A trait–environment relationship approach to participatory plant breeding for organic agriculture

Abstract

Summary The extent of intraspecific variation in trait–environment relationships is an open question with limited empirical support in crops. In organic agriculture, with high environmental heterogeneity, this knowledge could guide breeding programs to optimize crop attributes. We propose a three‐dimensional framework involving crop performance, crop traits, and environmental axes to uncover the multidimensionality of trait–environment relationships within a crop. We modeled instantaneous photosynthesis (Asat) and water‐use efficiency (WUE) as functions of four phenotypic traits, three soil variables, five carrot (Daucus carota) varieties, and their interactions in a national participatory plant breeding program involving a suite of farms across Canada. We used these interactions to describe the resulting 12 trait–environment relationships across varieties. We found one significant trait–environment relationship for Asat (taproot tissue density–soil phosphorus), which was consistent across varieties. For WUE, we found that three relationships (petiole diameter–soil nitrogen, petiole diameter–soil phosphorus, and leaf area–soil phosphorus) varied significantly across varieties. As a result, WUE was maximized by different combinations of trait values and soil conditions depending on the variety. Our three‐dimensional framework supports the identification of functional traits behind the differential responses of crop varieties to environmental variation and thus guides breeding programs to optimize crop attributes from an eco‐evolutionary perspective.

Changes in crop trait plasticity with domestication history: Management practices matter

“…It is hypothesized that modern crops may be unable to adequately shift root traits (i.e. express phenotypic plasticity) to maintain their yield rates when grown under different, and often more spatially and temporally heterogeneous, management regimes (Isaac et al., 2021; Rolhauser et al., 2022; Schmidt et al., 2016).…”

Plant trait relationships are maintained within a major crop species: lack of artificial selection signal and potential for improved agronomic performance

“…Our findings call for mobilizing breeding approaches that consider multidimensional phenotypic space to take into account plant trade‐offs and potentially even override them (Denison, 2015; Isaac & Martin, 2019; Rolhauser et al ., 2022). The existence of multiple phenotypic pathways to plot‐level performances opens new avenues for plant breeding programmes since several traits should be targeted simultaneously.…”

“…Adler et al ., 2014; Garnier et al ., 2018; Salguero‐Gómez et al ., 2018; Yang et al ., 2018). The first reason is that such a linkage is probably species‐ and environment‐dependent, and thus hardly detectable through interspecific comparisons (but see Rolhauser et al ., 2022). A second reason is that plant performance, and plant reproductive performance in particular, is multidimensional.…”

Shade tree trait diversity and functions in agroforestry systems: A review of which traits matter

“…Trait collections in agroforestry systems must account for the effects of pruning on all organs, leaves, canopy and trunk, of shade trees. Third, plant trait plasticity and genetic by environment interactions in agricultural systems are critical in shaping crop functional traits (Rolhauser et al., 2022), crop trait space (Sauvadet et al., 2021), and the role of ontogeny in crop trait trade‐offs and reproductive onset (Martin & Isaac, 2021). Further work is needed on shade tree genetics and ontogeny for a complete understanding of shade tree traits in ecosystem functions.…”