【作者】 郑日如；

【导师】 夏宜平；

【作者基本信息】 浙江大学 ， 观赏园艺， 2011， 博士

【摘要】 百合(Lilium spp.)是世界著名的球根花卉,东方系百合品种‘索邦’(Lilium Oriental Hybrids’Sorbonne’)是我国鲜切花市场上广受欢迎的主栽品种之一。长期以来,中国市场上的优质百合种球大多依赖进口,而进口种球成本约占总成本的80%。为了更好解决百合种球国产化过程中的繁育问题,本研究以东方百合‘索邦’为实验材料,施用三种外源生长延缓剂对营养生长初期的百合植株进行叶面喷施处理,比较其对更新鳞茎生长和养分合成的促进作用。在此基础上,从植株营养生长和同化物合成、鳞茎内源激素水平和鳞茎淀粉合成酶活性等几个方面探讨影响鳞茎养分积累的内在机理。同时,观测生长延缓剂对百合植株观赏性状的影响,以期为生产实践提供一定的参考。主要的研究结果如下：(1)百合植株生长与养分分配关系本研究测定了不同生育期的百合植株生长形态指标与地下鳞茎的养分代谢动态变化。百合植株中养分在各个器官中的分配情况与生长发育阶段有紧密的联系。鳞茎内养分转化主要可以划分为四个阶段：定植后0-6周期间,鳞茎淀粉含量下降,蔗糖含量上升,淀粉分解为可溶性糖,供植株营养生长所需；定植后6-9周期间,鳞茎淀粉和蔗糖含量同时上升,说明此时已不需再为营养生长分解贮藏物质,并开始合成少量淀粉；定植后第10一12周期间,鳞茎蔗糖含量上升,淀粉含量下降,鳞茎内的贮藏物质再次分解,供给花芽生长所需；定植后第13一18周期间,鳞茎蔗糖含量下降,淀粉含量上升,养分开始从地上部分回流至鳞茎,鳞茎进入持续的淀粉积累阶段。鳞茎和营养器官(尤其是叶片)中的养分含量能部分反映出不同时期植株生长发育的特点。百合地上部茎叶与地下部鳞茎的生长发育表现协同关系,即营养生长时期,鳞茎能为地上部分提供养分,促进茎叶生长和开花；盛花期及以后,茎叶生长合成的同化物对后期鳞茎的更新和养分的积累有直接促进作用。花芽的生长发育是养分利用和分配的重要转折点。(2)生长延缓剂对百合鳞茎养分积累的促进作用氯化胆碱和烯效唑处理对开花后期和百合鳞茎生长和养分积累具明显的促进作用,其效果优于多效唑处理。在开花后期,烯效唑处理组的鳞茎淀粉含量高于对照组达47.65%-69.81%,氯化胆碱处理组的鳞茎淀粉含量高于对照组达28.11%-51.24%；而多效唑处理组的鳞茎淀粉含量仅高于对照组19.65%-30.38%。(3)生长延缓剂对百合鳞茎淀粉合成酶活性的影响本研究首次报道了球根花卉贮藏器官的淀粉合成酶(AGPase、SSS和GBSS)的活性变化。研究表明,百合鳞茎中的三种淀粉合成酶在盛花期和花后期表现活跃,而在营养生长期间其活性较低甚至无法测得。三种生长延缓剂均在百合开花后期显著提高了鳞茎内AGPase、SSS和GBSS活性,对淀粉的合成和积累起到了直接的促进作用。以烯效唑80mg/L处理为例,处理组鳞茎在开花后期(定植后第18周)AGPase、SSS和GBSS的活性分别高于对照组的131.65%、80.47%和31.47%,直接促进了其淀粉合成量。在第18周时达到453.05 mg/gFW,高于对照组69.81%,达到极显著水平。(4)生长延缓剂对百合鳞茎内源激素水平的影响实验证实了三个处理组均降低了鳞茎内源GA含量,这是促进更新鳞茎发生的重要因素之一。三个处理组均显著提高了开花后期鳞茎内源ZR和IAA水平,说明处理组更新鳞茎生长更为旺盛,这与淀粉合成酶的高活性表现一致。对照组的ABA含量均在盛花期和开花后期有所增加,多效唑处理提高了此时鳞茎的ABA含量,而氯化胆碱和烯效唑处理则降低了ABA含量,说明ABA含量的升高并不是淀粉积累的决定因素,但是鳞茎GA/ABA比值的降低应有利于鳞茎生长和养分积累。(5)生长延缓剂对百合植株营养生长的影响多效唑(100mg/L、200mg/L和400mg/L)和烯效唑(40mg/L、80mg/L和160mg/L)喷施处理均显著降低了植株株高,增加了叶片厚度,总叶面积略有减少,并使花朵直径和单花鲜重降低,不利于提升植株的观赏性和商品价值。而氯化胆碱处理则有助于植株地上部分茎叶和花朵的生长,具体表现为叶片生长旺盛,叶片数、叶面积和叶片厚度均高于对照组,叶绿素含量提高,叶色更为鲜亮；在盛花期,100mg/L氯化胆碱处理组的花朵直径和单花鲜重达到21.86cm和17.4g,分别高于对照组16.89%和18.64%。因此低浓度氯化胆碱处理有助于植株地上茎叶和花朵生长,是提升百合观赏价值的有效方法。同时,烯效唑和氯化胆碱处理也提高了叶片叶绿素含量和碳水化合物含量,为鳞茎后期养分积累提供了充足的同化物；多效唑处理对叶绿素含量和叶片碳水化合物含量影响不明显。更多还原

