Submitted to: Pennsylvania Fruit News
Publication Type: Research Notes
Publication Acceptance Date: 12/1/2006
Publication Date: 2/1/2007
Citation: Myers, C.T., Glenn, D.M., Hull, L. 2007. Observation and evaluation of Malus germplasm for differential susceptibility to oriental fruit moth and codling moth attack. Pennsylvania Fruit News. Interpretive Summary:
Technical Abstract: Research is ongoing to evaluate numerous apple accessions (both domestic releases and exotic apple and crabapple species from around the world) for potential natural resistance to attack from these insect pests. Prior observations have indicated that there is significant variation in pest susceptibility among exotic Malus species housed at the USDA germplasm repository in Geneva, NY. Studies from 2006 indicate that Malus tschonoskii is very resistant to larval feeding by both oriental fruit moth (OFM) and codling moth (CM) in the laboratory. Larval survival on fruit of M. tschonoskii was zero or near zero. While M. tschonoskii has some negative horticultural traits that would be obstacles to breeding efforts, there is reason to believe it may possibly be a potential source for genetic resistance to internal feeders. Other Malus accessions, while previously appearing promising in the field, had varying susceptibility to internal feeders in the laboratory, and thus, are probably not good sources of genetic resistance. Several cultivars from the Purdue-Rutgers-Illinois (PRI) apple breeding program released with claims of insect pest resistance, are actually not resistant to attack from CM or OFM. These claims need to be revised in both the horticultural literature and in USDA’s online germplasm database. Significant variation was found in CM and OFM responses to commercially popular cultivars as well as new cultivar releases evaluated under USDA’s NE 183 program.