Systematic Studies of Polystichum (Dryopteridaceae) in Japan (I): P. fibrillosopaleaceum var. marginale is a Diploid Hybrid between P. fibrillosopaleaceum and P. igaense

Abstract

Abstract Morphological, cytological, and isozyme studies of three plants of Polystichum fibrillosopaleaceum var. marginale (Dryopteridaceae) from Gotenba, at the foot of Mt. Fuji, Shizuoka Prefecture, Japan, and comparative observations of their lamina, scales, sori, spores, and perispore ornamentation, revealed them to be intermediate between P. fibrillosopaleaceum and P. igaense. Cytologically, the meiotic chromosome number of n = c. 38II + 6I (2x) and the malformed spores of the three plants are characteristic of hybrid sterility. The electrophoretic polymorphisms of four isozymes (Pgi, Pgm-1, Pgm-2, and Skdh) were examined in the three plants and in 22 individuals of the putative parental species, P. fibrillosopaleaceum (11) and P. igaense (11). The heterozygous genetic patterns (Pgi-ab, Pgm-1ab, Pgm-2ab, and Skdh-ab) fixed in the putative hybrids indicate that they have a combination of the Pgi-b, Pgm-1b, Pgm-2a, and Skdh-a alleles of P. igaense and Pgi-a, Pgm-1a, Pgm-2b, and Skdh-b alleles of P. fib...