Preliminary results on inheritance of resistance to Plum pox virus in apricot obtained within gene pyramiding
Since 1981, the aim of the apricot breeding programme at the Faculty of Horticulture, Mendel University, in Lednice has been to obtain new adaptable cultivars that combine valuable biological traits. Resistance to Plum pox virus (PPV) was studied in 200 hybrids resulting from a controlled pollination between the immune cultivar 'Harlayne' and the resistant cultivar 'Betinka'. Each hybrid was inoculated with PPV (D and Rec strains) by an infected bud. PPV infection was evaluated over three consecutive growth periods through visual symptoms and ELISA test. Chi-squared analysis of the F1 progeny was performed to determine whether the segregation ratio differed from the expected ratio. Substantial differences were observed in the disease process among hybrids. On the basis of three years (2013, 2014 and 2015) of observations, the hybrids have been assigned to one of five groups to summarize their response to PPV infection: resistant, medium resistant, tolerant, susceptible and unclassified. About three-quarters of the F1 plants were found to be resistant and one-seventh tolerant to PPV. The simplest explanation for these results is that two dominant loci with epistatic interaction confer resistance to PPV in this genetic background. The progeny are being screened to confirm the hypothesis of inheritance of the resistance after gene pyramiding.
Krška, B., Pavelková, P. and Salava, J. 2017. Preliminary results on inheritance of resistance to Plum pox virus in apricot obtained within gene pyramiding. Acta Hort. (ISHS) 1163:13-18
Prunus armeniaca L., PPV, sharka disease, visual symptom, ELISA, chi-square test, breeding