PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Micronutrient malnutrition, commonly referred to as “hidden hunger”, continues to affect more than a billion people globally, particularly in developing nations where diets are heavily cereal-based. To combat this crisis sustainably, bio-fortification in rice represents a step towards that vision, one gene at a time. Rice, being the dominant cereal and a major staple food in Asia, is a prime target for bio-fortification to tackle micronutrient malnutrition in South Asia and Southeast Asia. Since zinc is an essential micronutrient for plants, its uptake is required for general metabolism, while Fe plays an irreplaceable role in oxygen transport via haemoglobin and myoglobin. In the present study, parental polymorphism between two parents was studied using rice microsatellite (RM) markers. The experiment was conducted at the Indian Institute of Rice Research, Rajendranagar, Hyderabad, India. Rice varieties RNR15048 and Karuppunel, which are rich in grain iron and zinc, were used to study parental polymorphism. Of the 1,600 SSR markers used for parental polymorphism, 210 markers exhibited polymorphism at the expected base-pair size, of which 38 Zn-related SSR markers were selected for further study. Therefore, these polymorphic rice microsatellite markers can be used for fine mapping of zinc-related genes in mapping populations obtained from these parents. ZBR (0.898619**) was positively correlated with ZPR. A total of 39 QTLs were identified on seven chromosomes, including 9 QTLs for plant height, 3 for number of tillers, 4 for number of productive tillers, 2 each for SPAD, DFF, and SPY, 6 for ZBR, and 11 for ZPR. Most QTLs for the different traits were identified on chromosome 1. The phenotypic variability explained ranged from 2.1037 to 12.958. Furthermore, exploiting information regarding molecular markers tightly linked to QTLs governing these traits will facilitate future crop improvement strategies in rice.