Interspecific and Intergeneric Hybridization of Pyrus

Abstract

Abstract The genus Pyrus has been classified into at least 22 primary species. These can be grouped by geographical distribution and/or taxonomic relationships. The European group includes P. communis L., P. nivalis Jacq., and P. cordata , (Desv.) Schneid. The North African group contains P. longipes Coss. and Dur., P. gharbiana Trab., and P. mamorensis Trab. The west Asian group consists of P. syriaca Boiss., P. elaeagrifolia Pall., and P. amygdaliformis Vill., P. salicifolia Pall., P. glabra Boiss., P. regellii Rehd., (syn. P. bucharica and P. heterophylla Reg. & Schmalh). The medium to large fruited east Asian species are P. pyrifolia (Burm.) Nak., P. kansuensis, P. ussuriensis Max., P. hondoensis Kik. and Nak., while the Asian “pea” pear species are P. calleryana Dcne., P. betulaefolia Bung., P.fauriei Schneid., P. dimorphophylla Makino, and P. koehnei Schneid. (3, 27). A number of nonprimary species also appear in the literature, which may be either botanical varieties, subspecies, or interspecific hybrids. Among the east Asian group, P. bretschneideri Rehd. is a probable hybrid of P. betulaefolia and the cultivated forms of P. pyrifolia; P. phaeocarpa Rehd. may be a P. betulaefolia × P. ussurensis hybrid, whereas P. serrulata Rehd. is a probable interspecific hybrid involving P. pyrifolia and P. calleryana .