Genetic markers for seed purity

ICRISAT, with the support of Irish Aid, is taking a comprehensive approach to seed sector development.  My recent post on Tanzania identified poor quality foundation seed as a significant factor in the supply chain.

Recently, I met ICRISAT Biotechnology scientist Santie de Villiers in Nairobi.  She is leading the development of a genetic fingerprinting initiative as part of the ICRISAT-Irish Aid Malawi project.  When she told me about her work, I asked her if she would write something for us.  This is what she sent (thanks, Santie!):

When crops are sold as seed, it is very difficult to differentiate seed from grain.  This is problematic since seed has  to be of high quality and genetically “true to type” to ensure that farmers achieve good yields. To test seed purity conventionally, seed samples are drawn from seed lots and grown out so that the morphological features of the plants can be compared against a set of descriptors. But this takes time and is expensive.

Alternatively, similar samples of seeds drawn from lots can be tested for purity by using a small set of molecular markers that can “genetically fingerprint” varieties. Such markers can be used directly on the seeds or on very small seedlings, and can therefore be applied at any time of the year. There is no need to grow plants to maturity to tell whether they are true to type. This method is not only quicker but also cheaper and can be done anywhere in the world where the appropriate technology exists. A farmer, breeder or seed company can send a few seeds to be analyzed for a small fee per sample and the results will be available within a few weeks, compared to a full growth season for conventional purity testing.

In a project funded by Irish Aid in Malawi, ICRISAT is now testing available molecular markers to determine which are suitable to use for genetic fingerprinting of groundnut and pigeon pea .  This will assist both breeders and seed regulatory agencies in ensuring that seed quality standards are maintained through maintenance breeding.

This is a modest intervention – relatively inexpensive, and launched in response to observed needs “on the ground”.  The outputs of this research are scaleable – the technology can easily be made available in other countries.  At this time of increased need to address food security with limited funding, this is one of several models which have been incubated by the ICRISAT-Irish Aid Malawi project.  I’ll be writing a post on a comparable software project in the near future. These are what I’d describe as smart investments in scaleable, need-driven interventions.

Post written by Peter Bloch, consultant to CAS-IP