Cytotaxonomic Study of 12 Species in the Polypodiaceae from Southern China

Abstract

Chromosome numbers and reproductive biologies of 12 fern species from eight genera in the Polypodiaceae, (Colysis, Lepidogrammitis, Lepisorus, Microsorium, Neolepisorus, Phymatopteris, Phymatosorus, and Pyrrosia) from the southern region of China (Yunnan, Guangxi and Hainan) were investigated. The base number is x = 36 in these genera of Polypodiaceae. The chromosome numbers for four species: 2n = 72 (2x) in Lepidogrammitis drymoglossoides, 2n = 72 (2x) in Neolepisorus ovatus, 2n = 72 (2x) in Phymatopteris rhynchophylla, and 2n = 72 (2x) in Phymatosorus hainanensis are here reported for the first time. Four records: 2n = 72 (2x) in Colysis hemionitidea, 2n = 72 (2x) in Lepisorus thunbergianus, 2n = 108 (3x) in Phymatopteris crenatopinnata, and 2n = 108 (3x) in Phymatosorus cuspidatus are new cytotypes. Lepisorus thunbergianus 2n = 72 (2x) has the base number of x = 36, diverging from those cited in previous reports (x = 25, 38, 50, and 51). The reproductive type in P. crenatopinnata and P. cuspidatus is apogamous, whereas in the other species it is of the sexual reproductive type.