ISHS Acta Horticulturae 577: VII International Symposium on Plum and Prune Genetics, Breeding and Pomology
SEARCH FOR MOLECULAR MARKERS LINKED TO FUSICOCCUM TOLERANCE IN ALMOND |
| Authors: | M. Martins, D. Sarmento, M.M. Oliveira, I. Batlle, F.J. Vargas |
| Keywords: | Almond; Fusicoccum; Molecular markers; Prunus dulcis Mill.; RAPD analysis |
| Abstract:
Almond trees (Prunus dulcis Mill.) growing in the Mediterranean region are attacked by Fusicoccum amygdali which causes Fusicoccum canker, a damaging and economically important fungal disease. This disease, which affects mainly twigs of the lower part of the trees, is particularly damaging on wet environments. The development of molecular markers linked to Fusicoccum tolerant phenotypes could be of high value for breeders because in the field it takes several years for the plant to develop symptoms and artificial inoculation is still unreliable. In this work we have used cultivars showing or not symptoms of the disease, corresponding to sensitive or tolerant phenotypes growing in the field under natural contamination conditions. This material was studied using the bulked DNA analysis approach and applying RAPD techniques. Two DNA bulks were constructed, each using 7 cultivars with either tolerance or susceptibility for the disease. One hundred and twenty RAPD primers were tested to screen for tolerance associated markers. The primers that produced polymorphic PCR products between the two bulks were tested again for each cultivar, individually, for the presence of the polymorphism. Of the 120 primers screened, 4 RAPD primers consistently showed polymorphic bands between the two groups of plants (tolerant and sensitive). The fragments obtained possibly correspond to tolerance/sensitivity associated markers and have to be validated in progenies from controlled crosses. To evaluate the co-segregation of the bands with the tolerance or sensitivity phenotypes, two crosses of tolerant x sensitive cultivars, resulting in two unselected progenies of 65 seedlings in total (25 tolerant and 40 sensitive) are being assessed using the discriminating primers. | |
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