An Efficient Suspension Culture System for In Vitro Rose Regeneration
Anna Nelson, MS Seminar
Thursday, November 2, 2023, 9:00 am
(Under the direction of Dr. Wusheng Liu, Chair)

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 Nelson.Abstr.pdf

Abstract:
Roses (Rosa hybrida L.) are used for a variety of purposes, ranging from cut flower production to perfumes and oils. Despite the wide variety of roses available in the market, there have only been a limited number of reports that have indicated successful Agrobacterium-mediated transformation. The intent of this project was to develop an efficient suspension culture system for rose regeneration to facilitate plant transformation. Since tissue culture tends to be highly genotype-dependent, we utilized the cultivars Carefree Beauty™, Italian Ice®, and Ringo All-Star™ in a multi-part study to identify the best method of inducing rapid somatic embryogenesis in suspension culture. We explored the role of auxins in callus response, carbohydrate sources, and auxins in suspension culture, the importance of regeneration mediums, and the subsequent propagation and rooting transfer processes. We found that the greatest amount of regenerative callus developed on solid callus induction media containing 4.52 μM of 2,4-Dichlorophenoxyacetic acid (2,4-D) and 30 g L-1 sucrose for Italian Ice® (470 ± 15.28). The greatest amount of embryogenesis occurred when leaf callus explants were transferred to media containing MS media supplemented with 4.52 μM of 2,4-D and 34 g L-1 of sucrose for Italian Ice® and continually refreshed in suspension culture for eight weeks (1356 ± 207). Regenerative callus harvested from suspension was also capable of organogenesis and somatic embryogenesis, with the highest rates of somatic embryogenesis occurring in 16/8 light culture on solid regeneration media containing 2.22 μM of 6-benzylaminopurine (BAP) and 30 g L-1 sucrose for Italian Ice® (60% ± 6%). Somatic embryos transferred to germination media were most successful at developing into plants on media simulating osmotic stress (37.5% ± 3.7%). As a result, we developed a highly efficient suspension culture system for plant regeneration in Italian Ice®, permitting Agrobacterium-mediated transformation and gene editing.