【Abstract】 Lilium Oriental Hybrids’Sorbonne’is one of the most popular lily cultivars in Chinese market. Most qualified lily bulbs are imported and the purchase of bulbs approximately accounts for 80% of total production cost. In order to solve problems for domestic breeding of bulbs, we applied three plant growth retardants to test their influences on carbohydrate accumulation in bulbs. Morphological parameter, endogenous hormone contents and starch-synthesizing enzyme activities have been detected to explain the internal mechanism of carbohydrate accumulation in bulbs. The following are the main results:(1) The association between plant growth developments and carbohydrate distributionThe distribution of carbohydrates is closely associated with plant growth developments. The lily plant development was divided into four periods according to the conversion of carbohydrates in bulbs:At 0-6 WAP, the starch content decreased while the sucrose content increased in bulbs, demonstrating that reserve material in bulbs was hydrolyzed and utilized for vegetative growth. At 6-9 WAP, starch and sucrose contents in bulbs increased simultaneously, which indicated that bulbs did not provide carbohydrates for vegetative growth any longer. At 10-12 WAP, starch content decreased but sucrose content increased, suggesting the starch was hydrolyzed again for bud growth. At 13-18 WAP, starch content regained a persistent and remarkable increase, which indicated the assimilates began to be accumulated in bulbs.The source organs and sink organs exhibit a partner relationship in lily plants. The bulbs provide reserves for stem and leave growth at vegetative growth period, and the leaves synthesize assimilates and transit to bulbs after blossoming as feedback. The flower bud formation and development is a key turning point of carbohydrate conversion in bulbs.(2) The promotion of carbohydrate accumulation in bulbs in response to plant growth retardantsThe results demonstrated that CCC and UCZ are more effective in promoting carbohydrate accumulation in lily bulbs when compared to PBZ. After blossoming, the UCZ treatments could improve starch content up to 47.65% to 69.81%, while the CCC treatments could elevate starch content up to 28.11% to 51.24%; however, the PBZ treatments could only increase starch content by 19.65% to 30.38%. (3) The influence of plant growth retardants on starch-synthesizing enzyme activities in bulbsThe starch-synthesizing enzyme activities (AGPase, SSS and GBSS) were first reveals in storage organs of bulb flowers. It was found that the activities of three enzymes were quite low or even undetectable during vegetative growth period, but increased markedly at blossoming period. The peak values of enzyme activities were achieved after blossoming, suggesting massive starch synthesis. The plant growth retardants significantly increased enzyme activities thereby resulting in superior starch accumulation. Taking uniconazole treatment (80mg/L) for example, the AGPase, SSS and GBSS activities were 131.65%,80.47% and 31.47% higher than those of control, respectively, leading to a 69.81% increase in starch accumulation when compared to that of control.(4) The influence of plant growth retardants on endogenous hormone contents in bulbsAll plant growth retardant treatments decrease GA content to improve the formation of interior scales and accumulation of carbohydrates, which proved that decreased GA content was an essential condition for interior scale renewal. The increase of ZR and IAA contents were detected in both treated and un-treated bulbs since blossoming, which might mainly be due to the formation of new interior scales. Plant growth retardants could improve scale formation and carbohydrate accumulation by elevating ZR and IAA contents. The increase of ZR and IAA content also coincided with the high starch-synthesizing enzyme activities. ABA contents in bulbs of all treated and un-treated plants increased since full blossoming period, suggesting ABA could facilitate carbohydrate accumulation. However, the increases of ABA content in treated bulbs were lower than that of control, suggesting ABA was not the definitive factor in carbohydrate accumulation. However, the low ratio of GA/ABA was still considered to facilitate assimilates transfer from leaves to bulbs.(5) The influence of plant growth retardants on vegetative growth of lily plantsTreatments of paclobutraol (100mg/L,200mg/L,400mg/L) and uniconazole (40mg/L, 80mg/L,160mg/L) significantly decreased plant height and appreciably diminished leaf area, however increase leaf thickness with a small coefficient. These two treatments also depress the flower diameter and flower fresh weight which is not considered to be favorable commercial value. In contrary, chlorocholine chloride significantly improved vegetative growth in lily plants. The leaf number, leaf area, leaf thickness and chlorophyll contents of treated plants were significantly higher than those of control. The flower diameter and flower fresh weight reached 21.86cm and 17.4g, respectively, at full blossoming period. Thus, low dose of chlorocholine chloride was a promising way to improve ornamental value by promoting vegetative growth and flower development.Moreover, uniconazole and chlorocholine chloride could increase chlorophyll contents and carbohydrate contents in leaves thereby providing abundant assimilates for bulb growth during and after blossoming period. Paclobutraol did not exert significant influence on leaf growth.更多还原