S-genotype of Japanese pear 'Hosui'

Abstract

The S-genotype of 'Hosui', a self-incompatible cultivar of the Japanese pear (Pyrus pyrifolia Nakai), was determined by a combination of two-dimensional gel electrophoresis (2D-PAGE) and N-terminal sequence analysis for S-proteins. Four protein spots that migrated to the S-protein zone were detected and individually assigned to S3a-, S3b-, S5a-, and S5b-RNases by comparing their electrophoretic behavior with that of S3- and S5-RNases. Analyses of the amino acid sequences of the four proteins confirmed their assignments leading us to postulate that the S-genotype of 'Hosui' is S3S5.