F₁ Hybrid Production using Doubled Haploid of Microspore-derived 'Moriguchi' Radish (Raphanus sativus L.)

Abstract

F₁ hybrids were produced by using doubled haploid radishes, which were derived from microspore culture and maintained their homozygosity by selfing through bud-pollination three days before anthesis. The bud-pollination of doubled haploid was also undertaken to obtain seeds of F₁ hybrids. The regenerants developed weak roots with small diameters and small leaves. However, good growth was restored in F₁ hybrids that were crossed among the doubled haploid progenies of the regenerants. They grew uniformly and showed hybrid vigour. It was proven that haploid breeding was effective to establish a genetically fixed radish (Raphanus sativus L.) plant and a new type of 'Moriguchi' radish with a red, long, slender root.