorship opportunities visit the CHA website.


Horticulture Industry News

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Genetic tolerance to ash dieback identified
Scientists have identified the first ash tree in the UK that shows tolerance to ash dieback, raising the possibility of using selective breeding to develop strains of trees that are tolerant to the disease. In one woodland in Norfolk, a great number of trees are infected. However, there are exceptions which demonstrate very low levels of infection by the ash dieback fungus and here researchers have identified one tree, nicknamed ‘Betty’, as having a strong tolerance to the disease. The researchers
compared the genetics of trees with different levels of tolerance to ash dieback disease. From there, they developed three genetic markers which enabled them to predict whether or not a tree is likely to be tolerant to the disease – even whether it is likely to be ‘mildly’ or ‘strongly’ tolerant. Betty, they discovered, was predicted to show strong tolerance.

Polarized light helps spread disease
The leaves of virus-infected plants reflect light differently to attract the attention of disease-spreading greenfly, new research suggests. Scientists have shown for the first time that plant viruses alter the surface of leaves, influencing how light is polarized and helping insects to potentially 'see' infected plants. Transmission of plant viruses by insects is of huge importance to agriculture and the environment. Much of the historical work carried out has been within the visible wavelengths of light.
However, insects can see polarized light regions, and this research does in fact show that plant virus infection can affect the percentage of polarization of light reflected from leaves – meaning bugs such as greenfly have the potential to 'see' which plants are infected.

Practice makes perfect – even for bees
Scientists have discovered that wild bumblebees are born with the ability to remove pollen from nectarless flowers using high-frequency vibrations. This study is the first to show that the ability to vibrate flowers to extract pollen is an innate behaviour in bumblebees and one that is refined over time and gives a rare insight into the complexity of the pollination services provided by these creatures. Captive bumblebees were studied from their very first exposure to flowers that need to be vibrated to extract pollen and found the creatures instinctively and almost immediately begin vibrating. They also found that over time and with practice, bees are able to tune down their vibrations, removing pollen while potentially saving energy. Initially bees tend to vibrate on the flower petals, but after two or three visits they focus their efforts exclusively on the part of the flower where pollen is produced.

New Centre for Crop Health and Protection
A new Centre for Crop Health and Protection (CHAP) has been established at Warwick University under the government’s Agri-Tech strategy, which was launched in 2013 to ensure that its investment in agriculture delivers material benefits for society and the economy in the UK and overseas. CHAP will lead the way in developing solutions to the challenges facing world agriculture, bringing together the best expertise, knowledge and insight from leading research organisations and industries in the sector. This collaboration between academia and industry will, for the first time, give farmers access to the best and most sustainable technologies, strategies and protocols to improve crop performance, making a real difference at the farm gate. CHAP will be developing novel control technologies to tackle a range of pests and diseases that are responsible for significant crop losses in fresh produce.

‘Organic’ copper sulphate kills stingless bees
Copper sulphate is widely used as a fungicide on organic and conventional crops, and it is also found in some fertilizer products. A new study has found that when used as a leaf fertilizer, it is lethal to the native Brazilian bee known as Friesella schrottkyi. In addition, the study found that sublethal exposure also affected the bee's behavior. The researchers collected four beehives and observed the activity of adult worker bees. They were surprised to find that, under oral exposure, the copper sulphate fertilizer killed all of the test bees within 72 hours, and was more lethal than the spinosad control. Copper sulphate and spinosad also led to the bees eating twice as much food as non-exposed bees, further underscoring the risk of exposure to copper sulphate. Take-off and flight activity was also much higher for workers exposed to copper sulphate. Simple contact with copper sulphate (such as brushing on legs) did not result in such severe effects, but did continue to increase food ingestion.

What makes plants 'clot'
Not much is known about the tiny communication channels between cells called plasmodesmata due to the technical challenges associated with their study. Researchers have recently been studying how plant cells regulate plasmodesmal gating to either facilitate or block intercellular movement in response to environmental challenges. Their finding made the connection for the first time that plasmodesmata are closed when plants are attacked by microbial pathogens as an innate immune response. It is almost as if plants are guarding the intercellular passageways limiting food supply or distribution, which would deter the invading pathogens like bacteria to proliferate. This latest research shows that in addition to closing the pathways due to immune response, the pathways are also closed in response to mechanical wounding.

A different route to anti-cancer compound
New research has revealed how a plant used in traditional Chinese medicine produces compounds which may help to treat cancer and liver diseases. The Chinese skullcap, Scutellaria baicalensis, is traditionally used as a treatment for fever, liver and lung complaints. Previous research on cells cultured in the lab has shown that certain compounds called flavones, found in the roots of this plant, not only have beneficial anti-viral and anti-oxidant effects, but they can also kill human cancers while leaving healthy cells untouched. As a group of compounds, the flavones are relatively well understood. But the beneficial flavones found in Huang-Qin roots, such as wogonin and baicalin, are different: a missing -OH (hydroxyl) group in their chemical structure left scientists scratching their heads as to how they were made in the plant. The latest work explored the possibility that Huang-Qin's root-specific flavones (RSFs) were made via a different biochemical pathway. Step-by-step, the scientists unravelled the mechanism involving new enzymes that make RSFs using a different building block called chrysin.

