Towards artificial seeds from microspore derived embryos of Brassica napus

Abstract

Microspore derived embryos are haploid and their immediate diploidization generates doubled haploid homozygous plants, whereas a normal breeding process would take 7–8 generations to attain homozygosity. However, the flexibility available in conventional seeds—storage, transport, variable planting time, and handling—is not possible with microspore derived embryos in breeding programs; they are continuously growing from induction of embryogenesis to planting in the soil, without a pause. Artificial seed technology can by-pass the expensive and time-consuming process of acclimatizing and loss of in vitro derived embryos in the green house. The doubled haploid technology in Brassica species has advanced considerably on many fronts—reliable induction of embryogenesis, in vitro diploidization, desiccation and conversion of embryos to plantlets. Although microspore derived embryos are bipolar, they are not considered within the scheme of artificial seeds. The development of artificial seeds in brassica, however, needs the input from other biotechnologies to develop vigorous embryos capable of conversion to plants. It is now necessary for empirical research on microspore derived embryos of Brassica to expand the applications available to the plant breeder by including the biotechnologies of encapsulation and embryo priming to develop artificial seeds. The objective of this review is to draw the attention of researchers to make the transition from microspore-derived embryos to artificial seeds in Brassica crop species, by bringing together relevant studies from the relevant biotechnologies. This would expand the present scope of artificial seeds and thus provide more options and flexibility to the Brassica plant breeder. Artificial seeds from microspore derived embryos enhance breeding of Brassica species.