生长调节剂对青榨槭扦插生根及其氧化酶活性的影响

以青榨槭为材料,采用L9(33)正交试验研究了生长调节剂α-萘乙酸 (NAA)、吲哚丁酸(IBA)和赤霉素(GA3)对青榨槭扦插生根及生根过程中过氧化物酶(POD)、吲哚乙酸氧化酶(IAAO)和多酚氧化酶(PPO)活性的影响.结果显示:NAA 、IBA和GA3处理均显著提高了青榨槭插条生根率、生根数量和根长,并以NAA的影响最大;400 mg/L IBA+400 mg/L NAA+20 mg/L GA3组合处理的插条生根效果最好,其生根率、生根数和根长分别达88.5%、6条和15.88 cm,分别比无生长调节剂对照显著增加108%、200%和285%;NAA 、IBA和GA3处理可提高青榨槭插穗POD活性,降低IAAO活性,加速PPO活性高峰的出现.研究表明,生长调节剂可以调节青榨槭插穗的POD、IAAO和PPO活性,有效缩短青榨槭插穗生根时间,显著提高其生根率.     

插壤温度对四倍体刺槐硬枝插条生根过程中生理生化的影响

取四倍体刺槐3年生采穗圃中1年生硬枝插条为材料,研究扦插过程中插壤温度对插穗内源激素含量、酶活性和营养物质含量的影响,揭示四倍体刺槐扦插生根机制。结果表明：四倍体刺槐硬枝扦插过程中,插壤经加热处理,插穗内源IAA含量降低,ABA和ZR含量升高;根原基诱导期插穗内源IAA含量的变化趋势与未加热插穗相反,ABA和ZR含量的变化趋势与未加热插穗相同。插壤经加热处理,插穗IAAO、PPO和POD活性的变化趋势与未加热插穗相同,两处理间插穗IAAO、PPO和POD活性差异不显著。插壤经加热处理,可显著提高插穗可溶性蛋白和可溶性糖含量,而对淀粉和植物总氮含量的影响差异不显著。因此,插壤加热处理,主要是通过降低四倍体刺槐硬枝插穗内源IAA含量,提高插穗可溶性蛋白和可溶性糖含量来促进插条不定根发生。     

光叶楮扦插生根的吲哚乙酸氧化酶、多酚氧化酶、过氧化物酶活性变化研究

对光叶楮扦插生根过程中吲哚乙酸氧化酶（IAAO）、多酚氧化酶（PPO）、过氧化物酶（POD）3种酶进行了动态跟踪分析。结果表明：IAAO活性在扦插初期逐渐上升,第10d上升到高峰,之后下降再上升,第30d达到新高峰,然后迅速下降;前25d POD活性变化规律与IAAO相似,但30d以后活性一直上升;PPO活性在扦插前期缓慢上升,第20d上升到了最高点,此后变化不大。还研究了IAAO、PPO、POD与不定根的发生和发展关系,认为光叶楮扦插生根可分为愈伤组织形成期、根诱导期和根的伸长期3个阶段,愈伤组织形成期3种酶活性都呈上升趋势,根诱导期IAAO和POD的活性达到高峰;而根伸长期IAAO和POD活性下降,PPO活性上升。     

