In this first blog contribution, we are looking at the genotyping project currently underway and being managed by the Scientific Research Organisation of Samoa (SROS) and Massey University of New Zealand (Massey). This project is part of the wider S.C.I.D.I. project, aimed at reinvigorating the Samoan cocoa export industry and aims to develop a supply of seed material and scion-wood for the SKIA nurseries that is high yielding, disease resistant, and of known parentage. This will enable SKIA to produce more vigorous and robust seedlings and grafted plants from trees selected for their positive attributes. The net effect will be that Samoan farmers will gain access to trees that fruit earlier, and produce a more consistent higher yield than is currently the case.
Genotyping is the act of testing a sample of genetic material of an organism (its DNA), and comparing the results of the test against known results to find similarities and differences for certain physical aspects. High similarities between results means a plant shares the characteristics being tested for.
SKIA is working with S.C.I.D.I. to genotype 200 cocoa trees across 4 sites on both Upolu and Savai’i in our first genotyping project. If successful, SKIA will then consider a second genotyping project to collect another 200 samples from 4 new sites.
This general method of genotyping for the project involves physically visiting each selected cocoa tree and determining its general physical characteristics such as tree shape, size, age, health, average yield, and the believed variety based on the shape and colour of the pods produced, before marking the trees with a label and tape to identify the tree from a distance. The tree’s precise location is then recorded via GPS, and entered into a database.
Once the trees have been marked, a team of scientists visits each tree and takes several leaf samples from each tree. These samples are then taken back to a laboratory, where the scientists extract the DNA from these samples. The DNA is then scanned and turned into data which allows a computer program to compare against other samples collected by this project, as well as other samples recorded in other project databases.
Through this process, the variety of the cocoa tree tested can be authoritatively established. This means that the nurseries will be able to grow, graft, and sell young cocoa plants by variety or cultivar, i.e. Criollo, Trinitario, Forastero, Lafi 7, etc.
Hopefully this gives you a little bit of insight into just one of the many projects SKIA and S.C.I.D.I. are currently involved in, and how SKIA pursues its strategy to revive Samoa’s cocoa industry to better meet the demand of international customers, who want to taste the world-class cocoa that Samoa was famous for, and can become known for again.