Assessing potential of teosinte in diversification of maize germplasm for kernel protein

Maize underwent domestication from the wild progenitor teosinte (Zea mays ssp. parviglumis) in the Balsas River valley of Mexico. During domestication and selective breeding, modern maize has probably lost many alleles for kernel size and composition leading to significant disparity in kernel protein content. To address the low protein content in maize kernel than its wild progenitor, we developed and investigated BC₁F_2:3 population derived from crossing between maize inbred line CML-451 and teosinte (Zea mays ssp. parviglumis). The data on ear traits and protein content were recorded on 126 BC₁F_2:3 individual cobs and parental lines. The protein content of among the BC₁F_2:3 lines had highly significant variation which varied from 9.53 to 16.49%. The results stipulated that protein content of teosinte introgressed maize lines is improved by 41.42% over CML-451. Proteins content, ear length (cm), ear width (cm), kernel rows/ear and test weight (g) are all significant contributors to maximum diversity among teosinte introgressed maize lines. Principal component analysis  and cluster analysis highlighted the diversity among lines; based on protein content and test weight and grouped them into six clusters. Cluster II lines were characterized by higher protein content and test weight values and were considered for wider use in breeding programmes. The results of the investigation highlight the substantial increase in the protein content of the teosinte derived maize lines and therefore indicates critical role of Zea mays ssp. parviglumis in protein biofortification of maize kernels.