Evaluation of Chenopodium quinoa × C. berlandieri recombinant inbred lines (RILs) for heat tolerance

There is growing interest in expanding quinoa (Chenopodium quinoa Willd.) cultivation; however, the main limitation is its sensitivity to temperatures above 32-35 °C. Chenopodium berlandieri Moq., the wild-weedy North American ancestor of quinoa, was employed as an exotic source of drought, heat, and salinity tolerance to enlarge genetic variation in cultivated quinoa. The present work aims to assess the influence of high temperatures on seed setting rate and production potential of two quinoa recombinant inbred lines (RILs), RIL2-4 and RIL2-5. Thus, trials were carried out in Morocco at Berrechid and Tiflet in 2017-2018 and Bouchane, Meknès, and El Kebab in 2018-2019. The field experiment design was a randomized complete block with four replicates. Ten quantitative traits were measured. The ANOVA showed significant variability for all the evaluated parameters. The seed setting rate had widely different degrees of variation among experimental sites, exceeding 120% at Berrechid and Tiflet while approaching 98% at Bouchane. Tiflet expressed the lowest seed setting at 11.26%. Pearson’s correlation matrix analysis showed a significant positive correlation between plant size at maturity and inflorescence length. An analysis of mixed model interactions (AMMI) revealed the first interaction; principal component axis explained 53.3% of the total variation while the second axis described 46.7%. Four homogeneous groups emerged. The recombinant inbred lines have segregated for tolerance to high temperatures as evidenced by their variable seed setting rates and grain and DM yields.