Title : Enhancing drought resilience in quinoa varieties (Chenopodium quinoa) through the combined application of biostimulants and organic amendments under field conditions
Abstract:
Drought is the most critical environmental stressor affecting crop production worldwide. Finding innovative solutions to alleviate its impacts is urgently needed. A field experiment was carried out in the semi-arid zone of Marrakesh, Morocco to test the potential roles of biostimulants, namely, arbuscular mycorrhizal fungi (AMF) consortium and green compost (Comp), applied separately or in combination, in improving the tolerance of two quinoa varieties to drought stress. The plants were grown in the field in a randomized bloc design under well-watered and drought conditions. The results showed that drought stress had a negative impact on quinoa growth, physiological and biochemical parameters while the combination of AMF and compost improved the plant tolerance to drought stress the most under both varieties. Specifically, an improvement of 46, 32, 142 and 160% was observed in shoot height, root elongation, plant dry weight and yield for Titicaca variety treated with AMF+Comp, respectively compared to the untreated control under drought conditions. The same parameters were improved in Puno variety by 42, 31, 128 and 138%, respectively after AMF and compost addition. The application of AMF, compost and their combination under drought conditions enhanced sugar content by 113, 98 and 151% in the leaves, respectively, and by 37, 41 and 59% in the seeds for Titicaca. For Puno, the same parameters showed an improvement of 76, 78 and 108% in the leaves, respectively, and 25, 22 and 52% in the seeds. Under drought stress, protein content in the leaves was enhanced by AMF and comp combination by 95% for Titicaca and 51% for Puno, while in seeds; protein content was improved by more than 57% for Titicaca and 43% for Puno. Seed phosphorus was improved by 146% for Titicaca and 120% for Puno under drought stress and the application of AMF+Comp. Furthermore, antioxidant enzyme activities decreased under the combination of AMF and compost for both varieties of quinoa regardless of water availability. Our results also revealed that Titicaca had a higher tolerance Index (76%) compared to Puno (54%). Overall, the findings of this study suggest that Titicaca is a stress tolerant quinoa variety maximizing crop yield and nutritional quality in response to biofertilizers under drought conditions. Harnessing synergies between microbial communities and organic amendments to confer drought tolerance to field crops is a promising strategy for sustainable agriculture under global climate change.
Keywords: Arbuscular mycorrhizal fungi, compost, Chenopodium quinoa, plant tolerance, drought stress.
