The 2012 ASHS Annual Conference

Four Pyrus communis L. clones and sixteen breeders’ selections and cultivars with interspecific pedigrees involving Pyrus ussuriensis Max. or P. pyrifolia (Burm.) Nakai crossed with P. communis were evaluated for resistance to pear psylla (Cacopsylla pyricola Förster) using a nymphal feeding antixenosis assay.  The most resistant clones were ‘Batjarka’ and ‘Zelinka’, two landrace cultivars from Eastern Europe.  Four P. ussuriensis × P. communis hybrid selections (NJ B9 R1 T117, NJ A2 R21 T89, NY 10355 and NY 10359) and one P. pyrifolia × P. communis hybrid selection (NJ Rock R25 T238) were also significantly less susceptible than the susceptible control, ‘Bartlett’ (P. communis).  As a species group, the P. communis clones were the most resistant, due to the Eastern European landrace cultivars.  The P. ussuriensis × P. communis and the P. pyrifolia × P. communis hybrid groups were not significantly different from each other.   These clones should be valuable genetic resources for the breeding of new pear cultivars with resistance to pear psylla.