Protocol for the Production of Doubled Haploid Plants of Brassica carinata

Brassica carinata, also known as Ethiopian or Abyssinian mustard, is a drought- and heat-tolerant oilseed with great potential as a dedicated industrial feedstock crop for use in biofuel and other bio-based applications. Doubled haploid technology, a system that allows for the rapid development of doubled haploid, completely homozygous plants through microspore embryogenesis, has been applied routinely in both B. carinata breeding and basic research. Here, we present a comprehensive isolated microspore culture protocol detailing the various steps involved in doubled haploid plant production for this species, from growing donor plants over harvesting flower buds and isolating, culturing and inducing microspores to regenerating doubled haploid embryos and plantlets.

Production of Haploid and Doubled Haploid Lines in Nut Crops: Persian Walnut, Almond, and Hazelnut

This chapter deals with induction of haploidy via parthenogenesis in Persian walnut and via microspore embryogenesis in almond and hazelnut. Haploid induction through in situ parthenogenesis using pollination with irradiated pollen to stimulate the embryogenic development of the egg cell, followed by in vitro culture of the immature haploid embryos. Microspore embryogenesis allows the induction of immature pollen grains (microspores), to move away from the normal gametophytic developmental route in the direction of the sporophytic one, yielding homozygous organisms (embryos in this case). Unlike other fruit crops (such as Citrus), regeneration of entire plants has not yet been obtained in our studied nut crops; however, it gives the methodology should be used to continue the roadmap.