沙生柽柳扦插生根过程插穗相关理化特征分析

选取沙生柽柳半木质化枝条进行苗床扦插,通过实验测定插穗生根过程中内源激素(IAA、GA3、ZR、ABA)含量、可溶性营养物质(糖、蛋白质)含量及相关氧化酶(PPO、POD、SOD、IAAO)活性的动态变化特征,探讨沙生柽柳插穗扦插生根机理。结果表明:(1)沙生柽柳插穗内源激素含量随生根进程而发生变化,其中,IAA含量在扦插35d最大,并出现较大的波动变化;ZR含量在扦插55d前后变化明显,呈现低水平向高水平转化趋势;ABA、GA3含量依次呈先升高后降低再升高的变化过程,并在扦插15d和55d(80d)呈现变化的峰值和谷值。(2)沙生柽柳扦插生根与相关氧化酶活性密切相关,其中,POD、IAAO活性在插穗扦插35d后长时间保持较高水平,直至插穗生根后POD活性明显降低,IAAO活性有所增加;PPO、SOD活性则在插穗扦插15d保持较高活性,且PPO活性的变化均匀,SOD活性的高低交替变化明显。(3)在沙生柽柳扦插生根期间,插穗可溶性糖含量呈现生根前消耗减少与生根后积累增加两大变化过程,可溶性蛋白质含量表现为扦插后逐步积累增加的变化趋势。研究表明,高水平的IAA、ZR和低水平的GA3、ABA共同调控着沙生柽柳插穗生根;IAA能够通过促进插穗POD、PPO、IAAO活性变化来影响生根,较高的POD、IAAO活性可调节插穗IAA水平,高水平的PPO活性则催化插穗IAA-酚酸复合物的形成,进而诱导插穗生根。     

木质素含量对四倍体刺槐嫩枝插穗扦插生根的影响

以四倍体刺槐1年生嫩枝插条为试验材料,分析插穗木质素含量与其横截面剪切强度、相关酶活性和激素关系,并探究不同木质素含量的插穗扦插生根性状的效应,为四倍体刺槐扦插选择合适插穗提供理论参考。结果表明:(1)插穗的木质素含量与其横截面剪切强度呈极显著正相关关系(相关系数为0.99),根据剪切强度可以间接地估算其木质素含量。(2)插穗的木质素含量与其POD和PPO活性呈极显著正相关关系(POD相关系数为0.98,PPO相关系数为0.92),也与激素ABA含量呈极显著的正相关关系(相关系数为0.97),而同IAA、IBA呈不显著的相关性,根据POD和PPO活性以及激素ABA含量对生根的影响可以推测木质素含量对生根有一定的影响。(3)不同木质素含量的插穗生根性状差异显著,木质素含量为19.47%时插穗生根能力最强,其插穗生根率为60.39%,平均每株生根量为9.70个,根长为4.85cm;木质素含量为10.60%时插穗生根能力最差。(4)生根性状最佳时的木质素含量为19.47%,其对应的剪切强度范围为40～50kg。     

合欢硬枝扦插生根解剖及相关酶活性变化研究

以合欢1年生硬枝为试材,通过石蜡切片法对合欢插穗不定根发生进行解剖学研究,同时,利用比色法对扦插后不同时间的材料进行了过氧化物酶(POD)、多酚氧化酶(PPO)和吲哚乙酸氧化酶(IAAO)测定。结果表明:合欢属于诱导型生根,观察到其不定根原基起源于形成层;在整个生根过程中,处理组和对照组的POD、PPO和IAAO酶活变化趋势基本一致,但3种酶活均高于对照。     

不同株龄日本落叶松插穗的内源激素含量与生根的关系

研究了日本落叶松母株年龄、插穗内源激素含量与生根之间的关系,以及外源IBA对插穗内源激素含量的影响及其对插穗生根的促进作用。结果表明：不同株龄插穗生根性状及插穗茎和叶中激素含量差异均达极显著水平,叶中激素含量对插穗生根力没有直接影响;插穗茎中生根抑制激素（ABA）含量随株龄增长而增加,生根促进激素与抑制激素的比值（IAA＋GA＋ZR）/ABA却随株龄的增长而递减,与生根力随株龄的变化趋势一致,且该比值与生根性状紧密相关,因此可作为评价母株（无性系）生根力的指标;插后13～32d是插穗愈伤组织形成和不定根诱导的关键期,此期生根促进激素消耗量大,茎中含量大幅度降低,进入根伸长生长阶段,含量上升;外源IBA促进插穗生根的机制在于通过外源激素的刺激,在不定根诱导期,插穗茎中ABA含量大幅度降低,从而有利于不定根的发生和发育。     

