嫁接植株形成过程中接合部组织学和生长素含量的变化

本文应用植物激素间接酶联免疫技术（ＥＬＩＳＡ）,第一次定量检测了嫁接植株形成过程中生长素（ＩＡＡ）的动态变化。结果表明：嫁接植株发育的前期,亲和性与非亲和性组合其ＩＡＡ含量的变化相似。在后期,不亲和组合ＩＡＡ含量急骤减少,而亲和性的组合在第八天即维管束桥分化形成的这一天,可见到ＩＡＡ高峰值的出现。     

电偶联原理在嫁接基础研究中的应用

通过对嫁接接合部位电阻的检测发现,接合部位电阻的变化与其组织学的变化相关。亲和性组合,电阻的变化可分为４ 个阶段：电阻略微下降阶段（嫁接后几小时）;电阻快速升高阶段（嫁接后几小时到２ ｄ 左右）;电阻逐渐下降阶段（约为嫁接后２—６ ｄ）和电阻趋于平稳并恢复到嫁接前水平阶段（嫁接６ ｄ 以后）。非亲和性组合,电阻的变化有３ 种情况：（１） 嫁接后第一天,电阻持续升高至最高点,此后,直至接穗萎蔫,电阻只是略微下降;（２） 嫁接１ ｄ 电阻持续升高后,２—３ ｄ 内很快下降,接着电阻逐渐上升;（３） 与（２）类似,只在后期,电阻很快上升。电阻法是一种新的检测嫁接植株形成过程和预测嫁接亲和性的方法     

嫁接对盐胁迫下西瓜幼苗体内离子和内源激素含量与分布的影响

以小型西瓜‘秀丽’为接穗、耐盐砧木瓠瓜‘超丰抗生王’为砧木,以自根嫁接苗为参照,分析了砧木嫁接对NaCl胁迫下西瓜幼苗根、茎、叶中离子和内源激素含量的影响。结果表明:(1)盐胁迫下,自根嫁接苗Na+主要积累在地上部,K+含量和K+/Na+比下降幅度大;砧木嫁接苗大部分Na+积累在根系中,K+含量和K+/Na+比下降幅度小且在不同部位皆高于自根嫁接苗。(2)盐胁迫下,自根嫁接苗吲哚-3-乙酸(IAA)以及玉米素和玉米核苷的总量(Z+ZR)在根系和接穗茎中显著增加,在叶片中明显下降,赤霉素(GA3)含量在不同部位保持不变或明显增加;而砧木嫁接苗不同部位IAA和(Z+ZR)的含量均显著增加,GA3含量在不同部位保持不变或明显下降。(3)盐胁迫下,两种嫁接组合根系和茎中脱落酸(ABA)含量均明显下降,叶片中ABA含量则显著增加。(4)盐胁迫下,自根嫁接苗和砧木嫁接苗根系和接穗茎中IAA/(Z+ZR)的比值均明显上升,叶片中明显下降,但砧木嫁接苗上升和下降幅度均远大于自根嫁接苗。研究表明,瓠瓜根系对进入根系的Na+具有截留作用;采用瓠瓜砧木嫁接可有效防止Na+在西瓜接穗地上部尤其是在叶片中的大量累积,从而防止离子毒害的发生;瓠瓜砧木嫁接植株体内具有较高的K+含量和K+/Na+比,可有效维持盐胁迫下西瓜嫁接植株体内的离子稳态;瓠瓜砧木嫁接植株体内具有较高的IAA和(Z+ZR)含量,IAA/(Z+ZR)比值较高,对提高西瓜嫁接植株盐胁迫耐性起到了积极的作用。     

