Screening of somatic hybrids of celery (Apium graveolens L.) and carrot (Daucus carota L.) with the chloroplast marker DcMP

In celery (Apium graveolens L.) breeding somatic hybridization might be used to induce male sterility, to introgress disease resistance, new variation in color and or size, or to increase yield. Therefore, we have developed protocols for protoplast isolation and established conditions that allow plant regeneration from isolated protoplasts. With the aim to induce cytoplasmatic male sterility (CMS) an asymmetric protoplasts electrofusion was performed between IOA treated celery suspension derived protoplasts and UV treated carrot (Daucus carota L.) mesophyll protoplasts. In total 55 independent plants and 6 Weck-jars of micro-plants were recovered 8 months after the asymmetric protoplast fusion. Screening of these regenerants with the chloroplast specific marker DcMP (Daucus carota Mitochondrial Plastid sequence) showed that none of the 55 independent plants contained carrot specific chloroplasts. However, one of the 6 micro-plants samples amplified for both celery and carrot DcMP, confirming the true asymmetric hybridity. Further screening with mitochondrial specific markers will be performed in order to validate the potential of the fusion for the development of CMS in celery.