Ontogenesis of Vascular Tissue in Haustoria of Santalum album L

Abstract:

In order to understand the development of vascular tissue in Santalum album haustoria, the ontogenesis of vascular tissue in haustoria was observed under laser scanning confocal microscope, light microscopy and transmission electron microscopy. The results showed that the differentiation of haustorium vascular tissue in S. album could be divided into two stages:before and after invasion. The differentiation of vascular tissues of haustorium begin at disk-shaped stage, originating from meristematic cells at thebase of haustorium, and then, they divided into two bunches. Before invasion, the vascular tissues of haustorium are located at the base of haustorium without apical differentiation. After invasion, the vascular tissue started to differentiate and connect into the host roots with absorption function. The vascular bundles of mature haustorium was inverted flask-shaped, and exist on two sides of kernel region. The vascular tissues contained only xylem without phloem. It was proposed that the development of haustorium vascular tissue of S. album was induced by two factors, genetic factor and host root factor. Therefore, these would provide a anatomic basis for studying on semiparasite in Santalum album.