ISHS Acta Horticulturae 522: XXV International Horticultural Congress, Part 12: Application of Biotechnology and Molecular Biology and Breeding - General Breeding, Breeding and Evaluation of Temperate Zone Fruits for the Tropics and the Subtropics.
NEW HARDY LEAF SPOT RESISTANT STRAWBERRY SELECTIONS |
| Authors: | S. Khanizadeh, O. Carisse, O. Champigny |
| Keywords: | disease severity, fragaria, leaf disease, leaf spot, selection, strawberry |
| Abstract:
Twenty advanced strawberry selections were compared to four known cultivars for susceptibility to leaf spot. A young and an old leaf from each plant were inoculated with Mycosphaerella fragariae on both surfaces until runoff, using an airbrush operated at 100 kPa of air pressure. The plants were placed in a mist chamber for 96 hrs and then relocated to the greenhouse for symptom development. A completely randomized design with four replicates per genotype was used. The plants were observed 10, 11, 14 and 21 days after inoculation. The level of susceptibility was evaluated based on the maximum disease severity (MDS) and on the area under the disease progress curve (AUDPC) for each kind of leaf. MDS was calculated for each replicate and the average was determined for each genotype and type of leaf (young or old). A homogeneity of variance test was conducted to determine if the MDS values could be pooled. A cluster analysis was used for both types of leaves to group genotypes with similar levels of susceptibility to leaf spot. SJ9327–17, SJ9323–3 and SJ9314–46 were the most resistant genotypes. These hardy, leaf spot resistant selections are under evaluation in four regions in Quebec. A different disease susceptibility was observed in the youngest or oldest leaves of one genotype, indicating that susceptibility to leaf spot is dependent on leaf age. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
