Bacopa monnieri (L.) Wettst. is a high value medicinally important plant used as a memory enhancer, the germplasm of which requires to be conserved long-term due to its over-exploitation. Access to an efficient shoot tips cryoconservation protocol that results in high post-thaw regrowth and is applicable to many genotypes is a prerequisite for long-term conservation of valuable germplasm. Experiments were conducted to assess the effect of shoot tip size and cryoconservation techniques, including vitrification (V) and droplet-vitrification (DV), to improve post-thaw regrowth in two accessions of B. monnieri. Optimal results after cryopreservation were obtained when small size (SS – 0.5 × 0.5 mm) shoot tips were excised from cultures pretreated on MS basal medium supplemented with 0.3 M sucrose (SM) for 4 to 16 wk, precultured on SM medium for 2 d and dehydrated with Plant Vitrification Solution-2 (PVS2) at 0 °C for 35 min. High post-thaw regrowth of > 50% was obtained using V technique, which was further enhanced by using DV technique (approximately 80%). Genetic integrity of regenerated plantlets after cryoconservation using V and DV showed no significant variation among the control and cryoconserved plants using 39 Inter Simple Sequence Repeats (ISSR) markers. Further, the developed protocol was evaluated in other four accessions and four-fold enhanced post-thaw regrowth (approximately 80%) and reduction of preparation time by approximately 20 wk was achieved. These results demonstrated that this improved protocol has potential to be implemented for cryobanking of in vitro germplasm of Bacopa monnieri.

假马齿苋(L.) Wettst。是一种具有高药用价值的重要植物，可用作记忆增强剂，但由于过度开发，其种质需要长期保存。获得有效的茎尖冷冻保存方案，可实现解冻后的高再生并适用于许多基因型，是长期保存有价值种质的先决条件。进行实验以评估茎尖尺寸和冷冻保存技术（包括玻璃化（V）和液滴玻璃化（DV））对改善两种 B. monnieri 种质解冻后再生的影响。当从在补充有 0.3 M 蔗糖 (SM) 的 MS 基础培养基上预处理 4 至 16 周的培养物中切下小尺寸 (SS – 0.5 × 0.5 mm) 的芽尖，在 SM 培养基上预培养 2 d 和使用植物玻璃化溶液-2 (PVS2) 在 0 °C 下脱水 35 分钟。使用 V 技术获得了 > 50% 的高解冻后再生率，并通过使用 DV 技术进一步增强了再生率（约 80%）。使用 V 和 DV 冷冻保存后再生植株的遗传完整性显示，使用 39 个简单序列重复 (ISSR) 标记的对照植物和冷冻保存植物之间没有显着差异。更远，所制定的方案在其他四个种质中进行了评估，解冻后再生速度提高了四倍（约 80%），并且制备时间缩短了约 20 周。这些结果表明，这种改进的方案有可能应用于冷冻银行假马齿苋离体种质。