Breeding for a certain trait is only possible when the phenotypic variation that is caused by genotypic variation can be estimated. For traits that strongly depend on environmental conditions, this can be extremely difficult and knowledge and collaboration with experts from other disciplines becomes essential. A well-known example is breeding for disease resistance. Here, we describe a similar approach to assist breeding against adverse leaf deformations that severely reduce the ornamental value of some chrysanthemum (Dendranthema × grandiflora) genotypes during greenhouse cultivation in winter. These leaf deformations occur rather unpredictably, but seem to be related to the increased use of assimilation light. To breed against this trait knowledge is needed (i) about inductive environments in which sensitive and insensitive genotypes are distinguishable, and (ii) about the physiological background associated with leaf epinasty. In this paper hypothetical physiological factors and mechanisms are discussed, which may mediate effects of light spectrum and greenhouse climate on leaf epinasty. One factor involved could be starch accumulation, since leaf epinasty usually aggravates after disbudding - a practice that most probably alters the sink-source balance. Additionally, light spectra can affect the circadian clock and thereby disturb starch synthesis and breakdown resulting in accumulation. Both within and independent of this process, plant hormones such as auxin and ethylene may play a role in leaf epinasty. This theoretical framework will be used to further investigate the physiological background of leaf epinasty and to come up with a test in which susceptibility for leaf epinasty can be assessed.
|Title of host publication||24th International Eucarpia Symposium Section Ornamentals "Ornamental Breeding", Warsaw, Poland September 2-5 , 2012|
|Publication status||Published - 2012|
|Event||Proceedings 24th International Eucarpia Symposium Section Ornamentals "Ornamental Breeding" - |
Duration: 2 Sep 2012 → 5 Sep 2012
|Conference||Proceedings 24th International Eucarpia Symposium Section Ornamentals "Ornamental Breeding"|
|Period||2/09/12 → 5/09/12|