Phellinus species on Betula. Mating tests, RFLP analysis of enzymatically amplified rDNA, and relations to Phellinus alni

摘要

Mainly based on collections from Fennoscandia, Estonia, and Central Europe, four species of the genus Phellinus Quel. (Hymenochaetaceae), all belonging to the P. igniarius (L.:Fr.) Quel. group, are shown to occur on Betula L. These species are P. nigricans (Fr.) P.Karsten, P. cinereus (Niemelae) Fischer, P. laevigatus (Fr. ex P.Karsten) Bourd. & Galz., and P. lundellii Niemelae. The occurrence of P. igniarius and P. alni (Bond.) Parm, on Betula remains in doubt. P. alni, P. nigricans, P. cinereus, P. laevigatus, and P. lundellii were characterized by pairing tests of single spore mycelia and RFLP (restriction fragment length polymorphism) data of enzymatically amplified ribosomal DNA. A unique RFLP phenotype was assignable to each species except P. nigricans, which was identical with P. alni. Distribution of the taxa is throughout the area under study; however, P. nigricans seems to be limited to Fennoscandia. Two stocks from North America proved to represent P. cinereus. Pairing relationships between P. nigricans, P. cinereus, and P. alni were examined in detail and were found to differ according to the geographic origin of the stocks. P. nigricans was positive in numerous pairings with P. alni from Fennoscandia, Estonia, and Central Europe. In addition, it is positive with P. cinereus from Fennoscandia, but negative with P. cinereus from Central Europe, Estonia, and the United States. P. laevigatus and P. lundellii were intersterile with all other taxa.