Haploids and Doubled Haploids: a New Powerful Tool for Genomics and Genetics Research in Palms

Haploid plants can occur either spontaneously or can be induced by modified pollination methods in vivo, by in vitro culture of immature male or female gametophytes, or by directed modification of centromeric proteins affecting chromosome behaviour. Haploids, particularly in highly heterozygous crops, have significant advantages as material for genome sequencing. They also represent an immediate, one-stage route to homozygous diploids and thence to F1 hybrid production. The commercial exploitation of heterosis in such F1 hybrids led to the development of hybrid seed companies and subsequently to the GM revolution in agriculture. This presentation describes evidence from the first high-throughput screen to identify spontaneously-formed haploid (H) and doubled haploid (DH) oil palm, the world’s most productive oil-food crop. Over 1,000 Hs and several DHs were produced from genetically diverse material and further DH/mixoploid palms were derived from Hs using colchicine. It is expected that such a method could be used to generate genetically diverse H/DH palms from which parental clones can be selected in sufficient numbers to enable the commercial-scale breeding of F1 varieties. The anticipated increase in productivity may help to relieve pressure to extend palm cultivation, and limit further expansion into biodiverse rainforest. The general applicability of this haploid induction technique, and various alternative methods, to other palms will also be considered.