Plasticity of barley in response to plant neighbors in cultivar mixtures

Iris Dahlin,Lars P Kiær,Velemir Ninkovic,Göran Bergkvist,Martin Weih

doi:10.1007/s11104-019-04406-1

Iris Dahlin, Lars P Kiær + Show 3 more

Open Access

https://doi.org/10.1007/s11104-019-04406-1

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Abstract

AimsCultivar mixtures can increase productivity through complementarity in resource use, but reported results are often conflicting and the role of plasticity in shaping plant-plant interactions is poorly understood. We aim to determine if individual cultivars show different phenotypic responses when grown in a mixture, whether these responses depend on the neighboring cultivar identity, and how they contribute to variations in productivity and nitrogen (N) use.MethodsFive spring barley cultivars were field-grown in pure stands and in mixtures during 2 years. Plant traits related to development, growth, N use, and reproduction were measured to identify temporal patterns of plastic responses to neighboring plants.ResultsPlants in mixtures were shorter and developed slower early in the season, but later on they grew faster and produced more grain than the corresponding pure stands. Some cultivars showed complementary N accumulation only when grown together with specific neighbors. Mechanisms of improved productivity differed between the individual mixtures.ConclusionsPlastic plant-plant interaction between cultivars is an important driver behind the variability in mixing effects. Results contribute to a better understanding of how productivity in cultivar mixtures is affected by plastic adaptation and differentiation of plant traits, depending on the environment created by neighboring genotypes.

Highlights

Higher diversity in plant communities can promote productivity and stability, and part of the increased productivity can arise from complementarity in resource use of the community components involved (Loreau and Hector 2001; Zuppinger-Dingley et al 2014)
Results contribute to a better understanding of how productivity in cultivar mixtures is affected by plastic adaptation and differentiation of plant traits, depending on the environment created by neighboring genotypes
Overall plastic response to mixing was evaluated by setting diversity level as the main factor, testing for differences in trait values between a genotype grown in mixtures and in pure stand

Summary

Introduction

Higher diversity in plant communities can promote productivity and stability, and part of the increased productivity can arise from complementarity in resource use of the community components involved (Loreau and Hector 2001; Zuppinger-Dingley et al 2014). Diversity effects on productivity and stability could be influenced by plastic responses of the involved community components, a mechanism which so far is rarely explored. Genotypic diversity can promote vegetative and reproductive yield (Cook-Patton et al 2011; Reiss and Drinkwater 2018). Reviews and meta-analyses have revealed substantial variability of this function in crop –stands containing mixtures of genotypes, which do not always show higher productivity than stands containing just one of the mixture’s genotypes (Borg et al 2018; Kiær et al 2009; Reiss and Drinkwater 2018). A better understanding of the processes underlying crop genotypic diversity on productivity is needed in order to (i) explain why some studies find positive effects whereas others do not, and (ii) enable predictive development of sustainable agricultural cropping systems based on genotype diversity

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