Stabilization of yield in plant genotype mixtures through compensation rather than complementation

Abstract

Background and AimsPlant genotypic mixtures have the potential to increase yield stability in variable, often unpredictable environments, yet knowledge of the specific mechanisms underlying enhanced yield stability remains limited. Field studies are constrained by environmental conditions which cannot be fully controlled and thus reproduced. A suitable model system would allow reproducible experiments on processes operating within crop genetic mixtures.MethodsPhenotypically dissimilar genotypes of Arabidopsis thaliana were grown in monocultures and mixtures under high levels of competition for abiotic resources. Seed production, flowering time and rosette size were recorded.Key ResultsMixtures achieved high yield stability across environments through compensatory interactions. Compensation was greatest when plants were under high levels of heat and nutrient stress. Competitive ability and mixture performance were predictable from above-ground phenotypic traits even though below-ground competition appeared to be more intense.ConclusionsThis study indicates that the mixing ability of plant genotypes can be predicted from their phenotypes expressed in a range of relevant environments, and implies that a phenotypic screen of genotypes could improve the selection of suitable components of genotypic mixtures in agriculture intended to be resilient to environmental stress.

Comparative analysis of performance and stability among composite cross populations, variety mixtures and pure lines of winter wheat in organic and conventional cropping systems

“…In a study on genotype mixtures of the annual weed species Arabidopsis thaliana it was found that seed yield stability, measured as standard deviation across growing environments, resulted from compensation among genotypes. As the fittest genotype overyielded in genetic mixtures, it compensated for the lower seed yield of genotypes with smaller fitness (Creissen et al, 2013). Interestingly, this effect was amplified when Arabidopsis plants were under abiotic stress.…”

“…This might be an advantage from an ecological point of view, as it implies higher shading of the soil and higher competitiveness against weeds. Creissen et al (2013) suggested that highly competitive genotypes may not perform well in monoculture but over-yield in mixture because of their yield potential and their ability to utilize limited resources. However, investment in vegetative growth can also be regarded as a disadvantage when allocation of resources to grain biomass is the main concern (Denison, 2012), and also because of the greater risk of lodging.…”

“…Because of compensation, complementation and facilitation effects in diverse plant material (Creissen et al, 2013), genetically heterogeneous crops are expected to be more stable-yielding over time and across different locations than genetically homogeneous pedigree lines, i.e. than most commercially traded varieties (Soliman and Allard, 1991;Wolfe, 2001;Döring et al, 2011;Murphy et al, 2013).…”

Engaging Farmers in Climate Change Adaptation Planning: Assessing Intercropping as a Means to Support Farm Adaptive Capacity

“…The type of intercropping, optimal densities of the intercrops and management need to be adjusted case by case [17] because low complementarity can lead to a lack of targeted, enhanced utilization of the growth resources by intercropping [18]. Facilitative and compensatory interactions between plants can dominate at high abiotic stress (e.g., [19]), further supporting the use of intercropping as a proactive adaptation action to protect yields from climate change-induced challenges. The increased productivity per acreage in intercropping can also contribute to higher soil organic matter accumulation and carbon sequestration [8], which is important for greenhouse gas mitigation in agriculture in low-carbon soils.…”

Managing resilience of forage crops to climate change through response diversity

“…For instance, while most of the timothy cultivars suffer from heat stress during the early stages of growth and from autumn precipitation, red clover and tall fescue benefit from similar weather. Cultivar mixtures (Creissen et al, 2013), such as a mixture of two timothy cultivars responding differently to weather, represent another application. Despite its potential, the yield performance in mixtures depends considerably on biological interactions (Fukai and Trenbath, 1993;Li et al, 2013).…”