【摘要】：北美香柏(Thuja occidentalis),又名北部白雪松(Northern white-cedar),主產于美國東部的一種常綠喬木。樹型優(yōu)美,葉色濃郁,可抗煙塵、二氧化硫,常作為環(huán)保型園林綠化樹種,其枝葉中富含黃酮、單寧等成分,因此具有良好的醫(yī)藥功效。以兩年生插穗為材料,從品種、基質、扦插時間、激素處理等方面著手,對北美香柏扦插繁殖體系進行優(yōu)化,通過分析不同處理插穗生根過程中內源激素含量、氧化酶活性、營養(yǎng)物質含量變化規(guī)律,探究北美香柏扦插生根機理,旨在為北美香柏扦插繁殖提供理論指導。研究結果如下:(1)不同品種、基質、扦插時期、激素種類、激素濃度、處理時間對插穗生根效果具有顯著影響。北美香柏最優(yōu)扦插繁殖體系為:以兩年生'Green Giant'枝條為材料,扦插基質為V(珍珠巖):V(泥炭土)=3:1,扦插時間為秋季,處理激素為K-IBA、質量濃度為8000mg/L、處理時間為10s,生根率達92.22%。(2)生根形態(tài)學觀察發(fā)現,北美香柏插穗既有基部愈傷組織生根,又有皮部生根,其中基部愈傷組織生根為主。其不定根的形成大致分為3個階段:0～24d,愈傷組織形成期,24~48d,不定根形成期,48～60d,不定根伸長期。(3)內源激素IAA、ABA、ZT、GA對不定根的形成具有重要的調控作用。IAA含量在愈傷組織形成期上升,不定根形成期、不定根伸長期下降;ABA含量在整個生根過程中呈下降趨勢;ZT與GA含量在愈傷組織形成期降低,不定根形成期、不定根伸長期上升。K-IBA的處理促進了 IAA的合成,抑制了 ABA、ZT、GA的合成,形成高IAA/ZT、IAA/ABA值,從而促進插穗生根。(4)氧化酶POD、PPO、IAAO的活性變化與不定根的形成聯系密切。愈傷組織形成期,POD、PPO活性上升,IAAO活性下降;不定根形成期,POD、PPO活性下降,IAAO活性上升;不定根伸長期,POD活性微弱上升,PPO活性趨于穩(wěn)定,IAAO活性下降。外源激素K-IBA通過提高POD、PPO活性,降低IAAO活性來促進北美香柏插穗不定根的形成。(5)營養(yǎng)物質的代謝對不定根形成具有重要的影響。愈傷組織形成期,可溶性蛋白、可溶性糖、總氮含量升高,淀粉含量下降,不定根形成期,可溶性蛋白、可溶性糖含量下降,淀粉含量上升,總氮含量保持穩(wěn)定,不定根生長期,各營養(yǎng)物質含量上升。K-IBA的處理,有利于可溶性蛋白、可溶性糖的積累,提高了插穗對淀粉的利用率,形成高C/N值,插穗生根效果更好。
[Abstract]:North American cedar (Thuja occidentalis), also known as the northern white cedar (Northern white-cedar), chiefly in the eastern United States of an evergreen tree. The tree type is beautiful, the leaf color is rich, can resist the smoke dust, the sulfur dioxide, often as the environmental protection garden greening tree species, its branches and leaves are rich in flavonoids, tannins and so on, therefore has the good medicine effect. Taking biennial cuttings as materials, the cutting propagation system of cedar in North America was optimized from the aspects of variety, substrate, cutting time, hormone treatment and so on. The content of endogenous hormones and the activity of oxidase in the rooting process of cuttings in different treatments were analyzed. To explore the rooting mechanism of cedar cuttage in order to provide theoretical guidance for cutting propagation of cedar. The results were as follows: (1) different varieties, stroma, cutting period, hormone type, hormone concentration and treatment time had significant effects on rooting effect of cuttings. The optimum cutting propagation system of Cypress cedar was as follows: using biennial 'Green Giant' branch as material, cutting medium V (perlite): V (peat soil) = 3, cutting time as autumn, treatment hormone as kg IBA, mass concentration of 8 000 mg / L, the optimum cutting medium was V (perlite): V (peat soil) = 3%, the cutting time was autumn, and the concentration was 8 000 mg / L. The rooting rate was 92.22% after 10 s treatment. (2) the morphological observation of rooting showed that the cuttings of cedar in North America had both basal and cutaneous roots, among which the basal calli were the main ones. (2) the rooting morphology of the cuttings showed that there were not only basal calli but also bark roots in the cuttings. The formation of adventitious roots is divided into three stages: 0 ~ 24 days, callus formation, 24 ~ 48 days, adventitious root formation, 48 ~ 60 days, and adventitious root extension. (3) the endogenous hormone IAA,ABA,ZT, GA content increased in callus formation stage, adventitious root formation stage, and adventitious root extension period decreased in adventitious root formation stage. (2) the content of IAA in adventitious root formation stage was higher than that in adventitious root formation stage. The content of ABA decreased in the whole rooting process. The contents of ZT and GA decreased in callus formation stage, adventitious root formation stage and adventitious root elongation stage. K-IBA treatment promoted the synthesis of IAA, inhibited the synthesis of ABA,ZT,GA and formed high IAA/ZT,IAA/ A value. (4) the activity of oxidase POD,PPO,IAAO was closely related to the formation of adventitious roots. During callus formation, POD,PPO activity increased, IAAO activity decreased, POD,PPO activity decreased and IAAO activity increased during adventitious root formation, POD activity slightly increased, PPO activity tended to stabilize and IAAO activity decreased during adventitious root extension. Exogenous hormone K-IBA promoted adventitious root formation of cedar cuttings by increasing POD,PPO activity and decreasing IAAO activity. (5) the metabolism of nutrients had an important effect on adventitious root formation. During callus formation, soluble protein, soluble sugar, total nitrogen content increased, starch content decreased, adventitious root formation stage, soluble protein, soluble sugar content decreased, starch content increased, total nitrogen content remained stable. During adventitious root growth period, the contents of nutrients increased, and the treatment of K-IBA was beneficial to the accumulation of soluble protein and soluble sugar, increased the utilization rate of starch, formed a high C / N value, and had a better rooting effect on cuttings.
【學位授予單位】：中南林業(yè)科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：S791
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本文編號：2461589