M (Marije) Scholte PhD

Raphanus sativus subsp. Oleiferus (fodder radish) is used as a cover crop to add organic nutrients, to improve the soil's texture, to prevent erosion and to capture carbon. Furthermore, nematode resistant R. sativus varieties can serve as alternatives to chemical products used to control plant-parasitic nematodes. In resistant plants the nematodes do enter the roots, but after penetration they cannot complete their life cycle. As a result, the reproduction of nematodes will decrease. 

Several R. sativus varieties were bred that carry resistance against the nematode species Heterodera schachtii and Meloidogyne chitwoodi and combinations thereof. These varieties were bred by successive rounds of phenotypic selection and crossing. Raphanus sativus is an allogamous crop and each plant has a unique genotype. Since each plant can only be phenotyped for only one trait per generation, the breeding of resistant varieties and pyramiding of resistances against different nematodes takes great effort.

In my EngD research we will develop marker-assisted selection to speed up the breeding process. We will use Raphanus sativus lines expressing contrasting phenotypes for resistance against e.g. Heterodera schachtii and Meloidogyne chitwoodi. Using QTL mapping techniques we aim to map the traits to allelic variation that can then be tracked for breeding purposes.