Isoperoxidase variability in pear rootstocks (Pyrus calleryana dcne and P. betulaefolia bunge)

Abstract

Shoot bark peroxidases of Pyrus calleryana Dcne and P. betulaefolia Bunge rootstocks were compared by polyacrylamide gel electrophoresis. Seven bands were detected in each one of the species. Three electrophoretic patterns were found in P. calleryana, which were differentiated by presence, absence or presence of two bands (R.M. values = 0.77 and 0.82). The presence of bands of R.M. 0.49 and 0.5 1, or bands of R.M. 0.54 and 0.56 or of these four bands allowed to distinguish three patterns in P. betulaefolia, Isoperoxidase analysis of clone XII indicates the occurrence of probable interspecific hybridization, due to the presence of common bands to both species. Variability found emphasizes the need of rootstock selection and identification to establish uniform pear orchards.