Among the biotechnological tools that can greatly help fruit
crop breeding, haploid and doubled haploid production, through
gametic embryogenesis, allows the single-step development of
complete homozygous lines from the heterozygous parents,
increasing the efficiency of perennial crop breeding programmes.
Haploid plants are sporophytes carrying the gametic chromosome
number (n instead of 2n), and doubled haploids (DHs) are haploids
that underwent, spontaneous or induced, chromosome duplication.
Haploid and DHs have a potential use in mutation research,
selection, genetic analysis, transformation and in the production of
homozygous cultivars also required to utilize as parental lines for
F1 hybrids (heterosis). Fruit crops are characterized by the high