Haplodiploidization of maize (Zea mays L) through induced gynogenesis assisted by glossy markers and its use in breeding

Abstract

Reliable detection of haploids at the seedling stage is a prerequisite for the use of haplodiploidization through in situ gynogenesis in maize breeding. The use of recessive alleles of glossy genes as markers makes this detection possible in various materials. Two synthetics with a wide genetic basis: flint glossy1 CGT and dent glossy6 DGT were studied. After pollination with the FIGH 1 inducer, they produced haploid seedlings at a rate of 0.64 and 0.93%, respectively. The rate is increased (0.94% on average) for the CGT (C0) synthetic after selfing, in S1 progenies. The distribution of 203 S1 families showed a significant deviation in comparison with a Poisson distribution. The DGT synthetic showed an increase in induction rate when a new synthetic was formed with doubled haploid (DH) lines, suggesting that 'inductibility' may have some genetic effects. No spontaneous doubling was shown by the haploid seedlings of either synthetic. Colchicine treatment allowed a recovery of male fertility in 30 to 60% of detected haploids according to the experiments. The progeny recovery rate was influenced by the genetic basis, as the DGT synthetic gave better results than the CGT synthetic. The growing period also had an influence upon the recovery of fertile ears. Hybrids produced from heterotic DH lines showed an agronomic potential similar to standard hybrids. It is concluded that in situ gynogenesis assisted by the use of glossy markers can now be used in maize breeding.