Rice grain nutritional traits and their enhancement using relevant genes and QTLs through advanced approaches

Abstract

Background: Rice breeding program needs to focus on development of nutrient dense rice for value addition and helping in reducing malnutrition. Mineral and vitamin deficiency related problems are common in the majority of the population and more specific to developing countries as their staple food is rice.

Results: Genes and QTLs are recently known for the nutritional quality of rice. By comprehensive literature survey and public domain database, we provided a critical review on nutritional aspects like grain protein and amino acid content, vitamins and minerals, glycemic index value, phenolic and flavonoid compounds, phytic acid, zinc and iron content along with QTLs linked to these traits. In addition, achievements through transgenic and advanced genomic approaches have been discussed. The information available on genes and/or QTLs involved in enhancement of micronutrient element and amino acids are summarized with graphical representation.

Conclusion: Compatible QTLs/genes may be combined together to design a desirable genotype with superior in multiple grain quality traits. The comprehensive review will be helpful to develop nutrient dense rice cultivars by integrating molecular markers and transgenic assisted breeding approaches with classical breeding.

Keywords: Grain amino acid; Grain nutraceutical properties; Grain nutritional properties; Grain phenolic and flavonoid compounds; Grain phytic acid; Grain protein; Grain vitamins and minerals; Molecular markers.

Fig. 1

Integration of phenotypic and molecular breeding approaches for improvement of neutraceutical properties in rice grain

Fig. 2

Depicted diagram of molecular marker positions associated with grain nutritional quality of rice distributed on 12 chromosomes from comprehensive literature survey. Molecular marker on right and their position (cM) on left side of the chromososmes. MPGQ milling properties of grain quality, GA grain appearance (red), CP cooking properties (blue), NF nutrition factors (pink), FRG fragrance of rice grain (green) (colors indicate markers related to nutritional quality traits in rice)