Inheritance of and molecular markers for susceptibility of Malus domestica to fruit ring rot (Botryosphaeria dothidea).

摘要

To analyse the inheritance of fruit ring rot (FRR) resistance and to screen for microsatellite markers linked to resistance/susceptibility, 875 apple hybrid seedlings (Malus domestica, Jonathan x Golden Delicious) were inoculated with five isolates of Botryosphaeria dothidea in 2 years (2008 and 2009). The results indicated that incidence and non-incidence were qualitatively segregated, and incidence was dominant to non-incidence. The variation in susceptibility within this population was attributed to the segregation of three major genes. For the phenotype of incidence, the severity of lesion development was a quantitative trait. From 230 published microsatellite primer pairs, six markers were identified that were linked to the susceptibility to FRR. CH04d02-120 and Hi08 g12-190, located in LG12 and LG2, respectively, were linked to susceptibility to the pathogen isolate Mx1, and their map distances to the susceptibility loci were 8.2 and 5.1 centimorgan (cM), respectively. CH01e01-120 and CH02c02b-100, which were linked to susceptibility to Ls1, were located in LG14 and LG4, and the map distances to the susceptibility loci were 16.9 and 8.4 cM, respectively. CH05d11-150 and CH03a03-230, linked to susceptibility to Lw048, were located in LG12 and LG14; for both of them, the map distance was 13.4 cM.