Cryopreservation combined with in vitro culture offers a safe and cost-effective method to conserve germplasm. Conservation of Persea spp. has been limited to heterozygous somatic embryos that are not true-to-type. A method for shoot-tip cryopreservation is vital to preserve the exact gene pool of interest. For the first time cryopreservation protocols for mature shoot tips of two avocado cultivars (cvs) ‘Velvick’ and ‘Reed’, were established. In vitro shoots were subjected to two different optimised pre-treatments; (1) cv ‘Velvick’—high sucrose (0.3 M) or (2) cv ‘Reed’—low temperature (10 °C) incubation, over a 2-week period prior shoot tip dissection. Two different plant vitrification solutions, plant vitrification solution 2 (PVS2) and vitrification solution L (VSL) were tested at 0 °C for 0, 10, 20, 30 and 40 min. Vitrified shoots were evaluated for survival and regrowth at 2 and 8 weeks after vitrification treatment and either with or without liquid nitrogen exposure. The study revealed that the optimal exposure time for each cultivar varied with the cryoprotectant used. After liquid nitrogen cv ‘Velvick’ highest regrowth levels were observed with 20 min exposure to either PVS2 or VSL, however, vigorous plants were produced only from VSL treated shoots. In the case of cv ‘Reed’ highest regrowth levels were observed with 10 min exposure to PVS2 however only morphologically normal plants were recovered from VSL treated shoots.

冷冻保存与体外培养相结合提供了一种保存种质的安全且经济高效的方法。保护Persea spp。已限于非真型的杂合体细胞胚。尖端冷冻保存的方法对于保存确切的目标基因库至关重要。首次对两个鳄梨（cvs）'Velvick'和'Reed'的成熟芽尖端进行冷冻保存，成立。对体外芽进行两种不同的优化预处理；（1）cv'Velvick'-高蔗糖（0.3 M）或（2）cv'Reed'-低温（10°C）孵育，在茎尖解剖前2周内进行。在0°C下分别测试了两种不同的植物玻璃化溶液，植物玻璃化溶液2（PVS2）和玻璃化溶液L（VSL）0、10、20、30和40分钟。在玻璃化处理后的2周和8周（有或没有液氮暴露）下评估了玻璃化的芽的存活和再生长。研究表明，每种品种的最佳暴露时间随所用的防冻剂的不同而不同。在暴露于PVS2或VSL 20分钟后，观察到液氮cv'Velvick'的最高再生水平，但是，仅由VSL处理的枝条才能产生有活力的植物。