氯化钠胁迫对嫁接黄瓜叶片多胺含量的影响

以日本耐盐品种‘帝王新土佐’南瓜为砧木,以’新泰密刺’黄瓜为接穗,在100 mmol·L^-1 NaCl胁迫下,对黄瓜嫁接和自根植株不同时期叶片中不同形态多胺含量的变化进行了研究.结果表明：NaCl胁迫下黄瓜嫁接植株游离态腐胺（Put）含量在胁迫2 d时与自根植株无显著差异,其余时间均显著高于自根植株;游离态亚精胺（Spd）和游离态精胺（Spm）含量在整个胁迫期间均显著高于自根植株;游离态多胺总量（PAs）在胁迫第4天出现峰值;嫁接植株游离态Put/PAs值在胁迫4 d时与自根植株无显著差异,其余胁迫时间均显著低于自根植株,而(Spd+Spm)/Put值在整个胁迫期间均显著高于自根植株;嫁接植株结合态和束缚态Put、Spd和Spm含量在整个胁迫期间均显著高于自根植株,结合态和束缚态PAs在胁迫第6天出现峰值;结合态多胺的Put/PAs值和(Spd+Spm)/Put值变化趋势与游离态多胺一致;嫁接植株束缚态Put/PAs值在胁迫6 d时与自根植株无显著差异,其余时间均显著低于自根植株,而(Spd+Spm)/Put值在整个胁迫期间均显著高于自根植株.表明黄瓜嫁接植株表现出较强的耐盐特征.     

NaCl胁迫对营养液栽培嫁接黄瓜生物量及离子分布的影响

以‘帝王新土佐’南瓜为砧木,以‘新泰密刺’黄瓜品种为接穗,在100 mmol.L-1NaCl胁迫下,对黄瓜嫁接和自根植株生物量及各器官离子含量的差异进行了研究。结果表明,(1)NaCl胁迫下,嫁接和自根植株生物量积累均受到显著抑制,嫁接植株受抑制较轻。(2)NaCl胁迫后,黄瓜嫁接、自根植株各器官Na 、Cl-含量均显著高于对照;嫁接植株除根系Na 含量显著高于自根植株外,其余各器官均显著低于自根植株;嫁接植株老叶、叶柄和根系的Cl-含量显著低于自根植株。(3)嫁接植株的根是主要的聚Na 部位,茎是主要的聚Cl-部位。(4)嫁接植株幼叶和根的K 、Ca2 、Mg2 含量均显著高于自根植株,嫁接植株的K /Na 、Ca2 /Na 、Mg2 /Na 值也均显著高于自根植株。以上结果证明,黄瓜嫁接植株根系和茎中盐离子的含量较高且对K 、Ca2 、Mg2 的选择性吸收、运输能力较强,在器官水平上盐分离子分布的区域化优于自根植株,从而使嫁接植株耐盐性强于自根植株。     

NaCl胁迫对嫁接黄瓜膜脂过氧化、渗透调节物质含量及光合特性的影响

以日本引进的耐盐品种‘帝王新土佐’南瓜为砧木,以‘津研4号’黄瓜品种为接穗,研究了NaCl胁迫对黄瓜嫁接植株和自根植株的膜脂过氧化、渗透调节物质含量及光合特性的影响。结果表明:在NaCl胁迫下,黄瓜嫁接植株叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性均显著高于自根植株,O·2-产生速率及丙二醛(MDA)含量显著低于自根植株,嫁接植株膜脂过氧化轻于自根植株;嫁接植株叶片游离脯氨酸、可溶性糖、可溶性蛋白质等渗透物质含量均显著高于自根植株;嫁接植株的净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、叶绿素含量均显著高于自根植株;虽然NaCl胁迫抑制光合作用,但嫁接植株仍表现出优势。以上结果证明,嫁接植株耐盐性优于自根植株。     

蜜柚不同砧穗组合苗期嫁接亲和性评价

为评价蜜柚砧穗的嫁接亲和性,以红绵蜜柚(Citrus grandis‘Hongmianmiyou’)、三红蜜柚(‘Sanhongmiyou’)、红肉蜜柚(‘Hongroumiyou’)、黄金蜜柚(‘Huangjinmiyou’)和琯溪蜜柚(‘Guanximiyou’)作接穗,枳(Poncirus trifoliata)、香橙(Citrus junos)、酸柚(Citrus grandis)作砧木,田间调查15个砧穗组合苗期生长指标,测定嫁接愈合期叶片多酚氧化酶(PPO)和过氧化物酶(POD)活性、可溶性蛋白和可溶性糖含量,采用主成分分析和聚类分析方法对蜜柚砧穗组合嫁接亲和性进行评价。结果表明,以柚作砧木的砧穗组合保存率高、生长势旺盛、抽梢能力强,以枳和香橙作砧木的砧穗组合部分指标存在差异,其中红绵蜜柚和黄金蜜柚以枳作砧木时表现出不亲和现象。不同砧穗组合嫁接愈合时期PPO、POD、可溶性蛋白和可溶性糖变化趋势基本一致。主成分分析结果表明,4个主成分基本反映了15个指标91.33%的数据信息。聚类分析将15个砧穗组合分为4类,与主成分分析结果基本一致。因此,琯溪蜜柚、红肉蜜柚和三红蜜柚嫁接可采用枳和柚作砧木,红绵蜜柚和黄金蜜柚嫁接可采用柚作砧木,红绵蜜柚和黄金蜜柚嫁接不可采用枳作砧木。     

