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Rice tocopherols, vitamin E compounds with antioxidant activity, play essential roles in human health. Even though the key genes involved in vitamin E biosynthetic pathways have been identified in plants, the genetic architecture of vitamin E content in rice grain remains unclear. A genome-wide association study (GWAS) on 179 genotypically diverse rice accessions with 34,323 SNP markers was conducted to detect QTLs that define total and α- tocopherol contents in rice grains. Total and α-tocopherol contents had a strong positive correlation and varied greatly across the accessions, ranging from 0.230-31.76 and 0.011-30.83 (μg/g), respectively. A total of 13 QTLs were identified, which were spread across five of the rice chromosomes. Among the 13 QTLs, 11 were considered major with phenotypic variation explained (PVE) greater than 10%. Twelve transcription factor (TF) genes, one microprotein (miP), and a transposon were found to be associated with the QTLs with putative roles in controlling tocopherol contents. Moreover, intracellular transport proteins, ABC transporters, nonaspanins, and SNARE, were identified as associated genes on chromosomes 1 and 8. In the vicinity of seven QTLs, protein kinases were identified as key signaling factors. Haplotype analysis revealed the QTLs qAlph1.1, qTot1.1, qAlph2.1, qAlph6.1, qTot6.1 , and qTot8.3 to have significant haplogroups. Quantitative RT-PCR validated the expression direction and magnitude of WRKY39 ( Os02g0265200 ), PIP5Ks ( Os08g0450800 ), and MADS59 ( Os06g0347700 ) in defining the major tocopherol contents. This study provides insights for ongoing biofortification efforts to breed and/or engineer vitamin E and antioxidant levels in rice and other cereals.

Responses of quinoa root characters are unknown while using different nutritional elements either in soil or foliar application, especially in alkaline soils. This research has been conducted in a controlled condition with a set of pot experiments to study the root responses of three cultivars of quinoa (Giza 1, Q26, Titicaca) as influenced by the various amount of triple superphosphate fertilizer (0, 6, 12, 18 mg/kg soil) and zinc sulfate foliar application (0, 4 and 8 g/l). Results showed that 18 mg/kg triple superphosphate produced the highest root dry weight (1.27 g/plant), number of root branches (218), root volume (2.06 cm3), and specific root weight (SRW) (46.39 mg/cm). The highest value of root surface belonged to the Q26 cultivar, and Giza 1, respectively. Regarding the three-fold interaction, the maximum values of root traits and grain production were found in the Q26 cultivar by using 18 mg/kg triple superphosphate and foliar application at the rate of 4 g/l zinc sulfate. The optimal combination of P and Zn nutrients improved the N, P, K accumulation in quinoa grain, especially in the Q26 cultivar, and nutrient content changes in Giza 1 and Titicaca cultivars were lower between control and optimal levels. It was concluded that better performance was achieved when optimal amounts of macro/microelements have been used with selecting cultivars with a wider root system and higher potential for nutrient uptake in alkaline soils.