Augmenting protein biofortification in maize using teosinte (Zea mays ssp. parviglumis)

Abstract

Maize underwent domestication from the wild species Teosinte (Zea mays ssp. parviglumis) in the Balsas River valley of Mexico. While domestication and selective breeding of maize lost major alleles for kernel size and composition, Teosintes have a huge repository of novel and diverse alleles for protein content; have doubled protein content and higher levels of methionine-rich zeins than cultivated maize. To address the issue of protein in maize, we developed and investigated BC1F2:3 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 BC1F2:3 individual cobs and parental lines. The protein content of among the BC1F2:3 lines had highly significant variation which varied from 9.53 % to 16.49 % for MP51 and MP6 lines, respectively. The results stipulated that protein content of teosinte introgressed maize lines is improved by 41.42% over CML-451. The introgressed population also exhibited significant variation for all ear traits investigated. Principal component analysis and cluster analysis have applied for estimation of genetic diversity among introgressed lines. 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. 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.