Meet the Ancestors (of the past, present and future)

On the John Innes Centre stand this year, three information boards described the different types of plants on the exhibit. These were wild plants, hybrids and new varieties.

Information Board 1 (wild plants)

Crops now cultivated around the world originated from regions with particular seasons, climates and soil conditions. As these crops were spread from their centres of origin they were ‘adapted’ to new environments by selecting for types that thrived under local conditions.

Many wild plants are unsuitable as crops or foods because the characters that we require in a good crop are often the opposite of the characters that enable a plant to compete and survive in a wild environment, such as:

· pods and seed heads that shatter easily to ensure that seeds are dispersed.

· low, straggly, prostrate growth that helps to smother competing plants.

· seed germination spread over a long period to ensure some seed germinates in conditions that are favourable for continuing growth.

· extended flowering to ensure that some seed is set even if adverse weather occurs during the flowering season.

· the presence of toxic chemicals, spines and sticky exudates, which discourage animals from feeding on the plant

Information Board 2 (hybrids)

Some crops are hybrids of wild ancestors (wheat and oilseed rape are two examples) while others demonstrate the extreme differences that can be achieved by selecting for different characteristics within the same species (cabbages and broccoli).

The crops familiar to us from fields and gardens are often the result of thousands of years of selecting for plants that combine the ‘right’ collection of genes to produce plants that are suitable as crops. Consequently, crop plants may be very different in appearance from their ancestors.

There are also less obvious differences that are important in converting a wild plant into a good crop:

· altered chemical composition of starches, oils, proteins and other components of grains and tubers so that the harvested material is better suited to its end use

· changes to the flowering and maturity times of crops to adapt them to particular environmental or agricultural systems

· relatively short flowering times to ensure seeds ripen at a similar time.

· low levels of toxins in the harvested parts of the plant to ensure they are safe for human and animal consumption.

Of course there are trade-offs in developing crop plants, for example some natural toxins may be important in protecting plants against disease and insect attack.

Information Board 3 (new varieties)

Even familiar crops are constantly changing. New varieties of garden vegetables are produced each year in different colours and shapes, with better disease or bolting resistance or improved flavour and keeping qualities.

Breeders use the wild ancestors and relatives of crops as important sources of new characteristics that can be bred into crops to improve their performance in the field or the quality of the harvested product.

The familiar pea has been replaced in many farmers’ fields by a semi-leafless version, because these types are as productive but less prone to disease and easier to harvest than the traditional varieties. A new ‘super sweet’ pea is in development, which has a sweeter taste because this type stores proportionally more sugar than starch in the mature pea.

Current scientific research is exploring how starch and oils are produced in plants. This will potentially lead to new varieties of existing plants (potatoes, peas and oilseed rape) or novel plants (coriander, rocket and marigold) that produce novel starches and oils, which can be used as renewable raw materials for making plastics, paints and other industrial products, and thus replace chemicals manufactured from non-renewable mineral oils.