black&white #06: Securing genetic diversity

3 min steep

Last week I spoke to Dr Paula Bramel, eminent plant geneticist, Professor of Agronomy and consultant at the Global Crop Diversity Trust. We first met at a BBQ, realised a common interest in tea, and met up again to talk about why genetic diversity in tea (coffee, vanilla, sorghum) is so important. 

Genetic diversity helps maintain the health of a species population because each plant has specific characteristics that allow it to thrive in its environment. If that environment changes then a plant population with greater genetic diversity will be able to adapt better - and survive.

The genetic variations also mean that one type of tea plant makes a deliciously smooth black tea, while another repels a particular type of pest. Cultivating huge fields of just one type of cloned tea, a widespread practice in large-scale tea farms, reduces diversity and risks losing the lot in one catastrophe. Think of the potato blight in Ireland or coffee crops in Sri Lanka. Conserving tea samples (or germplasm) in genebanks or seed fields (essentially, a living collection of tea plants) gives scientists and those tea growers the best chance of preserving old teas and breeding new, more resilient and delicious teas. Creating new varieties by cross breeding crops has been done by farmers for thousands of years (and nature even longer).

In our last newsletter, I mentioned that some of the world’s key tea-growing areas are predicted to be badly affected by climate change. In Kenya, for example, studies suggest that optimal tea-growing areas will be reduced by more than a quarter by 2050 because of changing rainfall patterns. Tea-growing regions in India, China and Sri Lanka are also under threat. 

In the face of these dire predictions, securing the genetic diversity of tea is crucial.  Flooding and the waterlogging of farms can prevent tea bushes from releasing the chemicals that help enhance the complex flavours of tea and create its prized antioxidant properties associated with so many of tea's health benefits.

To future-proof against this and to secure the livelihoods of millions of tea growers, Paula has been calling for change at the global level. Her research found that although institutions dedicated to conserving tea exist, there are no formal links between these national institutions and no mechanisms for international collaboration or knowledge sharing. If governments, international organisations (ie FAO and Crop Trust) and NGOs are serious about securing the future of tea in the long term, they need to support tea-conserving institutions, seed fields and genebanks to work together and address some of the most pressing issues in global tea production.

The small-scale, traditional farms and villages from where Canton sources its tea are an essential part of preserving the genetic diversity of tea because so many of them grow old, genetically diverse varieties – unlike the monocultures grown on huge industrial tea estates. So, alongside ethical working conditions, supporting local communities and producing tea sustainably, small-scale tea farms and co-operatives have another thing going for them: they hold the key to the future of tea itself.

- Jennifer Wood, Founder