**5. Biofortification challenges**

Some of the challenges faced in biofortification and introducing biofortified food grains as part of the daily diet in India are discussed below.


Zinc deficiency is a serious problem in developing countries where white rice is the staple food. The creation of bio-enriched rice varieties in India was sought with the help of Harvest Plus, the Biotechnology Department, and the Indian Agricultural Research Council due to the high genetic diversity of white rice's high zinc content. Through the All-India Collaborative Rice Improvement Project (AICRIP), the Indian Rice Research Institute (IIRR) has enabled the release of rice varieties and is supporting India's rice bioenhancement program. Different sets of germ plasms from several national institutions have been characterized for zinc content in IIRR of brown rice using energy dispersive X-ray fluorescence spectroscopy. This indicates that the zinc range is 7.3–52.7 mg/kg. Assessment of zinc content in various wild germ plasm mapping populations, native varieties, and cultivars demonstrated the feasibility of favorable rebinding of high zinc and high yields. Nine genotypes from genetic resources and 344 strains from the mapping population showed zinc levels of \_28 mg/kg in white rice, meeting the target zinc levels set by Harvest Plus. Through AICRIP biofortification trial constituted since 2013, 170 test entries were nominated by various national institutions until 2017, and four biofortified rice varieties were released. Only the test entry with target zinc content, yield, and quality parameters is promoted to the next year; thus, each test entry is evaluated for 3 years across 17 to 27 locations for their performance. Multilocation studies of two mapping populations and AICRIP biofortification trials indicated the zinc content to be highly influenced by environment. The bioavailability of a released biofortified rice variety, viz., DRR Dhan 45 was found to twice that of control IR64. The four released varieties generated through traditional breeding had technology efficacy ranging from 48 to 75 percent, with zinc consumption of 38 to 47 percent and 46 to 57 percent of the RDA for male and female, respectively. The results of germplasm characterization and population mapping for zinc content, as well as the construction of a national evaluation system for the release of biofortified rice varieties, have been reviewed in the context of the five biofortification programme criteria.
