【作者】 房伟民；

【导师】 郭维明； 陈俊愉；

【作者基本信息】 南京农业大学 ， 植物学， 2009， 博士

【摘要】 菊花(Chrysanthemum morifolium Tzvel.)是我国十大名花和世界四大切花之一,广泛应用于盆栽、切花和地被等方面,在花卉生产中占有重要地位,但其喜冷凉而不耐热、且耐盐能力也较弱。利用嫁接改进园艺植物的抗逆性已有大量报道,而嫁接对菊花的改良作用尤其是对提高耐热和耐盐性的影响及其相关生理机制的研究国内外未见开展,影响了嫁接技术在规模化生产上的进一步推广应用。此外,菊花需达到一定的生理年龄,才能感受光周期诱导,进入花芽分化,但植株苗龄对切花菊主栽品种花芽分化与品质的影响鲜有报道；同时生产上对切花菊营养特性了解不足,在矿质营养配比上缺乏参考标准,从而影响了我国切花菊精准生产技术的提高。为此,本文以两个蒿属植物为砧木,开展了嫁接对菊花生长发育及对抗高温、盐胁迫等逆境的影响及其相关生理基础的研究；同时以主栽品种‘神马’等为对象,研究了苗龄、氮磷钾不同配比与用量对切花菊生长发育与品质的影响,主要结果如下：1.嫁接对菊花生长发育影响及相关生理机理探讨以白蒿和黄蒿为砧木,以‘意大利红’、‘秋意’两个菊花品种为接穗,对菊花嫁接苗和扦插苗的生长发育指标和叶片光合指标、矿质元素含量、叶绿素、含水量、可溶性糖与蛋白质含量、GA和ABA含量及根系活力等指标进行比较研究。结果表明,嫁接明显促进了菊花的生长发育,两品种嫁接苗在株高、冠幅及叶面积指标上均好于扦插苗；嫁接菊花的叶、茎、根系和花序的鲜、干重均有不同程度的提高,根/冠比也高于扦插苗；但嫁接菊花的单株花序数量没有明显变化；且‘意大利红’与白蒿、‘秋意’与黄蒿为较利于生长发育的砧穗组合。嫁接苗与扦插苗的Chla含量无显著差异,Chlb含量高于扦插苗,Chla/b和Chl(a+b)/Car比值均低于扦插苗。除‘意大利红’黄蒿嫁接苗以外,嫁接苗光饱和点均高于扦插苗；两品种扦插苗光补偿点均高于嫁接苗处理；而表观量子效率无显著差异；两品种嫁接苗净光合速率日积分值、日净光合速率和蒸腾速率总体高于扦插苗,而胞间CO2浓度、气孔导度(Gs)差异均不显著。菊花嫁接苗的叶片全N、全P、K+、Ca2+、Mg2+、Cl和Na+含量均高于或接近扦插苗,含水量多低于扦插苗,可溶性糖、可溶性蛋白质含量则均无显著差异。两品种扦插苗叶片GA、ABA含量均高于嫁接苗,但IAA含量均低于嫁接苗,而ABA/GA比值均为嫁接苗高于扦插苗。两品种嫁接苗在生长期和开花期的根系活力均显著高于扦插苗,且嫁接苗后期根系活力的下降明显低于扦插苗。试验表明嫁接促进了菊花的生长发育,并提高了叶片光合效率、矿质元素吸收及根系活力等方面的指标。2.嫁接提高菊花高温抗性及相关生理生化机理研究以黄蒿和白蒿为砧木,比较了高温胁迫过程中菊花嫁接苗和扦插苗叶片含水量、膜透性、超氧阴离子自由基(O2·-)产生速率和SOD、CAT、APX等抗氧化酶活性及可溶性蛋白含量、可溶性糖、MDA、脯氨酸等渗透调节物质含量的变化。结果表明：高温胁迫下,与扦插苗比较,菊花嫁接苗叶片膜透性、MDA含量和02·-产生速率较低,含水量与SOD、CAT、APX活性较高,可溶性蛋白质、可溶性糖、脯氨酸的含量也相对较高,而两种不同砧木的理化指标多无显著差异。同时,高温下嫁接苗叶片卷缩、萎蔫和黄化等症状均不同程度好于扦插苗。试验表明,嫁接有利于菊花耐热能力的提高。3. NaCl胁迫对嫁接菊花生物量的影响及相关生理机理研究比较了NaCl胁迫下以黄蒿和白蒿为砧木的菊花‘意大利红’嫁接苗和扦插苗植株生物量、矿质元素与叶绿素含量、光合指标及叶片抗氧化酶活性、丙二醛(MDA)含量与超氧阴离子产生速率(02·-)产生速率的差异。结果表明,NaCl胁迫下嫁接苗的生物量指标多高于扦插苗,下降程度低于扦插苗。胁迫下嫁接苗根、茎、叶的K+、Ca2+、Mg2+含量(白蒿嫁接苗叶片除外)均极显著高于扦插苗,且下降程度明显低于扦插苗,而茎、叶的K+/Na+、Ca2+/Na+、Mg2+/Na+值均极显著高于扦插苗。NaCl胁迫下嫁接苗Chla、Chlb、Chl(a+b)含量与扦插苗均无显著差异,但下降的程度明显低于扦插苗；而叶片净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)均显著高于扦插苗,且下降程度低于扦插苗,而胞间CO2浓度(Ci)提高,但显著低于扦插苗,且提高程度低于扦插苗。两个嫁接苗处理的游离脯氨酸含量极显著高于扦插苗,而可溶性糖含量均显著高于扦插苗,可溶性蛋白质含量含量也高于扦插苗,但差异均不显著。NaCl胁迫下嫁接苗SOD、CAT、APX酶活性高于扦插苗,表现出较高且持续较长时间的升幅；而NaCl胁迫下嫁接苗MDA含量、02·-增幅明显低于扦插苗,处理后期极显著低于扦插苗。结果表明,NaCl胁迫下嫁接苗在光合作用、矿物质吸收及抗氧酶活性及渗透调节等方面指标均好于扦插苗,表现出较强的耐盐性。4.苗龄对切花菊花芽分化与切花品质的影响通过对不同苗龄植株短日诱导后花芽分化和开花进程的观察及切花品质指标的测定,研究了不同苗龄对切花菊秋花型品种‘神马’和夏花型‘精云’花芽分化及切花品质的影响。结果表明,苗龄对‘神马’、‘精云’的花芽创始均具有显著影响,苗龄越小花芽创始越迟。对于苗龄为0d(定植当天短日处理)的植株,‘神马’和‘精云’从诱导到花芽创始均需要18 d,显著长于成花诱导的最短反应时间4d。4d是‘神马’、‘精云’对成花诱导的最短反应时间,‘神马’和‘精云’达到成熟的成花感受态的苗龄分别为21 d和28 d。不同苗龄的‘神马’植株从花芽创始到花芽分化完成所需的时间在32-38d之间,而‘精云’相应为24-39d。苗龄越小,完成花芽分化所需的时间越长,花期越迟。苗龄对‘神马’和‘精云’切花品质均有显著影响,年龄越小,切花品质越差,要获得高品质切花,‘神马’苗龄要达到28 d以上、‘精云’苗龄要达到35 d以上才能进行成花诱导。5.氮磷钾配比对切花菊生长发育的影响采用氮、磷、钾不同水平的正交试验,研究了氮、磷、钾不同用量配比对切花菊‘神马’生长发育的影响,并筛选最适宜的营养液配方。结果表明：在本试验条件下,氮对‘神马’生长发育的影响最大,不同水平之间对茎粗、叶面积、花径、花瓣长、破蕾期、植株鲜干重、根长的影响差异显著；磷对茎粗、花颈长、破蕾期的影响显著；钾对花颈长、破蕾期、叶鲜重、茎鲜重的影响显著。最佳的氮、磷、钾摩尔浓度配比：营养生长期为N2：P2：K2=14.3：2.0：8.0,生殖生长期为N1：P3：K3=7.14：4.0：12.0。更多还原

