各生理因素对山苍子茎段插穗生根成活的影响

Effect of physiological factors on the rooting and survival of Litsea cubeba stem-cuttings

【目的】为进一步促进山苍子扦插生根成活提供参考。【方法】采取单因素随机试验,在山苍子扦插过程中分别随机抽取新鲜、有愈伤组织(未生根)、半枯、生根(愈伤组织生根型)的插穗茎段为研究对象,测定和分析4种插穗的营养物质及其分泌物含量,探究影响山苍子扦插成活的主要生理因素。【结果】山苍子插穗扦插初期消耗N、可溶性糖和可溶性淀粉为生根诱导提供能量,并且三者均为新鲜插穗中含量最高(P<0.05),分别为14.14、74.38、100.85 mg/g;在愈伤组织诱导期,插穗中黄酮、多酚含量上升,不利于其生根成活,此阶段半枯插穗的黄酮含量显著高于愈伤组织插穗和生根插穗(P<0.05);在愈伤组织形成阶段,插穗的全K和可溶性蛋白消耗量增加,此阶段插穗的全K和可溶性蛋白含量显著降低(P<0.05),分别为2.42、0.51 mg/g;在插穗生根后,其营养物质含量增加,黄酮、多酚含量降低,此时生根插穗的全K、可溶性蛋白、可溶性糖、可溶性淀粉含量均显著高于愈伤组织插穗(P<0.05),而黄酮和多酚含量显著降低(P<0.05),分别为3.66、6.93 mg/g。在4种插穗的组织分泌物中共鉴定出67种化合物。其中11种化合物(如十二甲基环六硅氧烷、二十五烷、十二甲基五硅氧烷等)可能对扦插生根成活具有促进作用,29种化合物(如芥酸酰胺、6,7-二甲氧基-1-甲基-1,2,3,4-四氢异喹啉、二十烷等)可能具有抑制作用。【结论】插穗中高含量的N、可溶性糖和可溶性淀粉有利于山苍子插穗的生根诱导,而插穗中积累过量的黄酮、多酚不利于或抑制愈伤组织形成和插穗成活;分泌物中11种化合物可能促进插穗生根成活,29种化合物可能抑制插穗生根成活。

【Objective】This research is used to provide references in order to improve the rooting and survival of Litsea cubeba stem cutting.【Method】The single factor randomized experiment was conducted for randomly selecting the fresh cuttings,callus cuttings(not rooted),half dead cuttings,and rooting cuttings(callus-rooting type)in the cutting process of L.cubeba stem cutting;and we analyzed and took measure of the nutrients and secretion components content of the four types of semi-hardwood cuttings.Moreover,we explored the main physiological factors affecting the survival of the L.cubeba stem cutting.【Result】The L.cubeba cuttings could provide energy for root induction at the early cutting stage by consuming N,soluble sugar and soluble starch,and three compound contents were significantly highest(P<0.05)in fresh cuttings with 14.14,74.38 and 100.85 mg/g,respectively;the stem cuttings were inclined to dead during the callus induction period on account of the rise in the flavonoid and polyphenol content,and the flavonoid content of the half dead cuttings was significantly higher than the callus cuttings and rooting cuttings(P<0.05);the consumption of stem cutting’s total K and soluble protein started to increase during the callus formation period.Moreover,the total K and soluble protein contents of the cuttings at this stage significantly decreased(P<0.05),and those contents were 2.42 and 0.51 mg/g respectively;the stem cutting’s nutrient content started to increase after rooted,but the flavonoid and polyphenol contents decreased;and the total K,soluble protein,soluble sugar and soluble starch contents of the rooting cuttings were significantly higher than the callus cuttings(P<0.05),while the flavonoid and polyphenol contents of the rooting cuttings significantly decreased(P<0.05),and those contents were 3.66 mg/g and 6.93 mg/g respectively.A total of 67 compounds were identified by GC-MS analysis in the secretions from four types of L.cubeba cuttings tissue;there were 11 substances in the secretion may promote the rooting and survival of L.cubeba stem cutting,such as the cyclohexasiloxane,dodecamethyl,pentacosane and pentasiloxane,dodecamethyl;there were 29 substances might inhibit the rooting and survival of L.cubeba stem cutting,such as the 13-Docosenamide,(Z),Isoquinoline,1,2,3,4-tetrahydro-6,7-dimethoxy-1-methyl and eicosane.【Conclusion】The high level content of N,soluble sugars and soluble starch in cuttings were favorable for root induction of the L.cubeba stem cutting,but it was unfavorable for callus formation and survival of cuttings that accumulating the excessive flavonoids and polyphenols in L.cubeba stem cuttings,which possess the inhibition effect;there were 11 secretions in cutting tissue extracts may promote rooting and survival of the cuttings,but there were 29 secretions may have inhibitory effect.