Location: Sugarbeet and Potato ResearchTitle: Development of an efficient doubled haploid system in sugarbeet
|Poore Fonseka, Rachael
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/13/2021
Publication Date: N/A
Technical Abstract: Doubled haploids (DHs) are ideal plant materials for trait evaluation, gene identification, genomic sequence analysis, and producing hybrids with the highest level of uniformity. The self-incompatibility nature of sugarbeet (Beta vulgaris L.) leads to a high level of genetic heterozygosity and heterogeneity in sugarbeet germplasm lines. Therefore, the development of DHs in sugarbeet provides a way to quickly produce homozygous inbred lines to simplify genetic research and accelerate the breeding process. Gynogenesis by culturing unpollinated female gametophytes has proved to be an effective DH induction method in sugarbeet, however, its haploid induction efficiency is still very limited. In this study, we compared the different effects of growth regulators towards forming an optimum growth medium to improve haploid regeneration efficiency during ovary culture. The Chu (N6) basal salt medium supplemented with 6-Benzylaminopurine (BAP) and kinetin showed the best effect on ovule growth with 44.3% of ovules had a significant size increase after culturing in a week, 2 – 5% higher than those of using other media. The Murashige and Skoog (MS) based media using phytagel as the sole gelling agent and supplemented with 6-BAP and kinetin had slightly better outcomes in callus formation, embryo-like structure induction, and green plant regeneration. The efficiency of using liquid media for ovary culture is under evaluation, and experiments of testing other growth regulators and chromosome doubling through colchicine treatment at different stages are ongoing. In addition, many green plants were obtained from the callus derived from a single ovule makes it possible to produce many DH plants from the male-sterile germplasm lines and can be directly used in hybrid production for heterosis evaluation. This study suggested that the use of gynogenesis to develop an efficient DH production system in sugarbeet has great potential to provide a solid platform for genetics research and breeding.