Phenotypic variation of fruit and ecophysiological traits among maqui (Aristotelia chilensis [Molina] Stuntz) provenances established in a common garden

Abstract

The domestication of forest species has traditionally relied on productivity issues. However, today there are concerns about the potential responses of natural populations and new cultivars to extreme climatic conditions derived from climate change and how to incorporate this knowledge into the domestication programs. Aristotelia chilensis (Molina) Stuntz ('Maqui') is a widely distributed native species in Chile. Its berry is considered a "super fruit" with an increasing interest in the food industry. This study investigated the phenotypic variation of growth, fruit, and ecophysiological traits of 20 A. chilensis clones originated from six provenances along the latitudinal gradient and established in a common-garden experiment in the Mediterranean zone of central Chile (center part of the species distribution). Differences among provenances were observed for most of the traits under study, especially between the northern and southernmost provenances (i.e., San Fernando versus Entre Lagos). Northern provenances showed higher development of vegetative tissue and fruit yield but lower intrinsic water use efficiency (WUE_int) compared with southern ones. Clonal variation within provenances was found significant for the ripening index, WUE_int, and fruit number and weight but not significant for traits related to the crown and leaf morphology. A genetic differentiation due to latitudinal cline was not evident in this study, but differences among provenances suggest local adaptation for some traits. The genotypic variation in productive traits must be considered in the outgoing domestication of the species and future selection programs.

Figure 1

View of the field trial scheme.

Figure 2

Mean ripening index for A. chilensis provenances and measurement date. *Significant differences at a probability level of 0.1.

Figure 3

Adjusted means (based on E-BLUP) of the ripening index for A. chilensis clones and measurement date. *Significant differences at a probability level of 0.1.

Figure 4

Means light-saturated photosynthetic rate (A_sat) for A. chilensis provenances and measurement date. *Significant differences at a probability level of 0.1. Horizontal dotted line represents the ripening period.

Figure 5

Means for leaf-physiological, morphological, crown, and fruit traits of A. chilensis provenances. Different letters indicate significant differences among provenances, at a probability level of 0.1 in the Tukey’s comparison test. Dashed and white bars correspond to northern and southern provenance origin, respectively.

Figure 6

Adjusted means (based on E-BLUP) for light-saturated photosynthetic rate (A_sat) (a), fruit number (b), and fruit dry weight for A. chilensis clones. Dashed and white bars correspond to northern and southern provenance origin, respectively.

Figure 7

Adjusted means (based on E-BLUP) of stomatal conductance (g_s), and intrinsic water use efficiency (WUE_int) for A.chilensis clones and measurement date. *Significant differences at a probability level of 0.1. Horizontal dotted line represents the ripening period.

Figure 8

Cluster analysis based on fruit number (FFW), twig length, leaf area (FA) and intrinsic water use efficiency (WUEint) based in the scale distance.