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


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.


High oil maize; Double Haploid lines; Testcrosses and DH lines evaluation; heterotic groups; subtropical maize germplasm

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