|Beckman, Thomas - Tom|
Submitted to: Acta Horticulture Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/26/1998
Publication Date: N/A
Technical Abstract: Two F1 peach (Prunus persica (L.) Batsch) genotypes, K62-68 and P101-41, developed from a cross by D. W. Ramming (USDA-ARS, Fresno, CA) of Lovell (homozygous susceptible to Meloidyne incognita and M. javanica) and Nemared (homozygous resistant to both root-knot nematodes), were selfed to produce two F2 seedling populations. Vegetative propagation by stem cuttings was used to produce 4 to 10 clones of each F2 seedling for treatment replications. Eggs of M. incognita and M. javanica were inoculated onto the root systems of the seedling clones. After about 120 days, seedlings were harvested and roots examined for signs and symptoms associated with root-knot nematode infection. Segregation ratios in both F2 families suggested that resistance to M. incognita in Nemared is controlled by two dominant genes (Mi, Mij), and resistance to M. javanica in Nemared is also controlled by two dominant genes (Mj, Mij), but one gene (Mij) is shared for the resistance to both M. incognita and M. javanica. These three genes (Mi, Mj, Mij) appeared to be in same linkage group, based on the actual segregation data which deviated from expected Mendelian ratios.