History and Current Status of Haploidization in Carrot (Daucus carota L.)

Abstract

The induction of haploid cell development into normal plants enables the production of doubled haploid lines, which are homozygous and can be used in breeding programs as an alternative to conventionally derived inbred lines. In this paper, we present the historical background and current status of the attempts of haploid induction in carrot (Daucus carota L.). Economically, carrot is one of the most important vegetables. It is an outcrossing diploid (2n = 2x = 18) species. Nowadays, the seeds of hybrid cultivars constitute the majority of the carrot seeds sold in the world. Hybrid cultivars of carrot are produced using inbred populations. Inbreeding in this species is difficult due to an inbreeding depression and is also time-consuming, as it is a biennial crop. Therefore, the implementation of the haploidization technology into the breeding programs of carrot is of high interest. Androgenesis, gynogenesis and induced parthenogenesis are the methods that have been used for haploid induction, and their potential in haploidization of carrot is discussed. The centromere-specific histone 3 variant (CENH3) and its manipulation in carrot is also acknowledged.