Identification of superior doubled haploid maize (Zea mays) inbred lines derived from high oil content subtropical populations

Abstract

High oil maize (HOM) hybrids, adapted to subtropical regions are needed to meet existing requirements for industrial and livestock purposes. Recently, the doubled haploid (DH) breeding technology is applied to reduce considerably the time to generate homozygous maize lines, however, information of heterotic response, per se productivity, stress, disease reaction, and adaptation to different environments are not known. In this work, field evaluations of per se and testcross high oil content DH lines adapted for subtropical environments were studied to identify superior DH lines with good heterotic response and agronomic characteristics. White and yellow kernel test crosses were formed using the different heterotic population as testers from which DH lines were derived. Test crosses were evaluated at three locations in Mexico. Superior DH lines from each tester presented high GCA effects through test crosses, with a range of grain yield across locations of 12.8 to 10.4 Mg ha-1 and 11.1 to 9.1 Mg ha-1 respectively. Per se DH lines were observed and screened for adaptation, productivity, disease reaction and other agronomic traits in five locations/year environments. Per se DH lines screening process across environments was able to obtain information for adaptation, productivity, and healthiness. Also of DH lines with high response of GCA, information regarding heterotic groups, and DH lines oil content determination was used to identify outstanding DH lines for developing HOM high-yielding hybrids adapted for subtropical regions, with fewer costs and time. This research demonstrated that it was feasible to identify subtropical elite DH lines with high oil content.