水杉异砧嫁接植株体内激素的分布和含量变化(简报)

同一生育期不同器官或同一器官不同生育期的水杉异砧嫁接植株砧穗各器官中均含有GA3、IAA、ZT和ABA,以GA3含量最高。10、11月休眠前期,接穗水杉叶片中GA3、ZT和ABA含量显著高于砧木叶片,砧木叶片中IAA含量分别是接穗叶片的1．5和1．9倍。砧木根和接穗叶芽、花芽中4种激素含量均高于砧穗的茎,而接穗的雌球花芽则高于雄球花芽。     

‘砀山酥梨’黄化叶复绿过程中内源IAA含量及其信号转导基因的表达量分析

为探讨IAA在梨黄化叶复绿过程中的作用,以‘砀山酥梨’(Pyrus bretschneideri Rehd.)黄化植株与正常植株为试材,对生长期黄化植株叶面喷施0.2%FeSO_4溶液,于处理后第3、6、9、12天分别观察黄化叶复绿情况,取样测定黄化叶片复绿过程中各时期叶片与对照组(正常、黄化)叶片的Fe~(2+)含量、内源IAA含量、IAA相关信号转导基因相对表达量,并分析Fe~(2+)、IAA含量及相关基因表达量之间相关性。结果表明:(1)FeSO_4溶液处理可使梨黄化叶片复绿,且黄化叶面在处理后第3天开始出现复绿斑点,在处理后第6、9天时出现大范围的复绿斑块,第12天整叶复绿。(2)ELISA测定结果显示,对照组正常叶的内源IAA含量显著高于对照组黄化叶,FeSO_4处理后各个时期的复绿叶内IAA含量均显著高于对照组(正常叶和黄化叶)。(3)qRT-PCR结果显示,对照组黄化叶内AUX1.1/1.3、GH3.1/3.2/3.5、SAUR1/2/3/4、AUX/IAA1/2/3/7表达量均显著高于对照组正常叶,FeSO_4处理后其表达量大多较黄化叶显著减少;而对照组黄化叶内TIR1.1、GH3.3/3.4、AUX/IAA4/5/6表达量均显著低于对照组正常叶,FeSO_4处理后其各时期表达量均较黄化叶显著增加。(4)对照组黄化叶内ARF3/4/5/6/7/8/9/10/15/17/18/19/20/21/22/23表达量均显著低于正常叶,FeSO_4处理显著促进了ARF3/5/6/9/19/20/21/22/23的表达;而对照组黄化叶内ARF1/2/11/12/13/14表达量显著高于正常叶,FeSO_4处理则显著抑制了ARF1/2的表达。(5)相关性分析结果表明,FeSO_4处理后复绿叶内显著增加的Fe~(2+)含量主要与AUX/IAA5、AUX/IAA6表达量显著上调相关;而IAA含量的显著增加则与GH3.3表达量显著上调、与SAUR1/2表达量显著下调相关。两者之间相关网络图错综复杂,其简要途径为:Fe~(2+)→AUX/IAA5、AUX/IAA6→(ARF14)→ARF5→SAUR1、AUX/IAA1→SAUR2/TIR1.1/GH3.3→IAA。研究认为,IAA及其信号转导基因在FeSO_4所诱导的‘砀山酥梨’缺铁黄化叶复绿过程中可能发挥重要作用。     

