Indian Journal of Biotechnology Vol. 18, July 2019, pp 224-234 Characterization of maize genotypes using microsatellite markers associated with QTLs for kernel iron and zinc Sunil K Jaiswal, Vignesh Muthusamy, Firoz Hossain*, Rajkumar U Zunjare, Rajat Goswami, Rashmi Chhabra, Gulab Chand, Sweta Dosad, Rakesh Bhowmick 1 , Satish K. Guleria 2 , Arunava Pattanayak 1 and Hari S. Gupta ICAR-Indian Agricultural Research Institute, New Delhi; 1 ICAR-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Almora; 2 CSK-Himachal Pradesh Krishi Vishvavidyalaya, Bajaura Centre I Received 29 March 2018; revised 23 March 2019; accepted 3 June 2019 Crop genetic resources rich in Fe and Zn provide sustainable and cost-effective solution to alleviate micronutrient malnutrition. Maize being the leading staple crop assumes great significance as a target crop for biofortification. We report here wide genetic variation for kernel Fe and Zn among 20 diverse maize inbreds lines, majority of which were bred for quality protein maize (QPM) and provitamin-A. Kernel Fe ranged from 30.0 - 46.13 mg/kg, while kernel Zn ranged from 18.68-39.56 mg/kg. Moderate but positive correlation was observed between the micronutrients. Characterization using 25 Single sequence repeats (SSRs) linked to QTLs for kernel Fe produced 58 alleles. Similarly, 86 alleles were identified from 35 SSRs linked to QTLs for kernel Zn. One unique allele for kernel Fe and three unique alleles for kernel Zn were identified. The mean polymorphic information content (PIC) was 0.40 for both kernel Fe and Zn. Jaccard’s dissimilarity coefficients varied from 0.25 - 0.91 with a mean of 0.58 for kernel-Fe while 0.27- 0.88 with a mean of 0.57 for kernel Zn. Principal coordinate analysis depicted diversity of inbreds. Cluster analysis grouped the inbreds into three major clusters for both kernel Fe and Zn. Potential cross combinations have been proposed to develop micronutrient rich hybrids and novel inbreds with higher Fe and Zn. The information generated here would help the maize biofortification programme to develop nutritionally enriched hybrids. Keywords: QPM, QTL, kernel Fe, kernel Zn micronutrient, SSR, biofortification, Introduction Micronutrient malnutrition has emerged as one of the alarming problems affecting an estimated two billion people worldwide 1 . The problem is more prevalent in the under-developed and developing world where resource poor people depend upon cereal-based diets that are inherently deficient in micronutrients 2 . Of the 667 million children worldwide under the age of five, 159 million are stunted, while 50 million do not weigh enough for their height 3 . As per global food policy report by IFPRI, South Asia is home to more than 35% of the world’s poor, and 21.9% of the population of India lives in poverty, and thus vulnerable to various health problems. Malnutrition poses severe socio- economic loss that amounts to 11% of the annual gross domestic product (GDP) of Asia and Africa, and India loses over $12 billion annually in GDP to micronutrient deficiencies (www.harvestplus.org). Among various micronutrients, iron (Fe) and zinc (Zn) deficiencies in humans are most pronounced worldwide 4 . Humans require Fe for basic cellular functions and proper functioning of the muscle, brain and red blood cells. Zn plays a crucial role for more than 300 enzymes in the human body for the synthesis and degradation of carbohydrates, lipids, proteins and nucleic acids 5 . Iron deficiency affects cognitive development, growth, reproductive performance and work productivity, while inadequate consumption of Zn leads to depression and psychosis, impaired growth and development besides affecting immune system 6 . It is estimated that over 60% of the world’s population are Fe-deficient while 30% are affected due to Zn deficiency 7 . In India, 70% and 48% of children under five are estimated to be deficient in Fe and Zn, respectively. Since, Fe and Zn cannot be synthesized in human body; they must be made available through diet. Various methods such as ‘food fortification’, ‘supplementation’ and ‘dietary diversification’ are practiced all over the world for alleviating the micronutrient deficiencies. —————— *Author for correspondence: Tel: +91-11-25841481; Fax: +91-11-25841481 fh_gpb@yahoo.com