Enriching zinc (Zn) and selenium (Se) levels, while reducing cadmium (Cd) concentration in rice grains is of great benefit for human diets and health. The large natural variations in grain Zn, Se and Cd concentrations in different rice accessions enable Zn/Se biofortification and Cd minimization through molecular breeding. Recently, a paper entitled “Development of nutritious rice with high zinc/selenium and low cadmium in grains through QTL pyramiding” published on Journal of Integrative Plant Biology from the Germplasm Innovation research group of CNRRI reported that the development of new elite varieties by pyramiding major QTLs that significantly contribute to high Zn/Se and low Cd accumulation in grains.

CSSL^GCC7, a chromosome segment substitution line with the PA64s-derived GCC7 allele in the 93-11 background, exhibited steadily higher Mn and lower Cd concentrations in grains than those of 93-11. This elite CSSL was used as the core breeding material to cross with CSSLs harboring other major QTLs for essential mineral elements, especially CSSL^GZC6 for grain Zn concentration and CSSL^GSC5 for grain Se concentration. The CSSL^GCC7+GZC6 and CSSL^GCC7+GSC5 exhibited lower Cd concentration with higher Zn and Se concentrations in grains, respectively. The study thus provides elite materials for rice breeding targeting high Zn/Se and low Cd concentrations in grains.

The research was supported by the National Natural Science Foundation of China (91735304 and 31671761) and the National Key Research and Development Program of China (2016YFD0100902-07). Click on the link below for more details:

https://onlinelibrary.wiley.com/doi/10.1111/jipb.12909