Researchers are brewing up medicines from beer hops
Traditional medicine has long used hops for everything from sedation to combatting infections. And researchers have noted that the plant’s chemical constituents appear to have anti-inflammatory, antibacterial, and anti-cancer activities. Yet chemists are still working out all the chemicals responsible for the potentially therapeutic effects and how to use them to brew up new medicines. Now, with two new studies, researchers report that they’re getting closer to pinning down and optimizing hop-based medicines. In one study a team of Italian researchers identified three previously unknown chemicals one of which has clear anti-inflammatory properties. In a second study researchers report figuring out a streamlined procedure for making synthetic versions of two key hop chemicals, humulone and lupulone, which are known to have antimicrobial and anticancer activity. With their artificial versions, the researchers plan to make an assortment of chemical tweaks to optimize the compounds for disease-busting drugs.


Events Calendar

SCI Horticulture Group events

Other Events of Interest:

Plant developmental evolution
15 - 19 May 2016, New Phytologist Trust
Beijing, China

Role of Plant Genetic Resources on Reclaiming Lands and Environment Deteriorated by Human and Natural Actions
16 - 20 May 2016, Plant Genetic Resources Commission of International Society for Horticultural Science
Shiraz, Iran

Post Graduate Horticulture Scientists
12 - 13 May 2016, International Society for Horticultural Science
Palermo, Italy

Light in Horticulture
22 - 26 May 2016, International Society for Horticultural Science
East Lancing, USA

Floral Biology and S-Incompatibility in Fruit Species
23 - 26 May 2016, ISHS Commission of Molecular Biology
Murcia, Spain

International Cool climate Wine Symposium
26 - 28 May 2016
B righton, UK

Iron Nutrition and Interactions in Plants
30 May 2016 - 3 Jun 2016,
Madrid, Spain

Lychee, Longan and Other Sapindaceae Fruits
31 May 2016 - 3 Jun 2016,
Sabour, India

How Plants Sense, Process, Integrate and Store Information
12 - 17 Jun 2016, Gordon Research Conferences
Holderness, USA

Tomato Diseases
13 - 16 Jun 2016, International Society of Horticultural Science
Malaga, Spain

Grapevine Physiology and Biotechnology
13 - 18 Jun 2016, International Society of Horticultural Science
Verona, Italy

Plant Biology for Sustainable Living
15 - 19 Jun 2016, Norwegian University for Science and Technology
Trondheim, Norway

Plant Biotech
19 - 21 Jun 2016, Canadian Association for Plant Biotechnology
Kingston, Canada

Landscape and Urban Horticulture
20 - 25 Jun 2016, International Society of Horticultural Science
Athens, Greece

Enhancing supply chain and consumer benefits: ethical and technological issues
21 - 24 Jun 2016, International Society of Horticultural Science
Cartagena, Spain

Plant Growth Substances
21 - 25 Jun 2016, The International Plant Growth Substances Association
Toronto, Canada

Virus Diseases of Ornamental Plants
26 - 29 Jun 2016, International Society of Horticultural Science
Singapore, Singapore

Multiscale Plant Vascular Biology
26 Jun 2016 - 1 Jul 2016, Gordon Research Confernces
Newry, USA

Exploiting novel sensors for detecting abiotic and biotic stress in crops
27 - 28 Jun 2016, Association of Applied Biologists
Sutton Bonnington, UK

Latin American and Caribbean Agricultural and Forestry Biotechnology
27 Jun 2016 - 1 Jul 2016

Flower Bulbs and Herbaceous Perennials
28 Jun 2016 - 2 Jul 2016, International Society of Horticultural Science
Kunming, China

Arabidopsis Research
29 Jun 2016 - 3 Jul 2016
Gyeong Ju, Korea

Frontiers and Techniques In Plant Science
1 - 21 July 2016, Cold Spring Harbour Laboratory
Cold Spring Harbour, USA

Pollinators, Predators and Productivity
12 July 2016, East Malling Research
East Malling, UK

Transforming Nutrition; Ideas, Policies and Outcomes
12 - 15 Jul 2016, Wageningen UR
Wageningen, The Netherlands

Fruit for the Future
14 Jul 2016, James Hutton Institute
Dundee, UK

Plum and Prune Genetics, Breeding and Pomology
17 - 21 Jul 2016, International Society of Horticultural Science
Freising-Weihenstephan, Germany

Molecular Plant-Microbe Interactions
17 - 21 Jul 2016, International Society for Plant Microbial Interactions
Portland, USA

Genetics and Breeding of Cucurbitaceae
24 - 28 Jul 2016, Eucarpia
Warsaw, Poland

Colonization of the terrestrial environment
25 - 27 Jul 2016, New Phytologist Trust
Bristol, UK


Horticulture Group Contact Details

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

Chairman - Tony Girard
Meetings Coordinator - Peter Grimbly
Minutes Secretary - Margaret Waddy
Newsletter co-ordinator - Sue Grimbly scihortigroup@btinternet.com


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