提高西瓜离体培养植株再生效率的研究

本文以"京欣1号"母本和"伊选"西瓜4天苗龄子叶为外植体,研究离体培养植株高频率再生体系.结果表明"伊选"子叶远轴端外植体的再生频率仅为10%,子叶近轴端外植体在5mg/LBA+0.1mg/L IAA的激素组合下植株再生频率为100%,平均每个外植体的丛生芽数在所有组合中最多,为10.3个;"京欣1号"母本子叶近轴端外植体在2mg/L BA+0.5mg/L IAA激素组合下植株再生频率为100%,平均每个外植体的丛生芽数在所有组合中最多,达6.9个.本试验条件下,子叶近轴端外植体接种4天即分化出不定芽,至再生苗的移栽仅需40天,在MS+0.1mg/L NAA的生根培养基上的生根率为97.3%,移栽成活率达98.5%.     

STUDIES OF VEGETATIVE COMPATIBILITY-INCOMPATIBILITY IN HIGHER PLANTS. IV. THE DEVELOPMENT OF TENSILE STRENGTH IN A COMPATIBLE AND AN INCOMPATIBLE GRAFT

Three phases of adhesion between the stock and scion are observable during the formation of a compatible autograft in Sedum telephoides and an incompatible heterograft between Sedum telephoides and Solanum pennellii. The first phase of adhesion is similar in both systems in that it 1) lasts 2 to 3 days, and 2) is characterized by an average increase in tensile strength of 1 g breaking weight (BW)/mm² graft area (GA)/day. In the compatible Sedum autograft, the second phase of adhesion lasts from Days 3 to 11 after grafting and is correlated with a 28-fold increase in the tensile strength of the graft union to approximately 56 g BW/mm² GA by 11 days after grafting. The third phase of adhesion in the compatible autograft is characterized by a leveling off of the tensile strength of the graft union at approximately 56 g BW/mm² GA, roughly equal to that of an ungrafted internode. Graft formation is now complete. These results suggest that the ratio of the tensile strength of the graft union : tensile strength of a comparable ungrafted internode provides an estimate of the percent development of compatible autografts. In the incompatible heterograft between Sedum and Solanum, Phase II adhesion 1) lasts from Days 2 to 5 after grafting, and 2) peaks at 12 g BW/mm² GA at 5 days after grafting. Phase III adhesion in the incompatible heterograft occurs subsequent to Day 5 after grafting and is characterized by an average decrease in the tensile strength of the graft union of 0.3 g BW/mm² GA/day. The results of this study are discussed relative to the quantitative contributions of various structural events to the tensile strength of a graft union.     

Application of Electric Coupling on Basic Research of Grafting

Electrical resistance changes in concert with the histological changes during the development of graft union. Four phases of change in electrical resistance of the compatible graft were demonstrated. Phase Ⅰ: There was a slight decrease of the electrical resistance, lasting about several hours. Phase Ⅱ The resistance values increase rapidly, lasting for two days or so. Phase Ⅲ: In the next four days, the resistance values decreased progressively. Phase Ⅳ: The resistance values levelled off and approximated equal to the level before grafting. In contrast to the compatible grafts, three types of resistance change were observed in the incompatible graft: (1) The resistance values increased rapidly on the first day after grafting but only slightly afterwards decreased. (2) The electrical resistance rose rapidly to its peak on the first day after grafting and decreased rapidly in 2--3 days followed by steady increase again. (3) The change of resistance follows the track as in (2) for 2--3 days and then increased rapidly afterwards. The results suggested that measurement of electrical resistance could be useful tool for the detection of graft compatibility/incompatibility in commercial practice and basic research of plant grafting.     

Graft establishment between compatible and incompatible Prunus spp

Graft compatibility has been studied in apricot (prunus armeniacaL.) grafted on Prunus cerasifera Ehrh. Two apricot cultivars,one compatible and one incompatible on this rootstock, wereselected for this study. In these species incompatibility isonly manifested by tree breakdown at a late phase of the tree'slife. The process of graft union formation was observed forthe first month following grafting. No differences were foundeither in the process of healing or in its kinetics. Thus, callusproliferation, callus differentiation and vascular connectionsare established in the same way and at the same time in bothcompatible and incompatible grafts. However, clear differencesexist in the level of differentiation of the callus produced.While in compatible grafts, callus quickly differentiates intocambium and vascular tissue, in incompatible grafts this differentiationis not complete and a portion of the tissue evolves into a parenchymatoustissue that coexists with the differentiated vascular tissue. Key words: Graft, Prunus, compatibility     

