ISHS Acta Horticulturae 663: XI Eucarpia Symposium on Fruit Breeding and Genetics
QTL ANALYSIS OF GROWTH CHARACTERISTICS IN APPLE |
| Authors: | K. Kenis, J. Keulemans |
| Keywords: | genetic control, genetic linkage map, AFLP, SSR, columnar growth habit |
| Abstract:
Tree form in apple is very important for production efficiency, fruit quality and labour input and is therefore one of the aims of breeding programmes. In order to study the genetic control of tree architecture in apple, QTL analysis was performed for growth characteristics of a cross between two apple cultivars with different growth habit. ‘Braeburn’ has a normal growth habit while ‘Telamon’ has a columnar growth habit. The progeny was scored for AFLP and SSR markers. Genetic linkage maps of ‘Braeburn’ and ‘Telamon’ were constructed with 262 and 256 markers covering 1246 cM and 1028 cM respectively. Growth measurements of the F1 seedlings included height increment, growth rate, number and length of internodes, number and length of branches, branching proportion and growth increment during the first two years of growth. QTL analysis was performed by interval mapping, MQM mapping and nonparametric mapping. Besides the main influence of the columnar gene (present in ‘Telamon’) on most growth traits, additional significant QTLs were found for most growth traits. The percentage of phenotypic variation explained by single QTLs ranged from 1.4% to 55.3%. For several characteristics, significant QTLs were found on corresponding linkage groups of both cultivars. | |
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