Intraspecific variability of carbon isotope discrimination and its correlation with grain yield in safflower: prospects for selection in a Mediterranean climate

ABSTRACT

The goals of the present study were to obtain a first estimate of intraspecific variability of carbon isotope discrimination (Δ) in safflower, a thistle-like herbaceous plant, and to determine the statistical relationship between Δ and grain yield as well as its components in a collection of 45 accessions of different origins. Grain yield and aboveground biomass, harvest index, average grain weight, and Δ (measured on the bulk leaf organic matter) were investigated in experimental field conditions. A large variability was noted for all traits but a principal component analysis (PCA) allowed to identify several homogeneous groups of accessions. Average grain yield per plant varied between 1 and 39 g. Δ varied between 21.3 and 25.2 ‰, i.e. a large variation of 3.9 ‰. In our experiment, the variation of Δ was not significantly related to that of grain yield in the whole accession sample. However, we found contrasting trends for this relation within accession groups. These initial results motivate further experiments to assess more in depth correlation between Δ and yield in safflower and are encouraging regarding the possibility of using Δ as an effective selection index in safflower to obtain genotypes that efficiently consume water. This study also highlighted one accession that combines the two characters required in the Mediterranean regions, i.e. high yield performance and high water-use efficiency.

KEYWORDS:

• Agriculture
• carbon-13
• Carthamus tinctorius
• genotypes
• irrigation
• isotope ecology
• plants
• rain
• water-use efficiency
• yield

Acknowledgements

We thank the experimental station of the Technical Institute of Field Crops (ITGC, Oued Smar, Algeria) for allowing us to conduct the field trial. The authors would like to thank Dr Pauline Haleux (Biotrial) and Dr Myckel Habets (Leiden University) for the critical reading of the manuscript and help with the English language.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We are grateful to Laboratoire d'Ecology, Systématique et Evolution (ESE, CNRS-UMR 8079, Orsay, France) for funding the isotopic analyses and the platform ‘Métabolisme–Métabolome’ of the Institue of Plant Science Paris-Saclay (IPS2) for technical assistance for isotope analyses.