嫁接早期IAA在西葫芦／南瓜嫁接面处薄壁细胞和维管分子中的免疫 …

Immuno-gold localization of IAA in cells of the graft union in the explant internode graft of Cucurbita pepo/Cucurbita moschata were investigated with electron microscopy. In parenchyma cells near the graft union, the gold particles were mainly accumulated in nucleus, plastid and endoplasmic reticulum, while no gold particles was detected in Golgi body, mitochondrion, cell wall and vacuoles. In the differentiating xylem element, the gold particles were labeled in secondary wall and cytoplasm. In the sieve element gold particles were found in the sieve plate, sieve pore and cytoplasm. There was a dense label of the gold particles in the companion cell. The role of IAA in the differentiation of the vascular elements was discussed.     

嫁接早期IAA在西葫芦/南瓜嫁接面处薄壁细胞和维管分子中的免疫细胞学定位

采用免疫胶体金法对IAA在西葫芦／南瓜离体茎段嫁接早期发育时期在嫁接面处的分布进行了超微结构水平的定位。电镜观察表明在嫁接面处的薄壁细胞中IAA主要定位于细胞核、质体、内质网等细胞器上。在高尔基体、线粒体、细胞壁和液泡中,未发现胶体金颗粒的标记。在分化中的管状分子中,胶体金颗粒位于次生壁上和细胞质中。在筛分子分化过程中,IAA主要定位于筛板、筛孔和细胞质中。在伴胞中有较高的金颗粒密度。对于IAA在嫁接体维管分子分化过程中的作用进行了讨论。     

Chlorophyll fluorescence imaging can reflect development of vascular connection in grafting union in some Solanaceae species

Graft union development in plants has been studied mainly by destructive methods such as histological studies. The aim of this work was to evaluate whether the chlorophyll fluorescence imaging (CFI) technique is sensitive enough to reflect changes at the cellular level in different Solanaceae grafted plants 30 d after grafting, when both grafted partners were well fused and strong enough in all plant combinations. The pepper cultivar ‘Adige’ was grafted onto different Capsicum spp. accessions typified with different compatibility degrees; eggplant was grafted on Solanum torvum and pepper homografts as compatible unions; pepper was grafted on S. torvum and on tomato as incompatible unions. ‘Adige’/’Adige’ and ‘Adige’/pepper A25 showed a higher maximum quantum efficiency of PSII associated with higher values of actual quantum efficiency of PSII and photochemical quenching as well as with vascular regeneration across the graft interface. Our results highlighted that CFI changes reflected histological observations in grafted Solanaceae plants.     

Early detection of graft incompatibility in apricot (Prunus armeniaca) using in vitro techniques

Graft compatibility has been studied in vitro using callus tissues of apricot ( Prunus armeniaca) and different Prunus rootstocks to form scion/rootstock combinations with different degrees of graft compatibility. In these species, incompatibility is manifested by a breakdown of the trees at the union area that can occur some years after grafting. Here, the possibility of obtaining an early detection method to determine graft incompatibility is explored by callus fusion in vitro. The adhesion of the two callus partners, the development of the cells at the contact surface (cell arrangement, intensity of cell-wall staining), and the presence of lipid and phenolic compounds have been studied during the first 3 weeks after grafting in both compatible and incompatible combinations. Differences were observed at the second and the third week of callus co-culture in most of the characters determined, although these differences were present as early as the first week in the case of phenolic compounds. The behaviour of the grafts grown in vitro was correlated to that of the same combinations in the field, suggesting that callus fusion in vitro could be a possible and reliable method for an early detection of graft incompatibility in different Prunus combinations.     

A MODEL FOR GRAFT COMPATIBILITY-INCOMPATIBILITY IN HIGHER PLANTS

All of the major events comprising the development of compatible and incompatible plant grafts can occur in the absence of direct cellular contact. A model for graft compatibility-incompatibility is presented which suggests that grafts will be incompatible only if naturally occurring morphogens that promote the formation of a successful graft are overriden by toxins that elicit graft incompatibility. According to this model, a positive recognition system need not be implicated in explaining graft compatibility-incompatibility in plants.