Carotenoid and SSR marker-based diversity assessment among short duration maize (Zea mays L) genotypes

Based on analysis of variance using a CRD model, significant variation for kernel carotenoid content was found to be present in 25 maize (Zea mays) genotypes. Total carotenoid content was found to be at a minimum (0.94 μg/g) in the white kernel line Sikkim primitive-1, whereas as much as 38.25 μg/g was observed in a dark yellow colored kernel line (1490). TLC profiling of total carotenoids showed that out of 25, 11 lines also had high provitamin-A content, in addition to high kernel carotenoids. Kernel color did not resolve any strong correlation with either total carotenoid content or provitamin-A. Thereby, selection of genotypes for high carotenoid and provitamin-A based on kernel color may not be successful. Jaccard’s similarity coefficients, based on SSR data, were found to vary from 0.17 to 0.97. The highest value of genetic similarity (0.97) was found between Pop31B and Pop31C and therefore they seem to be most similar, whereas inbred lines Pop31D and POB-3, and 1586 and Tarun-1 were most divergent (0.17). The UPGMA den¬drogram constructed using Jaccard similarity coefficients of SSR marker data divided the 25 lines into four groups (A, B, C, and D). Each broad group (Group A and B) was further divided into clusters, thus a total of seven clusters were formed. Cluster strength varied from a minimum of 1 member in cluster III of Group B to a maximum of 5 members in cluster II of Group B. Clustering patterns, in general, revealed that lines with high carotenoid content did not occupy the same cluster. A similar distribution was also observed for lines with a high provitamin-A con¬tent. The marker based clustering pattern therefore did not show strong correlation with quantitative data. Based on total carotenoids and relative provitamin-A content, 11 lines were identified to be a potential source for biofor¬tification of carotene in maize