Evolutionary System of Magnoliaceae Based on Chloroplast Genomic and Morphological Evolutionomy

Magnoliaceae Juss. are the most primitive taxa of Fructophyta D. L. Fu & H. Fu and have extremely important scientific values for the research of evolutionomy of fruit plants. Based on the evolutionary analysis of the complete chloroplast genomes of representative plants of Magnoliaceae in the NCBI (National Center for Biotechnology Information, USA) database, this paper firstly established the evolutionary systems of subgenera and sections of Magnolia L. and that of sections of Michelia L. and firstly proposed the evolutionary boundary of subgenera of Magnoliaceae Juss.. Magnoliaceae Juss. include 4 natural genera: Yulania Spach, Magnolia L., Michelia L. and Liriodendron L., which all have the same boundary: PHS (17bp) ≥ 0.9234 (intragenus) or PHS (17bp) ≤ 0.9232 (inter genera). The most primitive genus of Magnoliaceae Juss. is Yulania Spach not Magnolia L.. The genus Magnolia L. includes 7 natural subgenera and the evolutionary boundary is PHS (17bp) ≥ 0.938 (intrasubgenus) or PHS (17bp) ≤ 0.937 (inter subgenera). Magnolia subgen. Talauma (Juss.) Pierre includes 3 natural sections, Magnolia subgen. Manglietia (Blume) D.L.Fu includes 4 natural sections and Michelia L. includes 3 natural sections, which all have the same evolutionary boundary: PHS (17bp) ≥ 0.961 (intrasection) or PHS (17bp) ≤ 0.960 (inter sections). Moreover, 4 new subgeneric combinations, 1 new section and 3 new sectional combinations, 14 new specific names and 95 new specific combinations have been scientifically and validly published. This paper scientifically solves the confusion between the traditional classification system and the modern phylogenic system of Magnoliaceae, and lays a solid theoretical and practical foundation for the research of fruit plant evolution.