接种方式对大白菜下胚轴离体不定芽再生及生理指标的影响

Effects of inoculation methods on in vitro shoot regeneration and physiological indexes from hypocotyls of Chinese cabbge

以大白菜品种‘贵龙5号’的下胚轴为材料，以3种不同方式接种，观察不定芽分化情况．并比较不同接种方式的下胚轴不定芽再生过程中可溶性蛋白质含量、过氧化物酶（POD）、超氧化物歧化酶（S（）D）和过氧化氢酶（CAT）活性的变化。结果表明，以正插（形态学下端插入培养基）方式接种的下胚轴在接种8～10d时不定芽开始产生，不定芽分化率达87．8％，平均每外植体再生的不定芽数为15．1个，其不定芽再生能力显著大于反插（形态学上端插入培养基）和平放的外植体；下胚轴在不定芽分化过程中各生理指标呈现规律性的变化，可溶性蛋白质含量、POD和SOD活性在芽原基形成以前表现出上升趋势而CAT活性下降，不定芽分化后呈相反变化趋势；不同接种方式的下胚轴在不定芽发生过程中各生理指标的变化有一定差异。以上结果表明大白菜下胚轴不定芽发生过程中形态学变化和生理变化紧密相关。

Chinese cabbage （Brassica campestris ssp. pekinensis （L.） Olsson ） cultivar ‘Guilong No 5＇ was used as plant material in this experiment, Investigations were carried out on differentiation behaviors of hypocotyl explants which were inoculated with three different methods, and changes of soluble protein content, activities of peroxidase （POD）, superoxidase （SOD） and catalase （CAT） in hypocotyl explants inoculated differently were compared during shoot regeneration. The results were as follows. Adventitious shoots appeared from hypocotyls with their morphological lower ends inserted in the medium after 8 - 10 days of culture, shoot regeneration percentage reached 87.8 % and there were 15.1 shoots regenerated per explant, which showed the higher regeneration ability than those either inserted with their morphological rower ends upward or placed horizontally, Physiological indexes in explants changed rhythmically as adventitious shoots were differentiated. Soluble protein content, activities of POD and SOD were in the trend of increase but activity of CAT decreased before shoot primordium occurred, However, these indexes showed contrary changing trends after adventitious shoots were differentiated, Hypocotyls inoculated with different methods showed differences in changes of physiological indexes, The above results indicated that morphological changes were strongly associated with physiological changes during the process of adventitious shoot regeneration.