Adaptive responses of quinoa to diverse agro-ecological environments along an altitudinal gradient in North West Argentina

Abstract

Quinoa is an important Andean grain crop grown in a wide range of tropical and temperate environments. Time to flowering is an important trait determining grain yield. This work aimed to understand how responses to photoperiod and temperature might alter plant leaf and floral development. To assess the likely degree of G × E interactions, eleven quinoa accessions from a wide range of environments of origin within Northwest Argentina were grown in several sowing dates over two seasons at a high altitude site. In a third season at a low altitude site, a subset of six accessions planted in pots in the field was exposed to two artificially extended and a control (natural) photoperiod. Time to the appearance of floral buds and anthesis were recorded as was leaf number. A photothermal model developed for quinoa was used to compare responses to photoperiod. Plant development rates to visible floral buds and anthesis stages and phyllochron varied widely amongst accessions and across environments within a short day response though phyllochron varied mostly during the reproductive phase. There was a very strong association between time to flowering and altitude of origin (r = −0.98), mean temperature of the wettest quarter (r = 0.98) and Normalized Difference Vegetation Index values (r = 0.73). Photoperiod sensitivity was higher for accessions from the lowlands (normally late flowering), while temperature sensitivity was greatest for accessions from the highlands (early flowering); most variation for these traits detected at the species level was found in North West Argentina. Genotype by environment interactions for yield were related to the traits examined in this study and considering their high heritability it is suggested that quinoa breeding programs targeted for specific adaptation to a wide range of environments can be developed from this germplasm.