Varghese D, Berjak P, Pammenter N W
School of Biological and Conservation Sciences, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.
Cryo Letters. 2009 Jul-Aug;30(4):280-90.
This paper reports the successful cryopreservation of shoot tips of Trichilia emetica, a tropical tree species producing recalcitrant seeds. Preculture of shoot tips on MS medium with 0.7 M sucrose or with 0.3 M sucrose + 0.5 M glycerol followed by cryoprotection with a mixture of glycerol and DMSO or with PVS2 was crucial for successful recovery following cryostorage. Three cooling rates were applied to assess the effects on post-thaw regrowth of shoot tips. Slow cooling of the shoot tips (WC 1.24 g/g DW) precultured on medium with 0.3 M sucrose + 0.5 M glycerol and cryoprotected with PVS2 resulted in high shoot production (71 percent). Subsequent to relatively faster cooling, only 38 percent of the shoot tips developed shoots. Ultra-rapid cooling with PVS2 resulted in callus formation with 55 percent regrowth. We report one of the very few successful attempts to cryopreserve explants alternative to zygotic axes of tropical tree species producing recalcitrant seeds.
本文报道了对热带树种 Trichilia emetica（一种产生顽拗性种子的树种）茎尖进行成功冷冻保存的研究。将茎尖在含有0.7 M蔗糖的MS培养基上或含有0.3 M蔗糖 + 0.5 M甘油的MS培养基上进行预培养，随后用甘油和二甲基亚砜的混合物或PVS2进行冷冻保护，对于冷冻保存后的成功恢复至关重要。采用了三种降温速率来评估对茎尖解冻后再生长的影响。在含有0.3 M蔗糖 + 0.5 M甘油的培养基上预培养并经PVS2冷冻保护的茎尖（含水量1.24 g/g干重）进行缓慢降温，产生了较高的茎尖再生率（71%）。在相对较快降温后，只有38%的茎尖发育出茎。用PVS2进行超快速降温导致愈伤组织形成，再生率为55%。我们报道了极少数成功尝试冷冻保存除产生顽拗性种子的热带树种合子轴外的外植体的案例之一。
