Genetic Analysis of Tillering and Other Agronomic Characters in Foxtail Millet (Setaria italica (L.) P. Beauv.) Using the Progeny from the Cross between the Two Diverse Strains, Gai 53 and Kuromochi

Foxtail millet (Setana italica (L.) P. Beauv.) is a highly self-pollinated diploid grass of Eurasia that shows a remarkable diversity in agronomic characters. However, there has been very little information about the genetic mechanism controlling agronomic characters. In the present study, genetic analyses of agronomic characters were performed using the p2 population from the cross between two strains differing in their characters, Kuromochi (KM) and Gai 53 (G53), under two different daylength conditions. The agronomic characters examined were as follows: number of tillers including main culm (TN), culm length (CL), panicle length of the main culm (PL), total leaf number of the main culm (LN), caryopsis length (CRL), caryopsis width (CW), weight of 100 caryopses (WHC), seed set (SS) and yield from the main culm (YM). The frequency distributions of these characters were continuous, suggesting that many genes control these characters. Distribution patterns were different between the two daylength conditions, and many characters were negatively correlated with days to heading (DH). These results indicated that DH greatly influences the variance of other agronomic traits. The strategy for genetic dissection of agronomic traits was discussed