褪黑素对‘无核白’葡萄体细胞胚的诱导作用

Investigation of Melatonin on Somatic Embryo Induction for ‘Thompson Seedless’ Grapevine

以欧洲葡萄‘无核白’(Vitisvinifera ‘Thompson Seedless’)未开放的小花蕾为外植体,研究0、1.0、2.0、3.0 mg·L^-1褪黑素(Melatonin)对其体细胞胚的诱导效果。结果表明:‘无核白’小花蕾在MS+1.0~3.0 mg·L^-1褪黑素+2.0 mg·L-1 6-BA+30 g·L^-1蔗糖+3 g·L-1植物凝胶的培养基上继代培养30 d时愈伤组织诱导率较好,为73.67%~89.10%,显著高于2,4-D处理,愈伤组织形成所用时间较2,4-D处理缩短了14 d。愈伤组织诱导120 d时,不同浓度褪黑素均出现体细胞胚,其中,以MS+1.0mg·L^-1褪黑素+2.0 mg·L^-1 6-BA+30 g·L^-1蔗糖的培养基体细胞胚的发生率最高,180 d时达12.05%。体胚在MS+60 g·L-1蔗糖+0.5 g·L^-1活性炭的X6培养基中萌发30 d后,将萌发的子叶胚转移至MS+0.2 mg·L^-1 6-BA+0.1 mg·L^-1 NOA+30 g·L^-1蔗糖+0.5 g·L^-1活性炭的成苗培养基上,其中,1.0 mg·L^-1褪黑素诱导产生的体胚发育正常的数量较多,为14.84%。不同浓度褪黑素处理的体胚诱导率均于180 d后增长较快,且低浓度的褪黑素有利于体胚萌发与正常发育,2,4-D诱导的愈伤组织无体胚形成。

The effects of different concentrations of melatonin(0,1.0,2.0,3.0 mg·L-1)on the induction efficiency in Vitis vinifera‘Thompson Seedless’ via somatic embryogenesis were investigated with unopened flower buds as explants. The results showed that the callus induction rate was 73.67%–89.10% when subcultured on the medium of MS + 1.0–3.0 mg·L^-1 melatonin + 2.0 mg·L^-1 6-BA + 30 g·L^-1 sucrose + 3 g·L^-1 phytagel for 30 days,which was significantly higher than that of 2,4-D treatment. Concurrently,the callus formation time on the above-mentioned medium was shortened by 14 days compared to the corresponding control medium with 2,4-D. At 120 days after callus induction,somatic embryos appeared in different concentrations of melatonin,among which the highest incidence was on themedium of MS + 1.0 mg·L^-1 melatonin + 2.0 mg·L^-1 6-BA + 30 g·L^-1 sucrose,reaching 12.05% at 180 d. After 30 days of germination,the cotyledon embryos on X6 medium with MS + 60 g·L^-1 sucrose + 0.5 g·L^-1 activated carbon were transferred to the seedling medium with MS + 0.2 mg·L^-1 6-BA + 0.1 mg·L^-1 NOA + 30 g·L^-1 sucrose + 0.5 g·L^-1 activated carbon. Among them,1.0 mg·L^-1 melatonin induced a large number of normal somatic embryogenesis,and the induction rate was 14.84%. The results also demonstrated that the induction rate of somatic embryos treated with different concentrations of melatonin increased rapidly after 180 d,and low concentrations of melatonin was beneficial to somatic embryos germination and normal development,whereas the 2,4-D-induced callus had no somatic embryos formation.