【Abstract】 Chrysanthemum (Chrysanthemum morifolium Tzvel), a perennial plant of Composite, is one of the Ten Traditional Chinese Famous Flowers and of four important cut flowers all over the world, which is widely used as pot plant, cut flower and ground- covers, and plays an important role in flower producing. A horticultural practice of grafting chrysanthemum by using Artemisia has been reported, however, how a grafted chrysanthemum tolerates abiotic stress and the mechanisms involved in abiotic stress tolerance remained unknown. Chrysanthemum is not photoperiod inductive and floral inductive unless the plant is at a certain physiological development stage. But few knowledge of the floral initiation in popular cut chrysanthemum cultivars has been disclosed yet. Moreover, nutrition need of chrysanthemum remained to be further studied for a better mineral elements supply during producing practice. In present study, the effects of grafting on the heat tolerance and salt tolerance were investigated in grafted chrysanthemums using two Artemisia species as stocks. On the other hand, effects of the developmental stages and different levels and ratios of nitrogen, phosphorus and potassium on the growth and development as well as cut flower quality were monitored in chrysanthemum’Jinba’. The results are as follows.1、Grafted chrysanthemums were generated by using Artemisia lactiflora and Artemisia annua as root stocks, and chrysanthemum’Zaoyihong’and’Qiuyi’as cions. Growth and development index, photosynthetic parameters, mineral element contents, chlorophyll content, water content, soluble sugar and protein content, GA and ABA content, antioxidant enzyme activities and root ability were compared between the cuttings plants chrysanthemum and their grafted ones. The results showed that graft improved the growth of chrysanthemum, in grafted chrysanthemums, plant height, canopy diameter and leaf area were better than those in cuttings plants. The fresh weight and dry weight in the leaf, stem, root and inflorescence are improved in the grafted chrysanthemums. The root/canopy rate was higher than that in cuttings plants, whereas, number of inflorescence per plant of grafted chrysanthemum few changed. There is no significant difference in the content of chlorophyll a, while content of chlorophyll b is higher than cuttings plants. The values of Chla/b and Chl(a+b)/Caretonoids are lower than those in cuttings plants. The photosynthesis saturation point in grafted plants except the grafted plants generated from ’Yidalihong’-A.is higher than those in cuttings plants. Whereas photosynthesis compensation point in cuttings is higher than those in grafted plants. There is no significant difference in apparent quantum yield between cuttings and grafted plants.Net photosynthetic diurnal integral value, diurnal net photosynthetic rate (Pn) and transpiration rate in grafted plants are higher than those in cuttings plants, while intercellular CO2 concentration, stomatal conductance(Gs) remained unaffected by grafting. Nitrogen, phosphor, K+, Ca2+, Mg2+, Cl- and Na+ are higher or equal to those in cuttings plants. Water content in grafted plants is lower than those in cuttings plants, contents of soluble sugar and protein don’t change significantly. GA and ABA contents in cuttings plants both are higher than those in grafted ones, however, IAA content is lower in grafted plants. ABA/GA ratio is higher in grafted plants