机械损伤对重瓣玫瑰防御酶的诱导

为研究重瓣玫瑰（Rosa rugosa ‘plena’）的诱导抗虫性,采用机械损伤方式诱导处理重瓣玫瑰,研究机械损伤对重瓣玫瑰叶片防御酶活性的影响。结果表明,机械损伤可诱导重瓣玫瑰叶片苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)活性的增加,PPO、POD活性先升高后下降,PAL活性的升高持续时间较长。T3（打孔损伤,3孔/叶）处理为最适的损伤程度,诱导的PAL、PPO、POD活性分别在第7、3、5天达到最高值。因此认为,采用适度地损伤能够诱导重瓣玫瑰较高的防御酶活性,提高植株的防御能力。     

水杨酸、乙酰水杨酸对番茄幼苗叶片中PPO和POD的诱导作用

以番茄品种改良美国908和合作906为试验材料,研究了水杨酸(SA)和乙酰水杨酸(ASA)喷雾处理6-7叶期幼苗后,叶片内多酚氧化酶(PPO)和过氧化物酶(POD)活性在120 h内的变化.结果显示:SA和ASA对2个番茄品种的适宜诱导浓度分别为1 mmol/L和1.39 mmol/L;SA和ASA对PPO活性的诱导效果无显著差异,但对POD活性的诱导效果SA极显著强于ASA;合作906的PPO活性增幅显著大于改良美国908,而POD活性增幅却显著小于改良美国908,且合作906对诱导处理反应更敏感.研究表明,SA和ASA能显著提高番茄幼苗叶片的PPO、POD活性,而酶活性变化在品种和诱导剂间有显著差异.     

吲哚丁酸对桉树插条多酚氧化酶的影响及其与生根的关系

尾叶桉MLA无性系(简称MLA)为难生根植物,尾叶桉U6无性系(简称U6)和刚果12号桉W5无性系(简称W5)为易生根植物。MLA插条内的PPO活性比U6、W5的低。用吲哚丁酸(IBA)处理桉树的插条后,在扦插生根的不同阶段,插条内的PPO活性呈现规律性的变化。蛋白质含量呈上升趋势。PPO同工酶谱带也随生根的进程出现增多现象。讨论了多酚氧化酶与桉树插条生根的关系。     

长白落叶松插穗的内源激素水平及其与扦插生根的关系

长白落叶松 (Larixolgensis)扦插繁殖的试验结果表明 ,嫩枝扦插效果好于硬枝扦插 ,并且母树年龄是影响其扦插生根的重要因子。母树年龄为 2年生时 ,生根率达 95 %以上。本文在此试验的基础上 ,对嫩枝和硬枝插穗中内源植物激素水平进行了测定。结果发现嫩枝插穗中IAA、CTKs的含量要高于硬枝插穗中IAA、CTKs的含量 ,并且随母树年龄的增加而降低 ;相反 ,嫩枝插穗中ABA含量要低于硬枝插穗中ABA的含量 ,并且随着母树年龄的增加而增加。实验结果表明 :IAA、ABA的含量和扦插生根有密切关系。IAA促进生根 ,ABA抑制生根。IAA/ABA比值可以用来衡量长白落叶松的生根能力     

