Evidence for Maternal Ability in Hybridization of Apogamous Fern Species: Dryopteris tsushimense K. Hori & N. Murak. and D. subtsushimense K. Hori & N. Murak. (Dryopteridaceae), New Tetraploid Apogamous Pteridophytes of Hybrid Origin from Tsushima, Japan

Abstract

The Dryopteris erythrosora complex (Dryopteridaceae; subg. Erythrovariae sect. Erythrovariae Fraser- Jenk.) contains many apogamous species showing large morphological and genetic variation. This study reports two new tetraploid apogamous species: Dryopteris tsushimense (D. caudipinna + D. chinensis) and D. subtsushimense (D. chinensis + D. tsoongii). Their parents were postulated by use of a plastid DNA (rbcL) and nuclear DNA (G6PD) marker. Dryopteris tsushimense is similar to D. chinensis in its fresh green lamina, but differs in having narrowly triangular lamina. Dryopteris subtsushimense is also similar to D. chinensis in its fresh green lamina, but it differs in being evergreen lamina and in having scales with a serrated margin. This is the first report of maternal ability in natural populations of apogamous ferns.