Genotype × environment interactions for grain iron and zinc content in rice

Abstract

Background Nutrient deficiency in human beings especially in children and lactating women is a major concern to world's nutritional security. Increasing the micronutrient concentration in the staple crops like rice is one way to overcome the hidden hunger. Micronutrient content in rice specially Iron (Fe) and Zinc (Zn) are highly variable traits. Therefore, identification of rice genotypes that are naturally dense and consistent in Fe and Zn concentrations across environments is an important breeding target towards producing biofortified rice. Results Phenotypic correlations between grain Fe and Zn contents were positive and significant in all environments but a significant negative association between grain Fe and Zn with grain yield was observed. IR 82475‐110‐2‐2‐1‐2(Zn:20.24‐37.33 mg/kg; Fe:7.47‐14.65 mg/kg), IR 83294‐66‐2‐2‐3‐2(Zn:22‐37‐41.97mg/kg; Fe:9.43‐17.16), IR 83668‐35‐2‐2‐2(Zn:27.15‐42.73 mg/kg; Fe:6.01‐14.71),IR 68144‐2B‐2‐2‐3‐1‐166(Zn:23.53‐40.30 mg/kg; Fe:10.53‐17.80 mg/kg) and RP Bio 5478‐185M7(Zn:22.60‐40.07mg/kg; Fe:7.64‐14.73 mg/kg) were promising breeding lines with higher Zn or Fe content or both. Among these, IR82475‐110‐2‐2‐1‐2(Zn:20.24‐37.33 mg/kg; Fe:7.47‐14.65 mg/kg) is also high yielding with 3.75t/ha. Kelhrie Cha (Zn:17.76‐36.45 mg/kg; Fe:7.17‐14.77mg/kg), Dzuluorhe (Zn:17.48‐39.68 mg/kg; Fe:7.89‐19.90 mg/kg), Nedu (Zn:18.97‐43.55 mg/kg Fe:8.01‐19.51 mg/kg), Kuhusoi‐Ri‐Sareku (Zn:17.37‐44.14 mg/kg; Fe:8.99‐14.30 mg/kg) and Mima (Zn:17.10‐45.64 mg/kg; Fe:9.97‐17.40 mg/kg) were traditional donor genotypes possessing both high grain Fe, as well as Zn content. Conclusion Significant genotype×location (G×L) were observed in all traits except Fe, genetic variance was significant and considerably larger than that of G×L for grain Zn and Fe content traits except grain yield. Genotype × location × year variance component was significant in all cases.