IBA浓度、扦插时间对江西杜鹃和百合花杜鹃扦插生根的影响

为探明有鳞大花亚组杜鹃扦插生根的最佳IBA浓度和扦插时间,该研究以江西杜鹃、百合花杜鹃为材料,分别采用腐叶土+河沙(1:1)、泥炭+珍珠岩+蛭石(3:1:1)基质,开展了4个IBA浓度和4个扦插时间的生根试验.结果表明:IBA浓度对除老叶留存数外的所有指标有显著影响,其中100 mg·L-1 IBA处理生根率、新梢长最大,腐烂率最低,其它指标也表现良好,为最佳生根浓度;50 mg·L-1 IBA处理根幅、新梢率最大,但不定根数最少,效果其次;200 mg·L-1 IBA处理促进根系生长,但生根率较低、特别是显著抑制新梢发育;对照处理生根效果最差.扦插时间对所有生根指标均有显著影响,早春(04-18)木质化硬枝扦插除老叶留存数较差外,其它指标均表现极佳,为最适扦插时间;秋季(10-19)半木质-木质化过渡枝扦插效果其次;夏季(06-21)嫩枝及(08-16)半木质化枝生根效果极差,不宜进行扦插育苗.物种、基质对生根指标也有显著影响,百合花杜鹃扦插生根能力强于江西杜鹃,泥炭+珍珠岩+蛭石(3:1:1)基质生根效果优于腐叶土+河沙(1:1).该研究结果首次发现早春新梢萌发前采用木质化硬枝扦插可以显著提高两种杜鹃的生根效果,为该亚组杜鹃的扦插育苗提供了科学依据.     

Adventitious root formation of kiwifruit in relation to sampling date, IBA and Agrobacterium rubi inoculation

During the winters of 2001 and 2002, the effects of three strain of Agrobacterium rubi (A1, A16 and A18), a range of IBA concentrations (0, 2000, 4000 and 6000 ppm) alone and in combination with three strains of Agrobacterium rubi and date of cutting collection on the rooting of hardwood stem cuttings of kiwifruit cv. Hayward were evaluated. Treatments of hardwood stem cuttings of kiwifruit cv. Hayward with the bacteria, IBA and IBA plus bacteria were found to promote rooting. Highest rooting percentage was obtained from cuttings treated with 4000 ppm IBA plus A18 in cv. Hayward in both years. Higher rooting percentages were observed when shoots were collected in February rather than in January.     

几种木本植物插穗生根与内源IAA,ABA的关系

迄今为止,传统的插条繁殖仍是林业和园林工作者获得良种无性系和培育苗木的重要途径。在影响插穗不定根形成内外因素中,植物内源激素水平和生长调节剂应用占有重要地位。已知第一个根原基细胞的分裂依赖于内源生长素或外源的生长调节剂(Hartmann 1983,Haissig 1974),低浓度的ABA(1.26～20μg/ml)能促进     

Expression of the <Emphasis Type="Italic">rol</Emphasis>B gene enhances adventitious root formation in hardwood cuttings of aspen

Summary An elite aspen hybrid (Populus × canescens × P. grandidentata) was transformed with Agrobacterium tumefaciens strain EHA105 that harbored a binary vector (pBI121) carrying the nptII gene under the nos promoter and tandem rolB-uidA (GUS) genes with the CaMV 35S or heat shock promoter. Among 32 independent kanamycin-resistant plants, 25 plants were confirmed by polymerase chain reaction and Southern blot analyses to contain all three genes, whereas five plants contained only nptII or/and uidA genes and two plants had both the rolB and nptII or uidA genes. Integration of the rolB gene significantly increased rooting ability of hardwood cuttings. Heat shock-rolB-transformed plants rooted at significantly higher percentage than the CaMV 35S-rolB-transformed plants. Heat shock treatment further enhanced rooting of heat shock-rolB-transformed plants. Exposure to exogenous auxin did not significantly increase the rooting percentage of transgenic hardwood cuttings, but increased the number of roots induced. This research shows great potential to improve rooting of hardwood cuttings of difficult-to-root woody plants which are commercially important to the horticultural and forestry industry. The transgenic plants with gain-of-function in hardwood-cutting rooting can facilitate research in the understanding of adventitious rooting from hardwood cuttings of recalcitrant woody plants.     