than in cuttings plants. Root activity in grafted plants is significantly higher compared with cuttings ones during either vegetative or flowering stages, and decline in root ability is lower in grafted seedlings than in cuttings ones during late stage. In conclusion, grafting improved the growth and development, enhanced the photosynthesis, content of mineral elements and root ability.2、Using Artemisia lactiflora and Artemisia annua as root stocks, grafted chrysanthemum were created. The membrane permeability, O2·- production rate, and activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascrobate peroxidase (APX) and contents of soluble protein in leaves of the cuttings plants and grafted plants of chrysanthemum were studied under heat stress. The results showed that grafted plants had lower membrane permeability and O2·-production rate, while SOD, CAT and APX activities and soluble protein contents were higher compared with those in the cutting plants. However, there was no significant difference in O2·- production rate and activities of antioxidant enzymes between the grafted plants with different root stocks. The leaf curiling, wilting, yellowing were alleviated in grafted plants than those in cutting plants under heat stress. It suggested that grafting could improve the heat tolerance of chrysanthemum.3、Grafted chrysanthemums were generated by using Artemisia lactiflora and Artemisia annua as root stocks, and chrysanthemum’Zaoyihong’ as cions. The difference between plant biomass, mineral element contents, chlorophyll content, photosynthetic parameters, leaf protective enzyme activities, MDA content and production rate of O2·-under NaCl stress were compared between the cuttings and grafted plants of chrysanthemum. The results showed that biomass of grafted chrysanthemums were better than those in cuttings plants, and decreased degree of biomass indexes was lower than those in cuttings plants obviously. Under NaCl stress, the K+, Ca2+ and Mg2+ contents in the leaf, stem and root of the grafted chrysanthemums (excepted the leaf of grafted seedlings by A.annua) were extremely significantly better than those in cuttings plants, furthermore decreased degree of those indexes in the grafted chrysanthemums was obviously lower than cuttings plants. It showed that relatively strong mineral absorptive capacity, moreover the ratios of K+/Na+, Ca2+/Na+ and Mg2+/Na+ of leaves and stems in grafted plants were significantly higher than those in cuttings plants. There was no significant difference between two grafted chrysanthemums. There was no significant difference between grafted chrysanthemums and cuttings plants under NaCl stress in terms of the contents of Chla, Chlb and Chl(a+b), but decreased degree reduced greatly in grafted chrysanthemum. Leaf net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) also decreased greatly, while intercellular CO2 concentration improved slightly. All these indexes are significantly different between grafted and cuttings plants, and the degree of decrease/improvement of these indexes was obviously lower than that in cuttings