Seed dormancy and longevity
Seed quality is very important to the Dutch seed companies, which aim for optimized seed production and seed germination. Two major characteristics that control seed quality are seed dormancy and seed longevity (storability). Seed dormancy can be seen as a survival mechanism of plants, to avoid seed germination at moments that do not allow the plant to complete its life cycle. Seed companies apply laborious and costly priming techniques to overcome seed dormancy and speed up and synchronize seed germination. However priming is a pre-germination treatment, which may lead to substantial reduction of seed longevity. Apart from high levels of seed dormancy also the complete lack of seed dormancy causes problems, this leads to pre-harvest sprouting. This is a problem for example in tomato and (sweet) peppers where the seeds already germinate within the fruits. Knowledge on the genetic control of dormancy and seed longevity is essential to breed varieties that have the required level of seed dormancy but that are storable for longer times, so that priming is not necessary or that less laborious “priming” techniques can be applied and problems with storability can be avoided. Previous research using natural genetic variation present in accessions of the model plant Arabidopsis thaliana led to the identification of several positions of the Arabidopsis genome that significantly affect seed dormancy and or seed longevity. Three of the positions that affect seed dormancy co-locate with positions that control seed longevity. It is very important to know if these two seed traits are regulated by the same genes, as most companies are aiming for low levels of seed dormancy and long seed longevity. Here it is proposed to investigate seed dormancy and seed longevity and to develop markers for these traits. A set of advanced genetic materials representing positions on the Arabidopsis genome that control these traits in nature will be studied using gene cloning, genomics and proteomics. This combination of techniques brings robust information about biological functions involved in physiological changes.