Direct cryopreservation of winter-acclimated buds of Dracocephalum austriacum (Lamiaceae) from field material

Abstract

This study develops protocols for the micropropagation and cryopreservation of Dracocephalum austriacum (Lamiaceae). It is a perennial herbaceous plant that overwinters with ground-level sprouts and is classified as critically endangered in Europe. In vitro cultures were initiated from seeds on growth-regulator-free Murashige & Skoog (MS) medium after nicking the seed coat. Propagation via shoot culture was achieved on ½ MS medium with 1 µM benzyl adenine (BAP). Rooting on various indole-3-butyric acid (IBA)-media was not reliable, but the rooting success was 80% after 10 weeks on medium with 1 µM BAP. Two starting materials underwent cryopreservation: (1) shoot tips from cold-acclimated in vitro plantlets and (2) axillary buds from winter shoots from field plants. For the cryopreservation of in vitro shoots, plant vitrification solution (PVS)3 and incubation over ice yielded the best results (~ 34% regeneration success). However, regeneration using winter acclimated buds were 100, 76 and 30% for collections in December, February and March, respectively, using the same protocol. Moreover, the ploidy levels of cryopreserved plantlets were estimated using flow cytometry. The use of winteracclimated field material of temperate herbaceous plants or subshrubs has high potential as explant source for cryopreservation and calls for exploring this technique for other species.

Shoot Tip Cryopreservation and Elimination of SMV and CMV Virus from Infected Stocks of Pinellia ternata (Thunb.) Breit.

“…The first report on freezing woody plant dormant branches in liquid nitrogen using slow freezing technique was by Sakai in 1960(Sakai 1960. Up to date, successful dormant bud cryopreservation was reported for several species, such as blackcurrant (Rantala et al 2021), persimmon (Matsumoto et al 2004), peony (Seo et al 2007), aspen (Aronen and Ryynänen 2014), Dracocephalum austriacum (Rasl et al 2020) and American elm (Uchendu et al 2013). In the US Department of Agriculture-Agricultural Research Service (USDA-ARS), National Plant Germplasm System (NPGS), dormant buds were used for cryopreservation of a wide range of Malus (apple) accessions (Towill and Bonnart 2005), and Salix (Towill and tubers, higher regeneration rate was obtained in dormant tubers.…”

iTRAQ-Based Proteomic and Physiological Analyses Reveal the Mechanisms of Dehydration and Cryopreservation Tolerance of Sophora tonkinensis Gagnep. Seeds

“…Pradeep et al [78] found that the germination percentage of guava pollen was not significantly different from that of fresh state after cryopreservation, thus overcoming the problem of asynchronous flowering. Thomas Rasl reported that the regeneration percentage of winter-acclimated buds of Dracocephalum austriacum L. after cryopreservation reached up to 100% [79].…”

Exploring the Structure and Substance Metabolism of a Medicago sativa L. Stem Base

“…The stem base, serving as the crucial junction between the root and stem, plays an essential role in the plant’s physiology by facilitating the transport of nutrients, photosynthates, water, minerals, and organic compounds throughout the plant. This key region supports the plant’s growth, enhances its resilience to environmental stressors, and contributes significantly to its productivity [ 9 , 10 , 11 , 12 ]. In alfalfa, the stem base is not merely a physical junction, but a vital hub of resilience, underpinning the plant’s remarkable ability to recover and regenerate [ 13 ].…”