紫山药愈伤组织的诱导及其分化

摘要

以紫山药无菌苗为试材,研究了植物生长调节剂种类、材料类型、光暗条件等对其愈伤组织诱导及其分化的影响.结果表明:(1)细胞分裂素6-BA和KT对紫山药愈伤组织的诱导效果差异不显著,适合紫山药茎段愈伤组织诱导的最佳植物生长调节剂组合为KT 2.0 mg·L-1+NAA 2.0mg·L-1或6-BA 2.0mg·L-1+NAA2.0mg·L-1;(2)同一培养基上不同外植体愈伤诱导效果存在差异,在植物生长调节剂配比6-BA 2.0mg·L-1+NAA2.0 mg· L-1下,微型块茎、茎段的愈伤组织诱导率比叶片高,分别为91.167％、86.300％、45.167％;(3)添加0.25 g· L-1的活性炭能明显减轻紫山药茎段愈伤组织的褐化,愈伤生长良好,且愈伤组织的诱导率较高;(4)光暗条件对紫山药茎段愈伤组织诱导率的影响差异不显著,但暗处有利于愈伤组织的增殖生长;(5)不同植物生长调节剂配比对愈伤组织不定芽分化的影响显著,适合紫山药愈伤组织再分化的最佳植物生长调节剂配比为MS+6-BA2.0 mg·L-1+NAA0.02 mg·L-1,诱导率达50％以上,芽苗生长粗壮.%Using aseptic seedings of Dioscorea alata L.,effects of various exogenous hormones,materials,and light conditions on the callus induction and differentiation of the stem-segments with nodes of D.alata were studied.The following results were obtained.(1) There was no significant difference on the callus induction between the applications of 6-BA and KT.The hormone combination most conducive to the stem callus induction was either KT 2 mg· L-1+NAA2 mg· L-1or 6-BA2 mg· L-1+NAA 2 mg· L-1.(2) The callus induction rates of different explants differed significantly on a same medium.For example,on the MS medium containing 6 BA 2 mg · L-1 + NAA2 mg · L-1,the rate of bulbil induction was 91.167％;that of stem,86.300％;and,that of leaf,considerably lower at 45.167％.(3) By addition of activated carbon at 0.25 g · L-1 to MS medium,browning of the calluses was significantly alleviated and the induction rate higher than the others.(4) Although there was no significant difference in the callus induction rate of the stems under light and darkness,the stems calluses proliferated more quickly in the dark than under light exposure.(5) The differentiation of adventitious buds from stem calluses was remarkably different at the presence of different hormones.6 BA stimulated the re-differentiation more than KT.The combination of 6-BA 2.0 mg · L-1 +NAA 0.02 mg · L-1 was the best for the regeneration with up to 50 ％ more adventitious buds and growth of shoots more vigorously than the others.