The Hidden Half


Grapevine (Vitis) from the plant family Vitaceae is a flowing vine plant with 79 different species and is an economically important source of grapes, both for the consumption of the fruit itself and as a fruit which can be fermented to produce wine.  The fermentation of grapes for wine is known to have its origins as early as 5000 BC.

The study of grapevines is called viticulture and at the Julius Kuehn Institute for Grapevine Breeding Geilweilerhof in Germany, grapevines are studied for safe guarding production through studying disease resistance and morphological characteristics in breeding of cultivars for the future. 

Image showing grapevine root system branching out from a cutting planted within soil.

The variety of grapevine shown here for the Hidden Half is unique to the Julius Kuehn Institute, Geilweilerhof.

Grapevines produce clusters of berries known as grapes, which can appear in many colours from white, red, black, blue, green and purple.  They are only produced once during commercial viticulture so it is important that pruning of the previous year’s growth takes place to promote new growth and new fruits for the next season.

Approximately 75,866 square kilometres of the world’s surface is dedicated to growing grapevines with worldwide production around 72 million tons a year. From this 71% is used for the production of wines, 27% for fresh fruit and 2% as dried food.  The largest grape producing country in the world is China, followed by Italy, United States, France and Spain.

3D Root Architecture

This video shows the growth and development of the grapevine cultivar from a woody cutting grown within a soil column after 4 weeks of growth.  In the foliage we can see the veins and structure of the grapevine leaf. The development of roots starts initially from the base of the cutting with around fifteen main roots developing over the four week period.  The upper part of the root system closest to the cutting has also developed a dense mat of lateral roots, whilst lower down these are less developed at this point in time.

Root Anatomy

The image to the left is a cross section through the grapevine primary root using a confocal microscope.

The root anatomy shows secondary growth in the central area (known as the stele) this is growing outwards, crushing the outer cortex cells and breaking the epidermal outer layer.

The star shaped red areas and larger holes in the center are xylem water vessels. The brighter green ring around these are phloem vessels. When fully developed the Phloem will encase the xylem.

Beyond the phloem are a layer of cells called the periderm which protects the vascular tissues (central red ring) and, after stele expansion, eventually replaces the epidermis as the outermost layer.

Grapevine primary root anatomy showing secondary growth.Grapevine Stele cross section



The Hidden Half would like to promote the collaboration of this work on grapevines with the Julius Kuehn Institute for Grapevine Breeding, Geilweilerhof.  The work was conducted through the European Plant Phenotyping Network (EPPN) as part of a broader study by the institute into grapevine breeding and root architecture development. 

European Plant Phenotyping Network
Julius Kuhn Institute

To find out more visit the Julius Kuehn Institute for Grapevine Breeding, Geilweilerhof webpage

Julius Kuehn Institute (Geilweilerhof)

The work conducted on the project is being done by Ronja Schmitz for more information please contact.

Ronja Schmitz



The Hidden Half

Hounsfield Facility (A03)
Sutton Bonington Campus
University of Nottingham
Loughborough, Leics, U.K.
LE12 5RD

Telephone: +44(0)115 951 6786