Effects of plant growth promoting rhizobacteria (PGPR) on rooting and root growth of kiwifruit (Actinidia deliciosa) stem cuttings

The effects of plant growth promoting rhizobacteria (PGPR) on the rooting and root growth of semi-hardwood and hardwood kiwifruit stem cuttings were investigated. The PGPR used were Bacillus RC23, Paenibacillus polymyxa RC05, Bacillus subtilis OSU142, Bacillus RC03, Comamonas acidovorans RC41, Bacillus megaterium RC01 and Bacillus simplex RC19. All the bacteria showed indole-3-acetic acid (IAA) producing capacity. Among the PGPR used, the highest rooting ratios were obtained at 47.50% for semi-hardwood stem cuttings from Bacillus RC03 and Bacillus simplex RC19 treatments and 42.50% for hardwood stem cuttings from Bacillus RC03. As well, Comamonas acidovorans RC41 inoculations indicated higher value than control treatments. The results suggest that these PGPR can be used in organic nursery material production and point to the feasibility of synthetic auxin (IBA) replacement by organic management based on PGPR.     

iTRAQ Protein Profiling of Adventitious Root Formation in Mulberry Hardwood Cuttings

The ability to form mature adventitious roots (AR) provides a competitive advantage for clonal multiplication of elite genotypic plant species, because high economic losses occur as a result of insufficient rooting. To better understand potential mechanisms involved in AR formation, we utilized an iTRAQ-based proteomic approach on mulberry hardwood cuttings. A total of 4427 proteins were identified from the base of cuttings, of which 595 and 231 proteins showed differential accumulations in the two periods of rooting, respectively. Three differentially expressed enzyme proteins were validated by an enzyme assay and qPCR. Functional annotation analysis showed that dysregulated proteins were involved in glucose metabolism, flavonoids biosynthesis, cell wall modification, and hormone regulation, indicating potential contributions to adventitious rooting. These results provide fundamental and important information for research on the molecular mechanism of AR development in mulberry cuttings and facilitate rooting efficiency in agricultural practice.     

Isolation, Purification, and Characterization of an Endogenous Root-promoting Factor Obtained from Basal Sections of Pear Hardwood Cuttings

Basal segments taken from Old Home and Bartlett pear hardwood cuttings collected at intervals during the rooting period in September were extracted with ethanol and fractionated by paper chromatography in different solvent systems. Different zones on the chromatograms were bioassayed by the mung bean rooting test, which showed high levels of promotion in Old Home basal extracts when the cuttings were obtained during the period of maximum rooting. Extracts from Bartlett cuttings, however, showed considerably less promotion activity in the bioassay but did show high levels of inhibitory activity.

After the easily-rooted Old Home cuttings had been in the rooting medium for 10 days, a highly active endogenous root-promoting material was found in extracts from basal segments of cuttings having buds and which had been treated with indolebutyric acid. Similar extracts obtained from disbudded cuttings, or from cuttings with buds but not treated with indolebutyric acid, lacked this rooting-factor. Extracts obtained from all types of the difficult-to-root Bartlett cuttings also lacked this rooting-factor. The latter is believed to be produced by physiologically active Old Home buds, and is very effective in the mung bean bioassay, even at extremely low concentrations.

From paper chromatographic studies, tests with spray reagents, solubility determinations, biological tests, UV spectrum analysis, and infrared spectroscopy, it is believed that this rooting factor could be a condensation product between exogenous auxin (indolebutyric acid) and a phenolic compound produced by physiologically active Old Home pear buds.

     

The Physiology of Rooting Populus Cuttings

Activity of endogenous cytokinin of cuttings was investigated in relation to the process of rotting. The levels of cytokinin in hardwood cuttings of easy-to-root Populus × euramericana (Dode) Guinier and difficult-to-root Populus tremula L. were monitored at various stages of root formation. In cuttings of P. tremula was found a higher cytokinin activity than in P. × euramericana and this condition persisted throughout the rooting period. There was a general initial decrease of cytokinin activity in both upper and lower halves of cuttings of both species. The declining level was reversed in the easy-to-root species when roots had formed and to a lesser extent in the difficult-to-root species when leaves expanded. In both cases this increase was relatively higher in the lower halves than in the upper halves.