|Pavek, Joe - (RETIRED) USDA-ARS|
|Lozoya-Saldana, Hector - PICTIPAPA METEPEC MEXICO|
|Hernandez-Vilchis, Alejandro - PICTIPAPA METEPEC MEXICO|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 19, 2001
Publication Date: June 1, 2001
Citation: Novy, R.G., Corsini, D.L., Pavek, J., Lozoya-Saldana, H., Hernandez-Vilchis, A. 2001. Analysis of segregation for late blight resistance in potato families screened at toluca valley, mexico. American Journal of Potato Research. 78:474. Technical Abstract: A primary objective of potato breeding programs is the development of potato cultivars with resistance to the newer, more aggressive, metalaxyl-resistant genotypes of Phytophthora infestans. Potato clones with resistance to these newer genotypes of P. infestans have been used extensively as parents in breeding programs. The large number of progeny obtained from the intercrossing of resistant parents precludes the screening of families for resistance to all pathotypes of P. infestans. Field selections are first made for suitable agronomic characteristics with screening for late blight resistance generally conducted 1 - 2 years later. Consequently, limited information is available to breeders regarding the percentages of resistant individuals and the degree of resistance within these families-important considerations for the breeder. Data obtained from the screening of 187 families for late blight resistance from 1996 - 2000 at Toluca Valley, Mexico, provide insights into the transmission of resistance from parent to progeny. For example, in comparisons of resistant x susceptible (R x S) parental crosses, S. bulbocastanum derived J-line clones are the most useful in transmitting a high level of resistance to a larger number of progeny. The data also suggest that the more commonly used sources of late blight resistance in North American breeding programs, such as AWN86514-2, B0718-2, and J-lines, can act in an additive fashion, with higher levels of resistance observed in R x R than in R x S families. These and other observations on the inheritance of late blight resistance will be discussed.