Iron and zinc are essential micronutrients for human growth, development, and immune system maintenance. Iron (Fe) and zinc (Zn) are necessary for psychomotor development, sustained physical activity and work capacity, infection resistance, and various metabolic functions. Currently, rice, preferred for being high in Fe and Zn, is also a choice for being low in anti-nutritional compounds, namely, phytic acid. The presented study sought to identify the phytic acid content in several biofortified rice lines and determine the correlation of phytic acid with Fe and Zn content and yield characters. The research ran during the dry season (DS) from January to September 2022, with an alluvial soil type at the Sukamandi Experimental Station of ICRIST – Subang, West Java, Indonesia (altitude of 40 masl). Testing of 10 rice (Oryza sativa L.) genotypes comprising six BC₄F₃ biofortified rice lines for high Zn and four check cultivars (Inpari IR Nutri Zinc, Inpari 23, Ciherang, and Sintanur) used a randomized complete block design with three replications. Correlation analysis determined breeding strategies for high Zn/Fe rice with low phytic acid. The results revealed that phytic acid did not significantly correlate with Zn content, 1000-grain weight, and yield per plant. However, phytic acid had a strong positive correlation with Fe content. The rice line WR10 occurred as the best line because it had the highest Zn content (33.80 mg kg^-1) and lower phytic acid and Zn ratio (PA: Zn) compared with all check cultivars, giving the highest yield potential and better yield than the Ciherang cultivar.

Keywords: Oryza sativa, iron and zinc content, essential micronutrients, phytic acid, correlation, grain yield

Key findings: The promising line WR10 with high Zn and lower PA: Zn molar ratio compared with the check varieties emerged. Noting phytic acid having a significant positive association with Fe and having no significant association with Zn, the breeding program for getting high Fe rice with low phytic acid becomes more challenging than breeding for acquiring high Zn rice with low phytic acid. Therefore, an advanced breeding approach may help obtain rice cultivars with high Fe and low phytic acid.