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Article|22 Feb 2017|OPEN
Selection for production-related traits in Pelargonium zonale: improved design and analysis make all the difference
Heike Molenaar1 , , Martin Glawe2 , Robert Boehm2 and Hans-Peter Piepho,1
1Institute of Crop Science, University of Hohenheim, Biostatistics Unit, Stuttgart 70599, Germany
2Klemm+Sohn GmbH & Co. KG, Stuttgart 70378, Germany
*Corresponding author. E-mail: Heike.Molenaar@uni-hohenheim.de

Horticulture Research 4,
Article number: 4 (2017)
doi: https://doi.org/10.1038/hortres.2017.4
Views: 677

Received: 01 Nov 2016
Revised: 01 Feb 2017
Accepted: 03 Feb 2017
Published online: 22 Feb 2017

Abstract

Ornamental plant variety improvement is limited by current phenotyping approaches and neglected use of experimental designs. The present study was conducted to show the benefits of using an experimental design and corresponding analysis in ornamental breeding regarding simulated response to selection in Pelargonium zonale for production-related traits. This required establishment of phenotyping protocols for root formation and stem cutting counts, with which 974 genotypes were assessed in a two-phase experimental design. The present paper evaluates this protocol. The possibility of varietal improvement through indirect selection on secondary traits such as branch count and flower count was assessed by genetic correlations. Simulated response to selection varied greatly, depending on the genotypic variances of the breeding population and traits. A varietal improvement of over 20% is possible for stem cutting count, root formation, branch count and flower count. In contrast, indirect selection of stem cutting count by branch count or flower count was found to be ineffective. The established phenotypic protocols and two-phase experimental designs are valuable tools for breeding of P. zonale.