火龙果茎段及花药愈伤组织内源激素含量的测定

Determination of Endogenous Hormones in Callus Originated from Stem and Anther Culture of Pitaya

通过高效液相色谱-质谱联用法(HPLC-MS/MS)测定火龙果茎段鲜样及不同来源愈伤组织的脱落酸(ABA)、吲哚-3-乙酸(IAA)、赤霉素(GA3)、玉米素(ZT)四个内源激素的含量,以期找到火龙果愈伤组织再分化率低的内源激素规律,为火龙果花药培养中合理添加外源激素提供一定的理论依据。结果表明:火龙果茎段中内源IAA和ZT含量较高易于愈伤组织的诱导。火龙果茎段鲜样中的GA3含量明显低于茎段或花药愈伤组织,ABA含量则高于茎段愈伤组织,小于花药愈伤组织。花药诱导的愈伤组织中IAA的含量明显低于茎段愈伤组织,而ABA的含量却高于茎段愈伤组织,花药愈伤组织的ABA/GA3、ABA/IAA的比例都明显高于茎段愈伤组织,其中未分化花药愈伤组织的ABA/GA3的比值是茎段愈伤的6.71倍、是可分化花药愈伤组织的3.82倍,ABA/IAA的比值是茎段愈伤的43.68倍、是可分化花药愈伤组织的16.02倍,不利于愈伤组织的再分化。由此表明,较高含量的ZT和IAA对花药愈伤组织不定芽的分化有明显优势,而高含量的GA3则会对不定芽分化产生较大的负面影响,GA3/ZT值保持在较低水平对于不定芽的分化显得尤为重要。

The concentrations of four endogenous hormones, such as abscisic acid（ABA）, indole acetic acid（IAA）,gibberellin（GA3） and zeatin（ZT） in fresh stems or different calluses induced from pitaya anthers or stems were mensurated by high performance liquid chromatography-mass spectrometry（HPLC-MS/MS）. The results showed that the higher callus induction rate of stem segments of was closely related to the higher content of endogenous IAA and ZT. The content of GA3 in fresh stem segments of pitaya was significantly lower than that in stem or anther callus, the content of ABA was higher than that in callus from stem segments, but lower than that in anther callus. The content of IAA in anther callus was significantly lower than that in the callus from stem segments, but the content of ABA was higher than that in the stem callus. The ratio of ABA/GA3, ABA/IAA in anther callus was significantly higher than that in the stem callus, the ratio of ABA/GA3 in the undifferentiated anther callus was 6.71 times higher than that in stem callus, is 3.82 times higher than that in differentiated anther callus. Most importantly,the ratio of ABA/IAA in the undifferentiated anther callus was 43.68 times and 16.02 times than that in stem callus and differentiated anther callus respectively, which was the critical factor for the lower redifferentiation of undifferentiated anther callus. The higher ZT and IAA contents were beneficial to the differentiation of adventitious buds in anther callus, while the high content of GA3 could inhibit the occurrence of adventitious buds, and the low level of GA3/ZT ratio was very important for the differentiation of adventitious buds.