Shortening of generation cycles in inbred lines of maize (Zea mays L.) through embryo rescue technique

Abstract

Embryo rescue techniques have been used as an approach to raise hybrids from incompatible crosses. These
techniques have also proved to be valuable tools for maize improvement, since they allow reducing the duration
of the generation cycles for speed breeding. The aim of this study was to identify an efficient embryo rescue
protocol to evaluate the response of maize (Zea mays L.) embryo culture and compare its generation time (seed
to seed) with the generation time of plants obtained by mature seed germination. To this purpose, we evaluated
the germination efficiency, in vitro protocol efficiency, and days to flowering of three advanced maize inbred lines
developed at the National Institute of Agricultural Technology of Argentina. A greenhouse traditional strategy
was used as control. The embryo rescue technique allowed obtaining nearly four generations per year compared
to the two generations obtained in greenhouse. All the plants obtained by the embryo rescue technique were
morphologically normal and fertile. The results confirmed the possibility of using embryo rescue strategies to
significantly reduce the duration of the generation cycles in maize.