Study of Maize Populations Contained Different Proportions of U.S. Corn Belt Germplasm

Abstract

The incorporation of exotic germplasm into tropical breeding materials can broaden and diversify the genetic base of the tropical maize, and also adding more desirable alleles. For effective utilization of the exotic germplasm, choice of exotic source and efficient method of incorporation of exotic germplasm into tropical material is needed. This study was conducted to asses a genetic potential and the effectiveness of different types of exotic germplasm introduced from U.S. Corn Belt in combination with tropical breeding materials. The results of the study implied: commercial hybrid was the most promising source to improve performance of the tropical inbred lines followed by Non-BSSS inbred lines and BSSS “Iowa Stiff Stalk Synthetic” inbred lines. Semi-exotic population with 50% exotic showed significantly lower grain yield, earlier days to silking and anthesis, lower grain moisture content and higher leaf disease infection than 25 and 12.5 % exotic. On the other hand, no significant difference was observed between 25 and 12.5 % exotic. Semi-exotic pipulations with 25 and 12.5 % commercial exotic hybrid also showed grain yield higher than the corresponding tropical population but were not statistically different to the best check variety “Suwan 1”.