The Evolution of Magnolia miocenica and 3 Ancient Tea Trees Based on the Anatomic Structure of Xylem

Abstrct: Taking Magnolia miocenica and 3 ancient tea plants at different stages of domestication on the same tea mountain as the research object, through the comparative analysis of xylem anatomical features of M. miocenica and 3 ancient tea plants, to explore the differences and connections between M. miocenica with 3 ancient tea plants in secondary xylem anatomy, and then the evolutionary order among 4 tree species was analyzed. The results show that the relatively primitive characteristics of M. miocenica are shown from the outline of vessel, vessel groupings, type of perforation plates, pattern of intervessel pits, pattern of vessel-ray pitting and height of wood ray. From the perspective of the evolution degree of the 3 ancient tea trees in different domestication stages, the Camellia taliensis was relatively primitive, the Camellia assamica tree was the most evolved, and the Camellia taliensis was in between. In general, there was a continuous evolutionary trend from M. miocenica to 3 ancient tea plants, which further provides a strong basis for the evolutionary process of Theaceae from the perspective of anatomy.