Today’s entry for the UBC Research Week series is courtesy of Kevin Kubeck (Greenhouse Manager / Horticulturist in the UBC Department of Botany) and Hannes Dempewolf, a graduate student in botany, who you may remember from the series last year on underutilized species. The photographer is Daniela Horna, who works for the International Food Policy Research Institute in Washington, D.C.
Kevin writes (with input from Hannes):
Here is a project to tantalize the taste buds as well as a great example of collaboration.
Theobroma cacao L. (Malvaceae) has already been featured on BPotD, so I’ll give some additional information in the context of this specific project.
World Cocoa Foundation, an umbrella group for sustainable cacao farming, remarks that there are between 5-6 million cacao farmers worldwide with a production of 3 million tons per year. Similar to coffee production, most of the cacao farming takes place in tropical regions of the world where issues of fair trade, economic and agricultural sustainability as well as biodiversity are tantamount. The hope is to increase the value of the cacao product, by identifying the best varieties for each region. Like a fine wine, single-source chocolate commands a better price on the market because of its gourmet qualities.
In a partnership between Bioversity International, the Ministry of Agriculture of Trinidad and Tobago, the Cronk and Rieseberg Labs, the USDA and the World Bank, PhD candidate Hannes Dempewolf hopes to use molecular techniques to address issues of interest to cacao farmers.
The primary goal is to try and find genetic markers that identify specific varieties of cacao, a chocolate fingerprint if you will. Many traditional markers rely on chromosomal DNA but these can confound lineages because chromosomes are inherited from both parents. Plastid DNA, the small circular DNA inside chloroplasts can be a more reliable test for lineage because the plastids are inherited maternally. The caveat is that the plastid is harder to isolate — a requirement for the subsequent sequencing step. Recent advances in ‘high throughput’ sequencing have opened up the possibility of rapidly sequencing multiple entire plastid genomes in order to compare them and identify variable regions for the establishment of a standardized fingerprinting method. This DNA fingerprinting technique can then be used to identify specific varities, allowing chocolate traders, exporters and manufacturers to reliably identify and trace varieties along the value chain. Chocophiles rejoice!
Theobroma used to be placed in the Sterculiaceae, but has been moved recently into the Malvaceae along with several other well known genera in families such as Bombaceae and Tiliaceae. The Malvaceae Info site details and displays the species now placed in the Malvaceae by the Angiosperm Phylogeny Group.