plants. Free proline content and soluble sugar content of grafted seedlings were extremely significant higher than those of cuttings plants, respectively, soluble protein content was also higher but not significantly higher in grafted chrysanthemum. SOD, CAT and APX enzyme activities of the grafted chrysanthemums under NaCl stress were higher than those in cuttings plants, high and long lasting time improvement was observed; however the MDA content and producing velocity of superoxide anion were lower than those of cuttings plants, especially during late stages of NaCl treatment. In conclusion, grafted chrysanthemums exhibited a great salt tolerance, enhanced the photosynthesis, mineral element absorption, anti-oxygenase activity, osmotic adjustment under NaCl stress.4、Effects of growth age on short day induced flower bud differentiation and quality of cut Chrysanthemum were studied using cultivar’Seiun’and’Jinba’. Flower bud differentiation, flowering process and flower quality were investigated in short day treated cuttings which were at different ages by modulating cutting and planting date. The result were as follows, grow age has great effects on flower bud initiation of cut Chrysanthemum’Seiun’ and’Jinba’, the younger grow age is, the later the flower bud initiation is. For’Seiun’and’Jinba’that grow age was 0 day,18 days were essential from flower bud induction to bud initiation, which longer distinctly than 4 days.21 d and 28 d is the physiological mature age that is perceivable to flower bud differentiation inducing for ’Jinba’ and’Seiun’. Time of different grow age’Jinba’ plants from flower bud induction to bud initiation is 32-38 days, and 24-39days for’Seiun’. The younger grow age of the’Seiun’and’Jinba’ was, the longer time required from flower bud induction to bud initiation was, and the later of bloom time was. Grow age also has great effects on quality of cut chrysanthemum, the younger grow age was, the poor quality of flower’s was. To obtain the high quality cutting flower according with the standard for export, grow age must achieve 28 days for’Jinba’ and 35 days for’ Seiun’when begin flower bud initiation.5、To determine the effects of N,P,K nutrients on the growth and development of cut chrysanthemum’Jinba’ and obtain the optimum formula,experiment with orthogonal experimental design with three factors including N,P,K nutrients at three levels was conducted.The results indicated that under the condition of this experiment,N was the most important factor influencing the growth and development,and stem diameter,leaves area,flower diameter,length of petal,growth days of flower bud break, plant weight and length of root among three levels was significant (P<0.05). The effects of P on stem diameter, length of flower neck and growth days of flower bud broke was significant. The effects of K on length of flower neck, growth days of flower bud broke,leaves fresh mass and stem fresh mass was significant. The optimum fertilization level of N,P,K was N:P:K= 14.3:2.0:8.0 during vegetative growth stage and N:P:K=7.1:4.0:12.0 during reproduction stage.更多还原