Iron biofortification in rice: in search of morphological traits for indirect selection in breeding programs

Iron (Fe) deficiency is an important cause of health concern in developing countries, demanding mitigation strate­gies to fight this disorder. The biofortification of staple foods, such as rice ( Oryza sativa L.), could be achieved via the development of improved cultivars. Iron quantification is relatively costly and time-consuming, making its rou­tine use impracticable in breeding programs. Therefore, the identification of traits to be used in indirect selection strategies would be of high interest. This study aimed to find promising traits for use in indirect selection programs aiming Fe biofortification in rice grains. A diverse set of 95 rice genotypes, mostly Brazilian, was grown at South­ern Brazil, in 2016/2017, and Fe content in brown and polished grains, as well as other 12 morphological traits, were assayed. Analysis of variance, linear correlation, and path analysis were carried out. Different levels of asso­ciation between traits were found, being panicles per plant and caryopsis width the most promising for use in indi­rect selection aiming increased Fe content in both brown and polished rice. However, secondary traits, such as caryopsis length, have also to be considered when performing selection aiming Fe biofortification in the cereal.