Effect of Drought on Bean Yield Is Mediated by Intraspecific Variation in Crop Mixtures

Abstract

Increasing plant diversity in agricultural systems provides promising solutions for sustainably increasing crop yield. It remains unclear; however, how plant–plant interactions in diverse systems are mediated by plant genetic variation. We conducted a greenhouse experiment in which we grew three varieties of common beans with three companion plant species (chickpeas, sorghum, and sunflower) in different combinations (crop mixtures, bean cultivar mixtures, and monocultures), with and without drought stress. We hypothesized that under drought stress, the effect of companion plant species on bean yield would be mediated by the drought tolerance potential of the species. We further hypothesized that this effect would vary across different bean cultivars. Overall, we show that the effect of companion plant species on bean yield was not influenced by drought stress; instead, it was dependent on the identity of the bean variety. This could partially be explained by variation in growth rate between bean varieties, where the fastest growing variety recorded the highest yield increase in plant mixtures. The effect of companion plant species on chickpea biomass, however, was potentially influenced by chickpea drought tolerance potential; chickpea biomass was recorded to be higher in plant mixtures than in its monoculture under drought conditions. Our study highlights that to develop plant mixtures, it is not only important to consider the functional traits of the interacting plant species, but also those of the different plant varieties. We further suggest that stress tolerance can be a useful trait for initial selection of plant varieties when developing crop mixtures.

Nitrogen fixation by beans in crop mixtures is influenced by functional traits of associated species

“…1). These results are consistent with our previous work (32). Within the two crop mixtures, the identity of the companion crop species (i.e.…”

“…In a previous pot-based crop mixture experiment, we found that chickpeas and Sorghum signi cantly improved bean yield in comparison to bean monocultures. However, we observed that these effects were different for the different bean varieties (32). In this study we have further explored the mechanisms that could explain the crop interactions we observed in our previous work.…”

Nitrogen fixation by common beans in crop mixtures is influenced by growth rate of associated species

“…In a previous pot-based crop mixture experiment, we found that chickpeas ( Cicer arietinum L.) and Sorghum ( Sorghum bicolor (L.) Moench) significantly improved bean yield in comparison to bean monocultures. However, we observed that these effects were different for the different bean varieties [ 34 ]. In this study we have further explored the mechanisms that could explain the crop interactions we observed in our previous work.…”

Drought-Induced miRNA Expression Correlated with Heavy Metal, Phenolic Acid, and Protein and Nitrogen Levels in Five Chickpea Genotypes

“…Drought, salt, and high temperatures are the main abiotic stresses limiting crop growth and development. − In the 21st century, agricultural lands and overall productivity are decreasing due to changes in the global ecosystem balance and climatic conditions. Drought is one of the major abiotic factors affecting agricultural production efficiency worldwide, including in Turkey. − Drought stress affects the physiological, biochemical, and molecular systems that allow plants to respond to micro/macroenvironmental changes at the cellular level.…”