Variability for kernel starch components in Indian maize germplasm and identification of polymorphic molecular marker for selected waxy maize genotypes

Abstract

Maize starch, especially kernel amylose and amylopectin possess immense potential in industrial applications and the health sector. The Indian maize breeding programs actively utilise several diverse maize accessions, however, the starch composition diversity of these lines is unknown. The present study evaluated 200 diverse accessions including 169 field corn lines (FC), 22 quality protein maize (QPM), five waxy corn (WC) and four popcorn lines (PC) for various starch attributes and estimated the correlation among the starch traits for the various classes of maize. A Significant variation for total starch (48.48% to 72.17%), amylose (5.00% to 34.66%) and amylopectin (65.34% to 95.00%) content were observed among the genotypes. Two genotypes, namely, 915D (95.00%) and 930G (92.69%) were found to have very high amylopectin content and could be used as potential donors in the development of waxy maize. The correlation analysis between total starch, amylose and amylopectin across the genotypes indicated a significant negative correlation between amylose and amylopectin. However, the correlation between amylose and starch varied across the subgroups of maize types and kernel colour indicating the effect of genetic background on the starch and amylose content values. Further, genotyping of the two waxy lines (915D and 930G) along with non-waxy accessions using seven waxy gene-specific markers revealed phi027 to be the most discriminating between the waxy and non-waxy lines. This can, hence, be utilized for foreground selection, in marker-assisted selection programs (MAS). This report will aid in the utilization of these genotypes in breeding programs for the improvement of starch attributes.